Sample records for existing cng infrastructure

  1. Building a Business Case for Compressed Natural Gas in Fleet Applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mitchell, G.

    2015-03-19

    Natural gas is a clean-burning, abundant, and domestically produced source of energy. Compressed natural gas (CNG) has recently garnered interest as a transportation fuel because of these attributes and because of its cost savings and price stability compared to conventional petroleum fuels. The National Renewable Energy Laboratory (NREL) developed the Vehicle Infrastructure and Cash-Flow Evaluation (VICE) model to help businesses and fleets evaluate the financial soundness of CNG vehicle and CNG fueling infrastructure projects.

  2. Costs Associated With Compressed Natural Gas Vehicle Fueling Infrastructure

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith, M.; Gonzales, J.

    2014-09-01

    This document is designed to help fleets understand the cost factors associated with fueling infrastructure for compressed natural gas (CNG) vehicles. It provides estimated cost ranges for various sizes and types of CNG fueling stations and an overview of factors that contribute to the total cost of an installed station. The information presented is based on input from professionals in the natural gas industry who design, sell equipment for, and/or own and operate CNG stations.

  3. Alternative Fuels Data Center: Compressed Natural Gas Fueling Stations

    Science.gov Websites

    infrastructure: time-fill and fast-fill. The main structural differences between the two systems are the amount fuel dispensed and the time it takes for CNG to be delivered. Most CNG stations include one of these into account. Learn more about filling CNG tanks. Time-Fill CNG Station Enlarge illustration Time-fill

  4. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Two online resources help fleets evaluate the economic soundness of a compressed natural gas program. The National Renewable Energy Laboratory's (NREL's) Vehicle Infrastructure and Cash-Flow Evaluation (VICE 2.0) model and the accompanying report, Building a Business Case for Compressed Natural Gas in Fleet Applications, are uniquely designed for fleet managers considering an investment in CNG and can help ensure wise investment decisions about CNG vehicles and infrastructure.

  5. COMPARISON OF CLEAN DIESEL BUSES TO CNG BUSES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lowell, D.; Parsley, W.; Bush,C

    2003-08-24

    Using previously published data on regulated and unregulated emissions, this paper will compare the environmental performance of current generation transit buses operated on compressed natural gas (CNG) to current generation transit buses operated on ultra low sulfur diesel fuel (ULSD) and incorporating diesel particulate filters (DPF). Unregulated emissions evaluated include toxic compounds associated with adverse health effects (carbonyl, PAH, NPAH, benzene) as well as PM particle count and size distribution. For all regulated and unregulated emissions, both technologies are shown to be comparable. DPF equipped diesel buses and CNG buses have virtually identical levels of PM mass emissions and particlemore » number emissions. DPF-equipped diesel buses have lower HC and CO emissions and lower emissions of toxic substances such as benzene, carbonyls and PAHs than CNG buses. CNG buses have lower NOx emissions than DPF-equipped buses, though CNG bus NOx emissions are shown to be much more variable. In addition, this paper will compare the capital and operating costs of CNG and DPF-equipped buses. The cost comparison is primarily based on the experience of MTA New York City Transit in operating CNG buses since 1995 and DPF-equipped buses fueled with ULSD since 2001. Published data on the experience of other large transit agencies in operating CNG buses is used to validate the NYCT experience. The incremental cost (compared to ''baseline'' diesel) of operating a typical 200-bus depot is shown to be six times higher for CNG buses than for ''clean diesel'' buses. The contributors to this increased cost for CNG buses are almost equally split between increased capital costs for purchase of buses and installation of fueling infrastructure, and increased operating costs for purchase of fuel, bus maintenance, and fuel station maintenance.« less

  6. Advanced Vehicle Testing Activity: Dodge Ram Wagon Van - Hydrogen/CNG Operations Summary - January 2003

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Karner, D.; Francfort, J.E.

    2003-01-16

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy's Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle, a Dodge Ram Wagon Van, operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline enginesmore » that were converted to run CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service's Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of 22,816 miles of testing for the Dodge Ram Wagon Van, operating on CNG fuel, and a blended fuel of 15% hydrogen-85% CNG.« less

  7. Advanced Vehicle Testing Activity: Dodge Ram Wagon Van -- Hydrogen/CNG Operations Summary

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Don Karner; Francfort, James Edward

    2003-01-01

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy’s Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle, a Dodge Ram Wagon Van, operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline enginesmore » that were converted to run CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service’s Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of 22,816 miles of testing for the Dodge Ram Wagon Van, operating on CNG fuel, and a blended fuel of 15% hydrogen–85% CNG.« less

  8. Advanced Vehicle Testing Activity: High-Percentage Hydrogen/CNG Blend Ford F-150 Operating Summary - January 2003

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Karner, D.; Francfort, J.E.

    2003-01-22

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy's Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to runmore » CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service's Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents the results of 4,695 miles of testing for one of the blended fuel vehicles, a Ford F-150 pickup truck, operating on up to 50% hydrogen-50% CNG fuel.« less

  9. Advanced Vehicle Testing Activity: Low-Percentage Hydrogen/CNG Blend, Ford F-150 -- Operating Summary

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Karner, D.; Francfort, James Edward

    2003-01-01

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy’s Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to runmore » CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service’s Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of 16,942 miles of testing for one of the blended fuel vehicles, a Ford F-150 pickup truck, operating on up to 30% hydrogen/70% CNG fuel.« less

  10. Advanced Vehicle Testing Activity: Low-Percentage Hydrogen/CNG Blend Ford F-150 Operating Summary - January 2003

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Karner, D.; Francfort, J.E.

    2003-01-22

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy's Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to runmore » CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service's Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents results of 16,942 miles of testing for one of the blended fuel vehicles, a Ford F-150 pickup truck, operating on up to 30% hydrogen/70% CNG fuel.« less

  11. Investigating the Methane Footprint of Compressed Natural Gas Stations in the Los Angeles Basin

    NASA Astrophysics Data System (ADS)

    Carranza, V.; Hopkins, F. M.; Randerson, J. T.; Bush, S.; Ehleringer, J. R.; Miu, J.

    2013-12-01

    In recent years, natural gas has taken on a larger role in the United States' discourse on energy policy because it is seen as a fuel that can alleviate the country's dependence on foreign energy while simultaneously reducing greenhouse gas emissions. To this end, the State of California promotes the use of vehicles fueled by compressed natural gas (CNG). However, the implications of increased CNG vehicles for greenhouse gas emission reduction are not fully understood. Specifically, methane (CH4) leakages from natural gas infrastructure could make the switch from conventional to CNG vehicles a source of CH4 to the atmosphere, and negate the greenhouse-gas reduction benefit of this policy. The goal of our research is to provide an analysis of potential CH4 leakages from thirteen CNG filling stations in Orange County, California. To improve our understanding of CH4 leakages, we used a mobile laboratory, which is a Ford Transit van equipped with cavity-ring down Picarro spectrometers, to measure CH4 mixing ratios in these CNG stations. MATLAB and ArcGIS were used to conduct statistical analysis and to construct spatial and temporal maps for each transect. We observed mean levels of excess CH4 (relative to background CH4 mixing ratios) ranging from 60 to 1700 ppb at the CNG stations we sampled. Repeated sampling of CNG stations revealed higher levels of excess CH4 during the daytime compared to the nighttime. From our observations, CNG storage tanks and pumps have approximately the same CH4 leakage levels. By improving our understanding of the spatial and temporal patterns of CH4 emissions from CNG stations, our research can provide valuable information to reduce the climate footprint of the natural gas industry.

  12. Advanced Vehicle Testing Activity: High-Percentage Hydrogen/CNG Blend, Ford F-150 -- Operating Summary

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Don Karner; Francfort, James Edward

    2003-01-01

    Over the past two years, Arizona Public Service, a subsidiary of Pinnacle West Capital Corporation, in cooperation with the U.S. Department of Energy’s Advanced Vehicle Testing Activity, tested four gaseous fuel vehicles as part of its alternative fueled vehicle fleet. One vehicle operated initially using compressed natural gas (CNG) and later a blend of CNG and hydrogen. Of the other three vehicles, one was fueled with pure hydrogen and two were fueled with a blend of CNG and hydrogen. The three blended-fuel vehicles were originally equipped with either factory CNG engines or factory gasoline engines that were converted to runmore » CNG fuel. The vehicles were variously modified to operate on blended fuel and were tested using 15 to 50% blends of hydrogen (by volume). The pure-hydrogen-fueled vehicle was converted from gasoline fuel to operate on 100% hydrogen. All vehicles were fueled from the Arizona Public Service’s Alternative Fuel Pilot Plant, which was developed to dispense gaseous fuels, including CNG, blends of CNG and hydrogen, and pure hydrogen with up to 99.9999% purity. The primary objective of the test was to evaluate the safety and reliability of operating vehicles on hydrogen and blended hydrogen fuel, and the interface between the vehicles and the hydrogen fueling infrastructure. A secondary objective was to quantify vehicle emissions, cost, and performance. Over a total of 40,000 fleet test miles, no safety issues were found. Also, significant reductions in emissions were achieved by adding hydrogen to the fuel. This report presents the results of 4,695 miles of testing for one of the blended fuel vehicles, a Ford F-150 pickup truck, operating on up to 50% hydrogen–50% CNG fuel.« less

  13. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mitchell, George

    VICE 2.0 is the second generation of the VICE financial model developed by the National Renewable Energy Laboratory for fleet managers to assess the financial soundness of converting their fleets to run on CNG. VICE 2.0 uses a number of variables for infrastructure and vehicles to estimate the business case for decision-makers when considering CNG as a vehicle fuel. Enhancements in version 2.0 include the ability to select the project type (vehicles and infrastructure or vehicle acquisitions only), and to decouple vehicle acquisition from the infrastructure investment, so the two investments may be made independently. Outputs now include graphical presentationsmore » of investment cash flow, payback period (simple and discounted), petroleum displacement (annual and cumulative), and annual greenhouse gas reductions. Also, the Vehicle Data are now built around several common conventionally fueled (gasoline and diesel) fleet vehicles. Descriptions of the various model sections and available inputs follow. Each description includes default values for the base-case business model, which was created so economic sensitivities can be investigated by altering various project parameters one at a time.« less

  14. U.S. Department of Energy FreedomCAR & Vehicle Technologies Program Advanced Vehicle Testing Activity, Hydrogen/CNG Blended Fuels Performance Testing in a Ford F-150

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    James E. Francfort

    2003-11-01

    Federal regulation requires energy companies and government entities to utilize alternative fuels in their vehicle fleets. To meet this need, several automobile manufacturers are producing compressed natural gas (CNG)-fueled vehicles. In addition, several converters are modifying gasoline-fueled vehicles to operate on both gasoline and CNG (Bifuel). Because of the availability of CNG vehicles, many energy company and government fleets have adopted CNG as their principle alternative fuel for transportation. Meanwhile, recent research has shown that blending hydrogen with CNG (HCNG) can reduce emissions from CNG vehicles. However, blending hydrogen with CNG (and performing no other vehicle modifications) reduces engine powermore » output, due to the lower volumetric energy density of hydrogen in relation to CNG. Arizona Public Service (APS) and the U.S. Department of Energy’s Advanced Vehicle Testing Activity (DOE AVTA) identified the need to determine the magnitude of these effects and their impact on the viability of using HCNG in existing CNG vehicles. To quantify the effects of using various blended fuels, a work plan was designed to test the acceleration, range, and exhaust emissions of a Ford F-150 pickup truck operating on 100% CNG and blends of 15 and 30% HCNG. This report presents the results of this testing conducted during May and June 2003 by Electric Transportation Applications (Task 4.10, DOE AVTA Cooperative Agreement DEFC36- 00ID-13859).« less

  15. Compressed natural gas bus safety: a quantitative risk assessment.

    PubMed

    Chamberlain, Samuel; Modarres, Mohammad

    2005-04-01

    This study assesses the fire safety risks associated with compressed natural gas (CNG) vehicle systems, comprising primarily a typical school bus and supporting fuel infrastructure. The study determines the sensitivity of the results to variations in component failure rates and consequences of fire events. The components and subsystems that contribute most to fire safety risk are determined. Finally, the results are compared to fire risks of the present generation of diesel-fueled school buses. Direct computation of the safety risks associated with diesel-powered vehicles is possible because these are mature technologies for which historical performance data are available. Because of limited experience, fatal accident data for CNG bus fleets are minimal. Therefore, this study uses the probabilistic risk assessment (PRA) approach to model and predict fire safety risk of CNG buses. Generic failure data, engineering judgments, and assumptions are used in this study. This study predicts the mean fire fatality risk for typical CNG buses as approximately 0.23 fatalities per 100-million miles for all people involved, including bus passengers. The study estimates mean values of 0.16 fatalities per 100-million miles for bus passengers only. Based on historical data, diesel school bus mean fire fatality risk is 0.091 and 0.0007 per 100-million miles for all people and bus passengers, respectively. One can therefore conclude that CNG buses are more prone to fire fatality risk by 2.5 times that of diesel buses, with the bus passengers being more at risk by over two orders of magnitude. The study estimates a mean fire risk frequency of 2.2 x 10(-5) fatalities/bus per year. The 5% and 95% uncertainty bounds are 9.1 x 10(-6) and 4.0 x 10(-5), respectively. The risk result was found to be affected most by failure rates of pressure relief valves, CNG cylinders, and fuel piping.

  16. Hypomethylation of CNG targets induced with dihydroxypropyladenine is rapidly reversed in the course of mitotic cell division in tobacco.

    PubMed

    Koukalová, B.; Votruba, I.; Fojtová, M.; Holý, A.; Kovarík, A.

    2002-10-01

    We followed the mitotic transmission of an experimentally induced hypomethylated state of several tobacco repetitive sequences in callus culture and plants. The initial hypomethylation was induced by a hypomethylation drug, dihydroxypropyladenine (DHPA), the competitive inhibitor of cellular S-adenosylhomocysteine hydrolase, which is known to preferentially inhibit methylation at CNG and non-symmetrical motifs while having a negligible effect on methylation at CG motifs. The deprivation of this drug resulted in an almost immediate remethylation of cytosines at CNG motifs ( MspI and EcoRII sites) leading us to conclude that, the hypomethylation effect of dihydroxypropyladenine is rather transient and differs from that of 5-azacytidine which often induces heritable changes in methylation patterns. The results suggest that de novo methylation of CNG motifs is a rapid and meiotically independent process on DNA sequences with pre-existing CG methylation.

  17. Natural Gas Vehicle Cylinder Safety, Training and Inspection Project

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hank Seiff

    2008-12-31

    Under the auspices of the National Energy Technology Laboratory and the US Department of Energy, the Clean Vehicle Education Foundation conducted a three-year program to increase the understanding of the safe and proper use and maintenance of vehicular compressed natural gas (CNG) fuel systems. High-pressure fuel systems require periodic inspection and maintenance to insure safe and proper operation. The project addressed the needs of CNG fuel containers (cylinders) and associated high-pressure fuel system components related to existing law, codes and standards (C&S), available training and inspection programs, and assured coordination among vehicle users, public safety officials, fueling station operators andmore » training providers. The program included a public and industry awareness campaign, establishment and administration of a cylinder inspector certification training scholarship program, evaluation of current safety training and testing practices, monitoring and investigation of CNG vehicle incidents, evaluation of a cylinder recertification program and the migration of CNG vehicle safety knowledge to the nascent hydrogen vehicle community.« less

  18. Project Startup: Evaluating the Performance of Electric Buses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    2016-04-01

    The National Renewable Energy Laboratory (NREL) is evaluating the in-service performance of fast-charge battery electric buses compared to compressed natural gas (CNG) buses operated by Foothill Transit in West Covina, California. Launched in 2015 in collaboration with the California Air Resources Board, this study aims to improve understanding of the overall use and effectiveness of fast-charge electric buses and associated charging infrastructure in transit operation.

  19. Geography of Existing and Potential Alternative Fuel Markets in the United States

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, C.; Hettinger, D.

    When deploying alternative fuels, it is paramount to match the right fuel with the right location, in accordance with local market conditions. We used six market indicators to evaluate the existing and potential regional market health for each of the five most commonly deployed alternative fuels: electricity (used by plug-in electric vehicles), biodiesel (blends of B20 and higher), E85 ethanol, compressed natural gas (CNG), and propane. Each market indicator was mapped, combined, and evaluated by industry experts. This process revealed the weight the market indicators should be given, with the proximity of fueling stations being the most important indicator, followedmore » by alternative fuel vehicle density, gasoline prices, state incentives, nearby resources, and finally, environmental benefit. Though markets vary among states, no state received 'weak' potential for all five fuels, indicating that all states have an opportunity to use at least one alternative fuel. California, Illinois, Indiana, Pennsylvania, and Washington appear to have the best potential markets for alternative fuels in general, with each sporting strong markets for four of the fuels. Wyoming showed the least potential, with weak markets for all alternative fuels except for CNG, for which it has a patchy market. Of all the fuels, CNG is promising in the greatest number of states--largely because freight traffic provides potential demand for many far-reaching corridor markets and because the sources of CNG are so widespread geographically.« less

  20. A new putative cyclic nucleotide-gated channel gene, cng-3, is critical for thermotolerance in Caenorhabditis elegans.

    PubMed

    Cho, Suk-Woo; Choi, Kyu Yeong; Park, Chul-Seung

    2004-12-10

    Cyclic nucleotide-gated (CNG) channels encoded by tax-4 and tax-2 genes are required for chemo- and thermo-sensation in Caenorhabditis elegans. Here we report the identification and the characterization of cng-3, a new CNG channel gene, found in C. elegans. CNG-3 contains six putative transmembrane regions and a cyclic nucleotide-binding domain that show high homology with CNG channels of higher animals as well as TAX-4. The expression of cng-3 is detected from early stages in worm development and restricted in five sensory neurons of amphid including AFD neuron. While a cng-3 null mutant displays normal chemotaxis to volatile odorants, the mutant worms exhibit impaired thermal tolerance. These results indicate that CNG-3, a new member of CNG channel subunits, may play a critical role in sensation or response of thermal stress in C. elegans.

  1. Alternative Fuels Data Center: ampCNG Puts Conventional Fuels Out to

    Science.gov Websites

    ; Steve Josephs, co-founder and director of engineering at ampCNG, Chicago, Illinois When ampCNG isn't the process. ampCNG's Cow-Powered Trucks ampCNG, a CNG station developer based in Chicago, Illinois interest in using more sustainable forms of fuel began in 2010, when the company partnered with Fair Oaks

  2. Structural implications of weak Ca2+ block in Drosophila cyclic nucleotide–gated channels

    PubMed Central

    Lam, Yee Ling; Zeng, Weizhong; Derebe, Mehabaw Getahun

    2015-01-01

    Calcium permeability and the concomitant calcium block of monovalent ion current (“Ca2+ block”) are properties of cyclic nucleotide–gated (CNG) channel fundamental to visual and olfactory signal transduction. Although most CNG channels bear a conserved glutamate residue crucial for Ca2+ block, the degree of block displayed by different CNG channels varies greatly. For instance, the Drosophila melanogaster CNG channel shows only weak Ca2+ block despite the presence of this glutamate. We previously constructed a series of chimeric channels in which we replaced the selectivity filter of the bacterial nonselective cation channel NaK with a set of CNG channel filter sequences and determined that the resulting NaK2CNG chimeras displayed the ion selectivity and Ca2+ block properties of the parent CNG channels. Here, we used the same strategy to determine the structural basis of the weak Ca2+ block observed in the Drosophila CNG channel. The selectivity filter of the Drosophila CNG channel is similar to that of most other CNG channels except that it has a threonine at residue 318 instead of a proline. We constructed a NaK chimera, which we called NaK2CNG-Dm, which contained the Drosophila selectivity filter sequence. The high resolution structure of NaK2CNG-Dm revealed a filter structure different from those of NaK and all other previously investigated NaK2CNG chimeric channels. Consistent with this structural difference, functional studies of the NaK2CNG-Dm chimeric channel demonstrated a loss of Ca2+ block compared with other NaK2CNG chimeras. Moreover, mutating the corresponding threonine (T318) to proline in Drosophila CNG channels increased Ca2+ block by 16 times. These results imply that a simple replacement of a threonine for a proline in Drosophila CNG channels has likely given rise to a distinct selectivity filter conformation that results in weak Ca2+ block. PMID:26283200

  3. Structural implications of weak Ca2+ block in Drosophila cyclic nucleotide-gated channels.

    PubMed

    Lam, Yee Ling; Zeng, Weizhong; Derebe, Mehabaw Getahun; Jiang, Youxing

    2015-09-01

    Calcium permeability and the concomitant calcium block of monovalent ion current ("Ca(2+) block") are properties of cyclic nucleotide-gated (CNG) channel fundamental to visual and olfactory signal transduction. Although most CNG channels bear a conserved glutamate residue crucial for Ca(2+) block, the degree of block displayed by different CNG channels varies greatly. For instance, the Drosophila melanogaster CNG channel shows only weak Ca(2+) block despite the presence of this glutamate. We previously constructed a series of chimeric channels in which we replaced the selectivity filter of the bacterial nonselective cation channel NaK with a set of CNG channel filter sequences and determined that the resulting NaK2CNG chimeras displayed the ion selectivity and Ca(2+) block properties of the parent CNG channels. Here, we used the same strategy to determine the structural basis of the weak Ca(2+) block observed in the Drosophila CNG channel. The selectivity filter of the Drosophila CNG channel is similar to that of most other CNG channels except that it has a threonine at residue 318 instead of a proline. We constructed a NaK chimera, which we called NaK2CNG-Dm, which contained the Drosophila selectivity filter sequence. The high resolution structure of NaK2CNG-Dm revealed a filter structure different from those of NaK and all other previously investigated NaK2CNG chimeric channels. Consistent with this structural difference, functional studies of the NaK2CNG-Dm chimeric channel demonstrated a loss of Ca(2+) block compared with other NaK2CNG chimeras. Moreover, mutating the corresponding threonine (T318) to proline in Drosophila CNG channels increased Ca(2+) block by 16 times. These results imply that a simple replacement of a threonine for a proline in Drosophila CNG channels has likely given rise to a distinct selectivity filter conformation that results in weak Ca(2+) block. © 2015 Lam et al.

  4. Biochemical Characterization of Cone Cyclic Nucleotide-gated (CNG) Channel Using the Infrared Fluorescence Detection System

    PubMed Central

    Ding, Xi-Qin; Matveev, Alexander; Singh, Anil; Komori, Naoka; Matsumoto, Hiroyuki

    2012-01-01

    Cone vision mediated by photoreceptor cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. Cone CNG channel is composed of two structurally related subunit types, CNGA3 and CNGB3. Naturally occurring mutations in cone CNG channel are associated with a variety of cone diseases including achromatopsia, progressive cone dystrophy, and some maculopathies. Nevertheless, our understanding of the structure of cone CNG channel is quite limited. This is, in part, due to the challenge of studying cones in a rod-dominant mammalian retina. We have demonstrated a robust expression of cone CNG channel and lack of rod CNG channel in the cone-dominant Nrl−/− retina and shown that the Nrl−/− mouse line is a valuable model to study cone CNG channel. This work examined the complex structure of cone CNG channel using infrared fluorescence Western detection combined with chemical cross-linking and blue native-PAGE. Our results suggest that the native cone CNG channel is a heterotetrameric complex likely at a stoichiometry of three CNGA3 and one CNGB3. PMID:22183405

  5. Impact of systemic inflammation on gastric cancer outcomes.

    PubMed

    Liu, Xuechao; Chen, Shangxiang; Liu, Jianjun; Xu, Dazhi; Li, Wei; Zhan, Youqing; Li, Yuanfang; Chen, Yingbo; Zhou, Zhiwei; Sun, Xiaowei

    2017-01-01

    The prognostic value of neutrophil-lymphocyte ratio (NLR) and Glasgow Prognostic Score (GPS) has been extensively validated in various cancers. We aimed to examine the usefulness of a combination of NLR and GPS (named CNG) for predicting survival outcomes in patients after curative resection for gastric cancer (GC). We retrospectively analyzed the records of 1056 patients who underwent curative resection as initial treatment for GC from October 2000 to September 2012. The preoperative CNG was calculated as follows: patients with hypoalbuminemia (< 35 g/L), elevated C-reactive protein (> 10 mg/L), and elevated NLR (≥ 2) were allocated a score of 3; patients with two, one, or no abnormal values were allocated a score of 2, 1, or 0, respectively. The NLR and GPS were the only inflammatory variables independently associated with overall survival (OS) in multivariate analysis. When they were replaced by CNG in multivariate analysis, CNG was independently associated with OS (hazard ratio [HR] for CNG 1 [1.367, 95% CI: 1.065-1.755; P = 0.014], CNG 2 [1.887, 95% CI: 1.182-3.011; P = 0.008], and CNG 3 [2.224, 95% CI: 1.238-3.997; P = 0.008]; P = 0.020). In stage-matched analysis, the prognostic significance was still maintained in stage I-III (P = 0.002, P = 0.042, and P < 0.001, respectively). In addition, 5-year survival rates ranged from 92% (stage I) to 35% (stage III) and from 65%(CNG 0) to 18%(CNG 3) with tumor-nodes-metastasis (TNM) stage or CNG alone. However, the combination of TNM and CNG stratified 5-year survival rates from 98% (TNM I, CNG 0) to 12% (TNM III, CNG 3). The preoperative CNG is a novel predictor of postoperative survival, and the combination of CNG and TNM effectively stratifies outcomes in patients after curative resection for GC.

  6. Impact of systemic inflammation on gastric cancer outcomes

    PubMed Central

    Xu, Dazhi; Li, Wei; Zhan, Youqing; Li, Yuanfang; Chen, Yingbo; Zhou, Zhiwei; Sun, Xiaowei

    2017-01-01

    Background The prognostic value of neutrophil-lymphocyte ratio (NLR) and Glasgow Prognostic Score (GPS) has been extensively validated in various cancers. We aimed to examine the usefulness of a combination of NLR and GPS (named CNG) for predicting survival outcomes in patients after curative resection for gastric cancer (GC). Methods We retrospectively analyzed the records of 1056 patients who underwent curative resection as initial treatment for GC from October 2000 to September 2012. The preoperative CNG was calculated as follows: patients with hypoalbuminemia (< 35 g/L), elevated C-reactive protein (> 10 mg/L), and elevated NLR (≥ 2) were allocated a score of 3; patients with two, one, or no abnormal values were allocated a score of 2, 1, or 0, respectively. Results The NLR and GPS were the only inflammatory variables independently associated with overall survival (OS) in multivariate analysis. When they were replaced by CNG in multivariate analysis, CNG was independently associated with OS (hazard ratio [HR] for CNG 1 [1.367, 95% CI: 1.065–1.755; P = 0.014], CNG 2 [1.887, 95% CI: 1.182–3.011; P = 0.008], and CNG 3 [2.224, 95% CI: 1.238–3.997; P = 0.008]; P = 0.020). In stage-matched analysis, the prognostic significance was still maintained in stage I-III (P = 0.002, P = 0.042, and P < 0.001, respectively). In addition, 5-year survival rates ranged from 92% (stage I) to 35% (stage III) and from 65%(CNG 0) to 18%(CNG 3) with tumor-nodes-metastasis (TNM) stage or CNG alone. However, the combination of TNM and CNG stratified 5-year survival rates from 98% (TNM I, CNG 0) to 12% (TNM III, CNG 3). Conclusion The preoperative CNG is a novel predictor of postoperative survival, and the combination of CNG and TNM effectively stratifies outcomes in patients after curative resection for GC. PMID:28358923

  7. 26 CFR 48.4041-21 - Compressed natural gas (CNG).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Compressed natural gas (CNG). 48.4041-21 Section... natural gas (CNG). (a) Delivery of CNG into the fuel supply tank of a motor vehicle or motorboat—(1) Imposition of tax. Tax is imposed on the delivery of compressed natural gas (CNG) into the fuel supply tank...

  8. Alternative Fuels Data Center: CNG Powers Law Enforcement in Arkansas

    Science.gov Websites

    CNG Powers Law Enforcement in Arkansas to someone by E-mail Share Alternative Fuels Data Center : CNG Powers Law Enforcement in Arkansas on Facebook Tweet about Alternative Fuels Data Center: CNG Powers Law Enforcement in Arkansas on Twitter Bookmark Alternative Fuels Data Center: CNG Powers Law

  9. 26 CFR 48.4041-21 - Compressed natural gas (CNG).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 16 2013-04-01 2013-04-01 false Compressed natural gas (CNG). 48.4041-21... natural gas (CNG). (a) Delivery of CNG into the fuel supply tank of a motor vehicle or motorboat—(1) Imposition of tax. Tax is imposed on the delivery of compressed natural gas (CNG) into the fuel supply tank...

  10. 26 CFR 48.4041-21 - Compressed natural gas (CNG).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 16 2012-04-01 2012-04-01 false Compressed natural gas (CNG). 48.4041-21... natural gas (CNG). (a) Delivery of CNG into the fuel supply tank of a motor vehicle or motorboat—(1) Imposition of tax. Tax is imposed on the delivery of compressed natural gas (CNG) into the fuel supply tank...

  11. 26 CFR 48.4041-21 - Compressed natural gas (CNG).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Compressed natural gas (CNG). 48.4041-21... natural gas (CNG). (a) Delivery of CNG into the fuel supply tank of a motor vehicle or motorboat—(1) Imposition of tax. Tax is imposed on the delivery of compressed natural gas (CNG) into the fuel supply tank...

  12. Identification and characterization of a putative cyclic nucleotide-gated channel, CNG-1, in C. elegans.

    PubMed

    Cho, Suk-Woo; Cho, Jeong-Hoon; Song, Hyun-Ok; Park, Chul-Seung

    2005-02-28

    Cyclic nucleotide-gated (CNG) channels encoded by the tax-4 and tax-2 genes are required for chemosensing and thermosensing in the nematode C. elegans. We identified a gene in the C. elegans genome, which we designated cng-1, that is highly homologous to tax-4. Partial CNG-1 protein tagged with green fluorescent protein was expressed in several sensory neurons of the amphid. We created a deletion mutant of cng-1, cng-1 (jh111), to investigate its in vivo function. The mutant worms had no detectable abnormalities in terms of their basic behavior or morphology. Whereas tax-4 and tax-2 mutants failed to respond to water-soluble or volatile chemical attractants, the cng-1 null mutant exhibited normal chemotaxis to such chemicals and a tax-4;cng-1 double mutant had a similar phenotype to tax-4 single mutants. Interestingly, cng-1 and tax-4 had a synergistic effect on brood size.

  13. Alternative Fuels Data Center: West Virginia CNG Corridor Now Open

    Science.gov Websites

    West Virginia CNG Corridor Now Open to someone by E-mail Share Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on Facebook Tweet about Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on Twitter Bookmark Alternative Fuels Data Center: West Virginia CNG Corridor Now Open on

  14. Apparatus for dispensing compressed natural gas and liquified natural gas to natural gas powered vehicles

    DOEpatents

    Bingham, Dennis A.; Clark, Michael L.; Wilding, Bruce M.; Palmer, Gary L.

    2007-05-29

    A fueling facility and method for dispensing liquid natural gas (LNG), compressed natural gas (CNG) or both on-demand. The fueling facility may include a source of LNG, such as cryogenic storage vessel. A low volume high pressure pump is coupled to the source of LNG to produce a stream of pressurized LNG. The stream of pressurized LNG may be selectively directed through an LNG flow path or to a CNG flow path which includes a vaporizer configured to produce CNG from the pressurized LNG. A portion of the CNG may be drawn from the CNG flow path and introduced into the CNG flow path to control the temperature of LNG flowing therethrough. Similarly, a portion of the LNG may be drawn from the LNG flow path and introduced into the CNG flow path to control the temperature of CNG flowing therethrough.

  15. Method and apparatus for dispensing compressed natural gas and liquified natural gas to natural gas powered vehicles

    DOEpatents

    Bingham, Dennis A.; Clark, Michael L.; Wilding, Bruce M.; Palmer, Gary L.

    2005-05-31

    A fueling facility and method for dispensing liquid natural gas (LNG), compressed natural gas (CNG) or both on-demand. The fueling facility may include a source of LNG, such as cryogenic storage vessel. A low volume high pressure pump is coupled to the source of LNG to produce a stream of pressurized LNG. The stream of pressurized LNG may be selectively directed through an LNG flow path or to a CNG flow path which includes a vaporizer configured to produce CNG from the pressurized LNG. A portion of the CNG may be drawn from the CNG flow path and introduced into the CNG flow path to control the temperature of LNG flowing therethrough. Similarly, a portion of the LNG may be drawn from the LNG flow path and introduced into the CNG flow path to control the temperature of CNG flowing therethrough.

  16. An endogenous RNA transcript antisense to CNG(alpha)1 cation channel mRNA.

    PubMed

    Cheng, Chin-Hung; Yew, David Tai-Wai; Kwan, Hiu-Yee; Zhou, Qing; Huang, Yu; Liu, Yong; Chan, Wing-Yee; Yao, Xiaoqiang

    2002-10-01

    CNG channels are cyclic nucleotide-gated Ca(2+)-permeable channels that are suggested to be involved in the activity-dependent alterations of synaptic strength that are thought to underlie information storage in the CNS. In this study, we isolated an endogenous RNA transcript antisense to CNG(alpha)1 mRNA. This transcript was capable of down-regulating the expression of sense CNG(alpha)1 in the Xenopus oocyte expression system. RT-PCR, Northern blot, and in situ hybridization analyses showed that the transcript was coexpressed with CNG(alpha)1 mRNA in many regions of human brain, notably in those regions that were involved in long-term potentiation and long-term depression, such as hippocampal CA1 and CA3, dentate gyrus, and cerebellar Purkinje layer. Comparison of expression patterns between adult and fetal cerebral cortex revealed that there were concurrent developmental changes in the expression levels of anti-CNG1 and CNG(alpha)1. Treatment of human glioma cell T98 with thyroid hormone T(3) caused a significant increase in anti-CNG1 expression and a parallel decrease in sense CNG(alpha)1 expression. These data suggest that the suppression of CNG(alpha)1 expression by anti-CNG1 may play an important role in neuronal functions, especially in synaptic plasticity and cortical development. Endogenous antisense RNA-mediated regulation may represent a new mechanism through which the activity of ion channels can be regulated in the human CNS.

  17. Barwood CNG Cab Fleet Study: Final Results

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Whalen, P.; Kelly, K.; John, M.

    1999-05-03

    This report describes a fleet study conducted over a 12-month period to evaluate the operation of dedicated compress natural gas (CNG) Ford Crown Victoria sedans in a taxicab fleet. In the study, we assess the performance and reliability of the vehicles and the cost of operating the CNG vehicles compared to gasoline vehicles. The study results reveal that the CNG vehicles operated by this fleet offer both economic and environmental advantages. The total operating costs of the CNG vehicles were about 25% lower than those of the gasoline vehicles. The CNG vehicles performed as well as the gasoline vehicles, andmore » were just as reliable. Barwood representatives and drivers have come to consider the CNG vehicles an asset to their business and to the air quality of the local community.« less

  18. Impact of CNG implementation on PAHs concentration in the ambient air of Delhi: a comparative assessment of pre- and post-CNG scenario.

    PubMed

    Khillare, P S; Agarwal, Tripti; Shridhar, Vijay

    2008-12-01

    The use of alternative fuel is considered to be an effective measure to improve the urban air quality. Concerned over deteriorating air quality in Delhi, the Delhi government initiated different measures including stringent emission norms, improved fuel quality and above all introduction of cleaner fuel-CNG in public transport system. The entire city bus fleet was converted to CNG mode by 2002. The present study reports the comparative assessment of the status of air quality with respect to PM(10) and PAH before and after the introduction of CNG in public transport system in Delhi. The study has been carried out for two different time periods: first in the year 1998 and second in the year 2004. Following the total conversion of public transport system to CNG in 2002, Post-CNG data indicate a sharp reduction of 51-74% in the PM(10) concentration and 58-68% in the TPAH concentration as compared to the Pre-CNG data.

  19. Pravastatin chitosan nanogels-loaded erythrocytes as a new delivery strategy for targeting liver cancer.

    PubMed

    Harisa, Gamaleldin I; Badran, Mohamed M; AlQahtani, Saeed A; Alanazi, Fars K; Attia, Sabry M

    2016-01-01

    Chitosan nanogels (CNG) are developed as one of the most promising carriers for cancer targeting. However, these carriers are rapidly eliminated from circulation by reticuloendothelial system (RES), which limits their application. Therefore, erythrocytes (ER) loaded CNG as multifunctional carrier may overcome the massive elimination of nanocarriers by RES. In this study, erythrocytes loaded pravastatin-chitosan nanogels (PR-CNG-ER) were utilized as a novel drug carrier to target liver cancer. Thus, PR-CNG formula was developed in nanosize, with good entrapment efficiency, drug loading and sustained release over 48 h. Then, PR-CNG loaded into ER were prepared by hypotonic preswelling technique. The resulting PR-CNG-ER showed 36.85% of entrapment efficiency, 66.82% of cell recovery and release consistent to that of hemoglobin over 48 h. Moreover, PR-CNG-ER exhibited negative zeta potential, increasing of hemolysis percent, marked phosphatidylserine exposure and stomatocytes shape compared to control unloaded erythrocytes. PR-CNG-ER reduced cells viability of HepG2 cells line by 28% compared to unloaded erythrocytes (UER). These results concluded that PR-CNG-ER are promising drug carriers to target liver cancer.

  20. Air quality and climate impacts of alternative bus technologies in Greater London.

    PubMed

    Chong, Uven; Yim, Steve H L; Barrett, Steven R H; Boies, Adam M

    2014-04-15

    The environmental impact of diesel-fueled buses can potentially be reduced by the adoption of alternative propulsion technologies such as lean-burn compressed natural gas (LB-CNG) or hybrid electric buses (HEB), and emissions control strategies such as a continuously regenerating trap (CRT), exhaust gas recirculation (EGR), or selective catalytic reduction with trap (SCRT). This study assessed the environmental costs and benefits of these bus technologies in Greater London relative to the existing fleet and characterized emissions changes due to alternative technologies. We found a >30% increase in CO2 equivalent (CO2e) emissions for CNG buses, a <5% change for exhaust treatment scenarios, and a 13% (90% confidence interval 3.8-20.9%) reduction for HEB relative to baseline CO2e emissions. A multiscale regional chemistry-transport model quantified the impact of alternative bus technologies on air quality, which was then related to premature mortality risk. We found the largest decrease in population exposure (about 83%) to particulate matter (PM2.5) occurred with LB-CNG buses. Monetized environmental and investment costs relative to the baseline gave estimated net present cost of LB-CNG or HEB conversion to be $187 million ($73 million to $301 million) or $36 million ($-25 million to $102 million), respectively, while EGR or SCRT estimated net present costs were $19 million ($7 million to $32 million) or $15 million ($8 million to $23 million), respectively.

  1. Alternative Fuels Data Center

    Science.gov Websites

    Department of Revenue (Department) uses a CNG gallon equivalent factor of 5.66 pounds (lbs.) and a liquefied gas gallon equivalent factor of 6.06 lbs. Liquefied gas is all combustible gas that exists in the

  2. Alternative Fuels Data Center: Leadership in CNG Propels Paper Transport

    Science.gov Websites

    Inc. Leadership in CNG Propels Paper Transport Inc. to someone by E-mail Share Alternative Fuels Data Center: Leadership in CNG Propels Paper Transport Inc. on Facebook Tweet about Alternative Fuels Data Center: Leadership in CNG Propels Paper Transport Inc. on Twitter Bookmark Alternative Fuels

  3. Alternative Fuels Data Center: CNG Vehicle Fueling Animation

    Science.gov Websites

    Vehicle Fueling Animation to someone by E-mail Share Alternative Fuels Data Center: CNG Vehicle Fueling Animation on Facebook Tweet about Alternative Fuels Data Center: CNG Vehicle Fueling Animation on Twitter Bookmark Alternative Fuels Data Center: CNG Vehicle Fueling Animation on Google Bookmark Alternative Fuels

  4. 49 CFR 393.68 - Compressed natural gas fuel containers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... containers. (a) Applicability. The rules in this section apply to compressed natural gas (CNG) fuel... auxiliary equipment installed on, or used in connection with commercial motor vehicles. (b) CNG containers... equipped with a CNG fuel tank must meet the CNG container requirements of FMVSS No. 304 (49 CFR 571.304) in...

  5. 49 CFR 393.68 - Compressed natural gas fuel containers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... containers. (a) Applicability. The rules in this section apply to compressed natural gas (CNG) fuel... auxiliary equipment installed on, or used in connection with commercial motor vehicles. (b) CNG containers... equipped with a CNG fuel tank must meet the CNG container requirements of FMVSS No. 304 (49 CFR 571.304) in...

  6. 49 CFR 393.68 - Compressed natural gas fuel containers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... containers. (a) Applicability. The rules in this section apply to compressed natural gas (CNG) fuel... auxiliary equipment installed on, or used in connection with commercial motor vehicles. (b) CNG containers... equipped with a CNG fuel tank must meet the CNG container requirements of FMVSS No. 304 (49 CFR 571.304) in...

  7. Will CNG threaten your future loads

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    A campaign to promote the use of natural gas as a fleet fuel is described and as a result, CNG conversions are beginning to take hold in some market segments. Only a few months after Ford Motor Co. announced production plans for an LPG-powered line of Granada/Cougar models, it unveiled an alternative-fuels concept car - a short-ranged metro sportscar - that could be ordered by the customer with any of four fuel systems (CNG, propane, ethanol, or methanol) offered on a dedicated or single-fuel basis. By including CNG in its alternative-fuels concept, Ford not only gave a boost to effortsmore » to build a motor fuel load for natural gas, but also indicated that CNG, as well as propane, is a viable alternative to gasoline in some applications. Recent reports of advances in CNG technology that enhance its potential as a motor fuel - together with other reports of at least one US firm launching production of a CNG motor fuel system and of several companies already marketing them - might be cause for the LPG industry to take another look at CNG's competitive potential.« less

  8. Retinal Cyclic Nucleotide-Gated Channels: From Pathophysiology to Therapy.

    PubMed

    Michalakis, Stylianos; Becirovic, Elvir; Biel, Martin

    2018-03-07

    The first step in vision is the absorption of photons by the photopigments in cone and rod photoreceptors. After initial amplification within the phototransduction cascade the signal is translated into an electrical signal by the action of cyclic nucleotide-gated (CNG) channels. CNG channels are ligand-gated ion channels that are activated by the binding of cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate (cAMP). Retinal CNG channels transduce changes in intracellular concentrations of cGMP into changes of the membrane potential and the Ca 2+ concentration. Structurally, the CNG channels belong to the superfamily of pore-loop cation channels and share a common gross structure with hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and voltage-gated potassium channels (KCN). In this review, we provide an overview on the molecular properties of CNG channels and describe their physiological role in the phototransduction pathways. We also discuss insights into the pathophysiological role of CNG channel proteins that have emerged from the analysis of CNG channel-deficient animal models and human CNG channelopathies. Finally, we summarize recent gene therapy activities and provide an outlook for future clinical application.

  9. Retinal Cyclic Nucleotide-Gated Channels: From Pathophysiology to Therapy

    PubMed Central

    Biel, Martin

    2018-01-01

    The first step in vision is the absorption of photons by the photopigments in cone and rod photoreceptors. After initial amplification within the phototransduction cascade the signal is translated into an electrical signal by the action of cyclic nucleotide-gated (CNG) channels. CNG channels are ligand-gated ion channels that are activated by the binding of cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate (cAMP). Retinal CNG channels transduce changes in intracellular concentrations of cGMP into changes of the membrane potential and the Ca2+ concentration. Structurally, the CNG channels belong to the superfamily of pore-loop cation channels and share a common gross structure with hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and voltage-gated potassium channels (KCN). In this review, we provide an overview on the molecular properties of CNG channels and describe their physiological role in the phototransduction pathways. We also discuss insights into the pathophysiological role of CNG channel proteins that have emerged from the analysis of CNG channel-deficient animal models and human CNG channelopathies. Finally, we summarize recent gene therapy activities and provide an outlook for future clinical application. PMID:29518895

  10. CNG site-specific and methyl-sensitive endonuclease WEN1 from wheat seedlings.

    PubMed

    Fedoreyeva, L I; Vanyushin, B F

    2011-06-01

    Endonuclease WEN1 with apparent molecular mass about 27 kDa isolated from cytoplasmic vesicular fraction of aging coleoptiles of wheat seedlings has expressed site specificity action. This is a first detection and isolation of a site-specific endonuclease from higher eukaryotes, in general, and higher plants, in particular. The enzyme hydrolyzes deoxyribooligonucleotides of different composition on CNG (N is G, A, C, or T) sites by splitting the phosphodiester bond between C and N nucleotide residues in CNG sequence independent from neighbor nucleotide context except for CCCG. WEN1 prefers to hydrolyze methylated λ phage DNA and double-stranded deoxyribooligonucleotides containing 5-methylcytosine sites (m(5)CAG, m(5)CTG) compared with unmethylated substrates. The enzyme is also able to hydrolyze single-stranded substrates, but in this case it splits unmethylated substrates predominantly. Detection in wheat seedlings of WEN1 endonuclease that is site specific, sensitive to the substrate methylation status, and modulated with S-adenosyl-L-methionine indicates that in higher plants restriction--modification systems or some of their elements, at least, may exist.

  11. Criteria pollutant and greenhouse gas emissions from CNG transit buses equipped with three-way catalysts compared to lean-burn engines and oxidation catalyst technologies.

    PubMed

    Yoon, Seungju; Collins, John; Thiruvengadam, Arvind; Gautam, Mridul; Herner, Jorn; Ayala, Alberto

    2013-08-01

    Engine and exhaust control technologies applied to compressed natural gas (CNG) transit buses have advanced from lean-burn, to lean-burn with oxidation catalyst (OxC), to stoichiometric combustion with three-way catalyst (TWC). With this technology advancement, regulated gaseous and particulate matter emissions have been significantly reduced. Two CNG transit buses equipped with stoichiometric combustion engines and TWCs were tested on a chassis dynamometer, and their emissions were measured. Emissions from the stoichiometric engines with TWCs were then compared to the emissions from lean-burn CNG transit buses tested in previous studies. Stoichiometric combustion with TWC was effective in reducing emissions of oxides of nitrogen (NO(x)), particulate matter (PM), and nonmethane hydrocarbon (NMHC) by 87% to 98% depending on pollutants and test cycles, compared to lean combustion. The high removal efficiencies exceeded the emission reduction required from the certification standards, especially for NO(x) and PM. While the certification standards require 95% and 90% reductions for NO(x) and PM, respectively, from the engine model years 1998-2003 to the engine model year 2007, the measured NO(x) and PM emissions show 96% and 95% reductions, respectively, from the lean-burn engines to the stoichiometric engines with TWC over the transient Urban Dynamometer Driving Schedule (UDDS) cycle. One drawback of stoichiometric combustion with TWC is that this technology produces higher carbon monoxide (CO) emissions than lean combustion. In regard to controlling CO emissions, lean combustion with OxC is more effective than stoichiometric combustion. Stoichiometric combustion with TWC produced higher greenhouse gas (GHG) emissions including carbon dioxide (CO2) and methane (CH4) than lean combustion during the UDDS cycle, but lower GHG emissions during the steady-state cruise cycle. Stoichiometric combustion with three-way catalyst is currently the best emission control technology available for compressed natural gas (CNG) transit buses to meet the stringent U.S. Environmental Protection Agency (EPA) 2010 heavy-duty engine NO(x) emissions standard. For existing lean-burn CNG transit buses in the fleet, oxidation catalyst would be the most effective retrofit technology for the control of NMHC and CO emissions.

  12. Assessment of on-road emissions of four Euro V diesel and CNG waste collection trucks for supporting air-quality improvement initiatives in the city of Milan.

    PubMed

    Fontaras, Georgios; Martini, Giorgio; Manfredi, Urbano; Marotta, Alessandro; Krasenbrink, Alois; Maffioletti, Francesco; Terenghi, Roberto; Colombo, Mauro

    2012-06-01

    This paper summarizes the results of an extensive experimental study aiming to evaluate the performance and pollutant emissions of diesel and CNG waste collection trucks under realistic and controlled operating conditions in order to support a fleet renewal initiative in the city of Milan. Four vehicles (1 diesel and 3 CNG) were tested in two phases using a portable emission measurement system. The first phase included real world operation in the city of Milan while the second involved controlled conditions in a closed track. Emissions recorded from the diesel truck were on average 2.4 kg/km for CO(2), 0.21 g/km for HC, 7.4 g/km for CO, 32.3 g/km for NO(x) and 46.4 mg/km for PM. For the CNG the values were 3.6 kg/km for CO(2), 2.19 g/km for HC, 15.8 g/km for CO, 4.38 g/km for NO(x) and 11.4 mg/km for PM. CNG vehicles presented an important advantage with regards to NO(x) and PM emissions but lack the efficiency of their diesel counterparts when it comes to CO, HC and particularly greenhouse gas emissions. This tradeoff needs to be carefully analyzed prior to deciding if a fleet should be shifted towards either technology. In addition it was shown that existing emission factors, used in Europe for environmental assessment studies, reflect well the operation for CNG but were not so accurate when it came to the diesel engine truck particularly for CO(2) and NO(x). With regard to NO(x), it was also shown that the limits imposed by current emission standards are not necessarily reflected in real world operation, under which the diesel vehicle presented almost 4 times higher emissions. Regarding CO(2), appropriate use of PEMS data and vehicle information allows for accurate emission monitoring through computer simulation. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Alternative Fuels Data Center: Kansas City Kansas Public Schools Invests in

    Science.gov Websites

    station for up to 70 CNG school buses, one mobile CNG refueling unit, and CNG safety modifications to the buses and fast-fill dispensers for public access. After receiving only one response, KCKPS simplified , or at one of the City of Kansas City, Missouri's private fast-fill stations. The first CNG bus was

  14. Function and dysfunction of CNG channels: insights from channelopathies and mouse models.

    PubMed

    Biel, Martin; Michalakis, Stylianos

    2007-06-01

    Channels directly gated by cyclic nucleotides (CNG channels) are important cellular switches that mediate influx of Na+ and Ca2+ in response to increases in the intracellular concentration of cAMP and cGMP. In photoreceptors and olfactory receptor neurons, these channels serve as final targets for cGMP and cAMP signaling pathways that are initiated by the absorption of photons and the binding of odorants, respectively. CNG channels have been also found in other types of neurons and in non-excitable cells. However, in most of these cells, the physiological role of CNG channels has yet to be determined. CNG channels have a complex heteromeric structure. The properties of individual subunits that assemble in specific stoichiometries to the native channels have been extensively investigated in heterologous expression systems. Recently, mutations in human CNG channel genes leading to inherited diseases (so-called channelopathies) have been functionally characterized. Moreover, mouse knockout models were generated to define the role of CNG channel proteins in vivo. In this review, we will summarize recent insights into the physiological and pathophysiological role of CNG channel proteins that have emerged from genetic studies in mice and humans.

  15. Contribution of the cyclic nucleotide gated channel subunit, CNG-3, to olfactory plasticity in Caenorhabditis elegans.

    PubMed

    O'Halloran, Damien M; Altshuler-Keylin, Svetlana; Zhang, Xiao-Dong; He, Chao; Morales-Phan, Christopher; Yu, Yawei; Kaye, Julia A; Brueggemann, Chantal; Chen, Tsung-Yu; L'Etoile, Noelle D

    2017-03-13

    In Caenorhabditis elegans, the AWC neurons are thought to deploy a cGMP signaling cascade in the detection of and response to AWC sensed odors. Prolonged exposure to an AWC sensed odor in the absence of food leads to reversible decreases in the animal's attraction to that odor. This adaptation exhibits two stages referred to as short-term and long-term adaptation. Previously, the protein kinase G (PKG), EGL-4/PKG-1, was shown necessary for both stages of adaptation and phosphorylation of its target, the beta-type cyclic nucleotide gated (CNG) channel subunit, TAX-2, was implicated in the short term stage. Here we uncover a novel role for the CNG channel subunit, CNG-3, in short term adaptation. We demonstrate that CNG-3 is required in the AWC for adaptation to short (thirty minute) exposures of odor, and contains a candidate PKG phosphorylation site required to tune odor sensitivity. We also provide in vivo data suggesting that CNG-3 forms a complex with both TAX-2 and TAX-4 CNG channel subunits in AWC. Finally, we examine the physiology of different CNG channel subunit combinations.

  16. Hydrogen, CNG, and HCNG Dispenser System – Prototype Report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    James Francfort

    2005-02-01

    The U.S. Department of Energy’s Advanced Vehicle Testing Activity is currently testing a prototype gaseous fuel dispenser developed by the Electric Transportation Engineering Corporation (ETEC). The dispenser (Figure 1) delivers three types of fuels: 100% hydrogen, 100% compressed natural gas (CNG), and blends of hydrogen and CNG (HCNG) using two independent single nozzles (Figure 2). The nozzle for the 100% hydrogen dispensing is rated at 5,000 psig and used solely for 100% hydrogen fuel. The second nozzle is rated at 3,600 psig and is used for both CNG and HCNG fuels. This nozzle connects to both a CNG supply linemore » and a hydrogen supply line and blends the hydrogen and CNG to supply HCNG levels of 15, 20, 30, and 50% (by volume).« less

  17. Thermodynamic stability of RNA structures formed by CNG trinucleotide repeats. Implication for prediction of RNA structure.

    PubMed

    Broda, Magdalena; Kierzek, Elzbieta; Gdaniec, Zofia; Kulinski, Tadeusz; Kierzek, Ryszard

    2005-08-16

    Trinucleotide repeat expansion diseases (TREDs) are correlated with elongation of CNG DNA and RNA repeats to pathological level. This paper shows, for the first time, complete data concerning thermodynamic stabilities of RNA with CNG trinucleotide repeats. Our studies include the stability of oligoribonucleotides composed of two to seven of CAG, CCG, CGG, and CUG repeats. The thermodynamic parameters of helix propagation correlated with the presence of multiple N-N mismatches within CNG RNA duplexes were also determined. Moreover, the total stability of CNG RNA hairpins, as well as the contribution of trinucleotide repeats placed only in the stem or loop regions, was evaluated. The improved thermodynamic parameters allow to predict much more accurately the thermodynamic stabilities and structures of CNG RNAs.

  18. Technical evaluation and assessment of CNG/LPG bi-fuel and flex-fuel vehicle viability

    NASA Astrophysics Data System (ADS)

    Sinor, J. E.

    1994-05-01

    This report compares vehicles using compressed natural gas (CNG), liquefied petroleum gas (LPG), and combinations of the two in bi-fuel or flex-fuel configurations. Evidence shows that environmental and energy advantages can be gained by replacing two-fuel CNG/gasoline vehicles with two-fuel or flex-fuel systems to be economically competitive, it is necessary to develop a universal CNG/LPG pressure-regulator-injector and engine control module to switch from one tank to the other. For flex-fuel CNG/LPG designs, appropriate composition sensors, refueling pumps, fuel tanks, and vaporizers are necessary.

  19. CNG-Modulin: a novel Ca-dependent modulator of ligand sensitivity in cone photoreceptor cGMP-gated ion channels

    PubMed Central

    Rebrik, Tatiana I.; Botchkina, Inna; Arshavsky, Vadim Y.; Craft, Cheryl M.; Korenbrot, Juan I.

    2012-01-01

    The transduction current in several different types of sensory neurons arises from the activity of cyclic nucleotide gated ion channels (CNG channels). The channels in these sensory neurons vary in structure and function, yet each one demonstrates calcium-dependent modulation of ligand sensitivity mediated by the interaction of the channel with a soluble modulator protein. In cone photoreceptors, the molecular identity of the modulator protein was previously unknown. We report the discovery and characterization of CNG-modulin, a novel 301 amino acid protein that interacts with the N-terminus of the β-subunit of the cGMP-gated channel, and modulates the cGMP sensitivity of the channels in cone photoreceptors of striped bass (Morone saxitilis). Immunohistochemistry and single cell PCR demonstrate that CNG-modulin is expressed in cone, but not rod photoreceptors. Adding purified recombinant CNG-modulin to cone membrane patches containing the native CNG channels shifts the midpoint of cGMP-dependence from ~91 μM in the absence of Ca2+ to ~332 μM in the presence of 20 μM Ca2+. At a fixed cGMP concentration, the midpoint of the Ca2+ dependence is ~857 nM Ca2+. These restored physiological features are statistically indistinguishable from the effects of the endogenous modulator. CNG-modulin binds Ca2+ with a concentration dependence that matches the calcium dependence of channel modulation. We conclude that CNG-modulin is the authentic Ca2+-dependent modulator of cone CNG channel ligand sensitivity. CNG-modulin is expressed in other tissues, such as brain, olfactory epithelium and the inner ear and may modulate the function of ion channels in those tissues as well. PMID:22378887

  20. CNG-modulin: a novel Ca-dependent modulator of ligand sensitivity in cone photoreceptor cGMP-gated ion channels.

    PubMed

    Rebrik, Tatiana I; Botchkina, Inna; Arshavsky, Vadim Y; Craft, Cheryl M; Korenbrot, Juan I

    2012-02-29

    The transduction current in several different types of sensory neurons arises from the activity of cyclic nucleotide-gated (CNG) ion channels. The channels in these sensory neurons vary in structure and function, yet each one demonstrates calcium-dependent modulation of ligand sensitivity mediated by the interaction of the channel with a soluble modulator protein. In cone photoreceptors, the molecular identity of the modulator protein was previously unknown. We report the discovery and characterization of CNG-modulin, a novel 301 aa protein that interacts with the N terminus of the β subunit of the cGMP-gated channel and modulates the cGMP sensitivity of the channels in cone photoreceptors of striped bass (Morone saxatilis). Immunohistochemistry and single-cell PCR demonstrate that CNG-modulin is expressed in cone but not rod photoreceptors. Adding purified recombinant CNG-modulin to cone membrane patches containing the native CNG channels shifts the midpoint of cGMP dependence from ∼91 μM in the absence of Ca(2+) to ∼332 μM in the presence of 20 μM Ca(2+). At a fixed cGMP concentration, the midpoint of the Ca(2+) dependence is ∼857 nM Ca(2+). These restored physiological features are statistically indistinguishable from the effects of the endogenous modulator. CNG-modulin binds Ca(2+) with a concentration dependence that matches the calcium dependence of channel modulation. We conclude that CNG-modulin is the authentic Ca(2+)-dependent modulator of cone CNG channel ligand sensitivity. CNG-modulin is expressed in other tissues, such as brain, olfactory epithelium, and the inner ear, and may modulate the function of ion channels in those tissues as well.

  1. Clean Air Program : cylinder issues associated with alternative fuels

    DOT National Transportation Integrated Search

    1999-01-01

    A number of incidents of compressed natural gas (CNG) cylinder leaks have occurred while transit buses were either in service or at a bus maintenance facility. This study was initiated to determine the degree to which cylinder problems still exist in...

  2. Assessment of air quality after the implementation of compressed natural gas (CNG) as fuel in public transport in Delhi, India.

    PubMed

    Ravindra, Khaiwal; Wauters, Eric; Tyagi, Sushil K; Mor, Suman; Van Grieken, René

    2006-04-01

    Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM(10), CO, SO(2) and NO(x)) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO(2) and CO concentrations, while the NO(x) level was increased in comparison to those before the implementation of CNG. Further, SPM, PM(10), and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.

  3. Technology demonstration of dedicated compressed natural gas (CNG) original equipment manufacturer (OEM) vehicles at Ft. Bliss, Texas. Interim report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alvarez, R.A.; Yost, D.M.

    1995-11-01

    A technology demonstration program of dedicated compressed natural gas (CNG) original equipment manufacturer (OEM) vehicles was conducted at FL Bliss, Texas to demonstrate the use of CNG as an alternative fuel. The demonstration program at FL Bliss was the first Army initiative with CNG-fueled vehicles under the legislated Alternative Motor Fuels Act. This Department of Energy (DOE)-supported fleet demonstration consisted of 48 General Services Administration (GSA)-owned, Army-leased 1992 dedicated CNG General Motors (GM) 3/4-ton pickup trucks and four 1993 gasoline-powered Chevrolet 3/4-ton pickup trucks.

  4. Alternative Fuels Data Center

    Science.gov Websites

    Compressed Natural Gas (CNG) and Propane Tax Retail sales for CNG and liquefied petroleum gas (propane) used to operate vehicles are subject to a modified tax based on energy content. CNG is taxed per

  5. Insulin receptor regulates photoreceptor CNG channel activity

    PubMed Central

    Gupta, Vivek K.; Rajala, Ammaji

    2012-01-01

    Photoreceptor cyclic nucleotide gated (CNG) channels are critical elements in phototransduction and light adaptation. Here we report that insulin receptor (IR), an integral membrane protein, directly phosphorylates the CNGA1 subunit of CNG channels that in turn affects the function of these channels negatively. The IR phosphorylates Tyr498 and Tyr503 residues on CNGA1 that are situated at the membrane-cytoplasmic interface. The IR tyrosine kinase activity is essential for the inhibition of CNG channel. To maintain the channels in an off state, it is necessary not only to have a precise balance of the cGMP levels but also to have a control on the cGMP sensitivity of the CNG channels itself. In this study, we observed that the channel opens at a lower concentration of cGMP in IR−/− mice. These studies suggest that IR regulates the modulation of CNG channel activity in vivo. PMID:23032687

  6. Insulin receptor regulates photoreceptor CNG channel activity.

    PubMed

    Gupta, Vivek K; Rajala, Ammaji; Rajala, Raju V S

    2012-12-01

    Photoreceptor cyclic nucleotide gated (CNG) channels are critical elements in phototransduction and light adaptation. Here we report that insulin receptor (IR), an integral membrane protein, directly phosphorylates the CNGA1 subunit of CNG channels that in turn affects the function of these channels negatively. The IR phosphorylates Tyr(498) and Tyr(503) residues on CNGA1 that are situated at the membrane-cytoplasmic interface. The IR tyrosine kinase activity is essential for the inhibition of CNG channel. To maintain the channels in an off state, it is necessary not only to have a precise balance of the cGMP levels but also to have a control on the cGMP sensitivity of the CNG channels itself. In this study, we observed that the channel opens at a lower concentration of cGMP in IR(-/-) mice. These studies suggest that IR regulates the modulation of CNG channel activity in vivo.

  7. MET gene copy number gain is an independent poor prognostic marker in Korean stage I lung adenocarcinomas.

    PubMed

    Jin, Yan; Sun, Ping-Li; Kim, Hyojin; Seo, An Na; Jheon, Sanghoon; Lee, Choon-Taek; Chung, Jin-Haeng

    2014-02-01

    MET gene copy number gain (CNG) and protein overexpression have been reported in lung cancer, but the clinical implications in early stage adenocarcinoma remain unclear. We investigated MET gene copy number and protein expression in 141 cases of surgically resected stage I pulmonary adenocarcinoma. MET gene CNG was determined by silver in situ hybridization, and MET protein expression was assessed by immunohistochemistry. The correlation between MET gene CNG/protein expression and clinicopathologic parameters and prognostic significance was analyzed. MET gene CNG was found in 24.1% (34 of 141) of the cases and was associated with larger tumor size, pleural invasion, and lymphatic vessel invasion. MET gene CNG was inversely correlated with the presence of lepidic subtype (r = -0.17, p = 0.045) and was not associated with EGFR, KRAS mutation, or ALK gene rearrangement. In addition, MET gene CNG was significantly associated with shorter disease-free survival (DFS) (49 vs. 75 months; p < 0.001) and shorter overall survival (OS) (65 vs. 78 months; p = 0.01). Multivariate analysis confirmed that MET gene CNG was significantly associated with poorer DFS [p < 0.001; hazard ratio (HR) 5.5; 95% confidence interval (CI) 2.2-13.9] but was not significantly associated with OS. MET overexpression was observed in 71.3% of cases (97 of 136), but it was not correlated with gene CNG. MET gene CNG is an independent poor prognostic factor in patients with stage I lung adenocarcinoma. It is associated with aggressive pathologic features and is inversely correlated with the presence of lepidic subtype.

  8. Climate and health relevant emissions from in-use Indian three-wheelers fueled by natural gas and gasoline.

    PubMed

    Reynolds, Conor C O; Grieshop, Andrew P; Kandlikar, Milind

    2011-03-15

    Auto-rickshaws in India use different fuels and engine technologies, with varying emissions and implications for air quality and climate change. Chassis dynamometer emission testing was conducted on 30 in-use auto-rickshaws to quantify the impact of switching from gasoline to compressed natural gas (CNG) in spark-ignition engines. Thirteen test vehicles had two-stroke CNG engines (CNG-2S) and 17 had four-stroke CNG engines (CNG-4S), of which 11 were dual-fuel and operable on a back-up gasoline (petrol) system (PET-4S). Fuel-based emission factors were determined for gaseous pollutants (CO(2), CH(4), NO(X), THC, and CO) and fine particulate matter (PM(2.5)). Intervehicle variability was high, and for most pollutants there was no significant difference (95% confidence level) between "old" (1998-2001) and "new" (2007-2009) age-groups within a given fuel-technology class. Mean fuel-based PM(2.5) emission factor (mean (95% confidence interval)) for CNG-2S (14.2 g kg(-1) (6.2-26.7)) was almost 30 times higher than for CNG-4S (0.5 g kg(-1) (0.3-0.9)) and 12 times higher than for PET-4S (1.2 g kg(-1) (0.8-1.7)). Global warming commitment associated with emissions from CNG-2S was more than twice that from CNG-4S or PET-4S, due mostly to CH(4) emissions. Comprehensive measurements and data should drive policy interventions rather than assumptions about the impacts of clean fuels.

  9. One dimensional modeling of a diesel-CNG dual fuel engine

    NASA Astrophysics Data System (ADS)

    Azman, Putera Adam; Fawzi, Mas; Ismail, Muammar Mukhsin; Osman, Shahrul Azmir

    2017-04-01

    Some of the previous studies have shown that the use of compressed natural gas (CNG) in diesel engines potentially produce engine performance improvement and exhaust gas emission reduction, especially nitrogen oxides, unburned hydrocarbons, and carbon dioxide. On the other hand, there are other researchers who claimed that the use of CNG increases exhaust gas emissions, particularly nitrogen oxides. In this study, a one-dimensional model of a diesel-CNG dual fuel engine was made based on a 4-cylinder 2.5L common rail direct injection diesel engine. The software used is GT-Power, and it was used to analyze the engine performance and exhaust gas emissions of several diesel-CNG dual fuel blend ratios, i.e. 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. The effect of 100%, 75%, 50% engine loads on the exhaust gas emissions were also studied. The result shows that all diesel-CNG fuel blends produces higher brake torque and brake power at engine speed of 2000-3000 rpm compared with 100% diesel. The 50:50 diesel-CNG blend produces the highest brake torque and brake power, but also has the highest brake specific fuel consumption. As a higher percentage of CNG added to the dual fuel blend, unburned hydrocarbons and carbon monoxide emission increased while carbon dioxide emission decreased. The nitrogen oxides emission concentration is generally unaffected by any change of the dual fuel ratio.

  10. A comparison of exhaust emissions from vehicles fuelled with petrol, LPG and CNG

    NASA Astrophysics Data System (ADS)

    Bielaczyc, P.; Szczotka, A.; Woodburn, J.

    2016-09-01

    This paper presents an analysis of THC, NMHC, CO, NOx and CO2 emissions during testing of two bi-fuel vehicles, fuelled with petrol and gaseous fuels, on a chassis dynamometer in the context of the Euro 6 emissions requirements. The analyses were performed on one Euro 5 bi-fuel vehicle (petrol/LPG) and one Euro 5 bi-fuel vehicle (petrol/CNG), both with SI engines equipped with MPI feeding systems operating in closed-loop control, typical three-way-catalysts and heated oxygen sensors. The vehicles had been adapted by their manufacturers for fuelling with LPG or CNG by using additional special equipment mounted onto the existing petrol fuelling system. The vehicles tested featured multipoint gas injection systems. The aim of this paper was an analysis of the impact of the gaseous fuels on the exhaust emission in comparison to the emission of the vehicles fuelled with petrol. The tests subject to the analyses presented here were performed in the Engine Research Department of BOSMAL Automotive Research and Development Institute Ltd in Bielsko-Biala, Poland, within a research programme investigating the influence of alternative fuels on exhaust emissions from light duty vehicle vehicles with spark-ignition and compression-ignition engines.

  11. A comparative investigation of ultrafine particle number and mass emissions from a fleet of on-road diesel and CNG buses.

    PubMed

    Jayaratne, E R; He, C; Ristovski, Z D; Morawska, L; Johnson, G R

    2008-09-01

    Particle number, particle mass, and CO2 concentrations were measured on the curb of a busy urban busway used entirely by a mix of diesel and CNG operated buses. With the passage of each bus, the ratio of particle number concentration and particle mass concentration to CO2 concentration in the diluted exhaust plume were used as measures of the particle number and mass emission factors, respectively. With all buses accelerating pastthe monitoring point, the results showed that the median particle mass emission from CNG buses was less than 9% of that from diesel buses. However, the median particle number emission from CNG buses was 6 times higher than the diesel buses, and the particles from the CNG buses were mainly in the nanoparticle size range. Using a thermodenuder to remove the volatile material from the sampled emissions showed that the majority of particles from the CNG buses, but not from the diesel buses, were volatile. Approximately, 82% of the particles from the CNG buses and 38% from the diesel buses were removed by heating the emissions to 300 degrees C.

  12. Interaction of 4.1G and cGMP-gated channels in rod photoreceptor outer segments.

    PubMed

    Cheng, Christiana L; Molday, Robert S

    2013-12-15

    In photoreceptors, the assembly of signaling molecules into macromolecular complexes is important for phototransduction and maintaining the structural integrity of rod outer segments (ROSs). However, the molecular composition and formation of these complexes are poorly understood. Using immunoprecipitation and mass spectrometry, 4.1G was identified as a new interacting partner for the cyclic-nucleotide gated (CNG) channels in ROSs. 4.1G is a widely expressed multifunctional protein that plays a role in the assembly and stability of membrane protein complexes. Multiple splice variants of 4.1G were cloned from bovine retina. A smaller splice variant of 4.1G selectively interacted with CNG channels not associated with peripherin-2-CNG channel complex. A combination of truncation studies and domain-binding assays demonstrated that CNG channels selectively interacted with 4.1G through their FERM and CTD domains. Using immunofluorescence, labeling of 4.1G was seen to be punctate and partially colocalized with CNG channels in the ROS. Our studies indicate that 4.1G interacts with a subset of CNG channels in the ROS and implicate this protein-protein interaction in organizing the spatial arrangement of CNG channels in the plasma membrane of outer segments.

  13. Design Guidelines for Bus Transit Systems Using Liquefied Petroleum Gas (LPG) as an Alternative Fuel.

    DOT National Transportation Integrated Search

    1996-09-01

    The use of alternative fuels to power transit buses is steadily increasing. Several fuels, including Liquefied Petroleum Gas (LPG), Compressed Natural Gas (CNG), and Methanol/Ethanol, are already being used in buses. At present, there do not exist co...

  14. Fracture mechanics analysis of NGV fuel cylinders. Part 1: Steel cylinders

    NASA Astrophysics Data System (ADS)

    Connolly, M. P.; Hudak, S. J.; Roy, S.

    1993-02-01

    Compressed natural gas (CNG) cylinders for natural gas vehicles (NGVs) are subject to a combination of pressure cycles, associated with periodic refueling, and a potentially corrosive CNG environment. Under these conditions it has been shown that the life of the cylinder is governed by the corrosion-fatigue crack growth of internal flaws such as voids, pits or folds that may be present after manufacture. For NGV applications, these cylinders are required to operate for at least 15 years and the report, through a detailed fracture mechanics analysis, describes approaches to achieving the desired life. The analysis shows that a 15 year cylinder life can be obtained by using quality control to ensure that no initial defects greater than 0.045 in. X 0.090 in. exist after manufacture. Alternatively, gas drying can be used at the distribution stations to reduce the detrimental effects of the remaining CNG impurities, and thereby, produce long cylinder lives. The analysis also considers the role of in-service inspection/retest and shows that in-service NDE has little advantage, either technically or economically, for ensuring the fitness-for-service of steel NGV cylinders. The analysis also shows that hydrostatic testing of cylinders, either at manufacture or in service, is ineffective for detecting fatigue cracks and therefore should not be implemented as part of a fitness-for-service plan for NGV fuel cylinders. The issue of cylinder geometry was also considered and the analysis shows that improperly designed flat-bottomed CNG cylinders can result in premature fatigue failures originating at the inner wall in the transition region between the cylinder end and sidewall.

  15. Elevated PDGFRB gene copy number gain (CNG) is prognostic for improved survival outcomes in resected malignant pleural mesothelioma

    PubMed Central

    Tsao, Anne S.; Harun, Nusrat; Fujimoto, Junya; Devito, Vikki; Lee, J. Jack; Kuhn, Elisabetta; Mehran, Reza; Rice, David; Moran, Cesar; Hong, Waun Ki; Shen, Li; Suraokar, Milind; Wistuba, Ignacio

    2014-01-01

    Background PDGF/PDGFR pathway has been implicated in malignant pleural mesothelioma (MPM) carcinogenesis and evidence suggests autocrine mechanisms of proliferation. We sought to evaluate the incidence of PDGFRB gene copy number gain (CNG) by fluorescence in situ hybridization (FISH) and PDGFR pathway protein expression by immunohistochemistry (IHC) and correlate it to patient clinical outcome. Methods 88 archived tumor blocks from resected MPM with full clinical information were used to perform IHC biomarkers (PDGFRα, PDGFRβ, p-PDGFRβ) and FISH analysis of PDGFRB gene CNG. Spearman's rank correlation, Wilcoxon rank-sum test, Kruskal-Wallis test, BLiP plots, and Kaplan-Meier method were used to analyze the biomarkers and correlation to clinical outcome. Results Several correlations between the IHC biomarkers were seen; however, none correlated to clinically relevant patient demographics or histology. In the CNG analysis, PDGFRB gene CNG in > 10% of tumor cells had lower cytoplasmic p-PDGFRβ (p=0.029), while PDGFRB gene CNG in > 40% of tumor cells had a higher cytoplasmic PDGFRβ (p=0.04). PDGFRB gene CNG status did not associate with patient demographics or tumor characteristics. PDGFR pathway IHC biomarkers did not associate with survival outcomes. However, patients with PDGFRB CNG > 40% of tumor cells had improved relapse-free survival [HR 0.25 (95% CI 0.09, 0.72), p=0.0096] and improved overall survival [HR 0.32 (95% CI 0.11, 0.89), p=0.029]. Conclusions PDGFRB CNG > 40% of MPM tumor cells is a potential prognostic biomarker for surgery and may identify a unique population of mesothelioma patients. Future validation of this biomarker in prospective trials is needed. PMID:24747001

  16. Modulation of renal CNG-A3 sodium channel in rats subjected to low- and high-sodium diets.

    PubMed

    Novaira, Horacio J; Botelho, Bruno F; Goldenberg, Regina C; Guggino, Sandra E; Morales, Marcelo M

    2004-10-11

    In this work, we studied the mRNA distribution of CNG-A3, an amiloride-sensitive sodium channel that belongs to the cyclic nucleotide-gated (CNG) family of channels, along the rat nephron. The possible involvement of aldosterone in this process was also studied. We also evaluated its expression in rats subjected to diets with different concentrations of sodium or to alterations in aldosterone plasma levels. Total RNA isolated from whole kidney and/or dissected nephron segments of Wistar rats subjected to low- and high-sodium diets, furosemide treatment, adrenalectomy, and adrenalectomy with replacement by aldosterone were analyzed by the use of Western blot, ribonuclease protection assay (RPA) and/or reverse transcription followed by semi-quantitative polymerase chain reaction (RT-PCR). CNG-A3 sodium channel mRNA and protein expression, in whole kidneys of rats subjected to high-Na+ diet, were lower than those in animals given a low-salt diet. Renal CNG-A3 mRNA expression was also decreased in adrenalectomized rats, and was normalized by aldosterone replacement. Moreover, a CNG-A3 mRNA expression study in different nephron segments revealed that aldosterone modulation is present in the cortical thick ascending loop (cTAL) and cortical collecting duct (CCD). This result suggests that CNG-A3 is responsive to the same hormone signaling as the amiloride sensitive sodium channel ENaC and suggests the CNG-A3 may have a physiological role in sodium reabsorption.

  17. Purification and DNA-binding properties of the cro-type regulatory repressor protein cng encoded by the Lactobacillus plantarum phage phi g1e.

    PubMed

    Kakikawa, M; Ohkubo, S; Sakate, T; Sayama, M; Taketo, A; Kodaira, K

    2000-05-16

    The putative repressor protein Cng (10kDa on an SDS gel) for the lytic pathway of Lactobacillus plantarum phage φg1e was purified using the Escherichia coli Pt7 system, and its DNA-binding ability for the seven operator-like sequences, the GATAC-boxes (Gb1 to Gb7), was investigated in vitro. In gel-shift assays, Cng selectively bound to the DNA fragments containing the GATAC-box(es). In addition, DNase I footprinting analysis with supercoiled DNA demonstrated that Cng can specifically cover about a 25bp region centered around each of the GATAC-boxes, although two boxes, Gb4 and Gb6, were only partially protected. Moreover, protein crosslinking experiments using glutaraldehyde suggested that Cng most likely functions as a dimer. On the other hand, the binding ability of Cpg for the GATAC-boxes in supercoiled DNA was also examined under the same conditions as in Cng; unlike Cng, Cpg covered Gb4 and Gb6 completely sufficiently as well as the other five boxes. Thus, the present and previous [Kakikawa et al., Gene 215 (1998) 371-379; 242 (2000) 155-166] results indicate a possibility that the two proteins Cng and Cpg selectively bind to the GATAC-boxes that act as operators, and can decide between the lytic or lysogenic pathways through repression of the promoter activity of P(R) as well as P(L).

  18. 46 CFR 184.240 - Gas systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... using liquefied petroleum gas (LPG) and compressed natural gas (CNG) must meet the following... design, installation and testing of each CNG system must meet ABYC A-22, “Marine Compressed Natural Gas (CNG) Systems,” Chapter 6 of NFPA 302, or other standard specified by the Commandant. (c) Cooking...

  19. Alternative Fuels Data Center: Indianapolis CNG Fueling Station Attracts

    Science.gov Websites

    Fueling Station Attracts Local Fleets, Turns into Profit Center on Facebook Tweet about Alternative Fuels Data Center: Indianapolis CNG Fueling Station Attracts Local Fleets, Turns into Profit Center on , Turns into Profit Center on Google Bookmark Alternative Fuels Data Center: Indianapolis CNG Fueling

  20. Fuels Performance | Transportation Research | NREL

    Science.gov Websites

    . Video Promotes Safe CNG Tank Decommissioning Practices A video on CNG fuel tank defueling instruct transit agencies and others about safe CNG tank end-of-life practices. The video was previewed at Biodiesel Performance in Modern Engines NREL is working cooperatively with the National Biodiesel Board on

  1. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part I. Black carbon.

    PubMed

    Wang, Yang; Xing, Zhenyu; Xu, Hui; Du, Ke

    2016-12-01

    Compressed natural gas (CNG) is considered to be a "cleaner" fuel compared to other fossil fuels. Therefore, it is used as an alternative fuel in motor vehicles to reduce emissions of air pollutants in transportation. To quantify "how clean" burning CNG is compared to burning gasoline, quantification of pollutant emissions under the same driving conditions for motor vehicles with different fuels is needed. In this study, a fleet of bi-fuel vehicles was selected to measure the emissions of black carbon (BC), carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NO x ) for driving in CNG mode and gasoline mode respectively under the same set of constant speeds and accelerations. Comparison of emission factors (EFs) for the vehicles burning CNG and gasoline are discussed. This part of the paper series reports BC EFs for bi-fuel vehicles driving on the real road, which were measured using an in situ method. Our results show that burning CNG will lead to 54%-83% reduction in BC emissions per kilometer, depending on actual driving conditions. These comparisons show that CNG is a cleaner fuel than gasoline for motor vehicles in terms of BC emissions and provide a viable option for reducing BC emissions cause by transportation. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. A postoperative anti-adhesion barrier based on photoinduced imine-crosslinking hydrogel with tissue-adhesive ability.

    PubMed

    Yang, Yunlong; Liu, Xiaolin; Li, Yan; Wang, Yang; Bao, Chunyan; Chen, Yunfeng; Lin, Qiuning; Zhu, Linyong

    2017-10-15

    Postoperative adhesion is a serious complication that can further lead to morbidity and/or mortality. Polymer anti-adhesion barrier material provides an effective precaution to reduce the probability of postoperative adhesion. Clinical application requires these materials to be easily handled, biocompatible, biodegradable, and most importantly tissue adherent to provide target sites with reliable isolation. However, currently there is nearly no polymer barrier material that can fully satisfy these requirements. In this study, based on the photoinduced imine-crosslinking (PIC) reaction, we had developed a photo-crosslinking hydrogel (CNG hydrogel) that composed of o-nitrobenzyl alcohol (NB) modified carboxymethyl cellulose (CMC-NB) and glycol chitosan (GC) as an anti-adhesion barrier material. Under light irradiation, CMC-NB generated aldehyde groups which subsequently reacted with amino groups distributed on GC or tissue surface to form a hydrogel barrier that covalently attached to tissue surface. Rheological analysis demonstrated that CNG hydrogel (30mg/mL polymer content) could be formed in 30s upon light irradiation. Tissue adhesive tests showed that the tissue adhesive strength of CNG hydrogel (30mg/mL) was about 8.32kPa-24.65kPa which increased with increasing CMC-NB content in CNG hydrogel. Toxicity evaluation by L929 cells demonstrated that CNG hydrogel was cytocompatible. Furthermore, sidewall defect-cecum abrasion model of rat was employed to evaluate the postoperative anti-adhesion efficacy of CNG hydrogel. And a significantly reduction of tissue adhesion (20% samples with low score adhesion) was found in CNG hydrogel treated group, compared with control group (100% samples with high score adhesion). In addition, CNG hydrogel could be degraded in nearly 14days and showed no side effect on wound healing. These findings indicated that CNG hydrogel can effectively expanded the clinical treatments of postoperative tissue adhesion. In this study, a tissue adhesive photo-crosslinking hydrogel (CNG) was developed based on photo-induced imine crosslinking reaction (PIC) for postoperative anti-adhesion. CNG hydrogel showed the features of easy and convenient operation, fast and controllable gelation, suitable gel strength, good biocompatibility, and most importantly strong tissue adhesiveness. Therefore, it shows very high performance to prevent postoperative tissue adhesion. Overall, our study provides a more suitable hydrogel barrier material that can overcome the shortcomings of current barriers for clinical postoperative anti-adhesion. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Elevated PDGFRB gene copy number gain is prognostic for improved survival outcomes in resected malignant pleural mesothelioma.

    PubMed

    Tsao, Anne S; Harun, Nusrat; Fujimoto, Junya; Devito, Vikki; Lee, J Jack; Kuhn, Elisabetta; Mehran, Reza; Rice, David; Moran, Cesar; Hong, Waun Ki; Shen, Li; Suraokar, Milind; Wistuba, Ignacio

    2014-06-01

    PDGF/PDGFR pathway has been implicated in malignant pleural mesothelioma (MPM) carcinogenesis, and evidence suggests autocrine mechanisms of proliferation. We sought to evaluate the incidence of PDGFRB gene copy number gain (CNG) by fluorescence in situ hybridization and PDGFR pathway protein expression by immunohistochemistry (IHC) and correlate it to patient clinical outcome. Eighty-eight archived tumor blocks from resected MPM with full clinical information were used to perform IHC biomarkers (PDGFRα, PDGFRβ, p-PDGFRβ) and fluorescence in situ hybridization analysis of PDGFRB gene CNG. Spearman rank correlation, Wilcoxon rank-sum test, Kruskal-Wallis test, BLiP plots, and Kaplan-Meier method were used to analyze the biomarkers and correlation to clinical outcome. Several correlations between the IHC biomarkers were seen; however, none correlated to clinically relevant patient demographics or histology. In the CNG analysis, PDGFRB gene CNG in >10% of tumor cells had lower cytoplasmic p-PDGFRβ (P=.029), while PDGFRB gene CNG in >40% of tumor cells had a higher cytoplasmic PDGFRβ (P=.04). PDGFRB gene CNG status did not associate with patient demographics or tumor characteristics. PDGFR pathway IHC biomarkers did not associate with survival outcomes. However, patients with PDGFRB CNG >40% of tumor cells had improved relapse-free survival (HR 0.25 [95% CI 0.09-0.72], P=.0096) and improved overall survival (HR 0.32 [95% CI 0.11-0.89], P=.029). PDGFRB CNG >40% of MPM tumor cells is a potential prognostic biomarker for surgery and may identify a unique population of mesothelioma patients. Future validation of this biomarker in prospective trials is needed. From a retrospective review of archived tissue specimens from patients with resected malignant pleural mesothelioma tumors, we show that patients with PDGFRB CNG >40% of tumor cells had improved relapse-free survival (HR 0.25 [95% CI 0.09-0.72], P=.0096) and improved overall survival (HR 0.32 [95% CI 0.11-0.89], P=.029). PDGFRB CNG >40% of MPM tumor cells is a potential prognostic biomarker for surgery and may identify a unique population of mesothelioma patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Anaplastic Lymphoma Kinase Gene Copy Number Gain in Inflammatory Breast Cancer (IBC): Prevalence, Clinicopathologic Features and Prognostic Implication

    PubMed Central

    Kim, Min Hwan; Lee, Soohyeon; Koo, Ja Seung; Jung, Kyung Hae; Park, In Hae; Jeong, Joon; Kim, Seung Il; Park, Seho; Park, Hyung Seok; Park, Byeong-Woo; Kim, Joo-Hang; Sohn, Joohyuk

    2015-01-01

    Background Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer, and its molecular pathogenesis still remains to be elucidated. This study aimed to evaluate the prevalence and implication of anaplastic lymphoma kinase (ALK) copy number change in IBC patients. Methods We retrospectively collected formalin-fixed, paraffin-embedded tumor tissues and medical records of IBC patients from several institutes in Korea. ALK gene copy number change and rearrangement were assessed by fluorescence in situ hybridization (FISH) assay, and ALK expression status was evaluated by immunohistochemical (IHC) staining. Results Thirty-six IBC patients including those with HER2 (+) breast cancer (16/36, 44.4%) and triple-negative breast cancer (13/36, 36.1%) were enrolled in this study. ALK copy number gain (CNG) was observed in 47.2% (17/36) of patients, including one patient who harbored ALK gene amplification. ALK CNG (+) patients showed significantly worse overall survival compared to ALK CNG (-) patients in univariate analysis (24.9 months vs. 38.1 months, p = 0.033). Recurrence free survival (RFS) after curative mastectomy was also significantly shorter in ALK CNG (+) patients than in ALK CNG (-) patients (n = 22, 12.7 months vs. 43.3 months, p = 0.016). Multivariate Cox regression analysis with adjustment for HER2 and ER statuses showed significantly poorer RFS for ALK CNG (+) patients (HR 5.63, 95% CI 1.11–28.44, p = 0.037). Conclusion This study shows a significant presence of ALK CNG in IBC patients, and ALK CNG was associated with significantly poorer RFS. PMID:25803816

  5. Matrix metalloproteinase-9 and -2 enhance the ligand sensitivity of photoreceptor cyclic nucleotide-gated channels.

    PubMed

    Meighan, Peter C; Meighan, Starla E; Rich, Elizabeth D; Brown, R Lane; Varnum, Michael D

    2012-01-01

    Photoreceptor cyclic nucleotide-gated (CNG) channels are the principal ion channels responsible for transduction of the light-induced change in cGMP concentration into an electrical signal. The ligand sensitivity of photoreceptor CNG channels is subject to regulation by intracellular signaling effectors, including calcium-calmodulin, tyrosine kinases and phosphoinositides. Little is known, however, about regulation of channel activity by modification to extracellular regions of CNG channel subunits. Extracellular proteases MMP9 and -2 are present in the interphotoreceptor matrix adjacent to photoreceptor outer segments. Given that MMPs have been implicated in retinal dysfunction and degeneration, we hypothesized that MMP activity may alter the functional properties of photoreceptor CNG channels. For heterologously expressed rod and cone CNG channels, extracellular exposure to MMPs dramatically increased the apparent affinity for cGMP and the efficacy of cAMP. These changes to ligand sensitivity were not prevented by destabilization of the actin cytoskeleton or by disruption of integrin mediated cell adhesion, but could be attenuated by inhibition of MMP catalytic activity. MMP-mediated gating changes exhibited saturable kinetic properties consistent with enzymatic processing of the CNG channels. In addition, exposure to MMPs decreased the abundance of full-length expressed CNGA3 subunits, with a concomitant increase in putative degradation products. Similar gating effects and apparent proteolysis were observed also for native rod photoreceptor CNG channels. Furthermore, constitutive apparent proteolysis of retinal CNGA1 and retinal MMP9 levels were both elevated in aged mice compared with young mice. Together, these results provide evidence that MMP-mediated proteolysis can regulate the ligand sensitivity of CNG channels.

  6. Matrix metalloproteinase-9 and -2 enhance the ligand sensitivity of photoreceptor cyclic nucleotide-gated channels

    PubMed Central

    Meighan, Peter C.; Meighan, Starla E.; Rich, Elizabeth D.; Brown, R. Lane; Varnum, Michael D.

    2012-01-01

    Photoreceptor cyclic nucleotide-gated (CNG) channels are the principal ion channels responsible for transduction of the light-induced change in cGMP concentration into an electrical signal. The ligand sensitivity of photoreceptor CNG channels is subject to regulation by intracellular signaling effectors, including calcium-calmodulin, tyrosine kinases and phosphoinositides. Little is known, however, about regulation of channel activity by modification to extracellular regions of CNG channel subunits. Extracellular proteases MMP9 and -2 are present in the interphotoreceptor matrix adjacent to photoreceptor outer segments. Given that MMPs have been implicated in retinal dysfunction and degeneration, we hypothesized that MMP activity may alter the functional properties of photoreceptor CNG channels. For heterologously expressed rod and cone CNG channels, extracellular exposure to MMPs dramatically increased the apparent affinity for cGMP and the efficacy of cAMP. These changes to ligand sensitivity were not prevented by destabilization of the actin cytoskeleton or by disruption of integrin mediated cell adhesion, but could be attenuated by inhibition of MMP catalytic activity. MMP-mediated gating changes exhibited saturable kinetic properties consistent with enzymatic processing of the CNG channels. In addition, exposure to MMPs decreased the abundance of full-length expressed CNGA3 subunits, with a concomitant increase in putative degradation products. Similar gating effects and apparent proteolysis were observed also for native rod photoreceptor CNG channels. Furthermore, constitutive apparent proteolysis of retinal CNGA1 and retinal MMP9 levels were both elevated in aged mice compared with young mice. Together, these results provide evidence that MMP-mediated proteolysis can regulate the ligand sensitivity of CNG channels. PMID:22699690

  7. Anaplastic lymphoma kinase gene copy number gain in inflammatory breast cancer (IBC): prevalence, clinicopathologic features and prognostic implication.

    PubMed

    Kim, Min Hwan; Lee, Soohyeon; Koo, Ja Seung; Jung, Kyung Hae; Park, In Hae; Jeong, Joon; Kim, Seung Il; Park, Seho; Park, Hyung Seok; Park, Byeong-Woo; Kim, Joo-Hang; Sohn, Joohyuk

    2015-01-01

    Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer, and its molecular pathogenesis still remains to be elucidated. This study aimed to evaluate the prevalence and implication of anaplastic lymphoma kinase (ALK) copy number change in IBC patients. We retrospectively collected formalin-fixed, paraffin-embedded tumor tissues and medical records of IBC patients from several institutes in Korea. ALK gene copy number change and rearrangement were assessed by fluorescence in situ hybridization (FISH) assay, and ALK expression status was evaluated by immunohistochemical (IHC) staining. Thirty-six IBC patients including those with HER2 (+) breast cancer (16/36, 44.4%) and triple-negative breast cancer (13/36, 36.1%) were enrolled in this study. ALK copy number gain (CNG) was observed in 47.2% (17/36) of patients, including one patient who harbored ALK gene amplification. ALK CNG (+) patients showed significantly worse overall survival compared to ALK CNG (-) patients in univariate analysis (24.9 months vs. 38.1 months, p = 0.033). Recurrence free survival (RFS) after curative mastectomy was also significantly shorter in ALK CNG (+) patients than in ALK CNG (-) patients (n = 22, 12.7 months vs. 43.3 months, p = 0.016). Multivariate Cox regression analysis with adjustment for HER2 and ER statuses showed significantly poorer RFS for ALK CNG (+) patients (HR 5.63, 95% CI 1.11-28.44, p = 0.037). This study shows a significant presence of ALK CNG in IBC patients, and ALK CNG was associated with significantly poorer RFS.

  8. Alternative Fuels Data Center: Triangle Clean Cities Resource Gives CNG

    Science.gov Websites

    , 2015 Triangle Clean Cities Resource Gives CNG Installation a Boost " Although North Carolina has ; Lacey Jane Wolfe, Triangle Clean Cities Coalition, Coordinator, Durham, North Carolina When the Triangle Clean Cities Coalition (TCCC) set out to promote compressed natural gas (CNG) fueling stations in North

  9. Alternative Fuel Vehicles: What Do the Drivers Say?

    Science.gov Websites

    ); dedicated compressed natural gas (CNG) models; CNG after-market conversions; flexible-fuel methanol models ; flexible-fuel ethanol models, and gasoline models. Overall, drivers reported positive experiences, with primary concerns being lack of range (particularly for the CNG models) and lack of convenient fueling

  10. Impact of CNG Crisis on Student's Academic Life

    ERIC Educational Resources Information Center

    Azeem, Kiran; Nadeem, Wajiha; Zia, Afsa; Shehzad, Shiza; Anwar, Zara

    2017-01-01

    The goal of this study is to determine the impact of Compressed Natural Gas (CNG) crisis on Student's Academic Life of Karachi Pakistan. This research helps in observing the behavior of students and their educational progress includes depression and anxiety, rate of absenteeism and undesirable results in exams threatens due to CNG crisis and…

  11. Alternative Fuels Data Center: Republic Services Reduces Waste with 87 CNG

    Science.gov Websites

    operating on CNG within the next five years. " Rachele Klein, Republic Services Business Development maintenance facilities. Baird and Republic Services teamed up to research and select vehicle manufacturers and operating on CNG within the next five years," Klein said. "The model that stemmed from this

  12. A comparative study of emission motorcycle with gasoline and CNG fuel

    NASA Astrophysics Data System (ADS)

    Sasongko, M. N.; Wijayanti, W.; Rahardja, R. A.

    2016-03-01

    A comparison of the exhaust emissions of the engine running gasoline and Compressed Natural Gas have been performed in this study. A gasoline engine 4 stroke single-cylinder with volume of 124.8 cc and compression ratio of 9.3:1 was converted to a CNG gaseous engine. The fuel injector was replaced with a solenoid valve system for injecting CNG gas to engine. The concentrations of CO, CO2, O2 and HC in the exhaust gas of engine were measured over the range of fuel flow rate from 25.32 mg/s to 70.22 mg/s and wide range of Air Fuel Ratio. The comparative analysis of this study showed that CNG engine has a lower HC, CO2 and CO emission at the stoichiometry mixture of fuel and air combustion. The emissions increased when the Air-Fuel ratio was switched from the stoichiometry condition. Moreover, CNG engine produced a lower HC and CO emission compared to the gasoline for difference air flow rate. The average of HC and CO emissions of the CNG was 92 % and 78 % lower than that of the gasoline

  13. Temporal variability of benzene concentration in the ambient air of Delhi: a comparative assessment of pre- and post-CNG periods.

    PubMed

    Khillare, P S; Hoque, Raza Rafiqul; Shridhar, Vijay; Agarwal, Tripti; Balachandran, S

    2008-06-15

    CNG (compressed natural gas) was fully implemented in public transport system in Delhi in December 2002. The study assesses the benzene concentration trends at two busy traffic intersections and a background site in Delhi, India. Monitoring was done for two different time periods viz; in the year 2001-2002 (pre-CNG) and two winter months (January and February) of the year 2007 (post-CNG) to assess the impact of various policy measures adopted by the government of Delhi to improve the air quality in the city. Annual average benzene concentration for the pre-CNG period was found to be 86.47+/-53.24 microg m(-3). Average benzene concentrations for the winter months (January-February) of pre- and post-CNG periods were 116.32+/-51.65 microg m(-3) and 187.49+/-22.50 microg m(-3), respectively. Enhanced values could be solely attributed to the increase in the vehicular population from 3.5 million in the year 2001-2002 to approximately 5.1 millions in the year 2007.

  14. Subunit stoichiometry of the CNG channel of rod photoreceptors.

    PubMed

    Weitz, Dietmar; Ficek, Nicole; Kremmer, Elisabeth; Bauer, Paul J; Kaupp, U Benjamin

    2002-12-05

    Cyclic nucleotide-gated (CNG) channels play a central role in the conversion of sensory stimuli into electrical signals. CNG channels form heterooligomeric complexes built of A and B subunits. Here, we study the subunit stoichiometry of the native rod CNG channel by chemical crosslinking. The apparent molecular weight (M(w)) of each crosslink product was determined by SDS-PAGE, and its composition was analyzed by Western blotting using antibodies specific for the A1 or B1 subunit. The number of crosslink products and their M(w) as well as the immunological identification of A1 and B1 subunits in the crosslink products led us to conclude that the native rod CNG channel is a tetramer composed of three A1 and one B1 subunit. This is an example of violation of symmetry in tetrameric channels.

  15. Role of estrogen and progesterone in the modulation of CNG-A1 and Na/K+-ATPase expression in the renal cortex.

    PubMed

    Gracelli, Jones B; Souza-Menezes, Jackson; Barbosa, Carolina M L; Ornellas, Felipe S; Takiya, Christina M; Alves, Leandro M; Wengert, Mira; Feltran, Georgia da Silva; Caruso-Neves, Celso; Moyses, Margareth R; Prota, Luiz F M; Morales, Marcelo M

    2012-01-01

    The steroid hormones, estrogen and progesterone, are involved mainly in the control of female reproductive functions. Among other effects, estrogen and progesterone can modulate Na(+) reabsorption along the nephron altering the body's hydroelectrolyte balance. In this work, we analyzed the expression of cyclic nucleotide-gated channel A1 (CNG-A1) and α1 Na(+)/K(+)-ATPase subunit in the renal cortex and medulla of female ovariectomized rats and female ovariectomized rats subjected to 10 days of 17β-estradiol benzoate (2.0 µg/kg body weight) and progesterone (1.7 mg/kg body weight) replacement. Na(+)/K(+) ATPase activity was also measured. Immunofluorescence localization of CNG-A1 in the cortex and medulla was performed in control animals. We observed that CNG-A1 is localized at the basolateral membrane of proximal and distal tubules. Female ovariectomized rats showed low expression of CNG-A1 and low expression and activity of Na(+)/K(+) ATPase in the renal cortex. When female ovariectomized rats were subjected to 17β-estradiol benzoate replacement, normalization of CNG-A1 expression and Na(+)/K(+) ATPase expression and activity was observed. The replacement of progesterone was not able to recover CNG-A1 expression and Na(+)/K(+) ATPase expression at the control level. Only the activity of Na(+)/K(+) ATPase was able to be recovered at control levels in animals subjected to progesterone replacement. No changes in expression and activity were observed in the renal medulla. The expression of CNG-A1 is higher in cortex compared to medulla. In this work, we observed that estrogen and progesterone act in renal tissues modulating CNG-A1 and Na(+)/K(+) ATPase and these effects could be important in Na(+) and water balance. Copyright © 2012 S. Karger AG, Basel.

  16. Ciliary targeting of olfactory CNG channels requires the CNGB1b subunit and the kinesin-2 motor protein, KIF17.

    PubMed

    Jenkins, Paul M; Hurd, Toby W; Zhang, Lian; McEwen, Dyke P; Brown, R Lane; Margolis, Ben; Verhey, Kristen J; Martens, Jeffrey R

    2006-06-20

    Nonmotile cilia on olfactory sensory neurons (OSNs) compartmentalize signaling molecules, including odorant receptors and cyclic nucleotide-gated (CNG) channels, allowing for efficient, spatially confined responses to sensory stimuli . Little is known about the mechanisms of the ciliary targeting of olfactory CNG channels, composed of three subunits: CNGA2, CNGA4, and CNGB1b . Recent reports suggest that subunit composition of the retinal CNG channel influences localization, leading to disease . However, the mechanistic role of subunits in properly targeting native olfactory CNG channels remains unclear. Here, we show that heteromeric assembly with CNGB1b, containing a critical carboxy-terminal motif (RVxP), is required for ciliary trafficking of olfactory CNG channels. Movement of proteins within the cilia is governed by intraflagellar transport (IFT), a process that facilitates bidirectional movement of cargo along microtubules. Work in C. elegans has established that heterotrimeric and homodimeric kinesin-2 family members play a critical role in anterograde transport . In mammalian systems, the heterotrimeric KIF3a/KIF3b/KAP-3 complex plays a clear role in IFT; however, no role has been established for KIF17, the mammalian homolog of OSM-3 . Here, we demonstrate that KIF17 is required for olfactory CNG channel targeting, providing novel insights into mechanisms of mammalian ciliary transport.

  17. Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert

    Science.gov Websites

    several years. Golden Eagle will convert all fleet vehicles to CNG in their six branch operations Entire Fleet to CNG Golden Eagle Distributors Inc. to Convert Entire Fleet to CNG to someone by E-mail Share Alternative Fuels Data Center: Golden Eagle Distributors Inc. to Convert Entire Fleet

  18. Alternative Fuels Data Center: Fleet Application for Refuse Collection

    Science.gov Websites

    CNG - Compressed Natural Gas 1 Electric 1 Hybrid - CNG 1 Hybrid - LNG 1 Hydraulic hybrid 9 LNG - Liquified Natural Gas icon for refuse collection vehicle application Autocar ACMD-Xpert Hybrid - CNG Hybrid - Compressed Natural Gas LNG - Liquified Natural Gas icon for refuse collection vehicle application BYD All

  19. 46 CFR 169.703 - Cooking and heating.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... compressed natural gas (CNG) is authorized for cooking purposes only. (1) The design, installation and..., installation, and testing of each CNG system must meet either Chapter 6 of NFPA 302 or ABYC A-22. (3) The... additional requirements must also be met: (i) LPG or CNG must be odorized in accordance with ABYC A-1.5.d or...

  20. 46 CFR 25.45-2 - Cooking systems on vessels carrying passengers for hire.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... stated therein, and liquefied petroleum gas (LPG), or compressed natural gas (CNG). (b) Cooking systems using LPG or CNG must meet the following requirements: (1) The design, installation, and testing of each... of each CNG system must meet ABYC A-22-78 or chapter 6 of NFPA 302. (3) Cooking systems using chapter...

  1. 46 CFR 169.703 - Cooking and heating.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... compressed natural gas (CNG) is authorized for cooking purposes only. (1) The design, installation and..., installation, and testing of each CNG system must meet either Chapter 6 of NFPA 302 or ABYC A-22. (3) The... additional requirements must also be met: (i) LPG or CNG must be odorized in accordance with ABYC A-1.5.d or...

  2. 46 CFR 169.703 - Cooking and heating.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... compressed natural gas (CNG) is authorized for cooking purposes only. (1) The design, installation and..., installation, and testing of each CNG system must meet either Chapter 6 of NFPA 302 or ABYC A-22. (3) The... additional requirements must also be met: (i) LPG or CNG must be odorized in accordance with ABYC A-1.5.d or...

  3. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part II. CO, HC and NOx.

    PubMed

    Huang, Xiaoyan; Wang, Yang; Xing, Zhenyu; Du, Ke

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Cytosine methylation at CG and CNG sites is not a prerequisite for the initiation of transcriptional gene silencing in plants, but it is required for its maintenance.

    PubMed

    Diéguez, M J; Vaucheret, H; Paszkowski, J; Mittelsten Scheid, O

    1998-08-01

    Transgenes integrated into plant chromosomes, and/or endogenous plant genes, may be subjected to epigenetic silencing at the transcriptional or post-transcriptional level. Transcriptional inactivation is correlated with hypermethylation of CG/CNG sites at the silent loci. It is not known whether local hypermethylation is part of the inactivation process, or just an outcome of the silent state. To address this issue, we generated transgenic tobacco lines containing a selectable marker gene controlled by a derivative of the 35S promoter of the cauliflower mosaic virus (CaMV) devoid of CG and CNG methylation acceptor sites. Silencing was triggered by crossing to the silencer locus of tobacco line 271. This line contains inactive and methylated copies of the 35S promoter and is able to silence homologous promoter copies at ectopic chromosomal positions. The mutated promoter lacking CG/CNG methylation acceptor sites was as susceptible to Trans-silencing as the unmodified 35S promoter control. Thus, methylation at CG and CNG sites is not a prerequisite for the initiation of epigenetic gene inactivation. Interestingly, while methylation of the remaining cytosines is usually only slightly affected by silencing, it was significantly increased in the absence of CG/CNG sequences. Since this sequence preference is the same as that of known methyltransferases, this may imply that silencing is accompanied or directly followed by recruitment of methyltransferase, which, in the absence of cytosines in the optimal sequence context, modifies other C residues in the affected area. However, silencing without CG/CNG methylation was immediately relieved in the absence of the silencer. Thus, CG/CNG methylation is probably essential for the maintenance of previously established epigenetic states.

  5. A structural, functional, and computational analysis suggests pore flexibility as the base for the poor selectivity of CNG channels

    PubMed Central

    Napolitano, Luisa Maria Rosaria; Bisha, Ina; De March, Matteo; Marchesi, Arin; Arcangeletti, Manuel; Demitri, Nicola; Mazzolini, Monica; Rodriguez, Alex; Magistrato, Alessandra; Onesti, Silvia; Laio, Alessandro; Torre, Vincent

    2015-01-01

    Cyclic nucleotide-gated (CNG) ion channels, despite a significant homology with the highly selective K+ channels, do not discriminate among monovalent alkali cations and are permeable also to several organic cations. We combined electrophysiology, molecular dynamics (MD) simulations, and X-ray crystallography to demonstrate that the pore of CNG channels is highly flexible. When a CNG mimic is crystallized in the presence of a variety of monovalent cations, including Na+, Cs+, and dimethylammonium (DMA+), the side chain of Glu66 in the selectivity filter shows multiple conformations and the diameter of the pore changes significantly. MD simulations indicate that Glu66 and the prolines in the outer vestibule undergo large fluctuations, which are modulated by the ionic species and the voltage. This flexibility underlies the coupling between gating and permeation and the poor ionic selectivity of CNG channels. PMID:26100907

  6. A structural, functional, and computational analysis suggests pore flexibility as the base for the poor selectivity of CNG channels.

    PubMed

    Napolitano, Luisa Maria Rosaria; Bisha, Ina; De March, Matteo; Marchesi, Arin; Arcangeletti, Manuel; Demitri, Nicola; Mazzolini, Monica; Rodriguez, Alex; Magistrato, Alessandra; Onesti, Silvia; Laio, Alessandro; Torre, Vincent

    2015-07-07

    Cyclic nucleotide-gated (CNG) ion channels, despite a significant homology with the highly selective K(+) channels, do not discriminate among monovalent alkali cations and are permeable also to several organic cations. We combined electrophysiology, molecular dynamics (MD) simulations, and X-ray crystallography to demonstrate that the pore of CNG channels is highly flexible. When a CNG mimic is crystallized in the presence of a variety of monovalent cations, including Na(+), Cs(+), and dimethylammonium (DMA(+)), the side chain of Glu66 in the selectivity filter shows multiple conformations and the diameter of the pore changes significantly. MD simulations indicate that Glu66 and the prolines in the outer vestibule undergo large fluctuations, which are modulated by the ionic species and the voltage. This flexibility underlies the coupling between gating and permeation and the poor ionic selectivity of CNG channels.

  7. Alternative Fuels Data Center: CNG Vehicle Fueling Animation Text Version

    Science.gov Websites

    - Gas rapidly cools CNG moves rapidly from the dispenser (high pressure) into the fuel tank (low off when the liquid reaches the top of the tank, a CNG dispenser stops when it reaches a certain rise. 5 minutes - Dispenser shuts off, operator disconnects The dispenser stops filling when it reaches

  8. Modeling of diesel/CNG mixing in a pre-injection chamber

    NASA Astrophysics Data System (ADS)

    Abdul-Wahhab, H. A.; Aziz, A. R. A.; Al-Kayiem, H. H.; Nasif, M. S.

    2015-12-01

    Diesel engines performance can be improved by adding combustible gases to the liquid diesel. In this paper, the propagation of a two phase flow liquid-gas fuel mixture into a pre-mixer is investigated numerically by computational fluid dynamics simulation. CNG was injected into the diesel within a cylindrical conduit operates as pre-mixer. Four injection models of Diesel-CNG were simulated using ANSYS-FLUENT commercial software. Two CNG jet diameters were used of 1 and 2 mm and the diesel pipe diameter was 9 mm. Two configurations were considered for the gas injection. In the first the gas was injected from one side while for the second two side entries were used. The CNG to Diesel pressure ratio was varied between 1.5 and 3. The CNG to Diesel mass flow ratios were varied between 0.7 and 0.9. The results demonstrate that using double-sided injection increased the homogeneity of the mixture due to the swirl and acceleration of the mixture. Mass fraction, in both cases, was found to increase as the mixture flows towards the exit. As a result, this enhanced mixing is likely to lead to improvement in the combustion performance.

  9. [Quantitative study of diesel/CNG buses exhaust particulate size distribution in a road tunnel].

    PubMed

    Zhu, Chun; Zhang, Xu

    2010-10-01

    Vehicle emission is one of main sources of fine/ultra-fine particles in many cities. This study firstly presents daily mean particle size distributions of mixed diesel/CNG buses traffic flow by 4 days consecutive real world measurement in an Australia road tunnel. Emission factors (EFs) of particle size distribution of diesel buses and CNG buses are obtained by MLR methods, particle distributions of diesel buses and CNG buses are observed as single accumulation mode and nuclei-mode separately. Particle size distributions of mixed traffic flow are decomposed by two log-normal fitting curves for each 30 min interval mean scans, the degrees of fitting between combined fitting curves and corresponding in-situ scans for totally 90 fitting scans are from 0.972 to 0.998. Finally particle size distributions of diesel buses and CNG buses are quantified by statistical whisker-box charts. For log-normal particle size distribution of diesel buses, accumulation mode diameters are 74.5-86.5 nm, geometric standard deviations are 1.88-2.05. As to log-normal particle size distribution of CNG buses, nuclei-mode diameters are 19.9-22.9 nm, geometric standard deviations are 1.27-1.3.

  10. PD-L1 (CD274) copy number gain, expression, and immune cell infiltration as candidate predictors for response to immune checkpoint inhibitors in soft-tissue sarcoma

    PubMed Central

    Budczies, Jan; Mechtersheimer, Gunhild; Denkert, Carsten; Klauschen, Frederick; Jöhrens, Korinna; Endris, Volker; Lier, Amelie; Lasitschka, Felix; Penzel, Roland; Dietel, Manfred; Brors, Benedikt; Gröschel, Stefan; Glimm, Hanno; Schirmacher, Peter; Renner, Marcus; Fröhling, Stefan; Stenzinger, Albrecht

    2017-01-01

    ABSTRACT Soft-tissue sarcomas (STS) are rare malignancies that account for 1% of adult cancers and comprise more than 50 entities. Current therapeutic options for advanced-stage STS are limited. Immune checkpoint inhibitors targeting the PD-1/PD-L1 signaling axis are being explored as new treatment modality in STS; however, the determinants of response to these agents are largely unknown. Using the sarcoma data set of The Cancer Genome Altas (TCGA) and an independent cohort of untreated high-grade STS, we analyzed DNA copy number status and mRNA expression of PD-L1 in a total of 335 STS cases. Copy number gains (CNG) were detected in 54 TCGA cases (21.1%), of which 21 (8.2%) harbored focal PD-L1 CNG and that were most prevalent in myxofibrosarcoma (35%) and undifferentiated pleomorphic sarcoma (34%). In the untreated high-grade STS cohort, we detected CNG in six cases (7.6%). Analysis of co-amplified genes identified a 5.6-Mb core region comprising 27 genes, including JAK2. Patients with PD-L1 CNG had higher PD-L1 expression compared with STS without CNG (fold change, 1.8; p = 0.02), an effect that was most pronounced in the setting of focal PD-L1 CNG (fold change, 3.0; p = 0.0027). STS with PD-L1 CNG showed a significantly higher mutational load compared with tumors with a diploid PD-L1 locus (median number of mutated genes; 58 vs. 40; p = 3.6E-06), and PD-L1 CNG were associated with inferior survival (HR = 1.82; p = 0.025). In contrast, T-cell infiltrates quantified by mRNA expression of CD3Z were associated with improved survival (HR = 0.88; p = 0.024) and consequently influenced the prognostic power of PD-L1 CNG, with low CD3Z levels conferring poor survival in cases with PD-L1 CNG (HR = 1.8; p = 0.049). These data demonstrate that PD-L1 GNG and elevated expression of PD-L1 occur in a substantial proportion of STS, have prognostic impact that is modulated by T-cell infiltrates, and thus warrant investigation as response predictors for immune checkpoint inhibition. PMID:28405504

  11. PD-L1 (CD274) copy number gain, expression, and immune cell infiltration as candidate predictors for response to immune checkpoint inhibitors in soft-tissue sarcoma.

    PubMed

    Budczies, Jan; Mechtersheimer, Gunhild; Denkert, Carsten; Klauschen, Frederick; Mughal, Sadaf S; Chudasama, Priya; Bockmayr, Michael; Jöhrens, Korinna; Endris, Volker; Lier, Amelie; Lasitschka, Felix; Penzel, Roland; Dietel, Manfred; Brors, Benedikt; Gröschel, Stefan; Glimm, Hanno; Schirmacher, Peter; Renner, Marcus; Fröhling, Stefan; Stenzinger, Albrecht

    2017-01-01

    Soft-tissue sarcomas (STS) are rare malignancies that account for 1% of adult cancers and comprise more than 50 entities. Current therapeutic options for advanced-stage STS are limited. Immune checkpoint inhibitors targeting the PD-1/PD-L1 signaling axis are being explored as new treatment modality in STS; however, the determinants of response to these agents are largely unknown. Using the sarcoma data set of The Cancer Genome Altas (TCGA) and an independent cohort of untreated high-grade STS, we analyzed DNA copy number status and mRNA expression of PD-L1 in a total of 335 STS cases. Copy number gains (CNG) were detected in 54 TCGA cases (21.1%), of which 21 (8.2%) harbored focal PD-L1 CNG and that were most prevalent in myxofibrosarcoma (35%) and undifferentiated pleomorphic sarcoma (34%). In the untreated high-grade STS cohort, we detected CNG in six cases (7.6%). Analysis of co-amplified genes identified a 5.6-Mb core region comprising 27 genes, including JAK2 . Patients with PD-L1 CNG had higher PD-L1 expression compared with STS without CNG (fold change, 1.8; p = 0.02), an effect that was most pronounced in the setting of focal PD-L1 CNG (fold change, 3.0; p = 0.0027). STS with PD-L1 CNG showed a significantly higher mutational load compared with tumors with a diploid PD-L1 locus (median number of mutated genes; 58 vs. 40; p = 3.6E-06), and PD-L1 CNG were associated with inferior survival (HR = 1.82; p = 0.025). In contrast, T-cell infiltrates quantified by mRNA expression of CD3Z were associated with improved survival (HR = 0.88; p = 0.024) and consequently influenced the prognostic power of PD-L1 CNG, with low CD3Z levels conferring poor survival in cases with PD-L1 CNG (HR = 1.8; p = 0.049). These data demonstrate that PD-L1 GNG and elevated expression of PD-L1 occur in a substantial proportion of STS, have prognostic impact that is modulated by T-cell infiltrates, and thus warrant investigation as response predictors for immune checkpoint inhibition.

  12. In-Use Performance Comparison of Hybrid Electric, CNG, and Diesel Buses at New York City Transit

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barnitt, R. A.

    2008-06-01

    The National Renewable Energy Laboratory (NREL) evaluated the performance of diesel, compressed natural gas (CNG), and hybrid electric (equipped with BAE Systems? HybriDrive propulsion system) transit buses at New York City Transit (NYCT). CNG, Gen I and Gen II hybrid electric propulsion systems were compared on fuel economy, maintenance and operating costs per mile, and reliability.

  13. cGMP and cyclic nucleotide-gated channels participate in mouse sperm capacitation.

    PubMed

    Cisneros-Mejorado, Abraham; Sánchez Herrera, Daniel P

    2012-01-20

    During capacitation of mammalian sperm intracellular [Ca(2+)] and cyclic nucleotides increase, suggesting that CNG channels play a role in the physiology of sperm. Here we study the effect of capacitation, 8Br-cAMP (8-bromoadenosine 3',5'-cyclic monophosphate) and 8Br-cGMP (8-bromoguanosine 3',5'-cyclic monophosphate) on the macroscopic ionic currents of mouse sperm, finding the existence of different populations of sperm, in terms of the recorded current and its response to cyclic nucleotides. Our results show that capacitation and cyclic nucleotides increase the ionic current, having a differential sensitivity to cGMP (cyclic guanosine monophosphate) and cAMP (cyclic adenosine monophosphate). Using a specific inhibitor we determine the contribution of CNG channels to macroscopic current and capacitation. Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  14. CNG and HCN channels: two peas, one pod.

    PubMed

    Craven, Kimberley B; Zagotta, William N

    2006-01-01

    Cyclic nucleotide-activated ion channels play a fundamental role in a variety of physiological processes. By opening in response to intracellular cyclic nucleotides, they translate changes in concentrations of signaling molecules to changes in membrane potential. These channels belong to two families: the cyclic nucleotide-gated (CNG) channels and the hyperpolarization-activated cyclic nucleotide-modulated (HCN) channels. The two families exhibit high sequence similarity and belong to the superfamily of voltage-gated potassium channels. Whereas HCN channels are activated by voltage and CNG channels are virtually voltage independent, both channels are activated by cyclic nucleotide binding. Furthermore, the channels are thought to have similar channel structures, leading to similar mechanisms of activation by cyclic nucleotides. However, although these channels are structurally and behaviorally similar, they have evolved to perform distinct physiological functions. This review describes the physiological roles and biophysical behavior of CNG and HCN channels. We focus on how similarities in structure and activation mechanisms result in common biophysical models, allowing CNG and HCN channels to be viewed as a single genre.

  15. Structural studies of CNG repeats

    PubMed Central

    Kiliszek, Agnieszka; Rypniewski, Wojciech

    2014-01-01

    CNG repeats (where N denotes one of the four natural nucleotides) are abundant in the human genome. Their tendency to undergo expansion can lead to hereditary diseases known as TREDs (trinucleotide repeat expansion disorders). The toxic factor can be protein, if the abnormal gene is expressed, or the gene transcript, or both. The gene transcripts have attracted much attention in the biomedical community, but their molecular structures have only recently been investigated. Model RNA molecules comprising CNG repeats fold into long hairpins whose stems generally conform to an A-type helix, in which the non-canonical N-N pairs are flanked by C-G and G-C pairs. Each homobasic pair is accommodated in the helical context in a unique manner, with consequences for the local helical parameters, solvent structure, electrostatic potential and potential to interact with ligands. The detailed three-dimensional profiles of RNA CNG repeats can be used in screening of compound libraries for potential therapeutics and in structure-based drug design. Here is a brief survey of the CNG structures published to date. PMID:24939898

  16. Capacitation and Ca(2+) influx in spermatozoa: role of CNG channels and protein kinase G.

    PubMed

    Cisneros-Mejorado, A; Hernández-Soberanis, L; Islas-Carbajal, M C; Sánchez, D

    2014-01-01

    Cyclic guanosine monophosphate (cGMP) has been recently shown to modulate in vitro capacitation of mammalian spermatozoa, but the mechanisms through which it influences sperm functions have not been clarified. There are at least two targets of cGMP, cyclic nucleotide-gated (CNG) channels and cGMP-dependent protein kinase (PKG), involved in several physiological events in mammalian spermatozoa. It has been suggested that CNG channels allow the influx of Ca(2+) to cytoplasm during capacitation, whereas PKG could trigger a phosphorylation pathway which might also, indirectly, mediate calcium entry. Using the patch-clamp technique in whole-cell configuration, we showed how l-cis-Diltiazem (a CNG-channel inhibitor) and KT5823 (a PKG inhibitor) decreased significantly the amplitude of macroscopic ion currents in a dose-response manner, and decreased in vitro capacitation. The inhibition of CNG channels completely abolishes the Ca(2+) influx induced by cyclic nucleotides in mouse spermatozoa. This work suggests that the downstream cGMP pathway is required in mammalian sperm capacitation and the mechanisms involved include CNG channels and PKG, highlighting these molecules as important therapeutic targets for infertility treatments or to develop new male contraceptives. © 2013 American Society of Andrology and European Academy of Andrology.

  17. Promoter/repressor system of Lactobacillus plantarum phage og1e: characterization of the promoters pR49-pR-pL and overproduction of the cro-like protein cng in Escherichia coli.

    PubMed

    Kakikawa, M; Watanabe, N; Funawatashi, T; Oki, M; Yasukawa, H; Taketo, A; Kodaira, K I

    1998-07-30

    The Lactobacillus plantarum phage og1e (42259bp) has two repressor-like genes cng and cpg oriented oppositely, accompanied by three potential promoters pR, pL and pR49, and seven operator-like sequences (GATAC-boxes) (Kodaira et al., 1997). In this study, the og1e putative promoters were introduced into the Escherichia coli promoter-detecting plasmid pKK232-8. In E. coli CK111, pR (pKPR1), pL (pKPL1) and pR49 (pKPR49) exhibited distinct CAT activities. When pKPR1 or pKPL1 was coexistent with a compatible plasmid pACYC184 carrying pR-cng (pA4PRCN1), the CAT activity was decreased significantly. On the other hand, cng directed a protein (Cng) of 10.1 kDa in E. coli under the control of T7 promoter. Gel mobility-shift assays demonstrated that Cng binds specifically to a DNA region containing the GATAC-boxes. In addition, primer extension analyses demonstrated that the two sequences pR and pL act as a promoter in L. plantarum as well as in E. coli. These results suggested that the potential promoters pR and pL probably function for the lytic and lysogenic pathways, respectively, and Cng may act as a repressor presumably through the GATAC-boxes as operators.

  18. cGMP accumulation causes photoreceptor degeneration in CNG channel deficiency: evidence of cGMP cytotoxicity independently of enhanced CNG channel function.

    PubMed

    Xu, Jianhua; Morris, Lynsie; Thapa, Arjun; Ma, Hongwei; Michalakis, Stylianos; Biel, Martin; Baehr, Wolfgang; Peshenko, Igor V; Dizhoor, Alexander M; Ding, Xi-Qin

    2013-09-11

    Photoreceptor cyclic nucleotide-gated (CNG) channels regulate Ca(2+) influx in rod and cone photoreceptors. cGMP, the native ligand of the photoreceptor CNG channels, has been associated with cytotoxicity when its levels rise above normal due to defects in photoreceptor phosphodiesterase (PDE6) or regulation of retinal guanylyl cyclase (retGC). We found a massive accumulation of cGMP in CNGA3-deficient retina and investigated whether cGMP accumulation plays a role in cone degeneration in CNG channel deficiency. The time course study showed that the retinal cGMP level in Cnga3(-/-);Nrl(-/-) mice with CNGA3 deficiency on a cone-dominant background was sharply increased at postnatal day 8 (P8), peaked around P10-P15, remained high through P30-P60, and returned to near control level at P90. This elevation pattern correlated with photoreceptor apoptotic death, which peaked around P15-P20. In Cnga3(-/-);Gucy2e(-/-) mice lacking retGC1, cone density and expression levels of cone-specific proteins were significantly increased compared with Cnga3(-/-), consistent with a role of cGMP accumulation as the major contributor to cone death caused by CNG channel deficiency. The activity and expression levels of cGMP-dependent protein kinase G (PKG) were significantly increased in Cnga3(-/-);Nrl(-/-) retina compared with Nrl(-/-), suggesting an involvement of PKG regulation in cell death. Our results indicate that cGMP accumulation in photoreceptors can itself exert cytotoxic effect in cones, independently of CNG channel activity and Ca(2+) influx.

  19. On-road emission characteristics of CNG-fueled bi-fuel taxis

    NASA Astrophysics Data System (ADS)

    Yao, Zhiliang; Cao, Xinyue; Shen, Xianbao; Zhang, Yingzhi; Wang, Xintong; He, Kebin

    2014-09-01

    To alleviate air pollution and lessen the petroleum demand from the motor vehicle sector in China, natural gas vehicles (NGVs) have been rapidly developed over the last several years. However, the understanding of the real-world emissions of NGVs is very limited. In this study, the emissions from 20 compressed-natural-gas-fueled bi-fuel taxis were measured using a portable emission measurement system (PEMS) under actual driving conditions in Yichang, China. The emission characteristics of the tested vehicles were analyzed, revealing that the average CO2, CO, HC and NOx emissions from the tested compressed-natural-gas (CNG) taxis under urban driving conditions were 1.6, 4.0, 2.0 and 0.98 times those under highway road conditions, respectively. The CO, HC and NOx emissions from Euro 3 CNG vehicles were approximately 40%, 55% and 44% lower than those from Euro 2 vehicles, respectively. Compared with the values for light-duty gasoline vehicles reported in the literature, the CO2 and CO emissions from the tested CNG taxis were clearly lower; however, significant increases in the HC and NOx emissions were observed. Finally, we normalized the emissions under the actual driving cycles of the entire test route to the New European Driving Cycle (NEDC)-based emissions using a VSP modes method developed by North Carolina State University. The simulated NEDC-based CO emissions from the tested CNG taxis were better than the corresponding emissions standards, whereas the simulated NEDC-based HC and NOx emissions greatly exceeded the standards. Thus, more attention should be paid to the emissions from CNG vehicles. As for the CNG-fueled bi-fuel taxis currently in use, the department of environmental protection should strengthen their inspection and supervision to reduce the emissions from these vehicles. The results of this study will be helpful in understanding and controlling emissions from CNG-fueled bi-fuel vehicles in China.

  20. A new mouse model for stationary night blindness with mutant Slc24a1 explains the pathophysiology of the associated human disease

    PubMed Central

    Vinberg, Frans; Wang, Tian; Molday, Robert S.; Chen, Jeannie; Kefalov, Vladimir J.

    2015-01-01

    Mutations that affect calcium homeostasis (Ca2+) in rod photoreceptors are linked to retinal degeneration and visual disorders such as retinitis pigmentosa and congenital stationary night blindness (CSNB). It is thought that the concentration of Ca2+ in rod outer segments is controlled by a dynamic balance between influx via cGMP-gated (CNG) channels and extrusion via Na+/Ca2+, K+ exchangers (NCKX1). The extrusion-driven lowering of rod [Ca2+]i following light exposure controls their light adaptation and response termination. Mutant NCKX1 has been linked to autosomal-recessive stationary night blindness. However, whether NCKX1 contributes to light adaptation has not been directly tested and the mechanisms by which human NCKX1 mutations cause night blindness are not understood. Here, we report that the deletion of NCKX1 in mice results in malformed outer segment disks, suppressed expression and function of rod CNG channels and a subsequent 100-fold reduction in rod responses, while preserving normal cone responses. The compensating loss of CNG channel function in the absence of NCKX1-mediated Ca2+ extrusion may prevent toxic Ca2+ buildup and provides an explanation for the stationary nature of the associated disorder in humans. Surprisingly, the lack of NCKX1 did not compromise rod background light adaptation, suggesting additional Ca2+-extruding mechanisms exist in these cells. PMID:26246500

  1. ROS1 gene rearrangement and copy number gain in non-small cell lung cancer.

    PubMed

    Jin, Yan; Sun, Ping-Li; Kim, Hyojin; Park, Eunhyang; Shim, Hyo Sup; Jheon, Sanghoon; Kim, Kwhanmien; Lee, Choon-Taek; Chung, Jin-Haeng

    2015-01-01

    ROS1 has attracted much attention as a possible oncogenic driver and ROS1-rearranged tumors show sensitivity to most ALK inhibitors. We aimed to clarify the prevalence of ROS1 gene rearrangement and investigate the clinical implications of ROS1 gene copy number gain (CNG) in non-small cell lung cancer (NSCLC) patients. We carried out fluorescent in situ hybridization with ROS1 and centromere enumeration 6 probes and immunohistochemistry for ROS1 protein expression. ROS1 rearrangement was detected in 3 of 375 samples (0.8 %); all of whom were female, never-smokers, and harbored an adenocarcinoma component. ROS1 gene CNG was found in 18 cases (4.8 %). ROS1 gene CNG was significantly associated with shorter disease-free survival (DFS, 12 vs. 58 months; p = 0.003) and shorter overall survival (OS, 40 vs. 67 months; p <0.001) than the group without CNG. Multivariate analysis confirmed that ROS1 gene CNG was significantly associated with poorer DFS (hazard ratio [HR]=2.16, 95 % confidence interval [CI] = 1.22-3.81, p = 0.008), and OS ([HR] = 2.53, 95 % [CI] = 1.31-4.89, p = 0.006). ROS1 protein overexpression was observed in 5.0 % (18 out of 357), of which 2 cases harbored ROS1 gene rearrangement. There was no statistically significant correlation between ROS1 gene CNG and protein overexpression. This study demonstrated ROS1 gene rearrangement was detected in 0.8 % of surgically resected NSCLC; and ROS1 gene CNG is an independent poor prognostic factor. This survival analyses may contribute to future studies on the utility of ROS1-targeted therapy for patients.

  2. Disease-associated mutations in CNGB3 promote cytotoxicity in photoreceptor-derived cells

    PubMed Central

    Liu, Chunming; Sherpa, Tshering

    2013-01-01

    Purpose To determine if achromatopsia associated F525N and T383fsX mutations in the CNGB3 subunit of cone photoreceptor cyclic nucleotide-gated (CNG) channels increases susceptibility to cell death in photoreceptor-derived cells. Methods Photoreceptor-derived 661W cells were transfected with cDNA encoding wild-type (WT) CNGA3 subunits plus WT or mutant CNGB3 subunits, and incubated with the membrane-permeable CNG channel activators 8-(4-chlorophenylthio) guanosine 3′,5′-cyclic monophosphate (CPT-cGMP) or CPT-adenosine 3′,5′-cyclic monophosphate (CPT-cAMP). Cell viability under these conditions was determined by measuring lactate dehydrogenase release. Channel ligand sensitivity was calibrated by patch-clamp recording after expression of WT or mutant channels in Xenopus oocytes. Results Coexpression of CNGA3 with CNGB3 subunits containing F525N or T383fsX mutations produced channels exhibiting increased apparent affinity for CPT-cGMP compared to WT channels. Consistent with these effects, cytotoxicity in the presence of 0.1 μM CPT-cGMP was enhanced relative to WT channels, and the increase in cell death was more pronounced for the mutation with the largest gain-of-function effect on channel gating, F525N. Increased susceptibility to cell death was prevented by application of the CNG channel blocker L-cis-diltiazem. Increased cytotoxicity was also found to be dependent on the presence of extracellular calcium. Conclusions These results indicate a connection between disease-associated mutations in cone CNG channel subunits, altered CNG channel-activation properties, and photoreceptor cytotoxicity. The rescue of cell viability via CNG channel block or removal of extracellular calcium suggests that cytotoxicity in this model depends on calcium entry through hyperactive CNG channels. PMID:23805033

  3. CNG channel subunit glycosylation regulates MMP-dependent changes in channel gating

    PubMed Central

    Meighan, Starla E.; Meighan, Peter C.; Rich, Elizabeth D.; Brown, R. Lane; Varnum, Michael D.

    2013-01-01

    Cyclic-nucleotide gated (CNG) channels are essential for phototransduction within retinal photoreceptors. We have demonstrated previously that enzymatic activity of matrix metalloproteinase-2 and -9, members of the MMP family of extracellular, Ca+2- and Zn+2-dependent proteases, enhances the ligand sensitivity of both rod (CNGA1 + CNGB1) and cone CNGA3 + CNGB3) CNG channels. Additionally, we have observed a decrease in maximal CNG channel current (IMAX) that begins late during MMP-directed gating changes. Here we demonstrate that CNG channels become non-conductive after prolonged MMP exposure. Concurrent with the loss of conductive channels is the increased relative contribution of channels exhibiting non-modified gating properties, suggesting the presence of a subpopulation of channels that are protected from MMP-induced gating effects. CNGA subunits are known to possess one extracellular core glycosylation site, located at one of two possible positions within the turret loop near the pore-forming region. Our results indicate that CNGA glycosylation can impede MMP-dependent modification of CNG channels. Furthermore, the relative position of the glycosylation site within the pore turret influences the extent of MMP-dependent proteolysis. Glycosylation at the site found in CNGA3 subunits was found to be protective, while glycosylation at the bovine CNGA1 site was not. Relocating the glycosylation site in CNGA1 to the position found in CNGA3 recapitulated CNGA3-like protection from MMP-dependent processing. Taken together, these data indicate that CNGA glycosylation may protect CNG channels from MMP-dependent proteolysis, consistent with MMP modification of channel function having a requirement for physical access to the extracellular face of the channel. PMID:24164424

  4. User Data Package for Compressed Natural Gas (CNG) Vehicles for Navy Applications

    DTIC Science & Technology

    1991-04-01

    already available). GENERAL CONSIDERATIONS The advantages and disadvantages for implementing a CNG-fueled vehicle fleet at a specific site vary. However...at the user’s site , if a guaranteed minimum quantity of CNG will be purchased annually by the fleet operator. Utilities are also establishing special...at low pressure and compressed on- site , several additional charges must be added to the cost charged by the natural gas supplier (see Table 1). The

  5. Fuels for urban transit buses: a cost-effectiveness analysis.

    PubMed

    Cohen, Joshua T; Hammitt, James K; Levy, Jonathan I

    2003-04-15

    Public transit agencies have begun to adopt alternative propulsion technologies to reduce urban transit bus emissions associated with conventional diesel (CD) engines. Among the most popular alternatives are emission controlled diesel buses (ECD), defined here to be buses with continuously regenerating diesel particle filters burning low-sulfur diesel fuel, and buses burning compressed natural gas (CNG). This study uses a series of simplifying assumptions to arrive at first-order estimates for the incremental cost-effectiveness (CE) of ECD and CNG relative to CD. The CE ratio numerator reflects acquisition and operating costs. The denominator reflects health losses (mortality and morbidity) due to primary particulate matter (PM), secondary PM, and ozone exposure, measured as quality adjusted life years (QALYs). We find that CNG provides larger health benefits than does ECD (nine vs six QALYs annually per 1000 buses) but that ECD is more cost-effective than CNG (dollar 270 000 per QALY for ECD vs dollar 1.7 million to dollar 2.4 million for CNG). These estimates are subject to much uncertainty. We identify assumptions that contribute most to this uncertainty and propose potential research directions to refine our estimates.

  6. A comparison of emissions from vehicles fueled with diesel or compressed natural gas.

    PubMed

    Hesterberg, Thomas W; Lapin, Charles A; Bunn, William B

    2008-09-01

    A comprehensive comparison of emissions from vehicles fueled with diesel or compressed natural gas (CNG) was developed from 25 reports on transit buses, school buses, refuse trucks, and passenger cars. Emissions for most compounds were highest for untreated exhaust emissions and lowest for treated exhaust CNG buses without after-treatment had the highest emissions of carbon monoxide, hydrocarbons, nonmethane hydrocarbons (NMHC), volatile organic compounds (VOCs; e.g., benzene, butadiene, ethylene, etc.), and carbonyl compounds (e.g., formaldehyde, acetaldehyde, acrolein). Diesel buses without after-treatment had the highest emissions of particulate matter and polycyclic aromatic hydrocarbons (PAHs). Exhaust after-treatments reduced most emissions to similar levels in diesel and CNG buses. Nitrogen oxides (NO(x)) and carbon dioxide (CO2) emissions were similar for most vehicle types, fuels, and exhaust after-treatments with some exceptions. Diesel school buses had higher CO2 emissions than the CNG bus. CNG transit buses and passenger cars equipped with three-way catalysts had lower NO(x) emissions. Diesel buses equipped with traps had higher nitrogen dioxide emissions. Fuel economy was best in the diesel buses not equipped with exhaust after-treatment.

  7. Structural studies of CNG repeats.

    PubMed

    Kiliszek, Agnieszka; Rypniewski, Wojciech

    2014-07-01

    CNG repeats (where N denotes one of the four natural nucleotides) are abundant in the human genome. Their tendency to undergo expansion can lead to hereditary diseases known as TREDs (trinucleotide repeat expansion disorders). The toxic factor can be protein, if the abnormal gene is expressed, or the gene transcript, or both. The gene transcripts have attracted much attention in the biomedical community, but their molecular structures have only recently been investigated. Model RNA molecules comprising CNG repeats fold into long hairpins whose stems generally conform to an A-type helix, in which the non-canonical N-N pairs are flanked by C-G and G-C pairs. Each homobasic pair is accommodated in the helical context in a unique manner, with consequences for the local helical parameters, solvent structure, electrostatic potential and potential to interact with ligands. The detailed three-dimensional profiles of RNA CNG repeats can be used in screening of compound libraries for potential therapeutics and in structure-based drug design. Here is a brief survey of the CNG structures published to date. © Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. EML1 (CNG-Modulin) Controls Light Sensitivity in Darkness and under Continuous Illumination in Zebrafish Retinal Cone Photoreceptors

    PubMed Central

    Mehta, Milap; Tserentsoodol, Nomingerel; Postlethwait, John H.; Rebrik, Tatiana I.

    2013-01-01

    The ligand sensitivity of cGMP-gated (CNG) ion channels in cone photoreceptors is modulated by CNG-modulin, a Ca2+-binding protein. We investigated the functional role of CNG-modulin in phototransduction in vivo in morpholino-mediated gene knockdown zebrafish. Through comparative genomic analysis, we identified the orthologue gene of CNG-modulin in zebrafish, eml1, an ancient gene present in the genome of all vertebrates sequenced to date. We compare the photoresponses of wild-type cones with those of cones that do not express the EML1 protein. In the absence of EML1, dark-adapted cones are ∼5.3-fold more light sensitive than wild-type cones. Previous qualitative studies in several nonmammalian species have shown that immediately after the onset of continuous illumination, cones are less light sensitive than in darkness, but sensitivity then recovers over the following 15–20 s. We characterize light sensitivity recovery in continuously illuminated wild-type zebrafish cones and demonstrate that sensitivity recovery does not occur in the absence of EML1. PMID:24198367

  9. Modulation of the olfactory CNG channel by Ptdlns(3,4,5)P3.

    PubMed

    Zhainazarov, A B; Spehr, M; Wetzel, C H; Hatt, H; Ache, B W

    2004-09-01

    Recent data suggest that the 3-phosphoinositides can modulate cyclic nucleotide signaling in rat olfactory receptor neurons (ORNs). Given the ability of diverse lipids to modulate ion channels, we asked whether phosphatidylinositol 3,4,5-trisphosphate (PIP3) can regulate the olfactory cyclic nucleotide-gated (CNG) channel as a possible mechanism for this modulation. We show that applying PIP3 to the intracellular side of inside-out patches from rat ORNs inhibits activation of the olfactory CNG channel by cAMP. The effect of PIP3 is immediate and partially reversible, and reflects an increase in the EC50 of cAMP, not a reduction in the single-channel current amplitude. The effect of PIP3 is significantly stronger than that of PIP2; other phospholipids tested have no appreciable effect on channel activity. PIP3 similarly inhibits the recombinant heteromeric (A2/A4) and homomeric (A2) olfactory CNG channel expressed in HEK293 cells, suggesting that PIP3 acts directly on the channel. These findings indicate that 3-phosphoinositides can be functionally important regulators of CNG channels.

  10. EML1 (CNG-modulin) controls light sensitivity in darkness and under continuous illumination in zebrafish retinal cone photoreceptors.

    PubMed

    Korenbrot, Juan I; Mehta, Milap; Tserentsoodol, Nomingerel; Postlethwait, John H; Rebrik, Tatiana I

    2013-11-06

    The ligand sensitivity of cGMP-gated (CNG) ion channels in cone photoreceptors is modulated by CNG-modulin, a Ca(2+)-binding protein. We investigated the functional role of CNG-modulin in phototransduction in vivo in morpholino-mediated gene knockdown zebrafish. Through comparative genomic analysis, we identified the orthologue gene of CNG-modulin in zebrafish, eml1, an ancient gene present in the genome of all vertebrates sequenced to date. We compare the photoresponses of wild-type cones with those of cones that do not express the EML1 protein. In the absence of EML1, dark-adapted cones are ∼5.3-fold more light sensitive than wild-type cones. Previous qualitative studies in several nonmammalian species have shown that immediately after the onset of continuous illumination, cones are less light sensitive than in darkness, but sensitivity then recovers over the following 15-20 s. We characterize light sensitivity recovery in continuously illuminated wild-type zebrafish cones and demonstrate that sensitivity recovery does not occur in the absence of EML1.

  11. The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber

    NASA Astrophysics Data System (ADS)

    Firmansyah; Aziz, A. R. A.; Heikal, M. R.

    2015-12-01

    The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.

  12. Alternative Fuels Data Center: CNG Fuel System and Tank Maintenance

    Science.gov Websites

    in this section... Natural Gas Basics Benefits & Considerations Stations Vehicles Availability fuel containers best practices document for more information. CNG Tank Inspection Performing a regular

  13. Low Quality Natural Gas Sulfur Removal and Recovery CNG Claus Sulfur Recovery Process

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Klint, V.W.; Dale, P.R.; Stephenson, C.

    1997-10-01

    Increased use of natural gas (methane) in the domestic energy market will force the development of large non-producing gas reserves now considered to be low quality. Large reserves of low quality natural gas (LQNG) contaminated with hydrogen sulfide (H{sub 2}S), carbon dioxide (CO{sub 2}) and nitrogen (N) are available but not suitable for treatment using current conventional gas treating methods due to economic and environmental constraints. A group of three technologies have been integrated to allow for processing of these LQNG reserves; the Controlled Freeze Zone (CFZ) process for hydrocarbon / acid gas separation; the Triple Point Crystallizer (TPC) processmore » for H{sub 2}S / C0{sub 2} separation and the CNG Claus process for recovery of elemental sulfur from H{sub 2}S. The combined CFZ/TPC/CNG Claus group of processes is one program aimed at developing an alternative gas treating technology which is both economically and environmentally suitable for developing these low quality natural gas reserves. The CFZ/TPC/CNG Claus process is capable of treating low quality natural gas containing >10% C0{sub 2} and measurable levels of H{sub 2}S and N{sub 2} to pipeline specifications. The integrated CFZ / CNG Claus Process or the stand-alone CNG Claus Process has a number of attractive features for treating LQNG. The processes are capable of treating raw gas with a variety of trace contaminant components. The processes can also accommodate large changes in raw gas composition and flow rates. The combined processes are capable of achieving virtually undetectable levels of H{sub 2}S and significantly less than 2% CO in the product methane. The separation processes operate at pressure and deliver a high pressure (ca. 100 psia) acid gas (H{sub 2}S) stream for processing in the CNG Claus unit. This allows for substantial reductions in plant vessel size as compared to conventional Claus / Tail gas treating technologies. A close integration of the components of the CNG Claus process also allow for use of the methane/H{sub 2}S separation unit as a Claus tail gas treating unit by recycling the CNG Claus tail gas stream. This allows for virtually 100 percent sulfur recovery efficiency (virtually zero SO{sub 2} emissions) by recycling the sulfur laden tail gas to extinction. The use of the tail gas recycle scheme also deemphasizes the conventional requirement in Claus units to have high unit conversion efficiency and thereby make the operation much less affected by process upsets and feed gas composition changes. The development of these technologies has been ongoing for many years and both the CFZ and the TPC processes have been demonstrated at large pilot plant scales. On the other hand, prior to this project, the CNG Claus process had not been proven at any scale. Therefore, the primary objective of this portion of the program was to design, build and operate a pilot scale CNG Claus unit and demonstrate the required fundamental reaction chemistry and also demonstrate the viability of a reasonably sized working unit.« less

  14. Alternative Fuels Data Center

    Science.gov Websites

    natural gas (LNG) and propane used as motor fuel in diesel gallon equivalents (DGEs). For taxation compressed natural gas (CNG) used as motor fuel in gasoline gallon equivalents (GGEs). CNG must be reported

  15. Cell- and subunit-specific mechanisms of CNG channel ciliary trafficking and localization in C. elegans

    PubMed Central

    Wojtyniak, Martin; Brear, Andrea G.; O'Halloran, Damien M.; Sengupta, Piali

    2013-01-01

    Summary Primary cilia are ubiquitous sensory organelles that concentrate transmembrane signaling proteins essential for sensing environmental cues. Mislocalization of crucial ciliary signaling proteins, such as the tetrameric cyclic nucleotide-gated (CNG) channels, can lead to cellular dysfunction and disease. Although several cis- and trans-acting factors required for ciliary protein trafficking and localization have been identified, whether these mechanisms act in a protein- and cell-specific manner is largely unknown. Here, we show that CNG channel subunits can be localized to discrete ciliary compartments in individual sensory neurons in C. elegans, suggesting that channel composition is heterogeneous across the cilium. We demonstrate that ciliary localization of CNG channel subunits is interdependent on different channel subunits in specific cells, and identify sequences required for efficient ciliary targeting and localization of the TAX-2 CNGB and TAX-4 CNGA subunits. Using a candidate gene approach, we show that Inversin, transition zone proteins, intraflagellar transport motors and a MYND-domain protein are required to traffic and/or localize CNG channel subunits in both a cell- and channel subunit-specific manner. We further find that TAX-2 and TAX-4 are relatively immobile in specific sensory cilia subcompartments, suggesting that these proteins undergo minimal turnover in these domains in mature cilia. Our results uncover unexpected diversity in the mechanisms that traffic and localize CNG channel subunits to cilia both within and across cell types, highlighting the essential contribution of this process to cellular functions. PMID:23886944

  16. Cell- and subunit-specific mechanisms of CNG channel ciliary trafficking and localization in C. elegans.

    PubMed

    Wojtyniak, Martin; Brear, Andrea G; O'Halloran, Damien M; Sengupta, Piali

    2013-10-01

    Primary cilia are ubiquitous sensory organelles that concentrate transmembrane signaling proteins essential for sensing environmental cues. Mislocalization of crucial ciliary signaling proteins, such as the tetrameric cyclic nucleotide-gated (CNG) channels, can lead to cellular dysfunction and disease. Although several cis- and trans-acting factors required for ciliary protein trafficking and localization have been identified, whether these mechanisms act in a protein- and cell-specific manner is largely unknown. Here, we show that CNG channel subunits can be localized to discrete ciliary compartments in individual sensory neurons in C. elegans, suggesting that channel composition is heterogeneous across the cilium. We demonstrate that ciliary localization of CNG channel subunits is interdependent on different channel subunits in specific cells, and identify sequences required for efficient ciliary targeting and localization of the TAX-2 CNGB and TAX-4 CNGA subunits. Using a candidate gene approach, we show that Inversin, transition zone proteins, intraflagellar transport motors and a MYND-domain protein are required to traffic and/or localize CNG channel subunits in both a cell- and channel subunit-specific manner. We further find that TAX-2 and TAX-4 are relatively immobile in specific sensory cilia subcompartments, suggesting that these proteins undergo minimal turnover in these domains in mature cilia. Our results uncover unexpected diversity in the mechanisms that traffic and localize CNG channel subunits to cilia both within and across cell types, highlighting the essential contribution of this process to cellular functions.

  17. cGMP/Protein Kinase G Signaling Suppresses Inositol 1,4,5-Trisphosphate Receptor Phosphorylation and Promotes Endoplasmic Reticulum Stress in Photoreceptors of Cyclic Nucleotide-gated Channel-deficient Mice*

    PubMed Central

    Ma, Hongwei; Butler, Michael R.; Thapa, Arjun; Belcher, Josh; Yang, Fan; Baehr, Wolfgang; Biel, Martin; Michalakis, Stylianos; Ding, Xi-Qin

    2015-01-01

    Photoreceptor cyclic nucleotide-gated (CNG) channels play a pivotal role in phototransduction. Mutations in the cone CNG channel subunits CNGA3 and CNGB3 are associated with achromatopsia and cone dystrophies. We have shown endoplasmic reticulum (ER) stress-associated apoptotic cone death and increased phosphorylation of the ER Ca2+ channel inositol 1,4,5-trisphosphate receptor 1 (IP3R1) in CNG channel-deficient mice. We also presented a remarkable elevation of cGMP and an increased activity of the cGMP-dependent protein kinase (protein kinase G, PKG) in CNG channel deficiency. This work investigated whether cGMP/PKG signaling regulates ER stress and IP3R1 phosphorylation in CNG channel-deficient cones. Treatment with PKG inhibitor and deletion of guanylate cyclase-1 (GC1), the enzyme producing cGMP in cones, were used to suppress cGMP/PKG signaling in cone-dominant Cnga3−/−/Nrl−/− mice. We found that treatment with PKG inhibitor or deletion of GC1 effectively reduced apoptotic cone death, increased expression levels of cone proteins, and decreased activation of Müller glial cells. Furthermore, we observed significantly increased phosphorylation of IP3R1 and reduced ER stress. Our findings demonstrate a role of cGMP/PKG signaling in ER stress and ER Ca2+ channel regulation and provide insights into the mechanism of cone degeneration in CNG channel deficiency. PMID:26124274

  18. Physical and Chemical Characterization of Real-World Particle Number and Mass Emissions from City Buses in Finland.

    PubMed

    Pirjola, Liisa; Dittrich, Aleš; Niemi, Jarkko V; Saarikoski, Sanna; Timonen, Hilkka; Kuuluvainen, Heino; Järvinen, Anssi; Kousa, Anu; Rönkkö, Topi; Hillamo, Risto

    2016-01-05

    Exhaust emissions of 23 individual city buses at Euro III, Euro IV and EEV (Enhanced Environmentally Friendly Vehicle) emission levels were measured by the chasing method under real-world conditions at a depot area and on the normal route of bus line 24 in Helsinki. The buses represented different technologies from the viewpoint of engines, exhaust after-treatment systems (ATS) and fuels. Some of the EEV buses were fueled by diesel, diesel-electric, ethanol (RED95) and compressed natural gas (CNG). At the depot area the emission factors were in the range of 0.3-21 × 10(14) # (kg fuel)(-1), 6-40 g (kg fuel)(-1), 0.004-0.88 g (kg fuel)(-1), 0.004-0.56 g (kg fuel)(-1), 0.01-1.2 g (kg fuel)(-1), for particle number (EFN), nitrogen oxides (EFNOx), black carbon (EFBC), organics (EFOrg), and particle mass (EFPM1), respectively. The highest particulate emissions were observed from the Euro III and Euro IV buses and the lowest from the ethanol and CNG-fueled buses, which emitted BC only during acceleration. The organics emitted from the CNG-fueled buses were clearly less oxidized compared to the other bus types. The bus line experiments showed that lowest emissions were obtained from the ethanol-fueled buses whereas large variation existed between individual buses of the same type indicating that the operating conditions by drivers had large effect on the emissions.

  19. A key role for cyclic nucleotide gated (CNG) channels in cGMP-related retinitis pigmentosa.

    PubMed

    Paquet-Durand, François; Beck, Susanne; Michalakis, Stylianos; Goldmann, Tobias; Huber, Gesine; Mühlfriedel, Regine; Trifunović, Dragana; Fischer, M Dominik; Fahl, Edda; Duetsch, Gabriele; Becirovic, Elvir; Wolfrum, Uwe; van Veen, Theo; Biel, Martin; Tanimoto, Naoyuki; Seeliger, Mathias W

    2011-03-01

    The rd1 natural mutant is one of the first and probably the most commonly studied mouse model for retinitis pigmentosa (RP), a severe and frequently blinding human retinal degeneration. In several decades of research, the link between the increase in photoreceptor cGMP levels and the extremely rapid cell death gave rise to a number of hypotheses. Here, we provide clear evidence that the presence of cyclic nucleotide gated (CNG) channels in the outer segment membrane is the key to rod photoreceptor loss. In Cngb1(-/-) × rd1 double mutants devoid of regular CNG channels, cGMP levels are still pathologically high, but rod photoreceptor viability and outer segment morphology are greatly improved. Importantly, cone photoreceptors, the basis for high-resolution daylight and colour vision, survived and remained functional for extended periods of time. These findings strongly support the hypothesis of deleterious calcium (Ca(2+))-influx as the cause of rapid rod cell death and highlight the importance of CNG channels in this process. Furthermore, our findings suggest that targeting rod CNG channels, rather than general Ca(2+)-channel blockade, is a most promising symptomatic approach to treat otherwise incurable forms of cGMP-related RP.

  20. PACS-1 Mediates Phosphorylation-Dependent Ciliary Trafficking of the CNG Channel in Olfactory Sensory Neurons

    PubMed Central

    Jenkins, Paul M.; Zhang, Lian; Thomas, Gary; Martens, Jeffrey R.

    2009-01-01

    Impaired ciliary protein transport in olfactory sensory neurons (OSNs) leads to anosmia, and is a newly recognized clinical manifestation of a class of human disorders called ciliopathies. Surprisingly little is known regarding the mechanisms controlling trafficking to this unique neuronal compartment. Here, we show a novel role for phosphofurin acidic cluster-sorting protein 1 (PACS-1) in the ciliary trafficking of the olfactory CNG channel. PACS-1 is an intracellular sorting protein that mediates its effects through the binding of acidic clusters on cargo protein. This interaction is dependent on CK2 phosphorylation of both PACS-1 and its cargo. We show that CNGB1b contains two putative PACS-1 binding sites, which are phosphorylated by the serine/threonine protein kinase, CK2. Additionally, we show that PACS-1 is expressed in OSNs and interacts in complex with the CNG channel. CK2 inhibition in native OSNs causes a loss of CNG channel from cilia and subsequent olfactory dysfunction, while adenoviral expression of mutant PACS-1 causes similar mislocalization. These results provide a mechanism for the subunit-dependent ciliary trafficking of the CNG channel and offer insight into the mechanisms of ciliary transport. PMID:19710307

  1. Compressed Natural Gas (CNG) Transit Bus Experience Survey: April 2009--April 2010

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adams, R.; Horne, D. B.

    2010-09-01

    This survey was commissioned by the U.S. Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) to collect and analyze experiential data and information from a cross-section of U.S. transit agencies with varying degrees of compressed natural gas (CNG) bus and station experience. This information will be used to assist DOE and NREL in determining areas of success and areas where further technical or other assistance might be required, and to assist them in focusing on areas judged by the CNG transit community as priority items.

  2. Low Diversity Cryptococcus neoformans Variety grubii Multilocus Sequence Types from Thailand Are Consistent with an Ancestral African Origin

    PubMed Central

    Simwami, Sitali P.; Khayhan, Kantarawee; Henk, Daniel A.; Aanensen, David M.; Boekhout, Teun; Hagen, Ferry; Brouwer, Annemarie E.; Harrison, Thomas S.; Donnelly, Christl A.; Fisher, Matthew C.

    2011-01-01

    The global burden of HIV-associated cryptococcal meningitis is estimated at nearly one million cases per year, causing up to a third of all AIDS-related deaths. Molecular epidemiology constitutes the main methodology for understanding the factors underpinning the emergence of this understudied, yet increasingly important, group of pathogenic fungi. Cryptococcus species are notable in the degree that virulence differs amongst lineages, and highly-virulent emerging lineages are changing patterns of human disease both temporally and spatially. Cryptococcus neoformans variety grubii (Cng, serotype A) constitutes the most ubiquitous cause of cryptococcal meningitis worldwide, however patterns of molecular diversity are understudied across some regions experiencing significant burdens of disease. We compared 183 clinical and environmental isolates of Cng from one such region, Thailand, Southeast Asia, against a global MLST database of 77 Cng isolates. Population genetic analyses showed that Thailand isolates from 11 provinces were highly homogenous, consisting of the same genetic background (globally known as VNI) and exhibiting only ten nearly identical sequence types (STs), with three (STs 44, 45 and 46) dominating our sample. This population contains significantly less diversity when compared against the global population of Cng, specifically Africa. Genetic diversity in Cng was significantly subdivided at the continental level with nearly half (47%) of the global STs unique to a genetically diverse and recombining population in Botswana. These patterns of diversity, when combined with evidence from haplotypic networks and coalescent analyses of global populations, are highly suggestive of an expansion of the Cng VNI clade out of Africa, leading to a limited number of genotypes founding the Asian populations. Divergence time testing estimates the time to the most common ancestor between the African and Asian populations to be 6,920 years ago (95% HPD 122.96 - 27,177.76). Further high-density sampling of global Cng STs is now necessary to resolve the temporal sequence underlying the global emergence of this human pathogen. PMID:21573144

  3. Low diversity Cryptococcus neoformans variety grubii multilocus sequence types from Thailand are consistent with an ancestral African origin.

    PubMed

    Simwami, Sitali P; Khayhan, Kantarawee; Henk, Daniel A; Aanensen, David M; Boekhout, Teun; Hagen, Ferry; Brouwer, Annemarie E; Harrison, Thomas S; Donnelly, Christl A; Fisher, Matthew C

    2011-04-01

    The global burden of HIV-associated cryptococcal meningitis is estimated at nearly one million cases per year, causing up to a third of all AIDS-related deaths. Molecular epidemiology constitutes the main methodology for understanding the factors underpinning the emergence of this understudied, yet increasingly important, group of pathogenic fungi. Cryptococcus species are notable in the degree that virulence differs amongst lineages, and highly-virulent emerging lineages are changing patterns of human disease both temporally and spatially. Cryptococcus neoformans variety grubii (Cng, serotype A) constitutes the most ubiquitous cause of cryptococcal meningitis worldwide, however patterns of molecular diversity are understudied across some regions experiencing significant burdens of disease. We compared 183 clinical and environmental isolates of Cng from one such region, Thailand, Southeast Asia, against a global MLST database of 77 Cng isolates. Population genetic analyses showed that Thailand isolates from 11 provinces were highly homogenous, consisting of the same genetic background (globally known as VNI) and exhibiting only ten nearly identical sequence types (STs), with three (STs 44, 45 and 46) dominating our sample. This population contains significantly less diversity when compared against the global population of Cng, specifically Africa. Genetic diversity in Cng was significantly subdivided at the continental level with nearly half (47%) of the global STs unique to a genetically diverse and recombining population in Botswana. These patterns of diversity, when combined with evidence from haplotypic networks and coalescent analyses of global populations, are highly suggestive of an expansion of the Cng VNI clade out of Africa, leading to a limited number of genotypes founding the Asian populations. Divergence time testing estimates the time to the most common ancestor between the African and Asian populations to be 6,920 years ago (95% HPD 122.96 - 27,177.76). Further high-density sampling of global Cng STs is now necessary to resolve the temporal sequence underlying the global emergence of this human pathogen.

  4. Circulating Tumor Cells with Aberrant ALK Copy Number Predict Progression-Free Survival during Crizotinib Treatment in ALK-Rearranged Non-Small Cell Lung Cancer Patients.

    PubMed

    Pailler, Emma; Oulhen, Marianne; Borget, Isabelle; Remon, Jordi; Ross, Kirsty; Auger, Nathalie; Billiot, Fanny; Ngo Camus, Maud; Commo, Frédéric; Lindsay, Colin R; Planchard, David; Soria, Jean-Charles; Besse, Benjamin; Farace, Françoise

    2017-05-01

    The duration and magnitude of clinical response are unpredictable in ALK -rearranged non-small cell lung cancer (NSCLC) patients treated with crizotinib, although all patients invariably develop resistance. Here, we evaluated whether circulating tumor cells (CTC) with aberrant ALK -FISH patterns [ ALK -rearrangement, ALK -copy number gain ( ALK -CNG)] monitored on crizotinib could predict progression-free survival (PFS) in a cohort of ALK -rearranged patients. Thirty-nine ALK -rearranged NSCLC patients treated with crizotinib as first ALK inhibitor were recruited prospectively. Blood samples were collected at baseline and at an early time-point (2 months) on crizotinib. Aberrant ALK -FISH patterns were examined in CTCs using immunofluorescence staining combined with filter-adapted FISH after filtration enrichment. CTCs were classified into distinct subsets according to the presence of ALK -rearrangement and/or ALK -CNG signals. No significant association between baseline numbers of ALK -rearranged or ALK -CNG CTCs and PFS was observed. However, we observed a significant association between the decrease in CTC number with ALK -CNG on crizotinib and a longer PFS (likelihood ratio test, P = 0.025). In multivariate analysis, the dynamic change of CTC with ALK -CNG was the strongest factor associated with PFS (HR, 4.485; 95% confidence interval, 1.543-13.030, P = 0.006). Although not dominant, ALK -CNG has been reported to be one of the mechanisms of acquired resistance to crizotinib in tumor biopsies. Our results suggest that the dynamic change in the numbers of CTCs with ALK -CNG may be a predictive biomarker for crizotinib efficacy in ALK -rearranged NSCLC patients. Serial molecular analysis of CTC shows promise for real-time patient monitoring and clinical outcome prediction in this population. Cancer Res; 77(9); 2222-30. ©2017 AACR . ©2017 American Association for Cancer Research.

  5. ALK gene copy number gain and its clinical significance in hepatocellular carcinoma.

    PubMed

    Jia, Shou-Wei; Fu, Sha; Wang, Fang; Shao, Qiong; Huang, Hong-Bing; Shao, Jian-Yong

    2014-01-07

    To examine the status and clinical significance of anaplastic lymphoma kinase (ALK) gene alterations in hepatocellular carcinoma (HCC) patients. A total of 213 cases of HCC were examined by fluorescent in situ hybridization using dual color break-apart ALK probes for the detection of chromosomal translocation and gene copy number gain. HCC tissue microarrays were constructed, and the correlation between the ALK status and clinicopathological variables was assessed by χ(2) test or Fisher's exact test. Survival analysis was estimated using the Kaplan-Meier approach with a Log-rank test. Univariate and multivariate analyses of clinical variables were performed using the Cox proportional hazards regression model. ALK gene translocation was not observed in any of the HCC cases included in the present study. ALK gene copy number gain (ALK/CNG) (≥ 4 copies/cell) was detected in 28 (13.15%) of the 213 HCC patients. The 3-year progression-free-survival (PFS) rate for ALK/CNG-positive HCC patients was significantly poorer than ALK/CNG-negative patients (27.3% vs 42.5%, P = 0.048), especially for patients with advanced stage III/IV (0% vs 33.5%, P = 0.007), and patients with grade III disease (24.8% vs 49.9%, P = 0.023). ALK/CNG-positive HCC patients had a significantly poorer prognosis than ALK/CNG-negative patients in the subgroup that was negative for serum hepatitis B virus DNA, with significantly different 3-year overall survival rates (18.2% vs 63.6%, P = 0.021) and PFS rates (18.2% vs 46.9%, P = 0.019). Multivariate Cox proportional hazards regression analysis suggested that ALK/CNG prevalence can predict death in HCC (HR = 1.596; 95%CI: 1.008-2.526, P = 0.046). ALK/CNG, but not translocation of ALK, is present in HCC and may be an unfavorable prognostic predictor.

  6. ALK gene copy number gain and its clinical significance in hepatocellular carcinoma

    PubMed Central

    Jia, Shou-Wei; Fu, Sha; Wang, Fang; Shao, Qiong; Huang, Hong-Bing; Shao, Jian-Yong

    2014-01-01

    AIM: To examine the status and clinical significance of anaplastic lymphoma kinase (ALK) gene alterations in hepatocellular carcinoma (HCC) patients. METHODS: A total of 213 cases of HCC were examined by fluorescent in situ hybridization using dual color break-apart ALK probes for the detection of chromosomal translocation and gene copy number gain. HCC tissue microarrays were constructed, and the correlation between the ALK status and clinicopathological variables was assessed by χ2 test or Fisher’s exact test. Survival analysis was estimated using the Kaplan-Meier approach with a Log-rank test. Univariate and multivariate analyses of clinical variables were performed using the Cox proportional hazards regression model. RESULTS: ALK gene translocation was not observed in any of the HCC cases included in the present study. ALK gene copy number gain (ALK/CNG) (≥ 4 copies/cell) was detected in 28 (13.15%) of the 213 HCC patients. The 3-year progression-free-survival (PFS) rate for ALK/CNG-positive HCC patients was significantly poorer than ALK/CNG-negative patients (27.3% vs 42.5%, P = 0.048), especially for patients with advanced stage III/IV (0% vs 33.5%, P = 0.007), and patients with grade III disease (24.8% vs 49.9%, P = 0.023). ALK/CNG-positive HCC patients had a significantly poorer prognosis than ALK/CNG-negative patients in the subgroup that was negative for serum hepatitis B virus DNA, with significantly different 3-year overall survival rates (18.2% vs 63.6%, P = 0.021) and PFS rates (18.2% vs 46.9%, P = 0.019). Multivariate Cox proportional hazards regression analysis suggested that ALK/CNG prevalence can predict death in HCC (HR = 1.596; 95%CI: 1.008-2.526, P = 0.046). CONCLUSION: ALK/CNG, but not translocation of ALK, is present in HCC and may be an unfavorable prognostic predictor. PMID:24415871

  7. ALK gene copy number gains in non-small-cell lung cancer: prognostic impact and clinico-pathological correlations.

    PubMed

    Peretti, U; Ferrara, R; Pilotto, S; Kinspergher, S; Caccese, M; Santo, A; Brunelli, M; Caliò, A; Carbognin, L; Sperduti, I; Garassino, M; Chilosi, M; Scarpa, A; Tortora, G; Bria, E

    2016-08-25

    The correlation between ALK gene copy number gain (ALK-CNG) and prognosis in the context of advanced non-small-cell lung cancer (NSCLC) remains a controversial issue. This study aimed to evaluate the association among ALK-CNG according to Fluorescent In Situ Hybridization (FISH), clinical characteristics and survival in resectable and advanced NSCLC. Clinical and pathological data of patients with resectable and advanced NSCLC were retrospectively collected. Tumor tissues were analyzed for ALK-CNG by FISH, and patients were divided in 3 groups/patterns on the basis of ALK signals: disomic [Pattern A], 3-7 signals [Pattern B], >7 signals [Pattern C]. The association between clinical and pathological features and ALK-CNG patterns was evaluated. Disease/progression-free and overall survival (DFS/PFS and OS) were estimated using the Kaplan-Meyer method. A number of 128 (76.6 %) out of the 167 eligible patients were evaluable for ALK-CNG, displaying pattern A, B and C in 71 (42.5 %), 42 (25.1 %) and 15 (9 %) patients, respectively. Gains in ALK-CNG appear to be more frequent in smokers/former smokers than in non-smokers (74.2 % versus 20.4 %, respectively, p = 0.03). Pattern A and C seem more frequently associated with higher T-stage (T3-4), while pattern B appears more represented in lower T-stage (T 1-2) (p = 0.06). No significant differences in survival rate were observed among the above groups. A high ALK-CNG pattern might be associated with smoking status and theoretically it might mirror genomic instability. The implications for prognosis should be prospectively investigated and validated in larger patients' series. We confirm that all the study was performed in accordance with relevant guidelines and regulations and that all the protocol (part of a larger project MFAG 2013 N.14282) was approved by the local Ethics Committee of the Azienda Ospedaliera Universitaria Integrata of Verona on November 11st, 2014.

  8. Alternative Fuels Data Center

    Science.gov Websites

    Compressed Natural Gas (CNG) and Propane Tax CNG and propane used in motor vehicles is subject to a state motor fuel tax rate of $0.26 per gasoline gallon equivalent (GGE). For taxation purposes, one GGE

  9. Dispersion of CNG Following a High-Pressure Release

    DOT National Transportation Integrated Search

    1996-05-01

    This report discusses the results of tests to determine the dispersive behavior of compressed natural gas (CNG) when released in enclosed areas such as transit bus facility, and presents the Volpe National Transportation Systems Center's (VNTSC) conc...

  10. Cost-effectiveness analysis of CNG urban taxi operations.

    DOT National Transportation Integrated Search

    1993-10-01

    Increased emphasis on energy efficiency and air quality has resulted in a number of state and federal initiatives : examining the use of alternative fuels for motor vehicles. Texas' program for alternate fuels includes compressed : natural gas (CNG)....

  11. An experimental investigation of performance of diesel to CNG engine

    NASA Astrophysics Data System (ADS)

    Misra, Sheelam; Gupta, Ayush; Garg, Ashutosh

    2018-05-01

    Over the past few decades, diesel engines are widely used in automobiles which is responsible for hazardous increase in pollution. Around the world, many countries are trying to reduce it by replacing diesel with CNG as a fuel which is more economical and leads to pollution free environment. Engineers came up with an idea to convert diesel engine to CNG engine. This conversion is possible by doing some alteration of engine components and it also include adding some extra components to the system which includes spark plug, valves etc. and by decreasing the compression ratio of the engine. It is used worldwide today and many countries have many programs to convert older, polluting diesel vehicles to CNG enable vehicles so that they can run on clean, economical natural gas. This is, an excellent way to reduce fuel cost, reduce pollution, reduce noise with minimum possible capital costs.first, second, and third level headings.

  12. Gaseous emissions from compressed natural gas buses in urban road and highway tests in China.

    PubMed

    Yue, Tingting; Chai, Fahe; Hu, Jingnan; Jia, Ming; Bao, Xiaofeng; Li, Zhenhua; He, Liqang; Zu, Lei

    2016-10-01

    The natural gas vehicle market is rapidly developing throughout the world, and the majority of such vehicles operate on compressed natural gas (CNG). However, most studies on the emission characteristics of CNG vehicles rely on laboratory chassis dynamometer measurements, which do not accurately represent actual road driving conditions. To further investigate the emission characteristics of CNG vehicles, two CNG city buses and two CNG coaches were tested on public urban roads and highway sections. Our results show that when speeds of 0-10km/hr were increased to 10-20km/hr, the CO 2 , CO, nitrogen oxide (NO x ), and total hydrocarbon (THC) emission factors decreased by (71.6±4.3)%, (65.6±9.5)%, (64.9±9.2)% and (67.8±0.3)%, respectively. In this study, The Beijing city buses with stricter emission standards (Euro IV) did not have lower emission factors than the Chongqing coaches with Euro II emission standards. Both the higher emission factors at 0-10km/hr speeds and the higher percentage of driving in the low-speed regime during the entire road cycle may have contributed to the higher CO 2 and CO emission factors of these city buses. Additionally, compared with the emission factors produced in the urban road tests, the CO emission factors of the CNG buses in highway tests decreased the most (by 83.2%), followed by the THC emission factors, which decreased by 67.1%. Copyright © 2016. Published by Elsevier B.V.

  13. Emission of a Dual-Fuel Turbocharged Compression Ignition Engine

    NASA Astrophysics Data System (ADS)

    Rózycki, Andrzej

    2012-02-01

    The paper describes the results of a four-cylinder dual fuel turbocharged compression ignition engine. The aim of the study was to determine the maximum CNG share in thefuel mixture delivered into the cylinder. Analysis of the investigation results showed that the CNG energy share in the fuel charge delivered into the cylinder can reach 45%. At that level of CNG energy share a 15% reduction in maximum torque is achieved in comparison with the standard fuelling. The unburnt hydrocarbon emission increases significantly. Emissions of other principal pollutants reach values comparable with those obtained at standard fuelling.

  14. Air quality and climate impacts due to CNG conversion of motor vehicles in Dhaka, Bangladesh.

    PubMed

    Wadud, Zia; Khan, Tanzila

    2013-12-17

    Dhaka had recently experienced rapid conversion of its motor vehicle fleet to run on compressed natural gas (CNG). This paper quantifies ex-post the air quality and climate benefits of the CNG conversion policy, including monetary valuations, through an impact pathway approach. Around 2045 (1665) avoided premature deaths in greater Dhaka (City Corporation) can be attributed to air quality improvements from the CNG conversion policy in 2010, resulting in a saving of around USD 400 million. Majority of these health benefits resulted from the conversion of high-emitting diesel vehicles. CNG conversion was clearly detrimental from climate change perspective using the changes in CO2 and CH4 only (CH4 emissions increased); however, after considering other global pollutants (especially black carbon), the climate impact was ambiguous. Uncertainty assessment using input distributions and Monte Carlo simulation along with a sensitivity analysis show that large uncertainties remain for climate impacts. For our most likely estimate, there were some climate costs, valued at USD 17.7 million, which is an order of magnitude smaller than the air quality benefits. This indicates that such policies can and should be undertaken on the grounds of improving local air pollution alone and that precautions should be taken to reduce the potentially unintended increases in GHG emissions or other unintended effects.

  15. CryoEM structure of a prokaryotic cyclic nucleotide-gated ion channel

    PubMed Central

    James, Zachary M.; Borst, Andrew J.; Haitin, Yoni; Frenz, Brandon; DiMaio, Frank; Zagotta, William N.; Veesler, David

    2017-01-01

    Cyclic nucleotide-gated (CNG) and hyperpolarization-activated cyclic nucleotide-regulated (HCN) ion channels play crucial physiological roles in phototransduction, olfaction, and cardiac pace making. These channels are characterized by the presence of a carboxyl-terminal cyclic nucleotide-binding domain (CNBD) that connects to the channel pore via a C-linker domain. Although cyclic nucleotide binding has been shown to promote CNG and HCN channel opening, the precise mechanism underlying gating remains poorly understood. Here we used cryoEM to determine the structure of the intact LliK CNG channel isolated from Leptospira licerasiae—which shares sequence similarity to eukaryotic CNG and HCN channels—in the presence of a saturating concentration of cAMP. A short S4–S5 linker connects nearby voltage-sensing and pore domains to produce a non–domain-swapped transmembrane architecture, which appears to be a hallmark of this channel family. We also observe major conformational changes of the LliK C-linkers and CNBDs relative to the crystal structures of isolated C-linker/CNBD fragments and the cryoEM structures of related CNG, HCN, and KCNH channels. The conformation of our LliK structure may represent a functional state of this channel family not captured in previous studies. PMID:28396445

  16. 46 CFR 25.45-2 - Cooking systems on vessels carrying passengers for hire.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... allowed for CNG: (i) The storage locker or housing access opening need not be in the top. (ii) The locker...) The storage locker or housing for CNG tank installations need not be above the waterline as required...

  17. 46 CFR 25.45-2 - Cooking systems on vessels carrying passengers for hire.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... allowed for CNG: (i) The storage locker or housing access opening need not be in the top. (ii) The locker...) The storage locker or housing for CNG tank installations need not be above the waterline as required...

  18. 46 CFR 25.45-2 - Cooking systems on vessels carrying passengers for hire.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... allowed for CNG: (i) The storage locker or housing access opening need not be in the top. (ii) The locker...) The storage locker or housing for CNG tank installations need not be above the waterline as required...

  19. 46 CFR 25.45-2 - Cooking systems on vessels carrying passengers for hire.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... allowed for CNG: (i) The storage locker or housing access opening need not be in the top. (ii) The locker...) The storage locker or housing for CNG tank installations need not be above the waterline as required...

  20. Guidance on Biogas used to Produce CNG or LNG under the Renewable Fuel Standard Program

    EPA Pesticide Factsheets

    Provides EPA’s interpretation of biogas quality and RIN generation requirements that apply to renewable fuel production pathways involving the injection into a commercial pipeline of biogas for use in producing renewable CNG or renewable LNG.

  1. TRESP II testing of AFS dual fuel system.

    DOT National Transportation Integrated Search

    2013-11-01

    A dual fuel CNG and diesel system was retrofitted to a 13 L Volvo semi tractor for testing to verify the : fuel economy and CNG substitution rate. The semi tractor was tested on interstate and mountainous : highway routes with a loaded trailer. Fuel ...

  2. On-road measurement of regulated pollutants from diesel and CNG buses with urea selective catalytic reduction systems

    NASA Astrophysics Data System (ADS)

    Guo, Jiadong; Ge, Yunshan; Hao, Lijun; Tan, Jianwei; Li, Jiaqiang; Feng, Xiangyu

    2014-12-01

    In this study, emissions from 13 buses operated in Beijing, including two Euro-III diesel buses, four Euro-IV diesel buses, three Euro-V diesel buses and four Euro-V CNG buses, were characterized in real world conditions. All of the buses tested were fitted with selective catalytic reduction (SCR) systems except for the Euro-III diesel buses. A SEMTECH-DS was used for testing the gaseous pollutants, and an electric low pressure impactor (ELPI) was used for measuring of particle numbers and size distributions. A comparison was made based on emission performance of these buses by employing the VSP approach and fuel- based emissions factors. Diesel buses emitted less CO and THC but more NOx and PM pollutants than CNG buses. The NOx reduction efficiencies of the SCR systems for CNG buses were higher because of the high exhaust temperature and high NO2/NOx ratio, whereas the efficiencies for diesel buses were lower. This resulted in extremely low NOx emissions from CNG buses, but the high NO2/NOx ratio needs further study. Failures of urea injection in the SCR systems were detected in this research, which resulted in very high NOx emissions. The CNG buses also emitted smaller numbers of particles and less particle mass with the presence of oxidation catalysts. Diesel buses satisfying the Euro-V standard performed better than Euro-IV and Euro-III diesel buses in terms of emission performance, except for more nuclei mode particles. Most of time, the Euro-IV diesel buses show no advantages in CO and NOx emissions compared with the Euro-III diesel buses.

  3. Particle and gaseous emissions from compressed natural gas and ultralow sulphur diesel-fuelled buses at four steady engine loads.

    PubMed

    Jayaratne, E R; Ristovski, Z D; Meyer, N; Morawska, L

    2009-04-01

    Exhaust emissions from thirteen compressed natural gas (CNG) and nine ultralow sulphur diesel in-service transport buses were monitored on a chassis dynamometer. Measurements were carried out at idle and at three steady engine loads of 25%, 50% and 100% of maximum power at a fixed speed of 60 km h(-1). Emission factors were estimated for particle mass and number, carbon dioxide and oxides of nitrogen for two types of CNG buses (Scania and MAN, compatible with Euro 2 and 3 emission standards, respectively) and two types of diesel buses (Volvo Pre-Euro/Euro1 and Mercedez OC500 Euro3). All emission factors increased with load. The median particle mass emission factor for the CNG buses was less than 1% of that from the diesel buses at all loads. However, the particle number emission factors did not show a statistically significant difference between buses operating on the two types of fuel. In this paper, for the very first time, particle number emission factors are presented at four steady state engine loads for CNG buses. Median values ranged from the order of 10(12) particles min(-)(1) at idle to 10(15) particles km(-)(1) at full power. Most of the particles observed in the CNG emissions were in the nanoparticle size range and likely to be composed of volatile organic compounds The CO2 emission factors were about 20% to 30% greater for the diesel buses over the CNG buses, while the oxides of nitrogen emission factors did not show any difference due to the large variation between buses.

  4. Impact of epidermal growth factor receptor protein and gene alteration on Taiwanese hepatocellular carcinomas.

    PubMed

    Su, Yu-Hung; Ng, Kwai-Fong; Yu, Ming-Chin; Wu, Ting-Jung; Yeh, Ta-Sen; Lee, Wei-Chen; Lin, Yong-Shiang; Hsieh, Tsung-Han; Lin, Chun-Yen; Yeh, Chau-Ting; Chen, Tse-Ching

    2015-09-01

    Epidermal growth factor receptor (EGFR) overexpression is associated with disease progression and poor survival in a variety of solid tumors. The role of EGFR in hepatocellular carcinoma (HCC) remains controversial. One hundred thirty-eight HCCs were analyzed for total EGFR (t-EGFR) and phospho-EGFR (p-EGFR) expression and gene amplification using immunohistochemistry and fluorescence in situ hybridization. The role of EGFR was analyzed in relation to the clinicopathological features. Weak to strong p-EGFR immunostaining was noted in 42 of the 138 HCCs. p-EGFR expression correlated with alcoholism (P = 0.03) and chronic hepatitis B infection (P = 0.041). There was no correlation between t-EGFR expression and any of the clinicopathological features. Amplification of the EGFR gene was not identified in the 138 HCCs, but 39.1% of the HCCs showed balanced polysomy of both the EGFR gene and centromere 7. Moreover, 65 tumors showed > 2.2 copies per tumor cell. EGFR copy number gain (CNG) was significantly correlated with gender (P = 0.0491), tumor grade (P = 0.006), and vascular invasion (P = 0.005). HCCs with EGFR CNG also had a poor recurrence-free survival (RFS), as compared with HCCs without EGFR CNG (P = 0.031). When exploring the impact of gender, a significant association of EGFR CNG was found with tumor grade (P = 0.044) and cirrhosis (P = 0.015) exclusively in the male group only; however, the OS and RFS analysis show no significant difference between male and female groups. EGFR CNG was related to crucial clinicopathological features and early recurrence, indicating that EGFR CNG might be a poor prognosis factor for Taiwanese HCC. © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  5. Influence of extensive compressed natural gas (CNG) usage on air quality

    NASA Astrophysics Data System (ADS)

    Suthawaree, Jeeranut; Sikder, Helena Akhter; Jones, Charlotte Emily; Kato, Shungo; Kunimi, Hitoshi; Mohammed Hamidul Kabir, Abu Naser; Kajii, Yoshizumi

    2012-07-01

    Compressed Natural Gas (CNG) is an inexpensive, indigenous energy resource which currently accounts for the majority of automobile and domestic energy consumption in Bangladesh. This extensive CNG usage, particularly within the capital city, Dhaka, heavily influences the atmospheric composition (and hence air quality), yet to date measurements of trace gases in regions dominated by CNG emissions are relatively limited. Here we report continuous observations of the atmospherically important trace gases O3, CO, SO2, NOx and volatile organic compounds (VOC), in ambient air in Dhaka City, Bangladesh, during May 2011. The average mixing ratios of O3, CO, SO2, and NOx for the measurement period were 18.9, 520.9, 7.6 and 21.5 ppbv, respectively. The ratios of CO to NO reveal that emissions from gasoline and CNG-fuelled vehicles were dominant during the daytime (slope of ˜26), while in contrast, owing to restrictions imposed on diesel fuelled vehicles entering Dhaka City, emissions from these vehicles only became significant during the night (slope of ˜10). The total VOC mixing ratio in Dhaka was ˜5-10 times higher than the levels reported in more developed Asian cities such as Tokyo and Bangkok, which consequently gives rise to a higher ozone formation potential (OFP). However, the most abundant VOC in Dhaka were the relatively long-lived ethane and propane (with mean mixing ratios of ˜115 and ˜30 ppbv, respectively), and as a consequence, the ozone formation potential per ppb carbon (ppbC) was lower in Dhaka than in Tokyo and Bangkok. Thus the atmospheric composition of air influenced by extensive CNG combustion may be characterized by high VOC mixing ratios, yet mixing ratios of the photochemical pollutant ozone do not drastically exceed the levels typical of Asian cities with considerably lower VOC levels.

  6. Gene replacement therapy for retinal CNG channelopathies.

    PubMed

    Schön, Christian; Biel, Martin; Michalakis, Stylianos

    2013-10-01

    Visual phototransduction relies on the function of cyclic nucleotide-gated channels in the rod and cone photoreceptor outer segment plasma membranes. The role of these ion channels is to translate light-triggered changes in the second messenger cyclic guanosine 3'-5'-monophosphate levels into an electrical signal that is further processed within the retinal network and then sent to higher visual centers. Rod and cone photoreceptors express distinct CNG channels. The rod photoreceptor CNG channel is composed of one CNGB1 and three CNGA1 subunits, whereas the cone channel is formed by one CNGB3 and three CNGA3 subunits. Mutations in any of these channel subunits result in severe and currently untreatable retinal degenerative diseases like retinitis pigmentosa or achromatopsia. In this review, we provide an overview of the human diseases and relevant animal models of CNG channelopathies. Furthermore, we summarize recent results from preclinical gene therapy studies using adeno-associated viral vectors and discuss the efficacy and translational potential of these gene therapeutic approaches.

  7. A conserved tripeptide in CNG and HCN channels regulates ligand gating by controlling C-terminal oligomerization.

    PubMed

    Zhou, Lei; Olivier, Nelson B; Yao, Huan; Young, Edgar C; Siegelbaum, Steven A

    2004-12-02

    Cyclic nucleotides directly enhance the opening of the tetrameric CNG and HCN channels, although the mechanism remains unclear. We examined why HCN and certain CNG subunits form functional homomeric channels, whereas other CNG subunits only function in heteromeric channels. The "defect" in the CNGA4 subunit that prevents its homomeric expression was localized to its C-linker, which connects the transmembrane domain to the binding domain and contains a tripeptide that decreases the efficacy of ligand gating. Remarkably, replacement of the homologous HCN tripeptide with the CNGA4 sequence transformed cAMP into an inverse agonist that inhibits HCN channel opening. Using analytical ultracentrifugation, we identified the structural basis for this gating switch: whereas cAMP normally enhances the assembly of HCN C-terminal domains into a tetrameric gating ring, inclusion of the CNGA4 tripeptide reversed this action so that cAMP now causes gating ring disassembly. Thus, ligand gating depends on the dynamic oligomerization of C-terminal binding domains.

  8. Olfactory CNG channel desensitization by Ca2+/CaM via the B1b subunit affects response termination but not sensitivity to recurring stimulation.

    PubMed

    Song, Yijun; Cygnar, Katherine D; Sagdullaev, Botir; Valley, Matthew; Hirsh, Sarah; Stephan, Aaron; Reisert, Johannes; Zhao, Haiqing

    2008-05-08

    Ca2+/calmodulin-mediated negative feedback is a prototypical regulatory mechanism for Ca2+-permeable ion channels. In olfactory sensory neurons (OSNs), such regulation on the cyclic nucleotide-gated (CNG) channel is considered a major mechanism of OSN adaptation. To determine the role of Ca2+/calmodulin desensitization of the olfactory CNG channel, we introduced a mutation in the channel subunit CNGB1b in mice that rendered the channel resistant to fast desensitization by Ca2+/calmodulin. Contrary to expectations, mutant OSNs showed normal receptor current adaptation to repeated stimulation. Rather, they displayed slower response termination and, consequently, reduced ability to transmit olfactory information to the olfactory bulb. They also displayed reduced response decline during sustained odorant exposure. These results suggest that Ca2+/calmodulin-mediated CNG channel fast desensitization is less important in regulating the sensitivity to recurring stimulation than previously thought and instead functions primarily to terminate OSN responses.

  9. Colorimetric determination of cyanide liberated from apricot kernels.

    PubMed

    Egli, K L

    1977-07-01

    A simple colorimetric method is described for determining the quantity of hydrogen cyanide produced by the spontaneous decomposition of amygdalin in apricot kernels. The evolved cyanide is collected in sodium hydroxide solution and assayed colorimetrically by reaction with picric acid. Results for duplicate assays, 3.02 and 3.06 mg CN-/g, compare well with those obtained by AOAC method 26.115 which specifies steam distillation and silver nitrate titration; results for triplicate assays were 3.02, 3.03, and 3.08 mg CN-/g by the latter. Recovery of cyanide from potassium cyanide at a level equivalent to 243 microgram CN-/g was 101.0%.

  10. Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.

    PubMed

    Luk, Jason M; Saville, Bradley A; MacLean, Heather L

    2015-04-21

    This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31 000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits.

  11. Ignition study of a petrol/CNG single cylinder engine

    NASA Astrophysics Data System (ADS)

    Khan, N.; Saleem, Z.; Mirza, A. A.

    2005-11-01

    Benefits of laser ignition over the electrical ignition system for Compressed Natural Gas (CNG) engines have fuelled automobile industry and led to an extensive research on basic characteristics to switch over to the emerging technologies. This study was undertaken to determine the electrical and physical characteristics of the electric spark ignition of single cylinder petrol/CNG engine to determine minimum ignition requirements and timeline of ignition events to use in subsequent laser ignition study. This communication briefly reviews the ongoing research activities and reports the results of this experimental study. The premixed petrol and CNG mixtures were tested for variation of current and voltage characteristics of the spark with speed of engine. The current magnitude of discharge circuit was found to vary linearly over a wide range of speed but the stroke to stroke fire time was found to vary nonlinearly. The DC voltage profiles were observed to fluctuate randomly during ignition process and staying constant in rest of the combustion cycle. Fire to fire peaks of current amplitudes fluctuated up to 10% of the peak values at constant speed but increased almost linearly with increase in speed. Technical barriers of laser ignition related to threshold minimum ignition energy, inter-pulse durations and firing sequence are discussed. Present findings provide a basic initiative and background information for designing suitable timeline algorithms for laser ignited leaner direct injected CNG engines.

  12. Alternative Fuels Data Center

    Science.gov Websites

    Light-Duty Alternative Fuel Vehicle Rebates The Texas Commission on Environmental Quality (TCEQ ) administers the Light-Duty Motor Vehicle Purchase or Lease Incentive Program for the purchase or lease of a new light-duty vehicle powered by compressed natural gas (CNG), propane, hydrogen, or electricity. CNG

  13. Alternative Fuels Data Center

    Science.gov Websites

    Vehicles Safety Regulations Vehicles converted to operate on compressed natural gas (CNG Motor Vehicle Safety Standards (FMVSS). The inspection must occur at the time of the conversion; every manufactured to use CNG or LNG must also be inspected for safety following any collision in which a vehicle was

  14. Case Study: Natural Gas Regional Transport Trucks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Laughlin, M.; Burnham, A.

    2016-08-01

    Learn about Ryder System, Inc.'s experience in deploying nearly 200 CNG and LNG heavy-duty trucks and construction and operation of L/CNG stations using ARRA funds. Using natural gas in its fleet, Ryder mitigated the effects of volatile fuel pricing and reduced lifecycle GHGs by 20% and petroleum by 99%.

  15. Application of Electromagnetic Induction Technique to Measure the Void Fraction in Oil/Gas Two Phase Flow

    NASA Astrophysics Data System (ADS)

    Wahhab, H. A. Abdul; Aziz, A. R. A.; Al-Kayiem, H. H.; Nasif, M. S.; Reda, M. N.

    2018-03-01

    In this work, electromagnetic induction technique of measuring void fraction in liquid/gas fuel flow was utilized. In order to improve the electric properties of liquid fuel, an iron oxide Fe3O4 nanoparticles at 3% was blended to enhance the liquid fuel magnetization. Experiments have been conducted for a wide range of liquid and gas superficial velocities. From the experimental results, it was realized that there is an existing linear relationship between the void fraction and the measured electromotive force, when induction coils were connected in series for excitation coils, regardless of increase or decrease CNG bubbles distribution in liquid fuel flow. Therefore, it was revealed that the utilized method yielded quite reasonable account for measuring the void fraction, showing good agreement with the other available measurement techniques in the two-phase flow, and also with the published literature of the bubbly flow pattern. From the results of the present investigation, it has been proven that the electromagnetic induction is a feasible technique for the actual measurement of void fraction in a Diesel/CNG fuel flow.

  16. Alternative Fuels Data Center: Choice Environmental Services Chooses

    Science.gov Websites

    been a hit with both drivers and maintenance staff. Drivers appreciate the reduction in diesel emissions while running their routes. Lower maintenance costs has also been an extremely pleasant surprise with the CNG trucks and found there is significantly less maintenance required on CNG trucks than on

  17. ASE Program Certification Standards for Light/Medium Duty CNG/LPG Training Programs.

    ERIC Educational Resources Information Center

    National Automotive Technicians Education Foundation, Herndon, VA.

    This publication provides the evaluation policies, procedures, and standards to which a compressed natural gas (CNG) and liquefied petroleum gas (LPG) technician training program must adhere to be granted certification by the National Institute for Automotive Service Excellence. The policies section has three parts: the automobile areas that may…

  18. 46 CFR 121.240 - Gas systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... section 1.12 are allowed for CNG: (1) The storage locker or housing access opening need not be in the top; and (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed. (1) The storage locker or housing for CNG tank installations need not be above the...

  19. 46 CFR 121.240 - Gas systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... section 1.12 are allowed for CNG: (1) The storage locker or housing access opening need not be in the top; and (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed. (1) The storage locker or housing for CNG tank installations need not be above the...

  20. 46 CFR 121.240 - Gas systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... section 1.12 are allowed for CNG: (1) The storage locker or housing access opening need not be in the top; and (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed. (1) The storage locker or housing for CNG tank installations need not be above the...

  1. 46 CFR 121.240 - Gas systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... section 1.12 are allowed for CNG: (1) The storage locker or housing access opening need not be in the top; and (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed. (1) The storage locker or housing for CNG tank installations need not be above the...

  2. 46 CFR 184.240 - Gas systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... are allowed for CNG: (1) The storage locker or housing access opening need not be in the top. (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed: (1) The storage locker or housing for CNG tank installations need not be above the waterline as...

  3. 46 CFR 184.240 - Gas systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... are allowed for CNG: (1) The storage locker or housing access opening need not be in the top. (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed: (1) The storage locker or housing for CNG tank installations need not be above the waterline as...

  4. 46 CFR 184.240 - Gas systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... are allowed for CNG: (1) The storage locker or housing access opening need not be in the top. (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed: (1) The storage locker or housing for CNG tank installations need not be above the waterline as...

  5. 46 CFR 121.240 - Gas systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... section 1.12 are allowed for CNG: (1) The storage locker or housing access opening need not be in the top; and (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed. (1) The storage locker or housing for CNG tank installations need not be above the...

  6. 46 CFR 184.240 - Gas systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... are allowed for CNG: (1) The storage locker or housing access opening need not be in the top. (2) The locker or housing need not be above the waterline. (h) The following variances from NFPA 302 are allowed: (1) The storage locker or housing for CNG tank installations need not be above the waterline as...

  7. 49 CFR 571.303 - Standard No. 303; Fuel system integrity of compressed natural gas vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... compressed natural gas vehicles. 571.303 Section 571.303 Transportation Other Regulations Relating to... system integrity of compressed natural gas vehicles. S1. Scope. This standard specifies requirements for the integrity of motor vehicle fuel systems using compressed natural gas (CNG), including the CNG fuel...

  8. Analysis of policies aimed at increasing use of natural gas in the transportation system : final report.

    DOT National Transportation Integrated Search

    2016-02-02

    In this paper we examine the implications of leveling the vehicle fuel choice playing field between : PHEV and CNG vehicles in the US. Currently, US policy provides a subsidy of $7,500 for most PHEV : vehicles but nothing for CNG vehicles. We use a m...

  9. Environmental implications of alternative-fueled automobiles: Air quality and greenhouse gas tradeoffs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    MaClean, H.L.; Lave, L.B.

    The authors analyze alternative fuel-powerstrain options for internal combustion engine automobiles. Fuel/engine efficiency, energy use, pollutant discharges, and greenhouse gas emissions are estimated for spark and compression ignited, direct injected (DI), and indirect injected (II) engines fueled by conventional and reformulated gasoline, reformulated diesel, compressed natural gas (CNG), and alcohols. Since comparisons of fuels and technologies in dissimilar vehicles are misleading, the authors hold emissions level, range, vehicle size class, and style constant. At present, CNG vehicles have the best exhaust emissions performance while DI diesels have the worst. Compared to a conventional gasoline fueled II automobile, greenhouse gases couldmore » be reduced by 40% by a DI CNG automobile and by 25% by a DI diesel. Gasoline- and diesel-fueled automobiles are able to attain long ranges with little weight or fuel economy penalty. CNG vehicles have the highest penalty for increasing range, due to their heavy fuel storage systems, but are the most attractive for a 160-km range. DI engines, particularly diesels, may not be able to meet strict emissions standards, at least not without lowering efficiency.« less

  10. Performance of CO2 enrich CNG in direct injection engine

    NASA Astrophysics Data System (ADS)

    Firmansyah, W. B.; Ayandotun, E. Z.; Zainal, A.; Aziz, A. R. A.; Heika, M. R.

    2015-12-01

    This paper investigates the potential of utilizing the undeveloped natural gas fields in Malaysia with high carbon dioxide (CO2) content ranging from 28% to 87%. For this experiment, various CO2 proportions by volume were added to pure natural gas as a way of simulating raw natural gas compositions in these fields. The experimental tests were carried out using a 4-stroke single cylinder spark ignition (SI) direct injection (DI) compressed natural gas (CNG) engine. The tests were carried out at 180° and 300° before top dead centre (BTDC) injection timing at 3000 rpm, to establish the effects on the engine performance. The results show that CO2 is suppressing the combustion of CNG while on the other hand CNG combustion is causing CO2 dissociation shown by decreasing CO2 emission with the increase in CO2 content. Results for 180° BTDC injection timing shows higher performance compared to 300° BTDC because of two possible reasons, higher volumetric efficiency and higher stratification level. The results also showed the possibility of increasing the CO2 content by injection strategy.

  11. Deciphering the function of the CNGB1b subunit in olfactory CNG channels.

    PubMed

    Nache, Vasilica; Wongsamitkul, Nisa; Kusch, Jana; Zimmer, Thomas; Schwede, Frank; Benndorf, Klaus

    2016-07-11

    Olfactory cyclic nucleotide-gated (CNG) ion channels are key players in the signal transduction cascade of olfactory sensory neurons. The second messengers cAMP and cGMP directly activate these channels, generating a depolarizing receptor potential. Olfactory CNG channels are composed of two CNGA2 subunits and two modulatory subunits, CNGA4, and CNGB1b. So far the exact role of the modulatory subunits for channel activation is not fully understood. By measuring ligand binding and channel activation simultaneously, we show that in functional heterotetrameric channels not only the CNGA2 subunits and the CNGA4 subunit but also the CNGB1b subunit binds cyclic nucleotides and, moreover, also alone translates this signal to open the pore. In addition, we show that the CNGB1b subunit is the most sensitive subunit in a heterotetrameric channel to cyclic nucleotides and that it accelerates deactivation to a similar extent as does the CNGA4 subunit. In conclusion, the CNGB1b subunit participates in ligand-gated activation of olfactory CNG channels and, particularly, contributes to rapid termination of odorant signal in an olfactory sensory neuron.

  12. Toxicity and mutagenicity of exhaust from compressed natural gas: Could this be a clean solution for megacities with mixed-traffic conditions?

    PubMed

    Agarwal, Avinash K; Ateeq, Bushra; Gupta, Tarun; Singh, Akhilendra P; Pandey, Swaroop K; Sharma, Nikhil; Agarwal, Rashmi A; Gupta, Neeraj K; Sharma, Hemant; Jain, Ayush; Shukla, Pravesh C

    2018-08-01

    Despite intensive research carried out on particulates, correlation between engine-out particulate emissions and adverse health effects is not well understood yet. Particulate emissions hold enormous significance for mega-cities like Delhi that have immense traffic diversity. Entire public transportation system involving taxis, three-wheelers, and buses has been switched from conventional liquid fuels to compressed natural gas (CNG) in the Mega-city of Delhi. In this study, the particulate characterization was carried out on variety of engines including three diesel engines complying with Euro-II, Euro-III and Euro-IV emission norms, one Euro-II gasoline engine and one Euro-IV CNG engine. Physical, chemical and biological characterizations of particulates were performed to assess the particulate toxicity. The mutagenic potential of particulate samples was investigated at different concentrations using two different Salmonella strains, TA98 and TA100 in presence and absence of liver S9 metabolic enzyme fraction. Particulates emitted from diesel and gasoline engines showed higher mutagenicity, while those from CNG engine showed negligible mutagenicity compared to other test fuels and engine configurations. Polycyclic aromatic hydrocarbons (PAHs) adsorbed onto CNG engine particulates were also relatively fewer compared to those from equivalent diesel and gasoline engines. Taken together, our findings indicate that CNG is comparatively safer fuel compared to diesel and gasoline and can offer a cleaner transport energy solution for mega-cities with mixed-traffic conditions, especially in developing countries. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Binding symmetry of extracellular divalent cations to conduction pore studied using tandem dimers of a CNG channel.

    PubMed

    Kwon, Ryuk-Jun; Ha, Tal Soo; Kim, Wonjae; Park, Chul-Seung

    2002-11-08

    Cyclic nucleotide-gated (CNG) channels are composed of the tetramer of alpha-subunit alone or alpha- and beta-subunits. The alpha-subunits of these channels have a conserved glutamate (Glu) residue within the pore-forming region and the residue determines the selectivity as well as the affinity for the extracellular divalent cations. Using the high-affinity mutant (E363D) of bovine retinal CNG channel in which the Glu at position 363 was replaced to Asp, we constructed tandem dimers and investigated the binding characteristics of divalent cations to the site. The gating and permeation characteristics of individual homomeric tandem dimers are indistinguishable to those of homo-tetramers formed by parental monomers. The heteromeric tandem dimers showed the binding affinity for Sr(2+) identical to the geometric mean of the affinities for two parent channels, indicating the energy additive and thus the simultaneous interaction. On the other hand, the binding affinity for Mg(2+) followed the harmonic mean of those parent channels indicating that Mg(2+) interacts more strongly with the subunit bearing Asp residue at the position. Thus the results strongly suggest that the Glu363 residues in the CNG channel pore be flexible enough to adapt different binding symmetries for different divalent cations. Moreover, the simultaneous interaction between the four Glu residues and Sr(2+) provides an important structural constraint to the CNG channel outer vestibule of unknown structure.

  14. New perspectives in cyclic nucleotide-mediated functions in the CNS: the emerging role of cyclic nucleotide-gated (CNG) channels.

    PubMed

    Podda, Maria Vittoria; Grassi, Claudio

    2014-07-01

    Cyclic nucleotides play fundamental roles in the central nervous system (CNS) under both physiological and pathological conditions. The impact of cAMP and cGMP signaling on neuronal and glial cell functions has been thoroughly characterized. Most of their effects have been related to cyclic nucleotide-dependent protein kinase activity. However, cyclic nucleotide-gated (CNG) channels, first described as key mediators of sensory transduction in retinal and olfactory receptors, have been receiving increasing attention as possible targets of cyclic nucleotides in the CNS. In the last 15 years, consistent evidence has emerged for their expression in neurons and astrocytes of the rodent brain. Far less is known, however, about the functional role of CNG channels in these cells, although several of their features, such as Ca(2+) permeability and prolonged activation in the presence of cyclic nucleotides, make them ideal candidates for mediators of physiological functions in the CNS. Here, we review literature suggesting the involvement of CNG channels in a number of CNS cellular functions (e.g., regulation of membrane potential, neuronal excitability, and neurotransmitter release) as well as in more complex phenomena, like brain plasticity, adult neurogenesis, and pain sensitivity. The emerging picture is that functional and dysfunctional cyclic nucleotide signaling in the CNS has to be reconsidered including CNG channels among possible targets. However, concerted efforts and multidisciplinary approaches are still needed to get more in-depth knowledge in this field.

  15. Pollution dilemma in Asian population: CNG and wound healing.

    PubMed

    Ejaz, Sohail; Chekarova, Irina; Ahmad, Mukhtar; Nasir, Amir; Ashraf, Muhammad; Lim, Chae Woong

    2009-11-01

    Automobile exhaust constituents contribute significantly to air pollution in urban areas and compressed natural gas (CNG) is considered one of the most promising fuel alternatives for the future. CNG-powered four-stroke engine auto-rickshaws are ubiquitous in South Asian cities as taxi and for commercial transportation. Automotive exhaust contains several toxins, which are overwhelmingly toxic to the processes of wound healing. By utilizing the in vivo mouse model of wound healing, this report analyzes the effects of CNG-powered four-stroke auto-rickshaws smoke solution (4SARSS) on different events of wound healing; dermal matrix regeneration, re-epithelialization and neovascularization. A total of 72 adult mice, divided in eight groups were exposed to 4SARSS for 12 days. A highly significant reduction (P<0.001) in wound closure was observed among all 4SARSS treated groups, at each time point of the experiment. An immature development in both the neoepidermis and the neodermis was observed among all 4SARSS treated wounds with defective re-epithelialization, dermal matrix regeneration and maturation of collagen bundles. Abbott curve, angular spectrum, 3D surface topographies, and histological investigations of wounds explicated highly significant activation (P<0.001) of delayed-neovascularization among 4SARSS treated wounds. All these annotations advocate excessive toxicity of emission from CNG-powered auto-rickshaws to the process of wound healing and people occupationally exposed to this toxic emissions may suffer varying degree of delayed wound healing. Crown Copyright © 2009. Published by Elsevier B.V. All rights reserved.

  16. Role of Cyclic Nucleotide-Gated Channels in the Modulation of Mouse Hippocampal Neurogenesis

    PubMed Central

    Podda, Maria Vittoria; Piacentini, Roberto; Barbati, Saviana Antonella; Mastrodonato, Alessia; Puzzo, Daniela; D’Ascenzo, Marcello; Leone, Lucia; Grassi, Claudio

    2013-01-01

    Neural stem cells generate neurons in the hippocampal dentate gyrus in mammals, including humans, throughout adulthood. Adult hippocampal neurogenesis has been the focus of many studies due to its relevance in processes such as learning and memory and its documented impairment in some neurodegenerative diseases. However, we are still far from having a complete picture of the mechanism regulating this process. Our study focused on the possible role of cyclic nucleotide-gated (CNG) channels. These voltage-independent channels activated by cyclic nucleotides, first described in retinal and olfactory receptors, have been receiving increasing attention for their involvement in several brain functions. Here we show that the rod-type, CNGA1, and olfactory-type, CNGA2, subunits are expressed in hippocampal neural stem cells in culture and in situ in the hippocampal neurogenic niche of adult mice. Pharmacological blockade of CNG channels did not affect cultured neural stem cell proliferation but reduced their differentiation towards the neuronal phenotype. The membrane permeant cGMP analogue, 8-Br-cGMP, enhanced neural stem cell differentiation to neurons and this effect was prevented by CNG channel blockade. In addition, patch-clamp recording from neuron-like differentiating neural stem cells revealed cGMP-activated currents attributable to ion flow through CNG channels. The current work provides novel insights into the role of CNG channels in promoting hippocampal neurogenesis, which may prove to be relevant for stem cell-based treatment of cognitive impairment and brain damage. PMID:23991183

  17. Genomic copy number gains of ErbB family members predict poor clinical outcomes in glioma patients

    PubMed Central

    Liu, Rui; Qu, Yiping; Chen, Lihong; Pu, Jun; Ma, Sharui; Zhang, Xiaozhi; Yang, Qi; Shi, Bingyin; Hou, Peng; Ji, Meiju

    2017-01-01

    The aim of this study was to investigate copy number of ErbB family members (including EGFR, HER2, HER3 and HER4) in a cohort of gliomas and benign meningiomas (control subjects), and explore the associations of their copy number with clinicopathological characteristics and clinical outcomes of glioma patients. Using real-time quantitative PCR assay, we demonstrated that copy number of EGFR, HER2, HER3 and HER4 in glioma patients was significantly increased compared to control subjects. Moreover, our data also showed that the risk of cancer-related death was positively associated with copy number gain (CNG) of EGFR, HER3 and HER4, but not HER2. CNG of EGFR and HER2 was positively related to radiotherapy, while CNG of HER3 and HER4 was negatively related to chemotherapy. Importantly, EGFR CNG significantly shortened median survival times of glioma patients regardless of gender, tumor grade and therapeutic regimens. Stratified analysis showed that CNG of HER2-4 almost did not influence the survival of male patients, patients with high-grade tumors and patients receiving chemotherapy, but dramatically shortened median survival times of female patients, those with low-grade tumors and those receiving radiotherapy. Collectively, our data not only demonstrate that the members of ErbB family are frequently amplified in gliomas, but also suggest that these common genetic events may be prognostic factors for poor clinical outcomes in glioma patients. PMID:29190914

  18. Defining Specificity Determinants of cGMP Mediated Gustatory Sensory Transduction in Caenorhabditis elegans

    PubMed Central

    Smith, Heidi K.; Luo, Linjiao; O’Halloran, Damien; Guo, Dagang; Huang, Xin-Yun; Samuel, Aravinthan D. T.; Hobert, Oliver

    2013-01-01

    Cyclic guanosine monophosphate (cGMP) is a key secondary messenger used in signal transduction in various types of sensory neurons. The importance of cGMP in the ASE gustatory receptor neurons of the nematode Caenorhabditis elegans was deduced by the observation that multiple receptor-type guanylyl cyclases (rGCs), encoded by the gcy genes, and two presently known cyclic nucleotide-gated ion channel subunits, encoded by the tax-2 and tax-4 genes, are essential for ASE-mediated gustatory behavior. We describe here specific mechanistic features of cGMP-mediated signal transduction in the ASE neurons. First, we assess the specificity of the sensory functions of individual rGC proteins. We have previously shown that multiple rGC proteins are expressed in a left/right asymmetric manner in the functionally lateralized ASE neurons and are required to sense distinct salt cues. Through domain swap experiments among three different rGC proteins, we show here that the specificity of individual rGC proteins lies in their extracellular domains and not in their intracellular, signal-transducing domains. Furthermore, we find that rGC proteins are also sufficient to confer salt sensory responses to other neurons. Both findings support the hypothesis that rGC proteins are salt receptor proteins. Second, we identify a novel, likely downstream effector of the rGC proteins in gustatory signal transduction, a previously uncharacterized cyclic nucleotide-gated (CNG) ion channel, encoded by the che-6 locus. che-6 mutants show defects in gustatory sensory transduction that are similar to defects observed in animals lacking the tax-2 and tax-4 CNG channels. In contrast, thermosensory signal transduction, which also requires tax-2 and tax-4, does not require che-6, but requires another CNG, cng-3. We propose that CHE-6 may form together with two other CNG subunits, TAX-2 and TAX-4, a gustatory neuron-specific heteromeric CNG channel complex. PMID:23695300

  19. Exposure assessment of particulates of diesel and natural gas fuelled buses in silico.

    PubMed

    Pietikäinen, Mari; Oravisjärvi, Kati; Rautio, Arja; Voutilainen, Arto; Ruuskanen, Juhani; Keiski, Riitta L

    2009-12-15

    Lung deposition estimates of particulate emissions of diesel and natural gas (CNG) fuelled vehicles were studied by using in silico methodology. Particulate emissions and particulate number size distributions of two Euro 2 petroleum based diesel buses and one Euro 3 gas bus were measured. One of the petroleum based diesel buses used in the study was equipped with an oxidation catalyst on the vehicle (DI-OC) while the second had a partial-DPF catalyst (DI-pDPF). The third bus used was the gas bus with an oxidation catalyst on the vehicle (CNG-OC). The measurements were done using a transient chassis dynamometer test cycle (Braunschweig cycle) and an Electric Low Pressure Impactor (ELPI) with formed particulates in the size range of 7 nm to 10 microm. The total amounts of the emitted diesel particulates were 88-fold for DI-OC and 57-fold for DI-pDPF compared to the total amount of emitted CNG particulates. Estimates for the deposited particulates were computed with a lung deposition model ICRP 66 using in-house MATLAB scripts. The results were given as particulate numbers and percentages deposited in five different regions of the respiratory system. The percentages of particulates deposited in the respiratory system were 56% for DI-OC, 51% for DI-pDPF and 77% for CNG-OC of all the inhaled particulates. The result shows that under similar conditions the total lung dose of particulates originating from petroleum diesel fuelled engines DI-OC and DI-pDPF was more than 60-fold and 35-fold, respectively, compared to the lung dose of particulates originating from the CNG fuelled engine. The results also indicate that a majority (35-50%) of the inhaled particulates emitted from the tested petroleum diesel and CNG engines penetrate deep into the unciliated regions of the lung where gas-exchange occurs.

  20. Particle and gaseous emissions from individual diesel and CNG buses

    NASA Astrophysics Data System (ADS)

    Hallquist, Å. M.; Jerksjö, M.; Fallgren, H.; Westerlund, J.; Sjödin, Å.

    2012-10-01

    In this study size-resolved particle and gaseous emissions from 28 individual diesel-fuelled and 7 compressed natural gas (CNG)-fuelled buses, selected from an in-use bus fleet, were characterised for real-world dilution scenarios. The method used was based on using CO2 as a tracer of exhaust gas dilution. The particles were sampled by using an extractive sampling method and analysed with high time resolution instrumentation EEPS (10 Hz) and CO2 with non-dispersive infrared gas analyser (LI-840, LI-COR Inc. 1 Hz). The gaseous constituents (CO, HC and NO) were measured by using a remote sensing device (AccuScan RSD 3000, Environmental System Products Inc.). Nitrogen oxides, NOx, were estimated from NO by using default NO2/NOx ratios from the road vehicle emission model HBEFA 3.1. The buses studied were diesel-fuelled Euro II-V and CNG-fuelled Enhanced Environmental Friendly Vehicles (EEVs) with different after-treatment, including selective catalytic reduction (SCR), exhaust gas recirculation (EGR) and with and without diesel particulate filter (DPF). The primary driving mode applied in this study was accelerating mode. However, regarding the particle emissions also a constant speed mode was analysed. The investigated CNG buses emitted on average higher number of particles but less mass compared to the diesel-fuelled buses. Emission factors for number of particles (EFPN) were EFPN, DPF = 8.0 ± 3.1 × 1014, EFPN, no DPF =2.8 ± 1.6 × 1015 and EFPN, CNG = 7.8 ± 5.7 × 1015 (kg fuel-1). In the accelerating mode size-resolved EFs showed unimodal number size distributions with peak diameters of 70-90 nm and 10 nm for diesel and CNG buses, respectively. For the constant speed mode bimodal average number size distributions were obtained for the diesel buses with peak modes of ~10 nm and ~60 nm. Emission factors for NOx expressed as NO2 equivalents for the diesel buses were on average 27 ± 7 g (kg fuel)-1 and for the CNG buses 41 ± 26 g (kg fuel)-1. An anti-relationship between EFNOx and EFPM was observed especially for buses with no DPF and there was a positive relationship between EFPM and EFCO.

  1. Particle and gaseous emissions from individual diesel and CNG buses

    NASA Astrophysics Data System (ADS)

    Hallquist, Å. M.; Jerksjö, M.; Fallgren, H.; Westerlund, J.; Sjödin, Å.

    2013-05-01

    In this study size-resolved particle and gaseous emissions from 28 individual diesel-fuelled and 7 compressed natural gas (CNG)-fuelled buses, selected from an in-use bus fleet, were characterised for real-world dilution scenarios. The method used was based on using CO2 as a tracer of exhaust gas dilution. The particles were sampled by using an extractive sampling method and analysed with high time resolution instrumentation EEPS (10 Hz) and CO2 with a non-dispersive infrared gas analyser (LI-840, LI-COR Inc. 1 Hz). The gaseous constituents (CO, HC and NO) were measured by using a remote sensing device (AccuScan RSD 3000, Environmental System Products Inc.). Nitrogen oxides, NOx, were estimated from NO by using default NO2/NOx ratios from the road vehicle emission model HBEFA3.1. The buses studied were diesel-fuelled Euro III-V and CNG-fuelled Enhanced Environmentally Friendly Vehicles (EEVs) with different after-treatment, including selective catalytic reduction (SCR), exhaust gas recirculation (EGR) and with and without diesel particulate filter (DPF). The primary driving mode applied in this study was accelerating mode. However, regarding the particle emissions also a constant speed mode was analysed. The investigated CNG buses emitted on average a higher number of particles but less mass compared to the diesel-fuelled buses. Emission factors for number of particles (EFPN) were EFPN, DPF = 4.4 ± 3.5 × 1014, EFPN, no DPF = 2.1 ± 1.0 × 1015 and EFPN, CNG = 7.8 ± 5.7 ×1015 kg fuel-1. In the accelerating mode, size-resolved emission factors (EFs) showed unimodal number size distributions with peak diameters of 70-90 nm and 10 nm for diesel and CNG buses, respectively. For the constant speed mode, bimodal average number size distributions were obtained for the diesel buses with peak modes of ~10 nm and ~60 nm. Emission factors for NOx expressed as NO2 equivalents for the diesel buses were on average 27 ± 7 g (kg fuel)-1 and for the CNG buses 41 ± 26 g (kg fuel)-1. An anti-relationship between EFNOx and EFPM was observed especially for buses with no DPF, and there was a positive relationship between EFPM and EFCO.

  2. Compressed Natural Gas Installation. A Video-Based Training Program for Vehicle Conversion. Instructor's Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This instructor's guide contains the materials required to teach four competency-based course units of instruction in installing compressed natural gas (CNG) systems in motor vehicles. It is designed to accompany an instructional videotape (not included) on CNG installation. The following competencies are covered in the four instructional units:…

  3. Alternative Fuels Data Center: Freedom CNG Reduces Emissions with Natural

    Science.gov Websites

    Gas in TexasA> Freedom CNG Reduces Emissions with Natural Gas in Texas to someone by E-mail Share . For information about this project, contact Houston-Galveston Clean Cities. Download QuickTime Video Magazine Provided by Maryland Public Television Related Videos Photo of a car Electric Vehicles Charge up

  4. Alternative Fuels Data Center: CNG Fleets Aid in Superstorm Recovery

    Science.gov Websites

    AddThis.com... May 24, 2013 CNG Fleets Aid in Superstorm Recovery " They were working around the clock aftermath, helping with recovery efforts. "They were working around the clock," said Rita Ebert accelerating. As part of GLICCC's efforts to build on the momentum, the coalition is now working with the New

  5. DEFECTIVE TRAFFICKING OF CONE PHOTORECEPTOR CNG CHANNELS INDUCES THE UNFOLDED PROTEIN RESPONSE AND ER STRESS-ASSOCIATED CELL DEATH

    PubMed Central

    Duricka, Deborah L.; Brown, R. Lane; Varnum, Michael D.

    2011-01-01

    SYNOPSIS Mutations that perturb the function of photoreceptor cyclic nucleotide-gated (CNG) channels are associated with several human retinal disorders, but the molecular and cellular mechanisms leading to photoreceptor dysfunction and degeneration remain unclear. Many loss-of-function mutations result in intracellular accumulation of CNG channel subunits. Accumulation of proteins in the endoplasmic reticulum (ER) is known to cause ER stress and trigger the unfolded protein response (UPR), an evolutionarily conserved cellular program that results in either adaptation via increased protein processing capacity or apoptotic cell death. We hypothesize that defective trafficking of cone photoreceptor CNG channels can induce UPR-mediated cell death. To test this idea, CNGA3 subunits bearing the R563H and Q655X mutations were expressed in photoreceptor-derived 661W cells with CNGB3 subunits. Compared to wild type, R563H and Q655X subunits displayed altered degradation rates and/or were retained in the ER. ER retention was associated with increased expression of UPR-related markers of ER stress and with decreased cell viability. Chemical and pharmacological chaperones (TUDCA, 4PBA, and the cGMP analog CPT-cGMP) differentially reduced degradation and/or promoted plasma-membrane localization of defective subunits. Improved subunit maturation was concordant with reduced expression of ER stress markers and improved viability of cells expressing localization-defective channels. These results indicate that ER stress can arise from expression of localization defective CNG channels, and may represent a contributing factor for photoreceptor degeneration. PMID:21992067

  6. Defective trafficking of cone photoreceptor CNG channels induces the unfolded protein response and ER-stress-associated cell death.

    PubMed

    Duricka, Deborah L; Brown, R Lane; Varnum, Michael D

    2012-01-15

    Mutations that perturb the function of photoreceptor CNG (cyclic nucleotide-gated) channels are associated with several human retinal disorders, but the molecular and cellular mechanisms leading to photoreceptor dysfunction and degeneration remain unclear. Many loss-of-function mutations result in intracellular accumulation of CNG channel subunits. Accumulation of proteins in the ER (endoplasmic reticulum) is known to cause ER stress and trigger the UPR (unfolded protein response), an evolutionarily conserved cellular programme that results in either adaptation via increased protein processing capacity or apoptotic cell death. We hypothesize that defective trafficking of cone photoreceptor CNG channels can induce UPR-mediated cell death. To test this idea, CNGA3 subunits bearing the R563H and Q655X mutations were expressed in photoreceptor-derived 661W cells with CNGB3 subunits. Compared with wild-type, R563H and Q655X subunits displayed altered degradation rates and/or were retained in the ER. ER retention was associated with increased expression of UPR-related markers of ER stress and with decreased cell viability. Chemical and pharmacological chaperones {TUDCA (tauroursodeoxycholate sodium salt), 4-PBA (sodium 4-phenylbutyrate) and the cGMP analogue CPT-cGMP [8-(4-chlorophenylthio)-cGMP]} differentially reduced degradation and/or promoted plasma-membrane localization of defective subunits. Improved subunit maturation was concordant with reduced expression of ER-stress markers and improved viability of cells expressing localization-defective channels. These results indicate that ER stress can arise from expression of localization-defective CNG channels, and may represent a contributing factor for photoreceptor degeneration.

  7. The cyclic nucleotide gated channel subunit CNG-1 instructs behavioral outputs in Caenorhabditis elegans by coincidence detection of nutritional status and olfactory input.

    PubMed

    He, Chao; Altshuler-Keylin, Svetlana; Daniel, David; L'Etoile, Noelle D; O'Halloran, Damien

    2016-10-06

    In mammals, olfactory subsystems have been shown to express seven-transmembrane G-protein-coupled receptors (GPCRs) in a one-receptor-one-neuron pattern, whereas in Caenorhabditis elegans, olfactory sensory neurons express multiple G-protein coupled odorant receptors per olfactory sensory neuron. In both mammalian and C. elegans olfactory sensory neurons (OSNs), the process of olfactory adaptation begins within the OSN; this process of negative feedback within the mammalian OSN has been well described in mammals and enables activated OSNs to desensitize their response cell autonomously while attending to odors detected by separate OSNs. However, the mechanism that enables C. elegans to adapt to one odor and attend to another odor sensed by the same olfactory sensory neuron remains unclear. We found that the cyclic nucleotide gated channel subunit CNG-1 is required to promote cross adaptation responses between distinct olfactory cues. This change in sensitivity to a pair of odorants after persistent stimulation by just one of these odors is modulated by the internal nutritional state of the animal, and we find that this response is maintained across a diverse range of food sources for C. elegans. We also reveal that CNG-1 integrates food related cues for exploratory motor output, revealing that CNG-1 functions in multiple capacities to link nutritional information with behavioral output. Our data describes a novel model whereby CNG channels can integrate the coincidence detection of appetitive and olfactory information to set olfactory preferences and instruct behavioral outputs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Alternative Fuels Data Center: Kentucky Trucking Company Adds CNG Vehicles

    Science.gov Websites

    run on compressed natural gas (CNG) in Lousiville, Kentucky. Download QuickTime Video QuickTime (.mov California Nov. 18, 2017 Photo of a car Smart Car Shopping Nov. 4, 2017 Photo of a truck Natural Gas Vehicles truck Idaho Transports Mail and Reduces Emissions with Natural Gas Trucks June 23, 2017 Photo of a

  9. Alternative Fuels Data Center: Happy Cab Fuels Taxi Fleet With CNG

    Science.gov Websites

    Happy Cab Fuels Taxi Fleet With CNG Find out how a cab company in Omaha, Nebraska, saves money fueling Go Electric in Florida Feb. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels

  10. Alternative Fuels Data Center: CNG Refuse Haulers Do Heavy Lifting in New

    Science.gov Websites

    YorkA> CNG Refuse Haulers Do Heavy Lifting in New York to someone by E-mail Share Alternative combat the rising cost of fuel. For information about this project, contact Greater Long Island Clean Maryland Public Television Related Videos Photo of a car Hydrogen Powers Fuel Cell Vehicles in California

  11. Evaluation of emission toxicity of urban bus engines: compressed natural gas and comparison with liquid fuels.

    PubMed

    Turrio-Baldassarri, Luigi; Battistelli, Chiara Laura; Conti, Luigi; Crebelli, Riccardo; De Berardis, Barbara; Iamiceli, Anna Laura; Gambino, Michele; Iannaccone, Sabato

    2006-02-15

    Emissions from a spark-ignition (SI) heavy-duty (HD) urban bus engine with a three-way catalyst (TWC), fuelled with compressed natural gas (CNG), were chemically analyzed and tested for genotoxicity. The results were compared with those obtained in a previous study on an equivalent diesel engine, fuelled with diesel oil (D) and a blend of the same with 20% vegetable oil (B20). Experimental procedures were identical, so that emission levels of the CNG engine were exactly comparable to the ones of the diesel engine. The experimental design was focused on carcinogenic compounds and genotoxic activity of exhausts. The results obtained show that the SI CNG engine emissions, with respect to the diesel engine fuelled with D, were nearly 50 times lower for carcinogenic polycyclic aromatic hydrocarbons (PAHs), 20 times lower for formaldehyde, and more than 30 times lower for particulate matter (PM). A 20-30 fold reduction of genotoxic activity was estimated from tests performed. A very high reduction of nitrogen oxides (NO(X)) was also measured. The impact of diesel powered transport on urban air quality, and the potential benefits deriving from the use of CNG for public transport, are discussed.

  12. Pravastatin chitosan nanogels-loaded erythrocytes as a new delivery strategy for targeting liver cancer

    PubMed Central

    Harisa, Gamaleldin I.; Badran, Mohamed M.; AlQahtani, Saeed A.; Alanazi, Fars K.; Attia, Sabry M.

    2015-01-01

    Chitosan nanogels (CNG) are developed as one of the most promising carriers for cancer targeting. However, these carriers are rapidly eliminated from circulation by reticuloendothelial system (RES), which limits their application. Therefore, erythrocytes (ER) loaded CNG as multifunctional carrier may overcome the massive elimination of nanocarriers by RES. In this study, erythrocytes loaded pravastatin–chitosan nanogels (PR–CNG–ER) were utilized as a novel drug carrier to target liver cancer. Thus, PR–CNG formula was developed in nanosize, with good entrapment efficiency, drug loading and sustained release over 48 h. Then, PR–CNG loaded into ER were prepared by hypotonic preswelling technique. The resulting PR–CNG–ER showed 36.85% of entrapment efficiency, 66.82% of cell recovery and release consistent to that of hemoglobin over 48 h. Moreover, PR–CNG–ER exhibited negative zeta potential, increasing of hemolysis percent, marked phosphatidylserine exposure and stomatocytes shape compared to control unloaded erythrocytes. PR–CNG–ER reduced cells viability of HepG2 cells line by 28% compared to unloaded erythrocytes (UER). These results concluded that PR–CNG–ER are promising drug carriers to target liver cancer. PMID:26903771

  13. PACS-1 mediates phosphorylation-dependent ciliary trafficking of the cyclic-nucleotide-gated channel in olfactory sensory neurons.

    PubMed

    Jenkins, Paul M; Zhang, Lian; Thomas, Gary; Martens, Jeffrey R

    2009-08-26

    Impaired ciliary protein transport in olfactory sensory neurons (OSNs) leads to anosmia, and is a newly recognized clinical manifestation of a class of human disorders called ciliopathies. Surprisingly little is known regarding the mechanisms controlling trafficking to this unique neuronal compartment. Here, we show a novel role for phosphofurin acidic cluster-sorting protein 1 (PACS-1) in the ciliary trafficking of the olfactory cyclic-nucleotide-gated (CNG) channel. PACS-1 is an intracellular sorting protein that mediates its effects through the binding of acidic clusters on cargo protein. This interaction is dependent on CK2 phosphorylation of both PACS-1 and its cargo. We show that CNGB1b contains two putative PACS-1 binding sites, which are phosphorylated by the serine/threonine protein kinase, CK2. Additionally, we show that PACS-1 is expressed in OSNs and interacts in complex with the CNG channel. CK2 inhibition in native OSNs causes a loss of CNG channel from cilia and subsequent olfactory dysfunction, while adenoviral expression of mutant PACS-1 causes similar mislocalization. These results provide a mechanism for the subunit-dependent ciliary trafficking of the CNG channel and offer insight into the mechanisms of ciliary transport.

  14. A Basic Behavior of CNG DI Combustion in a Spark-Ignited Rapid Compression Machine

    NASA Astrophysics Data System (ADS)

    Huang, Zuohua; Shiga, Seiichi; Ueda, Takamasa; Jingu, Nobuhisa; Nakamura, Hisao; Ishima, Tsuneaki; Obokata, Tomio; Tsue, Mitsuhiro; Kono, Michikata

    A basic characteristics of compressed natural gas direct-injection (CNG DI) combustion was studied by using a rapid compression machine. Results show that comparing with homogeneous mixture, CNG DI has short combustion duration, high pressure rise due to combustion, and high rate of heat release, which are considered to come from the charge stratification and the gas flow generated by the fuel injection. CNG DI can realize extremely lean combustion which reaches 0.03 equivalence ratio, φ. Combustion duration, maximum pressure rise due to combustion and combustion efficiency are found to be insensitive to the injection modes. Unburned methane showed almost the same level as that of homogeneous mixture combustion. CO increased steeply with the increase in φ when φ was greater than 0.8 due to the excessive stratification, and NOx peak value shifted to the region of lower φ. Combustion inefficiency maintains less than 0.08 in the range of φ from 0.1 to 0.9 and increases at very low φ due to bulk quenching and at higher φ due to excessive stratification. The combustion efficiency estimated from combustion products shows good agreement with that of heat release analysis.

  15. Technical, economic, and environmental impact study of converting Uzbekistan transportation fleets to natural gas operation. Export trade information

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1997-04-30

    This study, conducted by Radian International, was funded by the U.S. Trade and Development Agency. The report assesses the feasibility (technical, economic and environmental) of converting the Uzbek transportation fleets to natural gas operation. The study focuses on the conversion of high fuel use vehicles and locomotives to liquefied natural gas (LNG) and the conversion of moderate fuel use veicles to compressed natural gas (CNG). The report is divided into the following sections: Executive Summary; (1.0) Introduction; (2.0) Country Background; (3.0) Characterization of Uzbek Transportation Fuels; (4.0) Uzbek Vehicle and Locomotive Fleet Characterization; (5.0) Uzbek Natural Gas Vehicle Conversion Shops;more » (6.0) Uzbek Natural Gas Infrastructure; (7.0) Liquefied Natural Gas (LNG) for Vehicular Fuel in Uzbekistan; (8.0) Economic Feasibility Study; (9.0) Environmental Impact Analysis; References; Appendices A - S.« less

  16. Feasibility study of Northeast Thailand Gas Pipeline Project. Final report. Part 2. Compressed natural gas. Export trade information

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    The volume is the second part of a three part study submitted to the Petroleum Authority of Thailand. Part II analyzes the potential use of compressed natural gas (CNG) as a transportation fuel for high mileage vehicles traveling the highway system of Thailand. The study provides an initial estimate of buses and trucks that are potential candidates for converting to natural gas vehicles (NGV). CNG technology is briefly reviewed. The types of refueling stations that may be sited along the highway are discussed. The estimated capital investments and typical layouts are presented. The report also discusses the issues involved inmore » implementing a CNG program in Thailand, such as safety, user acceptability and the government's role.« less

  17. Performance, Efficiency, and Emissions Characterization of Reciprocating Internal Combustion Engines Fueled with Hydrogen/Natural Gas Blends

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kirby S. Chapman; Amar Patil

    2007-06-30

    Hydrogen is an attractive fuel source not only because it is abundant and renewable but also because it produces almost zero regulated emissions. Internal combustion engines fueled by compressed natural gas (CNG) are operated throughout a variety of industries in a number of mobile and stationary applications. While CNG engines offer many advantages over conventional gasoline and diesel combustion engines, CNG engine performance can be substantially improved in the lean operating region. Lean operation has a number of benefits, the most notable of which is reduced emissions. However, the extremely low flame propagation velocities of CNG greatly restrict the leanmore » operating limits of CNG engines. Hydrogen, however, has a high flame speed and a wide operating limit that extends into the lean region. The addition of hydrogen to a CNG engine makes it a viable and economical method to significantly extend the lean operating limit and thereby improve performance and reduce emissions. Drawbacks of hydrogen as a fuel source, however, include lower power density due to a lower heating value per unit volume as compared to CNG, and susceptibility to pre-ignition and engine knock due to wide flammability limits and low minimum ignition energy. Combining hydrogen with CNG, however, overcomes the drawbacks inherent in each fuel type. Objectives of the current study were to evaluate the feasibility of using blends of hydrogen and natural gas as a fuel for conventional natural gas engines. The experiment and data analysis included evaluation of engine performance, efficiency, and emissions along with detailed in-cylinder measurements of key physical parameters. This provided a detailed knowledge base of the impact of using hydrogen/natural gas blends. A four-stroke, 4.2 L, V-6 naturally aspirated natural gas engine coupled to an eddy current dynamometer was used to measure the impact of hydrogen/natural gas blends on performance, thermodynamic efficiency and exhaust gas emissions in a reciprocating four stroke cycle engine. The test matrix varied engine load and air-to-fuel ratio at throttle openings of 50% and 100% at equivalence ratios of 1.00 and 0.90 for hydrogen percentages of 10%, 20% and 30% by volume. In addition, tests were performed at 100% throttle opening, with an equivalence ratio of 0.98 and a hydrogen blend of 20% to further investigate CO emission variations. Data analysis indicated that the use of hydrogen/natural gas fuel blend penalizes the engine operation with a 1.5 to 2.0% decrease in torque, but provided up to a 36% reduction in CO, a 30% reduction in NOX, and a 5% increase in brake thermal efficiency. These results concur with previous results published in the open literature. Further reduction in emissions can be obtained by retarding the ignition timing.« less

  18. Solid Particle Number Emission Factors of Euro VI Heavy-Duty Vehicles on the Road and in the Laboratory

    PubMed Central

    Giechaskiel, Barouch

    2018-01-01

    Particulate matter (PM), and in particular ultrafine particles, have a negative impact on human health. The contribution of vehicle PM emissions to air pollution is typically quantified with emission inventories, which need vehicle emission factors as input. Heavy-duty vehicles, although they represent a small percentage of the vehicle population in nearly every major country, contribute the majority of the on-road PM emissions. However, the published data of modern heavy-duty vehicle emissions are scarce, and for the newest Euro VI technologies, almost non-existent. The main objective of this paper is to present Solid Particle Number (SPN) emission factors from Euro VI heavy-duty vehicles using diesel, Compressed Natural Gas (CNG), or Liquefied Natural Gas (LNG). Urban, rural and motorway (highway) emissions were determined on the road at various European cities using SPN Portable Emission Measurement Systems (PEMS). Additional tests on a heavy-duty chassis dynamometer showed that the solid sub-23 nm fraction, which is not covered at the moment in the European regulation, is high, especially for CNG engines. The significant contribution of regeneration events and the effect of ambient temperature and engine cold-start on particle emissions were also discussed. PMID:29425174

  19. Solid Particle Number Emission Factors of Euro VI Heavy-Duty Vehicles on the Road and in the Laboratory.

    PubMed

    Giechaskiel, Barouch

    2018-02-09

    Particulate matter (PM), and in particular ultrafine particles, have a negative impact on human health. The contribution of vehicle PM emissions to air pollution is typically quantified with emission inventories, which need vehicle emission factors as input. Heavy-duty vehicles, although they represent a small percentage of the vehicle population in nearly every major country, contribute the majority of the on-road PM emissions. However, the published data of modern heavy-duty vehicle emissions are scarce, and for the newest Euro VI technologies, almost non-existent. The main objective of this paper is to present Solid Particle Number (SPN) emission factors from Euro VI heavy-duty vehicles using diesel, Compressed Natural Gas (CNG), or Liquefied Natural Gas (LNG). Urban, rural and motorway (highway) emissions were determined on the road at various European cities using SPN Portable Emission Measurement Systems (PEMS). Additional tests on a heavy-duty chassis dynamometer showed that the solid sub-23 nm fraction, which is not covered at the moment in the European regulation, is high, especially for CNG engines. The significant contribution of regeneration events and the effect of ambient temperature and engine cold-start on particle emissions were also discussed.

  20. Turbulent piloted partially-premixed flames with varying levels of O2/N2: stability limits and PDF calculations

    NASA Astrophysics Data System (ADS)

    Juddoo, Mrinal; Masri, Assaad R.; Pope, Stephen B.

    2011-12-01

    This paper reports measured stability limits and PDF calculations of piloted, turbulent flames of compressed natural gas (CNG) partially-premixed with either pure oxygen, or with varying levels of O2/N2. Stability limits are presented for flames of CNG fuel premixed with up to 20% oxygen as well as CNG-O2-N2 fuel where the O2 content is varied from 8 to 22% by volume. Calculations are presented for (i) Sydney flame B [Masri et al. 1988] which uses pure CNG as well as flames B15 to B25 where the CNG is partially-premixed with 15-25% oxygen by volume, respectively and (ii) Sandia methane-air (1:3 by volume) flame E [Barlow et al. 2005] as well as new flames E15 and E25 that are partially-premixed with 'reconstituted air' where the O2 content in nitrogen is 15 and 25% by volume, respectively. The calculations solve a transported PDF of composition using a particle-based Monte Carlo method and employ the EMST mixing model as well as detailed chemical kinetics. The addition of oxygen to the fuel increases stability, shortens the flames, broadens the reaction zone, and shifts the stoichiometric mixture fraction towards the inner side of the jet. It is found that for pure CNG flames where the reaction zone is narrow (∼0.1 in mixture fraction space), the PDF calculations fail to reproduce the correct level of local extinction on approach to blow-off. A broadening in the reaction zone up to about 0.25 in mixture fraction space is needed for the PDF/EMST approach to be able to capture these finite-rate chemistry effects. It is also found that for the same level of partial premixing, increasing the O2/N2 ratio increases the maximum levels of CO and NO but shifts the peak to richer mixture fractions. Over the range of oxygenation investigated here, stability limits have shown to improve almost linearly with increasing oxygen levels in the fuel and with increasing the contribution of release rate from the pilot.

  1. Structures of pseudechetoxin and pseudecin, two snake-venom cysteine-rich secretory proteins that target cyclic nucleotide-gated ion channels: implications for movement of the C-terminal cysteine-rich domain

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suzuki, Nobuhiro; Department of Biochemistry, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602; Yamazaki, Yasuo

    2008-10-01

    The structures of pseudechetoxin and pseudecin suggest that both proteins bind to cyclic nucleotide-gated ion channels in a manner in which the concave surface occludes the pore entrance. Cyclic nucleotide-gated (CNG) ion channels play pivotal roles in sensory transduction by retinal photoreceptors and olfactory neurons. The elapid snake toxins pseudechetoxin (PsTx) and pseudecin (Pdc) are the only known protein blockers of CNG channels. These toxins belong to a cysteine-rich secretory protein (CRISP) family containing an N-terminal pathogenesis-related proteins of group 1 (PR-1) domain and a C-terminal cysteine-rich domain (CRD). PsTx and Pdc are highly homologous proteins, but their blocking affinitiesmore » on CNG channels are different: PsTx blocks both the olfactory and retinal channels with ∼15–30-fold higher affinity than Pdc. To gain further insights into their structure and function, the crystal structures of PsTx, Pdc and Zn{sup 2+}-bound Pdc were determined. The structures revealed that most of the amino-acid-residue differences between PsTx and Pdc are located around the concave surface formed between the PR-1 domain and the CRD, suggesting that the concave surface is functionally important for CNG-channel binding and inhibition. A structural comparison in the presence and absence of Zn{sup 2+} ion demonstrated that the concave surface can open and close owing to movement of the CRD upon Zn{sup 2+} binding. The data suggest that PsTx and Pdc occlude the pore entrance and that the dynamic motion of the concave surface facilitates interaction with the CNG channels.« less

  2. Estimating the health benefits from natural gas use in transport and heating in Santiago, Chile.

    PubMed

    Mena-Carrasco, Marcelo; Oliva, Estefania; Saide, Pablo; Spak, Scott N; de la Maza, Cristóbal; Osses, Mauricio; Tolvett, Sebastián; Campbell, J Elliott; Tsao, Tsao Es Chi-Chung; Molina, Luisa T

    2012-07-01

    Chilean law requires the assessment of air pollution control strategies for their costs and benefits. Here we employ an online weather and chemical transport model, WRF-Chem, and a gridded population density map, LANDSCAN, to estimate changes in fine particle pollution exposure, health benefits, and economic valuation for two emission reduction strategies based on increasing the use of compressed natural gas (CNG) in Santiago, Chile. The first scenario, switching to a CNG public transportation system, would reduce urban PM2.5 emissions by 229 t/year. The second scenario would reduce wood burning emissions by 671 t/year, with unique hourly emission reductions distributed from daily heating demand. The CNG bus scenario reduces annual PM2.5 by 0.33 μg/m³ and up to 2 μg/m³ during winter months, while the residential heating scenario reduces annual PM2.5 by 2.07 μg/m³, with peaks exceeding 8 μg/m³ during strong air pollution episodes in winter months. These ambient pollution reductions lead to 36 avoided premature mortalities for the CNG bus scenario, and 229 for the CNG heating scenario. Both policies are shown to be cost-effective ways of reducing air pollution, as they target high-emitting area pollution sources and reduce concentrations over densely populated urban areas as well as less dense areas outside the city limits. Unlike the concentration rollback methods commonly used in public policy analyses, which assume homogeneous reductions across a whole city (including homogeneous population densities), and without accounting for the seasonality of certain emissions, this approach accounts for both seasonality and diurnal emission profiles for both the transportation and residential heating sectors. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Structural basis of gating of CNG channels.

    PubMed

    Giorgetti, Alejandro; Nair, Anil V; Codega, Paolo; Torre, Vincent; Carloni, Paolo

    2005-03-28

    Cyclic nucleotide-gated (CNG) ion channels, underlying sensory transduction in vertebrate photoreceptors and olfactory sensory neurons, require cyclic nucleotides to open. Here, we present structural models of the tetrameric CNG channel pore from bovine rod in both open and closed states, as obtained by combining homology modeling-based techniques, experimentally derived spatial constraints and structural patterns present in the PDB database. Gating is initiated by an anticlockwise rotation of the N-terminal region of the C-linker, which is then, transmitted through the S6 transmembrane helices to the P-helix, and in turn from this to the pore lumen, which opens up from 2 to 5A thus allowing for ion permeation. The approach, here presented, is expected to provide a general methodology for model ion channels and their gating when structural templates are available and an extensive electrophysiological analysis has been performed.

  4. Low pressure storage of natural gas on activated carbon

    NASA Astrophysics Data System (ADS)

    Wegrzyn, J.; Wiesmann, H.; Lee, T.

    The introduction of natural gas to the transportation energy sector offers the possibility of displacing imported oil with an indigenous fuel. The barrier to the acceptance of natural gas vehicles (NGV) is the limited driving range due to the technical difficulties of on-board storage of a gaseous fuel. In spite of this barrier, compressed natural gas (CNG) vehicles are today being successfully introduced into the market place. The purpose of this work is to demonstrate an adsorbent natural gas (ANG) storage system as a viable alternative to CNG storage. It can be argued that low pressure ANG has reached near parity with CNG, since the storage capacity of CNG (2400 psi) is rated at 190 V/V, while low pressure ANG (500 psi) has reached storage capacities of 180 V/V in the laboratory. A program, which extends laboratory results to a full-scale vehicle test, is necessary before ANG technology will receive widespread acceptance. The objective of this program is to field test a 150 V/V ANG vehicle in FY 1994. As a start towards this goal, carbon adsorbents have been screened by Brookhaven for their potential use in a natural gas storage system. This paper reports on one such carbon, trade name Maxsorb, manufactured by Kansai Coke under an Amoco license.

  5. A novel dimerization interface of cyclic nucleotide binding domain, which is disrupted in presence of cAMP: implications for CNG channels gating.

    PubMed

    Gushchin, Ivan Y; Gordeliy, Valentin I; Grudinin, Sergei

    2012-09-01

    Cyclic nucleotide binding domain (CNBD) is a ubiquitous domain of effector proteins involved in signalling cascades of prokaryota and eukaryota. CNBD activation by cyclic nucleotide monophosphate (cNMP) is studied well in the case of several proteins. However, this knowledge is hardly applicable to cNMP-modulated cation channels. Despite the availability of CNBD crystal structures of bacterial cyclic nucleotide-gated (CNG) and mammalian hyperpolarization-activated cyclic nucleotide-modulated (HCN) channels in presence and absence of the cNMP, the full understanding of CNBD conformational changes during activation is lacking. Here, we describe a novel CNBD dimerization interface found in crystal structures of bacterial CNG channel MlotiK1 and mammalian cAMP-activated guanine nucleotide-exchange factor Epac2. Molecular dynamics simulations show that the found interface is stable on the studied timescale of 100 ns, in contrast to the dimerization interface, reported previously. Comparisons with cN-bound structures of CNBD show that the dimerization is incompatible with cAMP binding. Thus, the cAMP-dependent monomerization of CNBD may be an alternative mechanism of the cAMP sensing. Based on these findings, we propose a model of the bacterial CNG channel modulation by cAMP.

  6. Developing a Natural Gas-Powered Bus Rapid Transit Service. A Case Study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mitchell, George

    2015-11-01

    The Roaring Fork Transit Authority (RFTA) and its VelociRFTA Bus Rapid Transit (BRT) program are unique in many ways. For example, VelociRFTA was the first rural BRT system in the United States and the operational environment of the VelociRFTA BRT is one of the most severe in the country, with extreme winter temperatures and altitudes close to 8,000 feet. RFTA viewed high altitude operation as the most challenging characteristic when it began considering the use of natural gas. RFTA is the second-largest public transit system in Colorado behind Denver's Regional Transportation District (RTD), and it is one of the largestmore » rural public transit systems in the country. In 2013, RFTA accepted delivery of 22 new compressed natural gas (CNG) buses that went into service after completion of maintenance and refueling facilities earlier that year. This paper examines the lessons learned from RFTA's experience of investigating--and ultimately choosing--CNG for their new BRT program and focuses on the unique environment of RFTA's BRT application; the decision process to include CNG fueling in the project; unforeseen difficulties encountered in the operation of CNG buses; public perception; cost comparison to competing fuels; and considerations for indoor fueling facilities and project funding.« less

  7. Developing a Natural Gas-Powered Bus Rapid Transit Service: A Case Study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mitchell, G.

    2015-11-03

    The Roaring Fork Transit Authority (RFTA) and its VelociRFTA Bus Rapid Transit (BRT) program are unique in many ways. For example, VelociRFTA was the first rural BRT system in the United States and the operational environment of the VelociRFTA BRT is one of the most severe in the country, with extreme winter temperatures and altitudes close to 8,000 feet. RFTA viewed high altitude operation as the most challenging characteristic when it began considering the use of natural gas. RFTA is the second-largest public transit system in Colorado behind Denver's Regional Transportation District (RTD), and it is one of the largestmore » rural public transit systems in the country. In 2013, RFTA accepted delivery of 22 new compressed natural gas (CNG) buses that went into service after completion of maintenance and refueling facilities earlier that year. This paper examines the lessons learned from RFTA's experience of investigating--and ultimately choosing--CNG for their new BRT program and focuses on the unique environment of RFTA's BRT application; the decision process to include CNG fueling in the project; unforeseen difficulties encountered in the operation of CNG buses; public perception; cost comparison to competing fuels; and considerations for indoor fueling facilities and project funding.« less

  8. Compressed Natural Gas Technology for Alternative Fuel Power Plants

    NASA Astrophysics Data System (ADS)

    Pujotomo, Isworo

    2018-02-01

    Gas has great potential to be converted into electrical energy. Indonesia has natural gas reserves up to 50 years in the future, but the optimization of the gas to be converted into electricity is low and unable to compete with coal. Gas is converted into electricity has low electrical efficiency (25%), and the raw materials are more expensive than coal. Steam from a lot of wasted gas turbine, thus the need for utilizing exhaust gas results from gas turbine units. Combined cycle technology (Gas and Steam Power Plant) be a solution to improve the efficiency of electricity. Among other Thermal Units, Steam Power Plant (Combined Cycle Power Plant) has a high electrical efficiency (45%). Weakness of the current Gas and Steam Power Plant peak burden still using fuel oil. Compressed Natural Gas (CNG) Technology may be used to accommodate the gas with little land use. CNG gas stored in the circumstances of great pressure up to 250 bar, in contrast to gas directly converted into electricity in a power plant only 27 bar pressure. Stored in CNG gas used as a fuel to replace load bearing peak. Lawyer System on CNG conversion as well as the power plant is generally only used compressed gas with greater pressure and a bit of land.

  9. Sodium and potassium competition in potassium-selective and non-selective channels

    NASA Astrophysics Data System (ADS)

    Sauer, David B.; Zeng, Weizhong; Canty, John; Lam, Yeeling; Jiang, Youxing

    2013-11-01

    Potassium channels selectively conduct K+, primarily to the exclusion of Na+, despite the fact that both ions can bind within the selectivity filter. Here we perform crystallographic titration and single-channel electrophysiology to examine the competition of Na+ and K+ binding within the filter of two NaK channel mutants; one is the potassium-selective NaK2K mutant and the other is the non-selective NaK2CNG, a CNG channel pore mimic. With high-resolution structures of these engineered NaK channel constructs, we explicitly describe the changes in K+ occupancy within the filter upon Na+ competition by anomalous diffraction. Our results demonstrate that the non-selective NaK2CNG still retains a K+-selective site at equilibrium, whereas the NaK2K channel filter maintains two high-affinity K+ sites. A double-barrier mechanism is proposed to explain K+ channel selectivity at low K+ concentrations.

  10. Calmodulin permanently associates with rat olfactory CNG channels under native conditions.

    PubMed

    Bradley, Jonathan; Bönigk, Wolfgang; Yau, King-Wai; Frings, Stephan

    2004-07-01

    An important mechanism by which vertebrate olfactory sensory neurons rapidly adapt to odorants is feedback modulation of the Ca(2+)-permeable cyclic nucleotide-gated (CNG) transduction channels. Extensive heterologous studies of homomeric CNGA2 channels have led to a molecular model of channel modulation based on the binding of calcium-calmodulin to a site on the cytoplasmic amino terminus of CNGA2. Native rat olfactory CNG channels, however, are heteromeric complexes of three homologous but distinct subunits. Notably, in heteromeric channels, we found no role for CNGA2 in feedback modulation. Instead, an IQ-type calmodulin-binding site on CNGB1b and a similar but previously unidentified site on CNGA4 are necessary and sufficient. These sites seem to confer binding of Ca(2+)-free calmodulin (apocalmodulin), which is then poised to trigger inhibition of native channels in the presence of Ca(2+).

  11. Reach-Scale Channel Adjustments to Channel Network Geometry in Mountain Bedrock Streams

    NASA Astrophysics Data System (ADS)

    Plitzuweit, S. J.; Springer, G. S.

    2008-12-01

    Channel network geometry (CNG) is a critical determinant of hydrological response and may significantly affect incision processes within the Appalachian Plateau near Richwood, West Virginia. The Williams, Cherry, and Cranberry Rivers share drainage divides and their lower reaches flow atop resistant, quartz-rich sandstones. The lower two-thirds of the Cranberry and Williams Rivers display linear profiles atop the sandstones; whereas the Cherry is concave upwards atop the sandstones. Because lithologies and geological structures are similar among the watersheds, we tested whether differences in CNGs explain the profile shapes and reach-scale channel properties. Specifically, we quantified CNG by calculating reach- specific area-distance functions using DEMs. The area-distance functions were then converted into synthetic hydrographs to model hydrological responses. The Cherry River exhibits a classic dendritic drainage pattern, producing peaked hydrographs and low interval transit times. The Cranberry River displays a trellis-like drainage pattern, which produces attenuated hydrographs and high interval transit times. The upstream reaches of the Williams River have a dendritic drainage pattern, but the lower two-thirds of the watershed transitions into an elongated basin with trellis-like CNG. Reach gradients are steeper in the lower reaches of the Williams and Cranberry Rivers where hydrographs are attenuated. In contrast, peaked hydrographs within the Cherry River are associated with lower reach gradients despite resistant sandstone channel beds. Trellis-like CNG may restrict the ability of downstream reaches within the Williams and Cranberry Rivers to achieve the critical discharge needed to cause incision during floods (all other things being equal). If so, increased reach gradients may be hydraulic adjustments that compensate for comparatively low discharges. We are now applying the synthetic hydrographs to HEC-RAS flow models generated from field channel surveys in order to analyze whether stream power and shear stress are adjusted to reflect CNG at the reach- scale. These models are compared to those with discharges calculated using drainage area and precipitation totals alone. We conclude that gradients in bedrock mountain streams may reflect basin-scale hydrology (CNG) and not simply local geological or geomorphic factors. This challenges the conclusions of others who ascribe local channel adjustments to: i) lithology and structure alone, or ii) local colluvium grain sizes.

  12. Simultaneous Loss of NCKX4 and CNG Channel Desensitization Impairs Olfactory Sensitivity.

    PubMed

    Ferguson, Christopher H; Zhao, Haiqing

    2017-01-04

    In vertebrate olfactory sensory neurons (OSNs), Ca 2+ plays key roles in both mediating and regulating the olfactory response. Ca 2+ enters OSN cilia during the response through the olfactory cyclic nucleotide-gated (CNG) channel and stimulates a depolarizing chloride current by opening the olfactory Ca 2+ -activated chloride channel to amplify the response. Ca 2+ also exerts negative regulation on the olfactory transduction cascade, through mechanisms that include reducing the CNG current by desensitizing the CNG channel via Ca 2+ /calmodulin (CaM), to reduce the response. Ca 2+ is removed from the cilia primarily by the K + -dependent Na + /Ca 2+ exchanger 4 (NCKX4), and the removal of Ca 2+ leads to closure of the chloride channel and response termination. In this study, we investigate how two mechanisms conventionally considered negative regulatory mechanisms of olfactory transduction, Ca 2+ removal by NCKX4, and desensitization of the CNG channel by Ca 2+ /CaM, interact to regulate the olfactory response. We performed electro-olfactogram (EOG) recordings on the double-mutant mice, NCKX4 -/- ;CNGB1 ΔCaM , which are simultaneously lacking NCKX4 (NCKX4 -/- ) and Ca 2+ /CaM-mediated CNG channel desensitization (CNGB1 ΔCaM ). Despite exhibiting alterations in various response attributes, including termination kinetics and adaption properties, OSNs in either NCKX4 -/- mice or CNGB1 ΔCaM mice show normal resting sensitivity, as determined by their unchanged EOG response amplitude. We found that OSNs in NCKX4 -/- ;CNGB1 ΔCaM mice displayed markedly reduced EOG amplitude accompanied by alterations in other response attributes. This study suggests that what are conventionally considered negative regulatory mechanisms of olfactory transduction also play a role in setting the resting sensitivity in OSNs. Sensory receptor cells maintain high sensitivity at rest. Although the mechanisms responsible for setting the resting sensitivity of sensory receptor cells are not well understood, it has generally been assumed that the sensitivity is set primarily by how effectively the components in the activation cascade of sensory transduction can be stimulated. Our findings in mouse olfactory sensory neurons suggest that mechanisms that are primarily responsible for terminating the olfactory response are also critical for proper resting sensitivity. Copyright © 2017 the authors 0270-6474/17/370110-10$15.00/0.

  13. Abundance and Utility: For Military Operations, Liquid Fuels Remain a Solid Choice over Natural Gas

    DTIC Science & Technology

    2014-08-01

    and combat support vehicles, ships, and aircraft, the adoption of natural gas —whether as compressed natural gas (CNG) or liquefied natural gas (LNG...dangers to U.S. forces and vehicles. Natural gas has different flammability properties than traditional liquid fuels, and as CNG tanks are under high...tacticaldefensemedia.com16 | DoD Power & Energy Fall 2014 For Military Operations, Liquid Fuels Remain a Solid Choice over Natural Gas By Bret

  14. Hydrogen effects on materials for CNG/H2 blends.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Farese, David; Keller, Jay O.; Somerday, Brian P.

    2010-09-01

    No concerns for Hydrogen-Enriched Compressed Natural gas (HCNG) in steel storage tanks if material strength is < 950 MPa. Recommend evaluating H{sub 2}-assisted fatigue cracking in higher strength steels at H{sub 2} partial pressure in blend. Limited fatigue testing on higher strength steel cylinders in H{sub 2} shows promising results. Impurities in Compressed Natural Gas (CNG) (e.g., CO) may provide extrinsic mechanism for mitigating H{sub 2}-assisted fatigue cracking in steel tanks.

  15. Strategies for elimination of cyanogens from cassava for reducing toxicity and improving food safety.

    PubMed

    Nambisan, Bala

    2011-03-01

    Toxicity of cassava arises due to the presence of the cyanoglucosides linamarin and lotaustralin which are hydrolysed by endogenous enzyme linamarase to acetonecyanohydrin (ACN) and cyanide (CN) which are toxic. Major research efforts to eliminate/reduce cyanoglucosides have focused on (i) development of acyanogenic cassava varieties by breeding; (ii) controlling its metabolism; and (iii) processing to remove cyanogens. The cyanoglucoside (CNG) content in cassava is genetically controlled and cultivars may be classified as low (<50 μg/g), medium (50-100 μg/g) and high CN (>100 μg CN eq./g) varieties. Molecular techniques for reducing tuber CNG have focused on development of transgenic plants with reduced expression of cyt P 450 in leaves, or increased expression of hydroxynitrilelyase in tuber. For immediate solution, CNG content can be reduced using several processing methods. Traditional methods used for processing include boiling, drying, parboiling and drying, baking, steaming, frying and preparation of flour. These processes result in CN losses ranging from 25% to 98%. The cyanogen level in the final product is influenced both by the tuber CNG and the method of processing. In order to achieve safe levels of 10 μg/g in cassava products, new methods of processing, especially for cassava containing more than 250 μg CN eq./g, remains a challenging problem. Copyright © 2010. Published by Elsevier Ltd.

  16. Corn Ethanol: The Surprisingly Effective Route for Natural Gas Consumption in the Transportation Sector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Szybist, James P.; Curran, Scott

    2015-05-01

    Proven reserves and production of natural gas (NG) in the United States have increased dramatically in the last decade, due largely to the commercialization of hydraulic fracturing. This has led to a plentiful supply of NG, resulting in a significantly lower cost on a gallon of gasoline-equivalent (GGE) basis. Additionally, NG is a domestic, non-petroleum source of energy that is less carbon-intensive than coal or petroleum products, and thus can lead to lower greenhouse gas emissions. Because of these factors, there is a desire to increase the use of NG in the transportation sector in the United States (U.S.). However,more » using NG directly in the transportation sector requires that several non-trivial challenges be overcome. One of these issues is the fueling infrastructure. There are currently only 1,375 NG fueling stations in the U.S. compared to 152,995 fueling stations for gasoline in 2014. Additionally, there are very few light-duty vehicles that can consume this fuel directly as dedicated or bi-fuel options. For example, in model year 2013Honda was the only OEM to offer a dedicated CNG sedan while a number of others offered CNG options as a preparation package for LD trucks and vans. In total, there were a total of 11 vehicle models in 2013 that could be purchased that could use natural gas directly. There are additional potential issues associated with NG vehicles as well. Compared to commercial refueling stations, the at-home refueling time for NG vehicles is substantial – a result of the small compressors used for home refilling. Additionally, the methane emissions from both refueling (leakage) and from tailpipe emissions (slip) from these vehicles can add to their GHG footprint, and while these emissions are not currently regulated it could be a barrier in the future, especially in scenarios with broad scale adoption of CNG vehicles. However, NG consumption already plays a large role in other sectors of the economy, including some that are important to the transportation sector. Examples include steam reforming of natural gas to provide hydrogen for hydrotreating unit operations within the refinery and production of urea for use as a reductant for diesel after treatment in selective catalytic reduction (SCR). This discussion focuses on the consumption of natural gas in the production pathway of conventional ethanol (non-cellulosic) from corn through fermentation. Though it is clear that NG would also play a significant role in the cellulosic production pathways, those cases are not considered in this analysis.« less

  17. In-Use Fleet Evaluation of Fast-Charge Battery Electric Transit Buses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Prohaska, Robert; Kelly, Kenneth; Eudy

    2016-06-27

    With support from the U.S. Department of Energy's Vehicle Technologies Office, the National Renewable Energy Laboratory (NREL) conducts real-world performance evaluations of advanced medium- and heavy-duty fleet vehicles. Evaluation results can help vehicle manufacturers fine-tune their designs and assist fleet managers in selecting fuel-efficient, low-emission vehicles that meet their economic and operational goals. In 2015, NREL launched an in-service evaluation of 12 battery electric buses (BEBs) compared to conventional compressed natural gas (CNG) buses operated by Foothill Transit in West Covina, California. The study aims to improve understanding of the overall usage and effectiveness of fast-charge BEBs and associated chargingmore » infrastructure in transit operation. To date, NREL researchers have analyzed more than 148,000 km of in-use operational data, including driving and charging events. Foothill Transit purchased the BEBs with grant funding from the Federal Transit Administration's Transit Investments for Greenhouse Gas and Energy Reduction Program.« less

  18. Crumpled Nitrogen-Doped Graphene for Supercapacitors with High Gravimetric and Volumetric Performances.

    PubMed

    Wang, Jie; Ding, Bing; Xu, Yunling; Shen, Laifa; Dou, Hui; Zhang, Xiaogang

    2015-10-14

    Graphene is considered a promising electrochemical capacitors electrode material due to its high surface area and high electrical conductivity. However, restacking interactions between graphene nanosheets significantly decrease the ion-accessible surface area and impede electronic and ionic transfer. This would, in turn, severely hinder the realization of high energy density. Herein, we report a strategy for preparation of few-layer graphene material with abundant crumples and high-level nitrogen doping. The two-dimensional graphene nanosheets (CNG) feature high ion-available surface area, excellent electronic and ion transfer properties, and high packing density, permitting the CNG electrode to exhibit excellent electrochemical performance. In ionic liquid electrolyte, the CNG electrode exhibits gravimetric and volumetric capacitances of 128 F g(-1) and 98 F cm(-3), respectively, achieving gravimetric and volumetric energy densities of 56 Wh kg(-1) and 43 Wh L(-1). The preparation strategy described here provides a new approach for developing a graphene-based supercapacitor with high gravimetric and volumetric energy densities.

  19. Early flame development image comparison of low calorific value syngas and CNG in DI SI gas engine

    NASA Astrophysics Data System (ADS)

    >Ftwi Yohaness Hagos, A. Rashid A.; Sulaiman, Shaharin A.

    2013-06-01

    The early flame development stage of syngas and CNG are analysed and compared from the flame images taken over 20° CA from the start of ignition. An imitated syngas with a composition of 19.2% H2, 29.6% CO, 5.3% CH4 and balance with nitrogen and carbon dioxide, which resembles the typical product of wood biomass gasification, was used in the study. A CCD camera triggered externally through the signals from the camshaft and crank angle sensors was used in capturing of the images. The engine was accessed through an endoscope access and a self-illumination inside the chamber. The results of the image analysis are further compared with the mass fraction burn curve of both syngas and CNG analysed from the pressure data. The analysis result of the flame image of syngas validates the double rapid burning stage of the mass fraction burn of syngas analysed from in-cylinder pressure data.

  20. Structure of a eukaryotic cyclic nucleotide-gated channel

    PubMed Central

    Li, Minghui; Zhou, Xiaoyuan; Wang, Shu; Michailidis, Ioannis; Gong, Ye; Su, Deyuan; Li, Huan; Li, Xueming; Yang, Jian

    2018-01-01

    Summary Cyclic nucleotide-gated (CNG) channels are essential for vision and olfaction. They belong to the voltage-gated ion channel superfamily but their activities are controlled by intracellular cyclic nucleotides instead of transmembrane voltage. Here we report a 3.5 Å-resolution single-particle electron cryomicroscopy structure of a CNG channel from C. elegans in the cGMP-bound open state. The channel has an unusual voltage-sensor-like domain (VSLD), accounting for its deficient voltage dependence. A C-terminal linker connecting S6 and the cyclic nucleotide-binding domain interacts directly with both the VSLD and pore domain, forming a gating ring that couples conformational changes triggered by cyclic nucleotide binding to the gate. The selectivity filter is lined by the carboxylate side chains of a functionally important glutamate and three rings of backbone carbonyls. This structure provides a new framework for understanding mechanisms of ion permeation, gating and channelopathy of CNG channels and cyclic nucleotide modulation of related channels. PMID:28099415

  1. Odorant Inhibition of the Olfactory Cyclic Nucleotide-gated Channel with a Native Molecular Assembly

    PubMed Central

    Chen, Tsung-Yu; Takeuchi, Hiroko; Kurahashi, Takashi

    2006-01-01

    Human olfaction comprises the opposing actions of excitation and inhibition triggered by odorant molecules. In olfactory receptor neurons, odorant molecules not only trigger a G-protein–coupled signaling cascade but also generate various mechanisms to fine tune the odorant-induced current, including a low-selective odorant inhibition of the olfactory signal. This wide-range olfactory inhibition has been suggested to be at the level of ion channels, but definitive evidence is not available. Here, we report that the cyclic nucleotide-gated (CNG) cation channel, which is a key element that converts odorant stimuli into electrical signals, is inhibited by structurally unrelated odorants, consistent with the expression of wide-range olfactory inhibition. Interestingly, the inhibitory effect was small in the homo-oligomeric CNG channel composed only of the principal channel subunit, CNGA2, but became larger in channels consisting of multiple types of subunits. However, even in the channel containing all native subunits, the potency of the suppression on the cloned CNG channel appeared to be smaller than that previously shown in native olfactory neurons. Nonetheless, our results further showed that odorant suppressions are small in native neurons if the subsequent molecular steps mediated by Ca2+ are removed. Thus, the present work also suggests that CNG channels switch on and off the olfactory signaling pathway, and that the on and off signals may both be amplified by the subsequent olfactory signaling steps. PMID:16940558

  2. Emissions of toxic pollutants from compressed natural gas and low sulfur diesel-fueled heavy-duty transit buses tested over multiple driving cycles.

    PubMed

    Kado, Norman Y; Okamoto, Robert A; Kuzmicky, Paul A; Kobayashi, Reiko; Ayala, Alberto; Gebel, Michael E; Rieger, Paul L; Maddox, Christine; Zafonte, Leo

    2005-10-01

    The number of heavy-duty vehicles using alternative fuels such as compressed natural gas (CNG) and new low-sulfur diesel fuel formulations and equipped with after-treatment devices are projected to increase. However, few peer-reviewed studies have characterized the emissions of particulate matter (PM) and other toxic compounds from these vehicles. In this study, chemical and biological analyses were used to characterize the identifiable toxic air pollutants emitted from both CNG and low-sulfur-diesel-fueled heavy-duty transit buses tested on a chassis dynamometer over three transient driving cycles and a steady-state cruise condition. The CNG bus had no after-treatment, and the diesel bus was tested first equipped with an oxidation catalyst (OC) and then with a catalyzed diesel particulate filter (DPF). Emissions were analyzed for PM, volatile organic compounds (VOCs; determined on-site), polycyclic aromatic hydrocarbons (PAHs), and mutagenic activity. The 2000 model year CNG-fueled vehicle had the highest emissions of 1,3-butadiene, benzene, and carbonyls (e.g., formaldehyde) of the three vehicle configurations tested in this study. The 1998 model year diesel bus equipped with an OC and fueled with low-sulfur diesel had the highest emission rates of PM and PAHs. The highest specific mutagenic activities (revertants/microg PM, or potency) and the highest mutagen emission rates (revertants/mi) were from the CNG bus in strain TA98 tested over the New York Bus (NYB) driving cycle. The 1998 model year diesel bus with DPF had the lowest VOCs, PAH, and mutagenic activity emission. In general, the NYB driving cycle had the highest emission rates (g/mi), and the Urban Dynamometer Driving Schedule (UDDS) had the lowest emission rates for all toxics tested over the three transient test cycles investigated. Also, transient emissions were, in general, higher than steady-state emissions. The emissions of toxic compounds from an in-use CNG transit bus (without an oxidation catalyst) and from a vehicle fueled with low-sulfur diesel fuel (equipped with DPF) were lower than from the low-sulfur diesel fueled vehicle equipped with OC. All vehicle configurations had generally lower emissions of toxics than an uncontrolled diesel engine. Tunnel backgrounds (measurements without the vehicle running) were measured throughout this study and were helpful in determining the incremental increase in pollutant emissions. Also, the on-site determination of VOCs, especially 1,3-butadiene, helped minimize measurement losses due to sample degradation after collection.

  3. Cost effectiveness of converting to alternative motor vehicle fuels. A technical assistance study for the City of Longview

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McCoy, G.A.

    1983-11-18

    The City of Longview can obtain significant fuel savings benefits by converting a portion of their vehicle fleet to operate on either compressed natural gas (CNG) or liquid petroleum gas (LPG) fuels. The conversion of 41 vehicles including police units, sedans, pickups, and light duty trucks to CNG use would offset approximately 47% of the city's 1982 gasoline consumption. The CNG conversion capital outlay of $115,000 would be recovered through fuel cost reductions. The Cascade Natural Gas Corporation sells natural gas under an interruptible tariff for $0.505 per therm, equivalent to slightly less than one gallon of gasoline. The citymore » currently purchases unleaded gasoline at $1.115 per gallon. A payback analysis indicates that 39.6 months are required for the CNG fuel savings benefits to offset the initial or first costs of the conversion. The conversion of fleet vehicles to liquid petroleum gas (LPG) or propane produces comparable savings in vehicle operating costs. The conversion of 59 vehicles including police units, pickup and one ton trucks, street sweepers, and five cubic yard dump trucks would cost approximately $59,900. The annual purchase of 107,000 gallons of propane would offset the consumption of 96,300 gallons of gasoline, or approximately 67% of the city's 1982 usage. Propane is currently retailing for $0.68 to $0.74 per gallon. A payback analysis indicates that 27.7 months are required for the fuel savings benefits to offset the initial LPG conversion costs.« less

  4. IP3-gated channels and their occurrence relative to CNG channels in the soma and dendritic knob of rat olfactory receptor neurons.

    PubMed

    Kaur, R; Zhu, X O; Moorhouse, A J; Barry, P H

    2001-05-15

    Olfactory receptor neurons respond to odorants with G protein-mediated increases in the concentrations of cyclic adenosine 3',5'-monophosphate (cAMP) and/or inositol-1,4,5-trisphosphate (IP3). This study provides evidence that both second messengers can directly activate distinct ion channels in excised inside-out patches from the dendritic knob and soma membrane of rat olfactory receptor neurons (ORNs). The IP3-gated channels in the dendritic knob and soma membranes could be classified into two types, with conductances of 40 +/- 7 pS (n = 5) and 14 +/- 3 pS (n = 4), with the former having longer open dwell times. Estimated values of the densities of both channels from the same inside-out membrane patches were very much smaller for IP3-gated than for CNG channels. For example, in the dendritic knob membrane there were about 1000 CNG channels x microm(-2) compared to about 85 IP3-gated channels x microm(-2). Furthermore, only about 36% of the dendritic knob patches responded to IP3, whereas 83% of the same patches responded to cAMP. In the soma, both channel densities were lower, with the CNG channel density again being larger ( approximately 57 channels x microm(-2)) than that of the IP3-gated channels ( approximately 13 channels x microm(-2)), with again a much smaller fraction of patches responding to IP3 than to cAMP. These results were consistent with other evidence suggesting that the cAMP-pathway dominates the IP3 pathway in mammalian olfactory transduction.

  5. Surface acoustic wave sensors/gas chromatography; and Low quality natural gas sulfur removal and recovery CNG Claus sulfur recovery process

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Klint, B.W.; Dale, P.R.; Stephenson, C.

    This topical report consists of the two titled projects. Surface Acoustic Wave/Gas Chromatography (SAW/GC) provides a cost-effective system for collecting real-time field screening data for characterization of vapor streams contaminated with volatile organic compounds (VOCs). The Model 4100 can be used in a field screening mode to produce chromatograms in 10 seconds. This capability will allow a project manager to make immediate decisions and to avoid the long delays and high costs associated with analysis by off-site analytical laboratories. The Model 4100 is currently under evaluation by the California Environmental Protection Agency Technology Certification Program. Initial certification focuses upon themore » following organics: cis-dichloroethylene, chloroform, carbon tetrachloride, trichlorethylene, tetrachloroethylene, tetrachloroethane, benzene, ethylbenzene, toluene, and o-xylene. In the second study the CNG Claus process is being evaluated for conversion and recovery of elemental sulfur from hydrogen sulfide, especially found in low quality natural gas. This report describes the design, construction and operation of a pilot scale plant built to demonstrate the technical feasibility of the integrated CNG Claus process.« less

  6. Chemical and toxicological properties of emissions from CNG transit buses equipped with three-way catalysts compared to lean-burn engines and oxidation catalyst technologies

    NASA Astrophysics Data System (ADS)

    Yoon, Seungju; Hu, Shaohua; Kado, Norman Y.; Thiruvengadam, Arvind; Collins, John F.; Gautam, Mridul; Herner, Jorn D.; Ayala, Alberto

    2014-02-01

    Chemical and toxicological properties of emissions from compressed natural gas (CNG) fueled transit buses with stoichiometric combustion engines and three-way catalyst (TWC) exhaust control systems were measured using a chassis dynamometer testing facility and compared to the data from earlier CNG engine and exhaust control technologies. Gaseous and particulate matter emissions from buses with stoichiometric engines and TWC were significantly lower than the emissions from buses with lean-burn engines. Carbonyls and volatile organic compounds (VOCs) from buses with stoichiometric engines and TWC were lower by more than 99% compared to buses with lean-burn engines. Elemental and organic carbons (EC and OC), polycyclic aromatic hydrocarbons (PAHs), and trace elements from buses with stoichiometric engines and TWC were effectively controlled and significantly lower than the emissions from buses with lean-burn engines. Potential mutagenicity measured using a microsuspension modification of the Salmonella/microsome assay was lower by more than 99% for buses with stoichiometric engines and TWC, compared to buses with lean-burn engines and OxC.

  7. Assessment of the emissions and air quality impacts of biomass and biogas use in California.

    PubMed

    Carreras-Sospedra, Marc; Williams, Robert; Dabdub, Donald

    2016-02-01

    It is estimated that there is sufficient in-state "technically" recoverable biomass to support nearly 4000 MW of bioelectricity generation capacity. This study assesses the emissions of greenhouse gases and air pollutants and resulting air quality impacts of new and existing bioenergy capacity throughout the state of California, focusing on feedstocks and advanced technologies utilizing biomass resources predominant in each region. The options for bioresources include the production of bioelectricity and renewable natural gas (NG). Emissions of criteria pollutants and greenhouse gases are quantified for a set of scenarios that span the emission factors for power generation and the use of renewable natural gas for vehicle fueling. Emissions are input to the Community Multiscale Air Quality (CMAQ) model to predict regional and statewide temporal air quality impacts from the biopower scenarios. With current technology and at the emission levels of current installations, maximum bioelectricity production could increase nitrogen oxide (NOx) emissions by 10% in 2020, which would cause increases in ozone and particulate matter concentrations in large areas of California. Technology upgrades would achieve the lowest criteria pollutant emissions. Conversion of biomass to compressed NG (CNG) for vehicles would achieve comparable emission reductions of criteria pollutants and minimize emissions of greenhouse gases (GHG). Air quality modeling of biomass scenarios suggest that applying technological changes and emission controls would minimize the air quality impacts of bioelectricity generation. And a shift from bioelectricity production to CNG production for vehicles would reduce air quality impacts further. From a co-benefits standpoint, CNG production for vehicles appears to provide the best benefits in terms of GHG emissions and air quality. This investigation provides a consistent analysis of air quality impacts and greenhouse gas emissions for scenarios examining increased biomass use. Further work involving economic assessment, seasonal or annual emissions and air quality modeling, and potential exposure analysis would help inform policy makers and industry with respect to further development and direction of biomass policy and bioenergy technology alternatives needed to meet energy and environmental goals in California.

  8. Adenosine receptors regulate gap junction coupling of the human cerebral microvascular endothelial cells hCMEC/D3 by Ca2+ influx through cyclic nucleotide‐gated channels

    PubMed Central

    Bader, Almke; Bintig, Willem; Begandt, Daniela; Klett, Anne; Siller, Ina G.; Gregor, Carola; Schaarschmidt, Frank; Weksler, Babette; Romero, Ignacio; Couraud, Pierre‐Olivier; Hell, Stefan W.

    2017-01-01

    Key points Gap junction channels are essential for the formation and regulation of physiological units in tissues by allowing the lateral cell‐to‐cell diffusion of ions, metabolites and second messengers.Stimulation of the adenosine receptor subtype A2B increases the gap junction coupling in the human blood–brain barrier endothelial cell line hCMEC/D3.Although the increased gap junction coupling is cAMP‐dependent, neither the protein kinase A nor the exchange protein directly activated by cAMP were involved in this increase.We found that cAMP activates cyclic nucleotide‐gated (CNG) channels and thereby induces a Ca2+ influx, which leads to the increase in gap junction coupling.The report identifies CNG channels as a possible physiological link between adenosine receptors and the regulation of gap junction channels in endothelial cells of the blood–brain barrier. Abstract The human cerebral microvascular endothelial cell line hCMEC/D3 was used to characterize the physiological link between adenosine receptors and the gap junction coupling in endothelial cells of the blood–brain barrier. Expressed adenosine receptor subtypes and connexin (Cx) isoforms were identified by RT‐PCR. Scrape loading/dye transfer was used to evaluate the impact of the A2A and A2B adenosine receptor subtype agonist 2‐phenylaminoadenosine (2‐PAA) on the gap junction coupling. We found that 2‐PAA stimulated cAMP synthesis and enhanced gap junction coupling in a concentration‐dependent manner. This enhancement was accompanied by an increase in gap junction plaques formed by Cx43. Inhibition of protein kinase A did not affect the 2‐PAA‐related enhancement of gap junction coupling. In contrast, the cyclic nucleotide‐gated (CNG) channel inhibitor l‐cis‐diltiazem, as well as the chelation of intracellular Ca2+ with BAPTA, or the absence of external Ca2+, suppressed the 2‐PAA‐related enhancement of gap junction coupling. Moreover, we observed a 2‐PAA‐dependent activation of CNG channels by a combination of electrophysiology and pharmacology. In conclusion, the stimulation of adenosine receptors in hCMEC/D3 cells induces a Ca2+ influx by opening CNG channels in a cAMP‐dependent manner. Ca2+ in turn induces the formation of new gap junction plaques and a consecutive sustained enhancement of gap junction coupling. The report identifies CNG channels as a physiological link that integrates gap junction coupling into the adenosine receptor‐dependent signalling of endothelial cells of the blood–brain barrier. PMID:28075020

  9. Adenosine receptors regulate gap junction coupling of the human cerebral microvascular endothelial cells hCMEC/D3 by Ca2+ influx through cyclic nucleotide-gated channels.

    PubMed

    Bader, Almke; Bintig, Willem; Begandt, Daniela; Klett, Anne; Siller, Ina G; Gregor, Carola; Schaarschmidt, Frank; Weksler, Babette; Romero, Ignacio; Couraud, Pierre-Olivier; Hell, Stefan W; Ngezahayo, Anaclet

    2017-04-15

    Gap junction channels are essential for the formation and regulation of physiological units in tissues by allowing the lateral cell-to-cell diffusion of ions, metabolites and second messengers. Stimulation of the adenosine receptor subtype A 2B increases the gap junction coupling in the human blood-brain barrier endothelial cell line hCMEC/D3. Although the increased gap junction coupling is cAMP-dependent, neither the protein kinase A nor the exchange protein directly activated by cAMP were involved in this increase. We found that cAMP activates cyclic nucleotide-gated (CNG) channels and thereby induces a Ca 2+ influx, which leads to the increase in gap junction coupling. The report identifies CNG channels as a possible physiological link between adenosine receptors and the regulation of gap junction channels in endothelial cells of the blood-brain barrier. The human cerebral microvascular endothelial cell line hCMEC/D3 was used to characterize the physiological link between adenosine receptors and the gap junction coupling in endothelial cells of the blood-brain barrier. Expressed adenosine receptor subtypes and connexin (Cx) isoforms were identified by RT-PCR. Scrape loading/dye transfer was used to evaluate the impact of the A 2A and A 2B adenosine receptor subtype agonist 2-phenylaminoadenosine (2-PAA) on the gap junction coupling. We found that 2-PAA stimulated cAMP synthesis and enhanced gap junction coupling in a concentration-dependent manner. This enhancement was accompanied by an increase in gap junction plaques formed by Cx43. Inhibition of protein kinase A did not affect the 2-PAA-related enhancement of gap junction coupling. In contrast, the cyclic nucleotide-gated (CNG) channel inhibitor l-cis-diltiazem, as well as the chelation of intracellular Ca 2+ with BAPTA, or the absence of external Ca 2+ , suppressed the 2-PAA-related enhancement of gap junction coupling. Moreover, we observed a 2-PAA-dependent activation of CNG channels by a combination of electrophysiology and pharmacology. In conclusion, the stimulation of adenosine receptors in hCMEC/D3 cells induces a Ca 2+ influx by opening CNG channels in a cAMP-dependent manner. Ca 2+ in turn induces the formation of new gap junction plaques and a consecutive sustained enhancement of gap junction coupling. The report identifies CNG channels as a physiological link that integrates gap junction coupling into the adenosine receptor-dependent signalling of endothelial cells of the blood-brain barrier. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

  10. Regulation of cyclic nucleotide-gated channels and membrane excitability in olfactory receptor cells by carbon monoxide

    NASA Technical Reports Server (NTRS)

    Leinders-Zufall, T.; Shepherd, G. M.; Zufall, F.

    1995-01-01

    1. The effect of the putative neural messenger carbon monoxide (CO) and the role of the cGMP second-messenger system for olfactory signal generation was examined in isolated olfactory receptor neurons (ORNs) of the tiger salamander. 2. With the use of whole cell voltage-clamp recordings in combination with a series of ionic and pharmological tests, it is demonstrated that exogenously applied CO is a potent activator (K1/2 = 2.9 microM) of cyclic nucleotide-gated (CNG) channels previously described to mediate odor transduction. 3. Several lines of evidence suggest that CO mediates its effect through stimulation of a soluble guanylyl cyclase (sGC) leading to formation of the second-messenger cGMP. This conclusion is based on the findings that CO responses show an absolute requirement for guanosine 5'-triphosphate (GTP) in the internal solution, that no direct effect of CO on CNG currents in the absence of GTP is detectable, and that a blocker of sGC activation, LY85383 (10 microM), completely inhibits the CO response. 4. The dose-response curve for cGMP at CNG channels is used as a calibration to provide a quantitative estimate of the CO-stimulated cGMP formation. This analysis implies that CO is a potent activator of olfactory sGC. 5. Perforated patch recordings using amphotericin B demonstrate that low micromolar doses of CO effectively depolarize the membrane potential of ORNs through tonic activation of CNG channels. This effect in turn regulates excitable and adaptive properties of ORNs and modulates neuronal responsiveness. 6. These data argue for an important role of the cGMP pathway in olfactory signaling and support the idea that CO may function as a diffusible messenger in the olfactory system.

  11. Impact of non-petroleum vehicle fuel economy on GHG mitigation potential

    NASA Astrophysics Data System (ADS)

    Luk, Jason M.; Saville, Bradley A.; MacLean, Heather L.

    2016-04-01

    The fuel economy of gasoline vehicles will increase to meet 2025 corporate average fuel economy standards (CAFE). However, dedicated compressed natural gas (CNG) and battery electric vehicles (BEV) already exceed future CAFE fuel economy targets because only 15% of non-petroleum energy use is accounted for when determining compliance. This study aims to inform stakeholders about the potential impact of CAFE on life cycle greenhouse gas (GHG) emissions, should non-petroleum fuel vehicles displace increasingly fuel efficient petroleum vehicles. The well-to-wheel GHG emissions of a set of hypothetical model year 2025 light-duty vehicles are estimated. A reference gasoline vehicle is designed to meet the 2025 fuel economy target within CAFE, and is compared to a set of dedicated CNG vehicles and BEVs with different fuel economy ratings, but all vehicles meet or exceed the fuel economy target due to the policy’s dedicated non-petroleum fuel vehicle incentives. Ownership costs and BEV driving ranges are estimated to provide context, as these can influence automaker and consumer decisions. The results show that CNG vehicles that have lower ownership costs than gasoline vehicles and BEVs with long distance driving ranges can exceed the 2025 CAFE fuel economy target. However, this could lead to lower efficiency CNG vehicles and heavier BEVs that have higher well-to-wheel GHG emissions than gasoline vehicles on a per km basis, even if the non-petroleum energy source is less carbon intensive on an energy equivalent basis. These changes could influence the effectiveness of low carbon fuel standards and are not precluded by the light-duty vehicle GHG emissions standards, which regulate tailpipe but not fuel production emissions.

  12. Study of CNG/diesel dual fuel engine's emissions by means of RBF neural network.

    PubMed

    Liu, Zhen-tao; Fei, Shao-mei

    2004-08-01

    Great efforts have been made to resolve the serious environmental pollution and inevitable declining of energy resources. A review of Chinese fuel reserves and engine technology showed that compressed natural gas (CNG)/diesel dual fuel engine (DFE) was one of the best solutions for the above problems at present. In order to study and improve the emission performance of CNG/diesel DFE, an emission model for DFE based on radial basis function (RBF) neural network was developed which was a black-box input-output training data model not require priori knowledge. The RBF centers and the connected weights could be selected automatically according to the distribution of the training data in input-output space and the given approximating error. Studies showed that the predicted results accorded well with the experimental data over a large range of operating conditions from low load to high load. The developed emissions model based on the RBF neural network could be used to successfully predict and optimize the emissions performance of DFE. And the effect of the DFEmain performance parameters, such as rotation speed, load, pilot quantity and injection timing, were also predicted by means of this model. In resumé, an emission prediction model for CNG/diesel DFE based on RBF neural network was built for analyzing the effect of the main performance parameters on the CO, NOx, emissions of DFE. The predicted results agreed quite well with the traditional emissions model, which indicated that the model had certain application value, although it still has some limitations, because of its high dependence on the quantity of the experimental sample data.

  13. Peripherin-2 couples rhodopsin to the CNG channel in outer segments of rod photoreceptors.

    PubMed

    Becirovic, Elvir; Nguyen, O N Phuong; Paparizos, Christos; Butz, Elisabeth S; Stern-Schneider, Gabi; Wolfrum, Uwe; Hauck, Stefanie M; Ueffing, Marius; Wahl-Schott, Christian; Michalakis, Stylianos; Biel, Martin

    2014-11-15

    Outer segments (OSs) of rod photoreceptors are cellular compartments specialized in the conversion of light into electrical signals. This process relies on the light-triggered change in the intracellular levels of cyclic guanosine monophosphate, which in turn controls the activity of cyclic nucleotide-gated (CNG) channels in the rod OS plasma membrane. The rod CNG channel is a macromolecular complex that in its core harbors the ion-conducting CNGA1 and CNGB1a subunits. To identify additional proteins of the complex that interact with the CNGB1a core subunit, we applied affinity purification of mouse retinal proteins followed by mass spectrometry. In combination with in vitro and in vivo co-immunoprecipitation and fluorescence resonance energy transfer (FRET), we found that the tetraspanin peripherin-2 links CNGB1a to the light-detector rhodopsin. Using immunoelectron microscopy, we found that this peripherin-2/rhodopsin/CNG channel complex localizes to the contact region between the disk rims and the plasma membrane. FRET measurements revealed that the fourth transmembrane domain (TM4) of peripherin-2 is required for the interaction with rhodopsin. Quantitatively, the binding affinity of the peripherin-2/rhodopsin interaction was in a similar range as that observed for rhodopsin dimers. Finally, we demonstrate that the p.G266D retinitis pigmentosa mutation found within TM4 selectively abolishes the binding of peripherin-2 to rhodopsin. This finding suggests that the specific disruption of the rhodopsin/peripherin-2 interaction in the p.G266D mutant might contribute to the pathophysiology in affected persons. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Injection characteristics study of high-pressure direct injector for Compressed Natural Gas (CNG) using experimental and analytical method

    NASA Astrophysics Data System (ADS)

    Taha, Z.; Rahim, MF Abdul; Mamat, R.

    2017-10-01

    The injection characteristics of direct injector affect the mixture formation and combustion processes. In addition, the injector is converted from gasoline operation for CNG application. Thus measurement of CNG direct injector mass flow rate was done by independently tested a single injector on a test bench. The first case investigated the effect of CNG injection pressure and the second case evaluate the effect of pulse-width of injection duration. An analytical model was also developed to predict the mass flow rate of the injector. The injector was operated in a choked condition in both the experiments and simulation studies. In case 1, it was shown that mass flow rate through the injector is affected by injection pressure linearly. Based on the tested injection pressure of 20 bar to 60 bar, the resultant mass flow rate are in the range of 0.4 g/s to 1.2 g/s which are met with theoretical flow rate required by the engine. However, in Case 2, it was demonstrated that the average mass flow rate at short injection durations is lower than recorded in Case 1. At injection pressure of 50 bar, the average mass flow rate for Case 2 and Case 1 are 0.7 g/s and 1.1 g/s respectively. Also, the measured mass flow rate at short injection duration showing a fluctuating data in the range of 0.2 g/s - 1.3 g/s without any noticeable trends. The injector model able to predict the trend of the mass flow rate at different injection pressure but unable to track the fluctuating trend at short injection duration.

  15. Alternative Splicing Governs Cone Cyclic Nucleotide-gated (CNG) Channel Sensitivity to Regulation by Phosphoinositides*

    PubMed Central

    Dai, Gucan; Sherpa, Tshering; Varnum, Michael D.

    2014-01-01

    Precursor mRNA encoding CNGA3 subunits of cone photoreceptor cyclic nucleotide-gated (CNG) channels undergoes alternative splicing, generating isoforms differing in the N-terminal cytoplasmic region of the protein. In humans, four variants arise from alternative splicing, but the functional significance of these changes has been a persistent mystery. Heterologous expression of the four possible CNGA3 isoforms alone or with CNGB3 subunits did not reveal significant differences in basic channel properties. However, inclusion of optional exon 3, with or without optional exon 5, produced heteromeric CNGA3 + CNGB3 channels exhibiting an ∼2-fold greater shift in K1/2,cGMP after phosphatidylinositol 4,5-biphosphate or phosphatidylinositol 3,4,5-trisphosphate application compared with channels lacking the sequence encoded by exon 3. We have previously identified two structural features within CNGA3 that support phosphoinositides (PIPn) regulation of cone CNG channels: N- and C-terminal regulatory modules. Specific mutations within these regions eliminated PIPn sensitivity of CNGA3 + CNGB3 channels. The exon 3 variant enhanced the component of PIPn regulation that depends on the C-terminal region rather than the nearby N-terminal region, consistent with an allosteric effect on PIPn sensitivity because of altered N-C coupling. Alternative splicing of CNGA3 occurs in multiple species, although the exact variants are not conserved across CNGA3 orthologs. Optional exon 3 appears to be unique to humans, even compared with other primates. In parallel, we found that a specific splice variant of canine CNGA3 removes a region of the protein that is necessary for high sensitivity to PIPn. CNGA3 alternative splicing may have evolved, in part, to tune the interactions between cone CNG channels and membrane-bound phosphoinositides. PMID:24675082

  16. Transmembrane S1 mutations in CNGA3 from achromatopsia 2 patients cause loss of function and impaired cellular trafficking of the cone CNG channel.

    PubMed

    Patel, Kirti A; Bartoli, Kristen M; Fandino, Richard A; Ngatchou, Anita N; Woch, Gustaw; Carey, Jannette; Tanaka, Jacqueline C

    2005-07-01

    Achromatopsia 2, an inherited retinal disorder resulting in attenuation or loss of cone function, is caused by mutations in the alpha subunit of the cone cyclic nucleotide-gated (CNG) channel gene CNGA3. Examination of mutations that cluster in the first transmembrane segment of the protein may provide insight into its role in CNG channel structure, function, biogenesis, and pathophysiology. The human CNGA3 gene was tagged at the C terminus with green fluorescent protein. Four mutations, Y181C, N182Y, L186F, and C191Y, were expressed in human embryonic kidney cells. Protein expression was evaluated with immunoblot analysis and cellular localization was determined by immunocytochemistry. Channel function was evaluated by patch-clamp electrophysiology. All the mutations result in loss of channel function, as determined by the failure of cGMP to activate wild-type currents in excised patches. Full-length mutant proteins were synthesized but retained in the endoplasmic reticulum. Glycerol treatment did not rescue channel function nor did coexpression with CNGB3, a subunit of native hetero-tetrameric cone channels. A control mutant, C191S, exhibited cGMP current activation with significantly reduced cooperativity, suggesting that mutations in the first transmembrane domain alter in inter- or intrasubunit communication. The results implicate the first transmembrane segment in both maturation and function of CNG channels. The defects are not reversed with glycerol, a chemical chaperone that rescues channel function in some channelopathies. Molecular analysis of achromatopsia 2 mutations may be useful in evaluating potential therapeutic approaches for treatment of this channelopathy.

  17. Alternative splicing governs cone cyclic nucleotide-gated (CNG) channel sensitivity to regulation by phosphoinositides.

    PubMed

    Dai, Gucan; Sherpa, Tshering; Varnum, Michael D

    2014-05-09

    Precursor mRNA encoding CNGA3 subunits of cone photoreceptor cyclic nucleotide-gated (CNG) channels undergoes alternative splicing, generating isoforms differing in the N-terminal cytoplasmic region of the protein. In humans, four variants arise from alternative splicing, but the functional significance of these changes has been a persistent mystery. Heterologous expression of the four possible CNGA3 isoforms alone or with CNGB3 subunits did not reveal significant differences in basic channel properties. However, inclusion of optional exon 3, with or without optional exon 5, produced heteromeric CNGA3 + CNGB3 channels exhibiting an ∼2-fold greater shift in K1/2,cGMP after phosphatidylinositol 4,5-biphosphate or phosphatidylinositol 3,4,5-trisphosphate application compared with channels lacking the sequence encoded by exon 3. We have previously identified two structural features within CNGA3 that support phosphoinositides (PIPn) regulation of cone CNG channels: N- and C-terminal regulatory modules. Specific mutations within these regions eliminated PIPn sensitivity of CNGA3 + CNGB3 channels. The exon 3 variant enhanced the component of PIPn regulation that depends on the C-terminal region rather than the nearby N-terminal region, consistent with an allosteric effect on PIPn sensitivity because of altered N-C coupling. Alternative splicing of CNGA3 occurs in multiple species, although the exact variants are not conserved across CNGA3 orthologs. Optional exon 3 appears to be unique to humans, even compared with other primates. In parallel, we found that a specific splice variant of canine CNGA3 removes a region of the protein that is necessary for high sensitivity to PIPn. CNGA3 alternative splicing may have evolved, in part, to tune the interactions between cone CNG channels and membrane-bound phosphoinositides.

  18. Mutation of a single residue in the S2-S3 loop of CNG channels alters the gating properties and sensitivity to inhibitors.

    PubMed

    Crary, J I; Dean, D M; Maroof, F; Zimmerman, A L

    2000-12-01

    We previously found that native cyclic nucleotide-gated (CNG) cation channels from amphibian rod cells are directly and reversibly inhibited by analogues of diacylglycerol (DAG), but little is known about the mechanism of this inhibition. We recently determined that, at saturating cGMP concentrations, DAG completely inhibits cloned bovine rod (Brod) CNG channels while only partially inhibiting cloned rat olfactory (Rolf) channels (Crary, J.I., D.M. Dean, W. Nguitragool, P.T. Kurshan, and A.L. Zimmerman. 2000. J. Gen. Phys. 116:755-768; in this issue). Here, we report that a point mutation at position 204 in the S2-S3 loop of Rolf and a mouse CNG channel (Molf) found in olfactory epithelium and heart, increased DAG sensitivity to that of the Brod channel. Mutation of this residue from the wild-type glycine to a glutamate (Molf G204E) or aspartate (Molf G204D) gave dramatic increases in DAG sensitivity without changing the apparent cGMP or cAMP affinities or efficacies. However, unlike the wild-type olfactory channels, these mutants demonstrated voltage-dependent gating with obvious activation and deactivation kinetics. Interestingly, the mutants were also more sensitive to inhibition by the local anesthetic, tetracaine. Replacement of the position 204 glycine with a tryptophan residue (Rolf G204W) not only gave voltage-dependent gating and an increased sensitivity to DAG and tetracaine, but also showed reduced apparent agonist affinity and cAMP efficacy. Sequence comparisons show that the glycine at position 204 in the S2-S3 loop is highly conserved, and our findings indicate that its alteration can have critical consequences for channel gating and inhibition.

  19. In-vitro assessment and pharmacodynamics of nimesulide incorporated Aloe vera transemulgel.

    PubMed

    Vandana, K R; Yalavarthi, Prasanna R; Sundaresan, C R; Sriramaneni, Raghava N; Vadlamudi, Harini C

    2014-06-01

    The aim of the investigation was to prepare nimesulide emulsion for incorporation in Aloe vera gel base to formulate 'nimesulide - Aloe vera transemulgel' (NAE) and to carryout in-vitro assessment and in-vivo anti-inflammatory studies of the product. Although the use of nimesulide is banned for oral administration, due to its potential for inducing hepatotoxicity and thrombocytopenia, the use of nimesulide for topical delivery is prominent in the treatment of many inflammatory conditions including rheumatoid arthritis. The drug loading capacity of transdermal gels is low for hydrophobic drugs such as nimesulide. Nimesulide can be effectively incorporated into emulgels (a combination of emulsion and gel). Aloe vera has a mild anti-inflammatory effect and in the present study Aloe vera gel was formulated and used as a gel base to prepare NAE. The emulgels thus prepared were evaluated for viscosity, pH, in-vitro permeation, stability and skin irritation test. In-vivo anti-inflammatory studies were performed using carrageenan induced hind paw edema method in Wistar rats. The results were compared with that of commercial nimesulide gel (CNG). From the in-vitro studies, effective permeation of nimesulide from NAE (53.04 %) was observed compared to CNG (44.72 %) at 30 min indicating better drug release from NAE. Topical application of the emulgel found no skin irritation. Stability studies proved the integrity of the formulation. The percentage of inhibition of edema was highest for the prepared NAE (67.4 % inhibition after 240 min) compared to CNG (59.6 %). From our results, it was concluded that the Aloe vera gel acts as an effective gel base to prepare nimesulide emulgel with high drug loading capacity (86.4 % drug content) compared to CNG (70.5 % drug content) with significant anti-inflammatory effect.

  20. Aviation Gas Turbine Engine Emissions: Drop in Alternative Fuel and its Challenges

    NASA Astrophysics Data System (ADS)

    Noh, H. Mohd; Rodrigo, G. A.; Rahman, N. A. Abdul; Ismail, S.; Shafie, M. A.; Zainal Ariffin, M. W.; Ahmad, A. A.; Basit, R.; Khalid, A.; Yahaya, N. H. R.; Yusoff, M. R.; Othman, J.

    2018-05-01

    The growing demand of air travel in aviation industries contributes to increases in carbon emissions. As far as technological, infrastructure and operation is concerned, carbon-neutral growth (CNG) cannot be achieved due to fossil fuel usage. The involvement of biojet fuel is the only measures that can be adapted to reduce up to -50% of Carbon emissions. This paper will discuss the gas emissions from the aircraft engine and the challenges it poses to Airlines and operation as well as adapting the Alternative drop-in fuel as its solutions. Alternative fuel using biomass has been approved by American Society for Testing and Materials (ASTM) to be a drop-in fuel with no alteration on the gas turbine engine, hence will ease and generate cost saving for the Airlines. The challenges remain, as the concern on the fuel properties and characteristics, distributions, environment and economic, have been the focal point for policymakers and researchers. As a conclusion, the authority and the government need to join hand in creating the opportunity for alternative fuel in the aviation industries to ensure the reduction in aviation carbon emissions.

  1. Natural Gas Use On Minibuses, Engaged In The Carriage Of Passengers And Baggage On The Regular Routes, As A Measure For Decrease In Harmful Environment Effects

    NASA Astrophysics Data System (ADS)

    Chikishev, E.; Chikisheva, A.; Anisimov, I.; Chainikov, D.

    2017-01-01

    The paper deals with an option of increase the compressed natural gas use as a motor fuel for diesel minibuses to reduce emissions of harmful substances with exhaust gases. In terms of the Russian company LTD "WTC Automobilist", carrying passengers and baggage on regular routes by minibuses, the calculation of the park's natural gas needs is promoted. A mini CNG RS with optimal performance is suggested. The approximate payback period of the natural gas equipment installation on all buses of company and introduction into service period of mini CNG RS are calculated.

  2. Gram-scale, high-yield synthesis of a robust metal-organic framework for storing methane and other gases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wilmer, CE; Farha, OK; Yildirim, T

    We have synthesized and characterized a new metal-organic framework (MOF) material, NU-125, that, in the single-crystal limit, achieves a methane storage density at 58 bar (840 psi) and 298 K corresponding to 86% of that obtained with compressed natural gas tanks (CNG) used in vehicles today, when the latter are pressurized to 248 bar (3600 psi). More importantly, the deliverable capacity (58 bar to 5.8 bar) for NU-125 is 67% of the deliverable capacity of a CNG tank that starts at 248 bar. (For crystalline granules or powders, particle packing inefficiencies will yield densities and deliverable capacities lower than 86%more » and 67% of high-pressure CNG.) This material was synthesized in high yield on a gram-scale in a single-batch synthesis. Methane adsorption isotherms were measured over a wide pressure range (0.1-58 bar) and repeated over twelve cycles on the same sample, which showed no detectable degradation. Adsorption of CO2 and H-2 over a broad range of pressures and temperatures are also reported and agree with our computational findings.« less

  3. Development of CNG direct injection (CNGDI) clean fuel system for extra power in small engine

    NASA Astrophysics Data System (ADS)

    Ali, Yusoff; Shamsudeen, Azhari; Abdullah, Shahrir; Mahmood, Wan Mohd Faizal Wan

    2012-06-01

    A new design of fuel system for CNG engine with direct injection (CNGDI) was developed for a demonstration project. The development of the fuel system was done on the engine with cylinder head modifications, for fuel injector and spark plug openings included in the new cylinder head. The piston was also redesigned for higher compression ratio. The fuel rails and the regulators are also designed for the direct injection system operating at higher pressure about 2.0 MPa. The control of the injection timing for the direct injectors are also controlled by the Electronic Control Unit specially designed for DI by another group project. The injectors are selected after testing with the various injection pressures and spray angles. For the best performance of the high-pressure system, selection is made from the tests on single cylinder research engine (SCRE). The components in the fuel system have to be of higher quality and complied with codes and standards to secure the safety of engine for high-pressure operation. The results of the CNGDI have shown that better power output is produced and better emissions were achieved compared to the aspirated CNG engine.

  4. Characterization of Acoustic Emission Parameters During Testing of Metal Liner Reinforced with Fully Resin Impregnated CNG Cylinder

    NASA Astrophysics Data System (ADS)

    Kenok, R.; Jomdecha, C.; Jirarungsatian, C.

    The aim of this paper is to study the acoustic emission (AE) parameters obtained from CNG cylinders during pressurization. AE from flaw propagation, material integrity, and pressuring of cylinder was the main objective for characterization. CNG cylinders of ISO 11439, resin fully wrapped type and metal liner type, were employed to test by hydrostatic stressing. The pressure was step increased until 1.1 time of operating pressure. Two AE sensors, resonance frequency of 150 kHz, were mounted on the cylinder wall to detect the AE throughout the testing. From the experiment results, AE can be detected from pressuring rate, material integrity, and flaw propagation from the cylinder wall. AE parameters including Amplitude, Count, Energy (MARSE), Duration and Rise time were analyzed to distinguish the AE data. The results show that the AE of flaw propagation was different in character from that of pressurization. Especially, AE detected from flaws of resin wrapped and metal liner was significantly different. To locate the flaw position, both the AE sensors can be accurately used to locate the flaw propagation in a linear pattern. The error was less than ±5 cm.

  5. Influence of surface rectangular defect winding layer on burst pressure of CNG-II composite cylinder

    NASA Astrophysics Data System (ADS)

    You, H. X.; Peng, L.; Zhao, C.; Ma, K.; Zhang, S.

    2018-01-01

    To study the influence of composite materials’ surface defect on the burst pressure of CNG-II composite cylinder, the surface defect was simplified as a rectangular slot of certain size on the basis of actually investigating the shape of cylinder’s surface defect. A CNG-II composite cylinder with a rectangular slot defect (2mm in depth) was used for burst test, and the numerical simulation software ANSYS was used to calculate its burst pressure. Through comparison between the burst pressure in the test and the numerical analysis result, the correctness of the numerical analysis method was verified. On this basis, the numerical analysis method was conducted for composite cylinders with surface defect in other depth. The result showed that surface defect in the form of rectangular slot had no significant effect on the liner stress of composite cylinder. Instead, it had a great influence on the stress of fiber-wrapped layer. The burst pressure of the composite cylinder decreased as the defect depth increasing. The hoop stress at the bottom of the defect in the shape of rectangular slot exceeded the maximum of the composite materials’ tensile strength, which could result in the burst pressure of composite cylinders decreasing.

  6. Wavelength and energy dependent absorption of unconventional fuel mixtures

    NASA Astrophysics Data System (ADS)

    Khan, N.; Saleem, Z.; Mirza, A. A.

    2005-11-01

    Economic considerations of laser induced ignition over the normal electrical ignition of direct injected Compressed Natural Gas (CNG) engines has motivated automobile industry to go for extensive research on basic characteristics of leaner unconventional fuel mixtures to evaluate practical possibility of switching over to the emerging technologies. This paper briefly reviews the ongoing research activities on minimum ignition energy and power requirements of natural gas fuels and reports results of present laser air/CNG mixture absorption coefficient study. This study was arranged to determine the thermo-optical characteristics of high air/fuel ratio mixtures using laser techniques. We measured the absorption coefficient using four lasers of multiple wavelengths over a wide range of temperatures and pressures. The absorption coefficient of mixture was found to vary significantly over change of mixture temperature and probe laser wavelengths. The absorption coefficients of air/CNG mixtures were measured using 20 watts CW/pulsed CO2 laser at 10.6μm, Pulsed Nd:Yag laser at 1.06μm, 532 nm (2nd harmonic) and 4 mW CW HeNe laser at 645 nm and 580 nm for temperatures varying from 290 to 1000K using optical transmission loss technique.

  7. Compressed Natural Gas Vehicle Maintenance Facility Modification Handbook

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kelly, Kay L.; Ramsden, Margo M.; Gonzales, John E.

    To ensure the safety of personnel and facilities, vehicle maintenance facilities are required by law and by guidelines of the National Fire Protection Association (NFPA) and the International Fire Code (IFC) to exhibit certain design features. They are also required to be fitted with certain fire protection equipment and devices because of the potential for fire or explosion in the event of fuel leakage or spills. All fuels have an explosion or fire potential if specific conditions are present. The hazard presented by liquid fuels, such as gasoline and diesel, results from the spillage of these liquids and subsequent ignitionmore » of vapors, causing a fire or explosion. Facilities that maintain liquid-fueled vehicles and implement appropriate safety measures are protected with ventilation systems designed to capture liquid fuel vapors at or near floor level. To minimize the potential for ignition in the event of a spill, receptacles, electrical fixtures, and hot-work operations, such as welding, are located outside of these areas. Compressed natural gas (CNG) is composed of methane with slight amounts of heavier simple hydrocarbons. Maintenance facilities that maintain CNG vehicles indoors must be protected against fire and explosion. However, the means of ensuring safety are different from those employed for liquid fuels because of the gaseous nature of methane and the fact that it is lighter than air. Because CNG is lighter than air, a release will rise to the ceiling of the maintenance facility and quickly dissipate rather than remaining at or near floor level like liquid fuel vapors. Although some of the means of protection for CNG vehicle maintenance facilities are similar to those used for liquid-fueled vehicles (ventilation and elimination of ignition sources), the types and placement of the protection equipment are different because of the behavior of the different fuels. The nature of gaseous methane may also require additional safeguards, such as combustible gas detectors and control systems, or specialized space heating, which are not needed in facilities servicing liquid-fuel vehicles. This handbook covers maintenance facilities that service CNG-fueled vehicles. Although similar requirements are mandated for liquefied natural gas (LNG) or liquefied petroleum gas (LPG) fueled vehicles, LNG and LPG are not covered in this handbook.« less

  8. COMPARATIVE STUDY ON EXHAUST EMISSIONS FROM DIESEL- AND CNG-POWERED URBAN BUSES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    COROLLER, P; PLASSAT, G

    2003-08-24

    Couple years ago, ADEME engaged programs dedicated to the urban buses exhaust emissions studies. The measures associated with the reduction of atmospheric and noise pollution has particular importance in the sector of urban buses. In many cases, they illustrate the city's environmental image and contribute to reinforcing the attractiveness of public transport. France's fleet in service, presently put at about 14,000 units, consumes about 2 per cent of the total energy of city transport. It causes about 2 per cent of the HC emissions and from 4 to 6 per cent of the NOx emissions and particles. These vehicles typicallymore » have a long life span (about 15 years) and are relatively expensive to buy, about 150.000 euros per unit. Several technical solutions were evaluated to quantify, on a real condition cycle for buses, on one hand pollutants emissions, fuel consumption and on the other hand reliability, cost in real existing fleet. This paper presents main preliminary results on urban buses exhaust emission on two different cases: - existing Diesel buses, with fuel modifications (Diesel with low sulphur content), Diesel with water emulsion and bio-Diesel (30% oil ester in standard Diesel fuel); renovating CNG powered Euro II buses fleet, over representative driving cycles, set up by ADEME and partners. On these cycles, pollutants (regulated and unregulated) were measured as well as fuel consumption, at the beginning of a program and one year after to quantify reliability and increase/decrease of pollutants emissions. At the same time, some after-treatment technologies were tested under real conditions and several vehicles. Information such as fuel consumption, lubricant analysis, problem on the technology were following during a one year program. On the overall level, it is the combination of various action, pollution-reduction and renewal that will make it possible to meet the technological challenge of reducing emissions and fuel consumption by urban bus networks.« less

  9. 44 CFR 201.7 - Tribal Mitigation Plans.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of existing and future buildings, infrastructure, and critical facilities located in the identified... effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. (iii...

  10. Spaceflight-induced genetic and epigenetic changes in the rice (Oryza sativa L.) genome are independent of each other.

    PubMed

    Ou, Xiufang; Long, Likun; Wu, Ying; Yu, Yingjie; Lin, Xiuyun; Qi, Xin; Liu, Bao

    2010-07-01

    An array of studies have reported that the spaceflight environment is mutagenic and may induce phenotypic and genetic changes in diverse organisms. We reported recently that in at least some plant species (e.g., rice) the spaceflight environment can be particularly potent in generating heritable epigenetic changes in the form of altered cytosine methylation patterns and activation of transposable elements. To further study the issue of spaceflight-induced genomic instability, and in particular to test whether the incurred genetic and epigenetic changes are connected or independent of each other, we performed the present study. We subjected seeds of the standard laboratory rice (Oryza sativa L.) cultivar Nipponbare to a spaceflight in the spaceship Long March 2 for 18 days. We then investigated the genetic and DNA methylation stabilities of 11 randomly selected plants germinated from the spaceflown seeds by using two kinds of DNA markers, amplified fragment length polymorphism (AFLP) and methylation sensitive amplified polymorphism (MSAP). For AFLP, by using 15 primer combinations, we assessed 460 genomic loci and found that the frequencies of genetic changes across the 11 plants ranged from 0.7% to 6.7% with an average frequency of 3.5%. For MSAP, by using 14 primer combinations, we assessed 467 loci and detected the occurrence of four major types of cytosine methylation alterations at the CCGG sites, namely CG or CNG hypomethylation and CG or CNG hypermethylation. Collectively, the frequencies of the two kinds of hypermethylation, CG (1.95%) and CNG (1.44%), are about two times higher than those of the two kinds of hypomethylation, CG (0.76%) and CNG (0.80%), though different plants showed variable frequencies for each type of alteration. Further analysis suggested that both the genetic and cytosine methylation changes manifested apparent mutational bias towards specific genomic regions, but the two kinds of instabilities are independent of each other based on correlation analysis.

  11. Use of natural gas, methanol, and ethanol fuel emulsions as environmentally friendly energy carriers for mobile heat power plants

    NASA Astrophysics Data System (ADS)

    Likhanov, V. A.; Lopatin, O. P.

    2017-12-01

    The need for using environmentally friendly energy carriers for mobile heat power plants (HPPs) is grounded. Ecologically friendly sources of energy, such as natural gas as well as renewable methyl and ethyl alcohols, are investigated. In order to develop, determine, and optimize the composition of environmentally friendly energy carriers for an HPP, the latter has been tested when working on diesel fuel (DF), compressed natural gas (CNG), and methanol and ethanol fuel emulsions (MFE, EFE). It has been experimentally established that, for the application of environmentally friendly energy carriers for a 4Ch 11.0/12.5 diesel engine of a mobile fuel and power plant, it is necessary to maintain the following ratio of components when working on CNG: 80% gas and 20% DF primer portion. When working on an alcohol mixture, emulsions of the following composition were used: 25% alcohol (methanol or ethanol), 0.5% detergent-dispersant additive succinimide C-5A, 7% water, and 67.5% DF. When this diesel passed from oil DF to environmentally friendly energy sources, it allowed for the reduction of the content of exhaust gases (EG) (1) when working on CNG with recirculation of exhaust gases (EGR) (recirculation was used to eliminate the increased amount of nitric oxides by using CNG): carbon black by 5.8 times, carbon dioxide by 45.9%, and carbon monoxide by 23.8%; (2) when working on MFE: carbon black by 6.4 times, nitrogen oxides by 29.6%, carbon dioxide by 10.1%, and carbon oxide by 47.6%; (3) when working on EFE: carbon black by 4.8 times; nitrogen oxides by 40.3%, carbon dioxide by 26.6%, and carbon monoxide by 28.6%. The prospects of use of environmentally friendly energy carriers in diesels of mobile HPPs, such as natural gas, ethanol, and methanol, has been determined.

  12. CNGA3 achromatopsia-associated mutation potentiates the phosphoinositide sensitivity of cone photoreceptor CNG channels by altering intersubunit interactions

    PubMed Central

    Dai, Gucan

    2013-01-01

    Cyclic nucleotide-gated (CNG) channels are critical for sensory transduction in retinal photoreceptors and olfactory receptor cells; their activity is modulated by phosphoinositides (PIPn) such as phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3). An achromatopsia-associated mutation in cone photoreceptor CNGA3, L633P, is located in a carboxyl (COOH)-terminal leucine zipper domain shown previously to be important for channel assembly and PIPn regulation. We determined the functional consequences of this mutation using electrophysiological recordings of patches excised from cells expressing wild-type and mutant CNG channel subunits. CNGA3-L633P subunits formed functional channels with or without CNGB3, producing an increase in apparent cGMP affinity. Surprisingly, L633P dramatically potentiated PIPn inhibition of apparent cGMP affinity for these channels. The impact of L633P on PIPn sensitivity depended on an intact amino (NH2) terminal PIPn regulation module. These observations led us to hypothesize that L633P enhances PIPn inhibition by altering the coupling between NH2- and COOH-terminal regions of CNGA3. A recombinant COOH-terminal fragment partially restored normal PIPn sensitivity to channels with COOH-terminal truncation, but L633P prevented this effect. Furthermore, coimmunoprecipitation of channel fragments, and thermodynamic linkage analysis, also provided evidence for NH2-COOH interactions. Finally, tandem dimers of CNGA3 subunits that specify the arrangement of subunits containing L633P and other mutations indicated that the putative interdomain interaction occurs between channel subunits (intersubunit) rather than exclusively within the same subunit (intrasubunit). Collectively, these studies support a model in which intersubunit interactions control the sensitivity of cone CNG channels to regulation by phosphoinositides. Aberrant channel regulation may contribute to disease progression in patients with the L633P mutation. PMID:23552282

  13. CNGA3 achromatopsia-associated mutation potentiates the phosphoinositide sensitivity of cone photoreceptor CNG channels by altering intersubunit interactions.

    PubMed

    Dai, Gucan; Varnum, Michael D

    2013-07-15

    Cyclic nucleotide-gated (CNG) channels are critical for sensory transduction in retinal photoreceptors and olfactory receptor cells; their activity is modulated by phosphoinositides (PIPn) such as phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3). An achromatopsia-associated mutation in cone photoreceptor CNGA3, L633P, is located in a carboxyl (COOH)-terminal leucine zipper domain shown previously to be important for channel assembly and PIPn regulation. We determined the functional consequences of this mutation using electrophysiological recordings of patches excised from cells expressing wild-type and mutant CNG channel subunits. CNGA3-L633P subunits formed functional channels with or without CNGB3, producing an increase in apparent cGMP affinity. Surprisingly, L633P dramatically potentiated PIPn inhibition of apparent cGMP affinity for these channels. The impact of L633P on PIPn sensitivity depended on an intact amino (NH2) terminal PIPn regulation module. These observations led us to hypothesize that L633P enhances PIPn inhibition by altering the coupling between NH2- and COOH-terminal regions of CNGA3. A recombinant COOH-terminal fragment partially restored normal PIPn sensitivity to channels with COOH-terminal truncation, but L633P prevented this effect. Furthermore, coimmunoprecipitation of channel fragments, and thermodynamic linkage analysis, also provided evidence for NH2-COOH interactions. Finally, tandem dimers of CNGA3 subunits that specify the arrangement of subunits containing L633P and other mutations indicated that the putative interdomain interaction occurs between channel subunits (intersubunit) rather than exclusively within the same subunit (intrasubunit). Collectively, these studies support a model in which intersubunit interactions control the sensitivity of cone CNG channels to regulation by phosphoinositides. Aberrant channel regulation may contribute to disease progression in patients with the L633P mutation.

  14. Two structural components in CNGA3 support regulation of cone CNG channels by phosphoinositides.

    PubMed

    Dai, Gucan; Peng, Changhong; Liu, Chunming; Varnum, Michael D

    2013-04-01

    Cyclic nucleotide-gated (CNG) channels in retinal photoreceptors play a crucial role in vertebrate phototransduction. The ligand sensitivity of photoreceptor CNG channels is adjusted during adaptation and in response to paracrine signals, but the mechanisms involved in channel regulation are only partly understood. Heteromeric cone CNGA3 (A3) + CNGB3 (B3) channels are inhibited by membrane phosphoinositides (PIP(n)), including phosphatidylinositol 3,4,5-triphosphate (PIP(3)) and phosphatidylinositol 4,5-bisphosphate (PIP(2)), demonstrating a decrease in apparent affinity for cyclic guanosine monophosphate (cGMP). Unlike homomeric A1 or A2 channels, A3-only channels paradoxically did not show a decrease in apparent affinity for cGMP after PIP(n) application. However, PIP(n) induced an ∼2.5-fold increase in cAMP efficacy for A3 channels. The PIP(n)-dependent change in cAMP efficacy was abolished by mutations in the C-terminal region (R643Q/R646Q) or by truncation distal to the cyclic nucleotide-binding domain (613X). In addition, A3-613X unmasked a threefold decrease in apparent cGMP affinity with PIP(n) application to homomeric channels, and this effect was dependent on conserved arginines within the N-terminal region of A3. Together, these results indicate that regulation of A3 subunits by phosphoinositides exhibits two separable components, which depend on structural elements within the N- and C-terminal regions, respectively. Furthermore, both N and C regulatory modules in A3 supported PIP(n) regulation of heteromeric A3+B3 channels. B3 subunits were not sufficient to confer PIP(n) sensitivity to heteromeric channels formed with PIP(n)-insensitive A subunits. Finally, channels formed by mixtures of PIP(n)-insensitive A3 subunits, having complementary mutations in N- and/or C-terminal regions, restored PIP(n) regulation, implying that intersubunit N-C interactions help control the phosphoinositide sensitivity of cone CNG channels.

  15. Two structural components in CNGA3 support regulation of cone CNG channels by phosphoinositides

    PubMed Central

    Dai, Gucan; Peng, Changhong; Liu, Chunming

    2013-01-01

    Cyclic nucleotide-gated (CNG) channels in retinal photoreceptors play a crucial role in vertebrate phototransduction. The ligand sensitivity of photoreceptor CNG channels is adjusted during adaptation and in response to paracrine signals, but the mechanisms involved in channel regulation are only partly understood. Heteromeric cone CNGA3 (A3) + CNGB3 (B3) channels are inhibited by membrane phosphoinositides (PIPn), including phosphatidylinositol 3,4,5-triphosphate (PIP3) and phosphatidylinositol 4,5-bisphosphate (PIP2), demonstrating a decrease in apparent affinity for cyclic guanosine monophosphate (cGMP). Unlike homomeric A1 or A2 channels, A3-only channels paradoxically did not show a decrease in apparent affinity for cGMP after PIPn application. However, PIPn induced an ∼2.5-fold increase in cAMP efficacy for A3 channels. The PIPn-dependent change in cAMP efficacy was abolished by mutations in the C-terminal region (R643Q/R646Q) or by truncation distal to the cyclic nucleotide-binding domain (613X). In addition, A3-613X unmasked a threefold decrease in apparent cGMP affinity with PIPn application to homomeric channels, and this effect was dependent on conserved arginines within the N-terminal region of A3. Together, these results indicate that regulation of A3 subunits by phosphoinositides exhibits two separable components, which depend on structural elements within the N- and C-terminal regions, respectively. Furthermore, both N and C regulatory modules in A3 supported PIPn regulation of heteromeric A3+B3 channels. B3 subunits were not sufficient to confer PIPn sensitivity to heteromeric channels formed with PIPn-insensitive A subunits. Finally, channels formed by mixtures of PIPn-insensitive A3 subunits, having complementary mutations in N- and/or C-terminal regions, restored PIPn regulation, implying that intersubunit N–C interactions help control the phosphoinositide sensitivity of cone CNG channels. PMID:23530136

  16. Negative feedback exerted by cAMP-dependent protein kinase and cAMP phosphodiesterase on subsarcolemmal cAMP signals in intact cardiac myocytes: an in vivo study using adenovirus-mediated expression of CNG channels.

    PubMed

    Rochais, Francesca; Vandecasteele, Grégoire; Lefebvre, Florence; Lugnier, Claire; Lum, Hazel; Mazet, Jean-Luc; Cooper, Dermot M F; Fischmeister, Rodolphe

    2004-12-10

    Intracardiac cAMP levels are modulated by hormones and neuromediators with specific effects on contractility and metabolism. To understand how the same second messenger conveys different information, mutants of the rat olfactory cyclic nucleotide-gated (CNG) channel alpha-subunit CNGA2, encoded into adenoviruses, were used to monitor cAMP in adult rat ventricular myocytes. CNGA2 was not found in native myocytes but was strongly expressed in infected cells. In whole cell patch-clamp experiments, the forskolin analogue L-858051 (L-85) elicited a non-selective, Mg2+ -sensitive current observed only in infected cells, which was thus identified as the CNG current (ICNG). The beta-adrenergic agonist isoprenaline (ISO) also activated ICNG, although the maximal efficiency was approximately 5 times lower than with L-85. However, ISO and L-85 exerted a similar maximal increase of the L-type Ca2+ current. The use of a CNGA2 mutant with a higher sensitivity for cAMP indicated that this difference is caused by the activation of a localized fraction of CNG channels by ISO. cAMP-dependent protein kinase (PKA) blockade with H89 or PKI, or phosphodiesterase (PDE) inhibition with IBMX, dramatically potentiated ISO- and L-85-stimulated ICNG. A similar potentiation of beta-adrenergic stimulation occurred when PDE4 was blocked, whereas PDE3 inhibition had a smaller effect (by 2-fold). ISO and L-85 increased total PDE3 and PDE4 activities in cardiomyocytes, although this effect was insensitive to H89. However, in the presence of IBMX, H89 had no effect on ISO stimulation of ICNG. This study demonstrates that subsarcolemmal cAMP levels are dynamically regulated by a negative feedback involving PKA stimulation of subsarcolemmal cAMP-PDE.

  17. CALS Infrastructure Analysis. Draft. Volume 21

    DOT National Transportation Integrated Search

    1990-03-01

    This executive overview to the DoD CALS Infrastructure Analysis Report summarizes the Components' current effort to modernize the DoD technical data infrastructure. This infrastructure includes all existing and planned capabilities to acquire, manage...

  18. Connected Vehicle Infrastructure : Deployment and Funding Overview

    DOT National Transportation Integrated Search

    2018-01-01

    This report reviews existing and proposed legislation relevant to connected vehicle infrastructure (CVI) implementation, identifies existing funding mechanisms for CVI implementation, reviews CVI pilot programs and case studies, and provides an overv...

  19. Beacons for supporting lunar landing navigation

    NASA Astrophysics Data System (ADS)

    Theil, Stephan; Bora, Leonardo

    2017-03-01

    Current and future planetary exploration missions involve a landing on the target celestial body. Almost all of these landing missions are currently relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. As soon as an infrastructure at the landing site exists, the requirements as well as conditions change for vehicles landing close to this existing infrastructure. This paper investigates the options for ground-based infrastructure supporting the onboard navigation system and analyzes the impact on the achievable navigation accuracy. For that purpose, the paper starts with an existing navigation architecture based on optical navigation and extends it with measurements to support navigation with ground infrastructure. A scenario of lunar landing is simulated and the provided functions of the ground infrastructure as well as the location with respect to the landing site are evaluated. The results are analyzed and discussed.

  20. CNG Cylinder Safety - Education, Outreach, and Next Steps (Presentation)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith, M.; Schroeder, A.

    2014-01-01

    Mr. Schroeder discussed the work that NREL is performing for the U.S. Department of Transportation on compressed natural gas cylinder end-of-life requirements. CNG vehicles are different from most other vehicles in that the CNG fuel storage cylinders have a pre-determined lifetime that may be shorter than the expected life of the vehicle. The end-of-life date for a cylinder is based on construction and test protocols, and is specific to the construction and material of each cylinder. The end-of-life date is important because it provides a safe margin of error against catastrophic cylinder failure or rupture. The end-of-life dates range frommore » 15 to 25 years from the date of manufacture. NREL worked to develop outreach materials to increase awareness of cylinder end-of-life dates, has provided technical support for individual efforts related to cylinder safety and removal, and also worked with CVEF to document best practices for cylinder removal or inspection after an accident. Mr. Smith discussed the engagement of the DOE Clean Fleets Partners, which were surveyed to identify best practices on managing cylinder inventories and approached to provide initial data on cylinder age in a fleet environment. Both DOE and NREL will continue to engage these fleets and other stakeholders to determine how to best address this issue moving forward.« less

  1. Fresh and Oxidized Emissions from In-Use Transit Buses Running on Diesel, Biodiesel, and CNG.

    PubMed

    Watne, Ågot K; Psichoudaki, Magda; Ljungström, Evert; Le Breton, Michael; Hallquist, Mattias; Jerksjö, Martin; Fallgren, Henrik; Jutterström, Sara; Hallquist, Åsa M

    2018-06-26

    The potential effect of changing to a nonfossil fuel vehicle fleet was investigated by measuring primary emissions (by extractive sampling of bus plumes) and secondary mass formation, using a Gothenburg Potential Aerosol Mass (Go:PAM) reactor, from 29 in-use transit buses. Regarding fresh emissions, diesel (DSL) buses without a diesel particulate filter (DPF) emitted the highest median mass of particles, whereas compressed natural gas (CNG) buses emitted the lowest ( Md EF PM 514 and 11 mg kg fuel -1 , respectively). Rapeseed methyl ester (RME) buses showed smaller Md EF PM and particle sizes than DSL buses. DSL (no DPF) and hybrid-electric RME (RME HEV ) buses exhibited the highest particle numbers ( Md EF PN 12 × 10 14 # kg fuel -1 ). RME HEV buses displayed a significant nucleation mode ( D p < 20 nm). EF PN of CNG buses spanned the highest to lowest values measured. Low Md EF PN and Md EF PM were observed for a DPF-equipped DSL bus. Secondary particle formation resulting from exhaust aging was generally important for all the buses (79% showed an average EF PM:AGED /EF PM:FRESH ratio >10) and fuel types tested, suggesting an important nonfuel dependent source. The results suggest that the potential for forming secondary mass should be considered in future fuel shifts, since the environmental impact is different when only considering the primary emissions.

  2. The influence of sequence context and length on the kinetics of DNA duplex formation from complementary hairpins possessing (CNG) repeats.

    PubMed

    Paiva, Anthony M; Sheardy, Richard D

    2005-04-20

    The formation of unusual structures during DNA replication has been invoked for gene expansion in genomes possessing triplet repeat sequences, CNG, where N = A, C, G, or T. In particular, it has been suggested that the daughter strand of the leading strand partially dissociates from the parent strand and forms a hairpin. The equilibrium between the fully duplexed parent:daugter species and the parent:hairpin species is dependent upon their relative stabilities and the rates of reannealing of the daughter strand back to the parent. These stabilities and rates are ultimately influenced by the sequence context of the DNA and its length. Previous work has demonstrated that longer strands are more stable than shorter strands and that the identity of N also influences the thermal stability [Paiva, A. M.; Sheardy, R. D. Biochemistry 2004, 43, 14218-14227]. Here, we show that the rate of duplex formation from complementary hairpins is also sequence context and length dependent. In particular, longer duplexes have higher activation energies than shorter duplexes of the same sequence context. Further, [(CCG):(GGC)] duplexes have lower activation energies than corresponding [(CAG):(GTC)] duplexes of the same length. Hence, hairpins formed from long CNG sequences are more thermodynamically stable and have slower kinetics for reannealing to their complement than shorter analogues. Gene expansion can now be explained in terms of thermodynamics and kinetics.

  3. Ultrafine PM emissions from natural gas, oxidation-catalyst diesel, and particle-trap diesel heavy-duty transit buses.

    PubMed

    Holmén, Britt A; Ayala, Alberto

    2002-12-01

    This paper addresses how current technologies effective for reducing PM emissions of heavy-duty engines may affect the physical characteristics of the particles emitted. Three in-use transit bus configurations were compared in terms of submicron particle size distributions using simultaneous SMPS measurements under two dilution conditions, a minidiluter and the legislated constant volume sampler (CVS). The compressed natural gas (CNG)-fueled and diesel particulate filter (DPF)-equipped diesel configurations are two "green" alternatives to conventional diesel engines. The CNG bus in this study did not have an oxidation catalyst whereas the diesel configurations (with and without particulate filter) employed catalysts. The DPF was a continuously regenerating trap (CRT). Particle size distributions were collected between 6 and 237 nm using 2-minute SMPS scans during idle and 55 mph steady-state cruise operation. Average particle size distributions collected during idle operation of the diesel baseline bus operating on ultralow sulfur fuel showed evidence for nanoparticle growth under CVS dilution conditions relative to the minidiluter. The CRT effectively reduced both accumulation and nuclei mode concentrations by factors of 10-100 except under CVS dilution conditions where nuclei mode concentrations were measured during 55 mph steady-state cruise that exceeded baseline diesel concentrations. The CVS data suggest some variability in trap performance. The CNG bus had accumulation mode concentrations 10-100x lower than the diesel baseline but often displayed large nuclei modes, especially under CVS dilution conditions. Partly this may be explained by the lack of an oxidation catalyst on the CNG, but differences between the minidiluter and CVS size distributions suggest that dilution ratio, temperature-related wall interactions, and differences in tunnel background between the diluters contributed to creating nanoparticle concentrations that sometimes exceeded diesel baseline concentrations when driving under load. The results do not support use of CVS dilution methodology for ultrafine particle sampling, and, despite attention to collection of tunnel blanks in this study, results indicate that a protocol needs to be determined and prescribed for taking into account tunnel blank "emissions" to obtain meaningful comparisons between different technologies. Of critical importance is determining how temperature differences between tunnel blank and test cycle sampling compare in terms of background particle numbers. Total particle number concentrations for the minidiluter sampling point were not significantly different for the two alternative technologies when considering all the steady-cycle data collected. Concentrations ranged from 0.8 to 3 x 10(6) for the baseline bus operating on ultralow sulfur fuel, from 0.5 to 9 x 10(4) for the diesel bus equipped with the CRT filter, and from 1 to 8 x 10(4) particles/cc for the CNG bus.

  4. EERE: Alternative Fuels Data Center Home Page

    Science.gov Websites

    facility safe with a first-of-its-kind CNG Maintenance Facility Modifications Handbook. Find Fleet & Equipment Maintenance Driving Behavior Fleet Rightsizing System Efficiency Locate Stations Search

  5. Fuzzy architecture assessment for critical infrastructure resilience

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Muller, George

    2012-12-01

    This paper presents an approach for the selection of alternative architectures in a connected infrastructure system to increase resilience of the overall infrastructure system. The paper begins with a description of resilience and critical infrastructure, then summarizes existing approaches to resilience, and presents a fuzzy-rule based method of selecting among alternative infrastructure architectures. This methodology includes considerations which are most important when deciding on an approach to resilience. The paper concludes with a proposed approach which builds on existing resilience architecting methods by integrating key system aspects using fuzzy memberships and fuzzy rule sets. This novel approach aids the systemsmore » architect in considering resilience for the evaluation of architectures for adoption into the final system architecture.« less

  6. A study of the feasibility of pneumatic transport of municipal solid waste and recyclables in Manhattan using existing transportation infrastructure.

    DOT National Transportation Integrated Search

    2013-07-01

    This study explored possibilities for using existing transportation infrastructure for the cost-effective : installation of pneumatic waste-collection technology in Manhattan. If shown to be economically and : operationally feasible, reducing the num...

  7. Computational exploration of cis-regulatory modules in rhythmic expression data using the "Exploration of Distinctive CREs and CRMs" (EDCC) and "CRM Network Generator" (CNG) programs.

    PubMed

    Bekiaris, Pavlos Stephanos; Tekath, Tobias; Staiger, Dorothee; Danisman, Selahattin

    2018-01-01

    Understanding the effect of cis-regulatory elements (CRE) and clusters of CREs, which are called cis-regulatory modules (CRM), in eukaryotic gene expression is a challenge of computational biology. We developed two programs that allow simple, fast and reliable analysis of candidate CREs and CRMs that may affect specific gene expression and that determine positional features between individual CREs within a CRM. The first program, "Exploration of Distinctive CREs and CRMs" (EDCC), correlates candidate CREs and CRMs with specific gene expression patterns. For pairs of CREs, EDCC also determines positional preferences of the single CREs in relation to each other and to the transcriptional start site. The second program, "CRM Network Generator" (CNG), prioritizes these positional preferences using a neural network and thus allows unbiased rating of the positional preferences that were determined by EDCC. We tested these programs with data from a microarray study of circadian gene expression in Arabidopsis thaliana. Analyzing more than 1.5 million pairwise CRE combinations, we found 22 candidate combinations, of which several contained known clock promoter elements together with elements that had not been identified as relevant to circadian gene expression before. CNG analysis further identified positional preferences of these CRE pairs, hinting at positional information that may be relevant for circadian gene expression. Future wet lab experiments will have to determine which of these combinations confer daytime specific circadian gene expression.

  8. Computational exploration of cis-regulatory modules in rhythmic expression data using the “Exploration of Distinctive CREs and CRMs” (EDCC) and “CRM Network Generator” (CNG) programs

    PubMed Central

    Staiger, Dorothee

    2018-01-01

    Understanding the effect of cis-regulatory elements (CRE) and clusters of CREs, which are called cis-regulatory modules (CRM), in eukaryotic gene expression is a challenge of computational biology. We developed two programs that allow simple, fast and reliable analysis of candidate CREs and CRMs that may affect specific gene expression and that determine positional features between individual CREs within a CRM. The first program, “Exploration of Distinctive CREs and CRMs” (EDCC), correlates candidate CREs and CRMs with specific gene expression patterns. For pairs of CREs, EDCC also determines positional preferences of the single CREs in relation to each other and to the transcriptional start site. The second program, “CRM Network Generator” (CNG), prioritizes these positional preferences using a neural network and thus allows unbiased rating of the positional preferences that were determined by EDCC. We tested these programs with data from a microarray study of circadian gene expression in Arabidopsis thaliana. Analyzing more than 1.5 million pairwise CRE combinations, we found 22 candidate combinations, of which several contained known clock promoter elements together with elements that had not been identified as relevant to circadian gene expression before. CNG analysis further identified positional preferences of these CRE pairs, hinting at positional information that may be relevant for circadian gene expression. Future wet lab experiments will have to determine which of these combinations confer daytime specific circadian gene expression. PMID:29298348

  9. Airborne biological hazards and urban transport infrastructure: current challenges and future directions.

    PubMed

    Nasir, Zaheer Ahmad; Campos, Luiza Cintra; Christie, Nicola; Colbeck, Ian

    2016-08-01

    Exposure to airborne biological hazards in an ever expanding urban transport infrastructure and highly diverse mobile population is of growing concern, in terms of both public health and biosecurity. The existing policies and practices on design, construction and operation of these infrastructures may have severe implications for airborne disease transmission, particularly, in the event of a pandemic or intentional release of biological of agents. This paper reviews existing knowledge on airborne disease transmission in different modes of transport, highlights the factors enhancing the vulnerability of transport infrastructures to airborne disease transmission, discusses the potential protection measures and identifies the research gaps in order to build a bioresilient transport infrastructure. The unification of security and public health research, inclusion of public health security concepts at the design and planning phase, and a holistic system approach involving all the stakeholders over the life cycle of transport infrastructure hold the key to mitigate the challenges posed by biological hazards in the twenty-first century transport infrastructure.

  10. Future CO2 Emissions and Climate Change from Existing Energy Infrastructure

    NASA Astrophysics Data System (ADS)

    Davis, S. J.; Caldeira, K.; Matthews, D.

    2010-12-01

    If current greenhouse gas (GHG) concentrations remain constant, the world would be committed to several centuries of increasing global mean temperatures and sea level rise. By contrast, near elimination of anthropogenic CO2 emissions would be required to produce diminishing GHG concentrations consistent with stabilization of mean temperatures. Yet long-lived energy and transportation infrastructure now operating can be expected to contribute substantial CO2 emissions over the next 50 years. Barring widespread retrofitting of existing power plants with carbon capture and storage (CCS) technologies or the early decommissioning of serviceable infrastructure, these “committed emissions” represent infrastructural inertia which may be the primary contributor to total future warming commitment. With respect to GHG emissions, infrastructural inertia may be thought of as having two important and overlapping components: (i) infrastructure that directly releases GHGs to the atmosphere, and (ii) infrastructure that contributes to the continued production of devices that emit GHGs to the atmosphere. For example, the interstate highway and refueling infrastructure in the United States facilitates continued production of gasoline-powered automobiles. Here, we focus only on the warming commitment from infrastructure that directly releases CO2 to the atmosphere. Essentially, we answer the question: What if no additional CO2-emitting devices (e.g., power plants, motor vehicles) were built, but all the existing CO2-emitting devices were allowed to live out their normal lifetimes? What CO2 levels and global mean temperatures would we attain? Of course, the actual lifetime of devices may be strongly influenced by economic and policy constraints. For instance, a ban on new CO2-emitting devices would create tremendous incentive to prolong the lifetime of existing devices. Thus, our scenarios are not realistic, but offer a means of gauging the threat of climate change from existing devices relative to those devices that have yet to be built. We developed scenarios of global CO2 emissions from the energy sector using datasets of power plants and motor vehicles worldwide, as well as estimates of fossil fuel emissions produced directly by industry, households, businesses, and other forms of transport. We estimated lifetimes and annual emissions of infrastructure from historical data. We projected changes in CO2 and temperature in response to our calculated emissions using an intermediate-complexity coupled climate-carbon model (UVic ESCM). We calculate cumulative future emissions of 496 (282 to 701) gigatonnes of CO2 from combustion of fossil fuels by existing infrastructure between 2010 and 2060, forcing mean warming of 1.3°C (1.1 to 1.4°C) above the preindustrial era and atmospheric concentrations of CO2 less than 430 parts per million (ppm). Because these conditions would likely avoid many key impacts of climate change, we conclude that sources of the most threatening emissions have yet to be built. However, CO2-emitting infrastructure will expand unless extraordinary efforts are undertaken to develop alternatives.

  11. Alternative Fuels Data Center

    Science.gov Websites

    Conference on Weights and Measures has established equivalent measures. Until the DOL standardizes measurements, a gasoline gallon equivalent is equal to 5.66 pounds (lbs.) of CNG and a diesel gallon equivalent

  12. Localized Fire Protection Assessment for Vehicle Compressed Hydrogen Containers

    DOT National Transportation Integrated Search

    2010-03-01

    Industry has identified localized flame impingement on high pressure composite storage cylinders as an area requiring research due to several catastrophic failures in recent years involving compressed natural gas (CNG) vehicles. Current standards and...

  13. Alternative Fuels Data Center

    Science.gov Websites

    the state, unless equivalent measures are established by the National Conference on Weights and Measures. According to current state law, one GGE is equal to 5.66 pounds (lbs.) of CNG. One DGE is equal

  14. Map of Water Infrastructure and Homes Without Access to Safe Drinking Water and Basic Sanitation on the Navajo Nation - October 2010

    EPA Pesticide Factsheets

    This document presents the results of completed work using existing geographic information system (GIS) data to map existing water and sewer infrastructure and homes without access to safe drinking water and basic sanitation on the Navajo Nation.

  15. Population as a proxy for infrastructure in the determination of event response and recovery resource allocations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stamber, Kevin L.; Unis, Carl J.; Shirah, Donald N.

    Research into modeling of the quantification and prioritization of resources used in the recovery of lifeline critical infrastructure following disruptive incidents, such as hurricanes and earthquakes, has shown several factors to be important. Among these are population density and infrastructure density, event effects on infrastructure, and existence of an emergency response plan. The social sciences literature has a long history of correlating the population density and infrastructure density at a national scale, at a country-to-country level, mainly focused on transportation networks. This effort examines whether these correlations can be repeated at smaller geographic scales, for a variety of infrastructure types,more » so as to be able to use population data as a proxy for infrastructure data where infrastructure data is either incomplete or insufficiently granular. Using the best data available, this effort shows that strong correlations between infrastructure density for multiple types of infrastructure (e.g. miles of roads, hospital beds, miles of electric power transmission lines, and number of petroleum terminals) and population density do exist at known geographic boundaries (e.g. counties, service area boundaries) with exceptions that are explainable within the social sciences literature. Furthermore, the correlations identified provide a useful basis for ongoing research into the larger resource utilization problem.« less

  16. Population as a proxy for infrastructure in the determination of event response and recovery resource allocations

    DOE PAGES

    Stamber, Kevin L.; Unis, Carl J.; Shirah, Donald N.; ...

    2016-04-01

    Research into modeling of the quantification and prioritization of resources used in the recovery of lifeline critical infrastructure following disruptive incidents, such as hurricanes and earthquakes, has shown several factors to be important. Among these are population density and infrastructure density, event effects on infrastructure, and existence of an emergency response plan. The social sciences literature has a long history of correlating the population density and infrastructure density at a national scale, at a country-to-country level, mainly focused on transportation networks. This effort examines whether these correlations can be repeated at smaller geographic scales, for a variety of infrastructure types,more » so as to be able to use population data as a proxy for infrastructure data where infrastructure data is either incomplete or insufficiently granular. Using the best data available, this effort shows that strong correlations between infrastructure density for multiple types of infrastructure (e.g. miles of roads, hospital beds, miles of electric power transmission lines, and number of petroleum terminals) and population density do exist at known geographic boundaries (e.g. counties, service area boundaries) with exceptions that are explainable within the social sciences literature. Furthermore, the correlations identified provide a useful basis for ongoing research into the larger resource utilization problem.« less

  17. Lifecycle analysis of renewable natural gas and hydrocarbon fuels from wastewater treatment plants’ sludge

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Uisung; Han, Jeongwoo; Urgun Demirtas, Meltem

    Wastewater treatment plants (WWTPs) produce sludge as a byproduct when they treat wastewater. In the United States, over 8 million dry tons of sludge are produced annually just from publicly owned WWTPs. Sludge is commonly treated in anaerobic digesters, which generate biogas; the biogas is then largely flared to reduce emissions of methane, a potent greenhouse gas. Because sludge is quite homogeneous and has a high energy content, it is a good potential feedstock for other conversion processes that make biofuels, bioproducts, and power. For example, biogas from anaerobic digesters can be used to generate renewable natural gas (RNG), whichmore » can be further processed to produce compressed natural gas (CNG) and liquefied natural gas (LNG). Sludge can be directly converted into hydrocarbon liquid fuels via thermochemical processes such as hydrothermal liquefaction (HTL). Currently, the environmental impacts of converting sludge into energy are largely unknown, and only a few studies have focused on the environmental impacts of RNG produced from existing anaerobic digesters. As biofuels from sludge generate high interest, however, existing anaerobic digesters could be upgraded to technology with more economic potential and more environmental benefits. The environmental impacts of using a different anaerobic digestion (AD) technology to convert sludge into energy have yet to be analyzed. In addition, no studies are available about the direct conversion of sludge into liquid fuels. In order to estimate the energy consumption and greenhouse gas (GHG) emissions impacts of these alternative pathways (sludge-to-RNG and sludge-to-liquid), this study performed a lifecycle analysis (LCA) using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model. The energy uses and GHG emissions associated with the RNG and hydrocarbon liquid are analyzed relative to the current typical sludge management case, which consists of a single-stage mesophilic digester with biogas flaring. Along with the alternative HTL process, four types of AD technologies with fuel production—single-stage mesophilic, mesophilic 2-stage, single-stage mesophilic with thermohydrolysis treatment, and mesophilicmesophilic acid/gas phase—are studied. Results show that the sludge-to-CNG pathway via AD and the sludge-to-liquid pathway via HTL reduce GHG emissions consumptions significantly. When we compare the GHG emissions of the alternative fuel production pathways to that of the counterfactual case in terms of the amount of sludge treated, reductions in GHG emissions are 39%–80% and 87% for alternative AD and HTL, respectively. Compared to petroleum gasoline and diesel GHG emission results in terms of MJ, the renewable CNG production pathway via AD and the renewable diesel production pathway via HTL reduce GHG emissions by 193% and 46%, respectively. These large reductions are mainly due to GHG credits from avoiding GHGs under the counterfactual scenario, and/or fertilizer displacement credits. Similarly, reductions in fossil fuel use for sludge-based fuels are huge. However, well-defined counterfactual scenarios are needed because the results of the study depend on the counterfactual scenario, which might vary over time.« less

  18. Eco-logical : an ecosystem approach to developing transportation infrastructure projects in a changing environment

    DOT National Transportation Integrated Search

    2009-09-13

    The development of infrastructure facilities can negatively impact critical habitat and essential ecosystems. There are a variety of techniques available to avoid, minimize, and mitigate negative impacts of existing infrastructure as well as future i...

  19. 77 FR 72673 - Critical Infrastructure Protection and Resilience Month, 2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    .... Cyber incidents can have devastating consequences on both physical and virtual infrastructure, which is... work within existing authorities to fortify our country against cyber risks, comprehensive legislation remains essential to improving infrastructure security, enhancing cyber information sharing between...

  20. Alternative Fuels Data Center

    Science.gov Websites

    : CNG: $0.08 per gasoline gallon equivalent (GGE) until September 30, 2023; $0.13 per GGE from October 1 diesel gallon equivalent (DGE) until September 30, 2023; $0.13 per DGE from October 1, 2023, until

  1. Alternative Fuels Data Center

    Science.gov Websites

    vehicle at 3,000 pounds (lbs.) per square inch and metered on a gasoline gallon equivalent (GGE ); liquefied natural gas (LNG) must be metered on a diesel gallon equivalent (DGE). One GGE of CNG is equal to

  2. Alternative Fuels Data Center

    Science.gov Websites

    Tax Compressed natural gas (CNG) used as a vehicle fuel is taxed on a gasoline gallon equivalent ) used as a vehicle fuel is taxed on a diesel gallon equivalent (DGE) basis as follows: $0.05 per DGE

  3. Featured Partner: Saddle Creek Logistics Services

    EPA Pesticide Factsheets

    This EPA fact sheet spotlights Saddle Creek Logistics as a SmartWay partner committed to sustainability in reducing greenhouse gas emissions and air pollution caused by freight transportation, partly by growing its compressed natural gas (CNG) vehicles for

  4. Compressed Natural Gas Safety in Transit Operations

    DOT National Transportation Integrated Search

    1995-09-14

    This report examines the safety issues relating to the use of Compressed Natural Gas (CNG) in transit service. The safety issues were determined by on-site surveys performed by Battelle of Columbus, Ohio and Science Applications International Corpora...

  5. Tracking costs of alternatively fueled buses in Florida - phase II, [summary].

    DOT National Transportation Integrated Search

    2013-04-01

    Many public transit agencies have invested in vehicles that use alternative fuels to reduce greenhouse gases, urban pollution, and fuel costs. Available alternatives include biodiesel, compressed natural gas (CNG), diesel-electric hybrid, electric, h...

  6. Alternative Fuels Data Center

    Science.gov Websites

    (ONG) offers rebates for NGVs purchased or converted after June 20, 2016, in the amount of $2,000 for a applicant, per calendar year. For more information, see the ONG CNG Rebate Program website. Point of Contact

  7. Annual Quality Assurance Conference Abstracts by Barbara Marshik

    EPA Pesticide Factsheets

    25th Annual Quality Assurance Conference. Abstracts: Material and Process Conditions for Successful Use of Extractive Sampling Techniques and Certification Methods Errors in the Analysis of NMHC and VOCs in CNG-Based Engine Emissions by Barbara Marshik

  8. Air quality assessment in Delhi: before and after CNG as fuel.

    PubMed

    Chelani, Asha B; Devotta, Sukumar

    2007-02-01

    A number of policy measures have been activated in India in order to control the levels of air pollutants such as particulate matter, sulphur dioxide (SO(2)) and nitrogen dioxide (NO(2)). Delhi, which is one of the most polluted cities in the world, is also going through the implementation phase of the control policies. Ambient air quality data monitored during 2000 to 2003, at 10 sites in Delhi, were analyzed to assess the impact of implementation of these measures, specifically fuel change in vehicles. This paper presents the impact of policy measures on ambient air quality levels and also the source apportionment. CO and NO(2) concentration levels in ambient air are found to be associated with the mobile sources. The temporal variation of air quality data shows the significant effect of shift to CNG (Compressed Natural Gas) in vehicles.

  9. An experimental study on premixed CNG/H2/CO2 mixture flames

    NASA Astrophysics Data System (ADS)

    Yilmaz, Ilker; Yilmaz, Harun; Cam, Omer

    2018-03-01

    In this study, the effect of swirl number, gas composition and CO2 dilution on combustion and emission behaviour of CNG/H2/CO2 gas mixtures was experimentally investigated in a laboratory scale combustor. Irrespective of the gas composition, thermal power of the combustor was kept constant (5 kW). All experiments were conducted at or near stoichiometric and the local atmospheric conditions of the city of Kayseri, Turkey. During experiments, swirl number was varied and the combustion performance of this combustor was analysed by means of centreline temperature distributions. On the other hand, emission behaviour was examined with respect to emitted CO, CO2 and NOx levels. Dynamic flame behaviour was also evaluated by analysing instantaneous flame images. Results of this study revealed the great impact of swirl number and gas composition on combustion and emission behaviour of studied flames.

  10. Conformational rearrangements in the transmembrane domain of CNGA1 channels revealed by single-molecule force spectroscopy

    NASA Astrophysics Data System (ADS)

    Maity, Sourav; Mazzolini, Monica; Arcangeletti, Manuel; Valbuena, Alejandro; Fabris, Paolo; Lazzarino, Marco; Torre, Vincent

    2015-05-01

    Cyclic nucleotide-gated (CNG) channels are activated by binding of cyclic nucleotides. Although structural studies have identified the channel pore and selectivity filter, conformation changes associated with gating remain poorly understood. Here we combine single-molecule force spectroscopy (SMFS) with mutagenesis, bioinformatics and electrophysiology to study conformational changes associated with gating. By expressing functional channels with SMFS fingerprints in Xenopus laevis oocytes, we were able to investigate gating of CNGA1 in a physiological-like membrane. Force spectra determined that the S4 transmembrane domain is mechanically coupled to S5 in the closed state, but S3 in the open state. We also show there are multiple pathways for the unfolding of the transmembrane domains, probably caused by a different degree of α-helix folding. This approach demonstrates that CNG transmembrane domains have dynamic structure and establishes SMFS as a tool for probing conformational change in ion channels.

  11. Engineering properties of douglas-fir lumber reclaimed from deconstructed buildings

    Treesearch

    Robert Falk; Derek Maul; Steven Cramer; James Evans; Victoria Herian

    2008-01-01

    A vast wood resource exists in our Nation's wood-framed building infrastructure. As the buildings in this infrastructure age and are remodeled or removed for redevelopment, the wood framing residing in these buildings has the potential to be recovered for reuse. However, little technical information exists on the residual engineering properties of reclaimed...

  12. CNGA3 deficiency affects cone synaptic terminal structure and function and leads to secondary rod dysfunction and degeneration.

    PubMed

    Xu, Jianhua; Morris, Lynsie M; Michalakis, Stylianos; Biel, Martin; Fliesler, Steven J; Sherry, David M; Ding, Xi-Qin

    2012-03-01

    To investigate rod function and survival after cone dysfunction and degeneration in a mouse model of cone cyclic nucleotide-gated (CNG) channel deficiency. Rod function and survival in mice with cone CNG channel subunit CNGA3 deficiency (CNGA3-/- mice) were evaluated by electroretinographic (ERG), morphometric, and Western blot analyses. The arrangement, integrity, and ultrastructure of photoreceptor terminals were investigated by immunohistochemistry and electron microscopy. The authors found loss of cone function and cone death accompanied by impairment of rods and rod-driven signaling in CNGA3-/- mice. Scotopic ERG b-wave amplitudes were reduced by 15% at 1 month, 30% at 6 months, and 40% at 9 months and older, while scotopic a-wave amplitudes were decreased by 20% at 9 months, compared with ERGs of age-matched wild-type mice. Outer nuclear layer thickness in CNGA3-/- retina was reduced by 15% at 12 months compared with age-matched wild-type controls. This was accompanied by a 30%-40% reduction in expression of rod-specific proteins, including rhodopsin, rod transducin α-subunit, and glutamic acid-rich protein (GARP). Cone terminals in the CNGA3-/- retina showed a progressive loss of neurochemical and ultrastructural integrity. Abnormalities were observed as early as 1 month. Disorganized rod terminal ultrastructure was noted by 12 months. These findings demonstrate secondary rod impairment and degeneration after cone degeneration in mice with cone CNG channel deficiency. Loss of cone phototransduction accompanies the compromised integrity of cone terminals. With time, rod synaptic structure, function, and viability also become compromised.

  13. 76 FR 18743 - Commission Information Collection Activities (FERC-603); Comment Request; Extension

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-05

    ... FERC-603 ``Critical Energy Infrastructure Information'' (OMB No. 1902-0197) is used by the Commission to implement procedures for gaining access to critical energy infrastructure information (CEII) that... information about ``existing or proposed critical infrastructure that (i) relates to the production...

  14. RDE-based assessment of a factory bi-fuel CNG/gasoline light-duty vehicle

    NASA Astrophysics Data System (ADS)

    Rašić, Davor; Rodman Oprešnik, Samuel; Seljak, Tine; Vihar, Rok; Baškovič, Urban Žvar; Wechtersbach, Tomaž; Katrašnik, Tomaž

    2017-10-01

    On-road exhaust emissions of a Euro 5 factory bi-fuel CNG/gasoline light-duty vehicle equipped with the TWC were assessed considering the Real Driving Emissions (RDE) guidelines. The vehicle was equipped with a Portable Emission Measurement System (PEMS) that enabled the measurement of THC, CO, NOx, CO2, and CH4. With respect to the characteristics of the vehicle, the appropriate Worldwide Harmonized Light-Duty Vehicle Test Cycles (WLTC) were selected and based on the requirements of the RDE legislation a suitable route was conceived. In addition to the moderate RDE-based route, an extended RDE-based route was also determined. The vehicle was driven along each defined route twice, once with each individual fuel option and with a fully warm vehicle. RDE routes feature a multitude of new driving patterns that are significantly different to those encountered in the NEDC. However, as these driving patterns can greatly influence the cumulative emissions an insight in to local time trace phenomena is crucial to understand, reason and to possibly reduce the cumulative emissions. Original contributions of this paper comprise analyses of the RDE-LDV local time resolved driving emissions phenomena of a CNG-powered vehicle that are benchmarked against the ones measured under the use of gasoline in the same vehicle and under similar operating conditions to reason emission trends through driving patterns and powertrain parameters and exposing the strong cold-start independent interference of CO and N2O infrared absorption bands in the non-dispersive infrared (NDIR) analyzer. The paper provides experimental evidence on this interference, which significantly influences on the readings of CO emissions. The paper further provides hypotheses why CO and N2O interference is more pronounced when using CNG in LDVs and supports these hypotheses by PEMS tests. The study reveals that the vehicle's NOx real-world emission values of both conceived RDE-based routes when using both fuels are within Euro 5 and type-approval limits. Additionally, the THC and the NMHC emissions of both RDE-based routes using both fuels are within the Euro 5 limits indicating reasonable CH4 emissions. Notable increases above the type-approval and Euro 5 limits appeared in the CO emissions profile when using gasoline, while the CO2 emissions profile expectedly also exceeded the type-approval specifications.

  15. Functional role of hCngb3 in regulation of human cone cng channel: effect of rod monochromacy-associated mutations in hCNGB3 on channel function.

    PubMed

    Okada, Akira; Ueyama, Hisao; Toyoda, Futoshi; Oda, Sanae; Ding, Wei-Guang; Tanabe, Shoko; Yamade, Shinichi; Matsuura, Hiroshi; Ohkubo, Iwao; Kani, Kazutaka

    2004-07-01

    The human cone photoreceptor cyclic nucleotide-gated (CNG) channel comprises alpha- and beta-subunits, which are respectively encoded by hCNGA3 and hCNGB3. The purpose was to examine the functional role of hCNGB3 in modulation of human cone CNG channels and to characterize functional consequences of rod monochromacy-associated mutations in hCNGB3 (S435F and D633G). Macroscopic patch currents were recorded from human embryonic kidney (HEK) 293 cells expressing homomeric (hCNGA3 and hCNGB3) and heteromeric (hCNGA3/hCNGB3, hCNGA3/hCNGB3-S435F, and hCNGA3/hCNGB3-D633G) channels using inside-out patch-clamp technique. Both hCNGA3 homomeric and hCNGA3/hCNGB3 heteromeric channels were activated by cGMP, with half-maximally activating concentration (K(1/2)) of 11.1 +/- 1.0 and 26.2 +/- 1.9 micro M, respectively. The hCNGA3 channels appeared to be more sensitive to inhibition by extracellular Ca(2+) compared with hCNGA3/hCNGB3 channels, when assessed by the degree of outward rectification. Coexpression of either of rod monochromacy-associated mutants of hCNGB3 with hCNGA3 significantly reduced K(1/2) value for cGMP but little affected the sensitivity to extracellular Ca(2+), compared with wild-type heteromeric channels. The selectivity of hCNGA3, hCNGA3/hCNGB3, hCNGA3/hCNGB3-S435F, and hCNGA3/hCNGB3-D633G channels for monovalent cations were largely similar. Immunoprecipitation experiments showed association of hCNGA3 subunit with both of wild-type and mutant hCNGB3 subunits. The hCNGB3 plays an important modulatory role in the function of human cone CNG channels with respect to cGMP and extracellular Ca(2+) sensitivities. The rod monochromacy-associated S435F and D633G mutations in hCNGB3 evokes a significant increase in the apparent affinity for cGMP, which should alter cone function and thereby contribute at least partly to pathogenesis of the disease.

  16. Alternative Fuels Data Center

    Science.gov Websites

    gallon equivalent of natural gas at the time fuel is dispensed or delivered into the tank of a motor vehicle. A gasoline gallon equivalent is equal to 5.66 lbs. of CNG and a diesel gallon equivalent is equal

  17. Alternative Fuels Data Center: Smithtown Selects CNG to Cut Refuse

    Science.gov Websites

    additional revenue to the state of $0.05 per gasoline gallon equivalent. Clean Energy expanded the Hauppauge started at $2.33 per diesel gallon equivalent (DGE) through 2008 and increase each year to conclude at

  18. SunLine Transit Agency Hydrogen-Powered Transit Buses : Evaluation Results Update

    DOT National Transportation Integrated Search

    2007-10-01

    In early 2007, the National Renewable Energy Laboratory (NREL) published a preliminary evaluation results report (January 2006 through November 2006) on hydrogen- and CNG-fueled buses operating at SunLine Transit Agency (SunLine) in Thousand Palms, C...

  19. Compressed Natural Gas and Liquefied Petroleum Gas Conversions: The National Renewable Energy Laboratory's Experience

    DOT National Transportation Integrated Search

    1996-04-01

    The National Renewable Energy Laboratory (NREL) contracted with conversion : companies in six states to convert approximately 900 light-duty Federal fleet : vehicles to operate on compressed natural gas (CNG) or liquefied petroleum gas : (LPG). After...

  20. Transportation of Large Wind Components: A Review of Existing Geospatial Data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mooney, Meghan; Maclaurin, Galen

    2016-09-01

    This report features the geospatial data component of a larger project evaluating logistical and infrastructure requirements for transporting oversized and overweight (OSOW) wind components. The goal of the larger project was to assess the status and opportunities for improving the infrastructure and regulatory practices necessary to transport wind turbine towers, blades, and nacelles from current and potential manufacturing facilities to end-use markets. The purpose of this report is to summarize existing geospatial data on wind component transportation infrastructure and to provide a data gap analysis, identifying areas for further analysis and data collection.

  1. Institutional Transformation Model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    2015-10-19

    Reducing the energy consumption of large institutions with dozens to hundreds of existing buildings while maintaining and improving existing infrastructure is a critical economic and environmental challenge. SNL's Institutional Transformation (IX) work integrates facilities and infrastructure sustainability technology capabilities and collaborative decision support modeling approaches to help facilities managers at Sandia National Laboratories (SNL) simulate different future energy reduction strategies and meet long term energy conservation goals.

  2. Clean air program : design guidelines for bus transit systems using hydrogen as an alternative fuel

    DOT National Transportation Integrated Search

    1999-04-01

    Alternative fuels such as Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG), Liquefied Petroleum Gas (LPG), and alcohol fuels (methanol, and ethanol) are already being used in commercial vehicles and transit buses in revenue service. Hydrogen...

  3. Alternative Fuels Data Center: Kern County Schools Expands CNG Station for

    Science.gov Websites

    23, 2016 Photo of a truck Fair Oaks Farm Harnesses the Power of Natural Gas from Cow Manure July 9 . 17, 2011 Natural Gas Powers Milk Delivery Trucks in Indiana Aug. 20, 2011 Reynolds Logistics Reduces

  4. 44 CFR 201.7 - Tribal Mitigation Plans.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... buildings, infrastructure, and critical facilities located in the identified hazard areas; (B) An estimate... particular emphasis on new and existing buildings and infrastructure. (iii) An action plan describing how the...

  5. PKA and cAMP/CNG Channels Independently Regulate the Cholinergic Ca(2+)-Response of Drosophila Mushroom Body Neurons

    PubMed

    Pavot, Pierre; Carbognin, Elena; Martin, Jean-René

    2015-01-01

    The mushroom bodies (MBs), one of the main structures in the adult insect brain, play a critical role in olfactory learning and memory. Though historical genes such as dunce and rutabaga, which regulate the level of cAMP, were identified more than 30 years ago, their in vivo effects on cellular and physiological mechanisms and particularly on the Ca(2+)-responses still remain largely unknown. In this work, performed in Drosophila, we took advantage of in vivo bioluminescence imaging, which allowed real-time monitoring of the entire MBs (both the calyx/cell-bodies and the lobes) simultaneously. We imaged neuronal Ca(2+)-activity continuously, over a long time period, and characterized the nicotine-evoked Ca(2+)-response. Using both genetics and pharmacological approaches to interfere with different components of the cAMP signaling pathway, we first show that the Ca(2+)-response is proportional to the levels of cAMP. Second, we reveal that an acute change in cAMP levels is sufficient to trigger a Ca(2+)-response. Third, genetic manipulation of protein kinase A (PKA), a direct effector of cAMP, suggests that cAMP also has PKA-independent effects through the cyclic nucleotide-gated Ca(2+)-channel (CNG). Finally, the disruption of calmodulin, one of the main regulators of the rutabaga adenylate cyclase (AC), yields different effects in the calyx/cell-bodies and in the lobes, suggesting a differential and regionalized regulation of AC. Our results provide insights into the complex Ca(2+)-response in the MBs, leading to the conclusion that cAMP modulates the Ca(2+)-responses through both PKA-dependent and -independent mechanisms, the latter through CNG-channels.

  6. CNGA3 Deficiency Affects Cone Synaptic Terminal Structure and Function and Leads to Secondary Rod Dysfunction and Degeneration

    PubMed Central

    Xu, Jianhua; Morris, Lynsie M.; Michalakis, Stylianos; Biel, Martin; Fliesler, Steven J.; Sherry, David M.

    2012-01-01

    Purpose. To investigate rod function and survival after cone dysfunction and degeneration in a mouse model of cone cyclic nucleotide-gated (CNG) channel deficiency. Methods. Rod function and survival in mice with cone CNG channel subunit CNGA3 deficiency (CNGA3−/− mice) were evaluated by electroretinographic (ERG), morphometric, and Western blot analyses. The arrangement, integrity, and ultrastructure of photoreceptor terminals were investigated by immunohistochemistry and electron microscopy. Results. The authors found loss of cone function and cone death accompanied by impairment of rods and rod-driven signaling in CNGA3−/− mice. Scotopic ERG b-wave amplitudes were reduced by 15% at 1 month, 30% at 6 months, and 40% at 9 months and older, while scotopic a-wave amplitudes were decreased by 20% at 9 months, compared with ERGs of age-matched wild-type mice. Outer nuclear layer thickness in CNGA3−/− retina was reduced by 15% at 12 months compared with age-matched wild-type controls. This was accompanied by a 30%–40% reduction in expression of rod-specific proteins, including rhodopsin, rod transducin α-subunit, and glutamic acid-rich protein (GARP). Cone terminals in the CNGA3−/− retina showed a progressive loss of neurochemical and ultrastructural integrity. Abnormalities were observed as early as 1 month. Disorganized rod terminal ultrastructure was noted by 12 months. Conclusions. These findings demonstrate secondary rod impairment and degeneration after cone degeneration in mice with cone CNG channel deficiency. Loss of cone phototransduction accompanies the compromised integrity of cone terminals. With time, rod synaptic structure, function, and viability also become compromised. PMID:22247469

  7. 44 CFR 201.6 - Local Mitigation Plans.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., infrastructure, and critical facilities located in the identified hazard areas; (B) An estimate of the potential... effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. All...

  8. 44 CFR 201.6 - Local Mitigation Plans.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., infrastructure, and critical facilities located in the identified hazard areas; (B) An estimate of the potential... effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. All...

  9. 44 CFR 201.6 - Local Mitigation Plans.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., infrastructure, and critical facilities located in the identified hazard areas; (B) An estimate of the potential... effects of each hazard, with particular emphasis on new and existing buildings and infrastructure. All...

  10. More Bang for the Buck: Integrating Green Infrastructure into Existing Public Works Projects

    EPA Pesticide Factsheets

    shares lessons learned from municipal and county officials experienced in coordinating green infrastructure applications with scheduled street maintenance, park improvements, and projects on public sites.

  11. When the New Application Smell Is Gone: Traditional Intranet Best Practices and Existing Web 2.0 Intranet Infrastructures

    ERIC Educational Resources Information Center

    Yoose, Becky

    2010-01-01

    With the growth of Web 2.0 library intranets in recent years, many libraries are leaving behind legacy, first-generation intranets. As Web 2.0 intranets multiply and mature, how will traditional intranet best practices--especially in the areas of planning, implementation, and evaluation--translate into an existing Web 2.0 intranet infrastructure?…

  12. Engineering Infrastructures: Problems of Safety and Security in the Russian Federation

    NASA Astrophysics Data System (ADS)

    Makhutov, Nikolay A.; Reznikov, Dmitry O.; Petrov, Vitaly P.

    Modern society cannot exist without stable and reliable engineering infrastructures (EI), whose operation is vital for any national economy. These infrastructures include energy, transportation, water and gas supply systems, telecommunication and cyber systems, etc. Their performance is commensurate with storing and processing huge amounts of information, energy and hazardous substances. Ageing infrastructures are deteriorating — with operating conditions declining from normal to emergency and catastrophic. The complexity of engineering infrastructures and their interdependence with other technical systems makes them vulnerable to emergency situations triggered by natural and manmade catastrophes or terrorist attacks.

  13. Alternative Fuel Trucks Case Studies: Running Refuse Haulers on Compressed Natural Gas

    DOT National Transportation Integrated Search

    1996-01-01

    Since 1992 the CNG trash trucks have accumulated more than 60,000 miles in : regular service in the New York City fleet. Overall, their performance has been : excellent. The Alternative Fuels Data Center (AFDC) at the Department of : Energy's Nationa...

  14. A tag-based approach for high-throughput analysis of CCWGG methylation.

    PubMed

    Denisova, Oksana V; Chernov, Andrei V; Koledachkina, Tatyana Y; Matvienko, Nicholas I

    2007-10-15

    Non-CpG methylation occurring in the context of CNG sequences is found in plants at a large number of genomic loci. However, there is still little information available about non-CpG methylation in mammals. Efficient methods that would allow detection of scarcely localized methylated sites in small quantities of DNA are required to elucidate the biological role of non-CpG methylation in both plants and animals. In this study, we tested a new whole genome approach to identify sites of CCWGG methylation (W is A or T), a particular case of CNG methylation, in genomic DNA. This technique is based on digestion of DNAs with methylation-sensitive restriction endonucleases EcoRII-C and AjnI. Short DNAs flanking methylated CCWGG sites (tags) are selectively purified and assembled in tandem arrays of up to nine tags. This allows high-throughput sequencing of tags, identification of flanking regions, and their exact positions in the genome. In this study, we tested specificity and efficiency of the approach.

  15. Cyclic-nucleotide–gated cation current and Ca2+-activated Cl current elicited by odorant in vertebrate olfactory receptor neurons

    PubMed Central

    Li, Rong-Chang; Ben-Chaim, Yair; Yau, King-Wai; Lin, Chih-Chun

    2016-01-01

    Olfactory transduction in vertebrate olfactory receptor neurons (ORNs) involves primarily a cAMP-signaling cascade that leads to the opening of cyclic-nucleotide–gated (CNG), nonselective cation channels. The consequent Ca2+ influx triggers adaptation but also signal amplification, the latter by opening a Ca2+-activated Cl channel (ANO2) to elicit, unusually, an inward Cl current. Hence the olfactory response has inward CNG and Cl components that are in rapid succession and not easily separable. We report here success in quantitatively separating these two currents with respect to amplitude and time course over a broad range of odorant strengths. Importantly, we found that the Cl current is the predominant component throughout the olfactory dose–response relation, down to the threshold of signaling to the brain. This observation is very surprising given a recent report by others that the olfactory-signal amplification effected by the Ca2+-activated Cl current does not influence the behavioral olfactory threshold in mice. PMID:27647918

  16. Hydrogen quantitative risk assessment workshop proceedings.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Groth, Katrina M.; Harris, Aaron P.

    2013-09-01

    The Quantitative Risk Assessment (QRA) Toolkit Introduction Workshop was held at Energetics on June 11-12. The workshop was co-hosted by Sandia National Laboratories (Sandia) and HySafe, the International Association for Hydrogen Safety. The objective of the workshop was twofold: (1) Present a hydrogen-specific methodology and toolkit (currently under development) for conducting QRA to support the development of codes and standards and safety assessments of hydrogen-fueled vehicles and fueling stations, and (2) Obtain feedback on the needs of early-stage users (hydrogen as well as potential leveraging for Compressed Natural Gas [CNG], and Liquefied Natural Gas [LNG]) and set priorities for %E2%80%9CVersionmore » 1%E2%80%9D of the toolkit in the context of the commercial evolution of hydrogen fuel cell electric vehicles (FCEV). The workshop consisted of an introduction and three technical sessions: Risk Informed Development and Approach; CNG/LNG Applications; and Introduction of a Hydrogen Specific QRA Toolkit.« less

  17. Effects of Exhaust Gas Recirculation on Performance and Emission Characteristic of SI Engine using Hydrogen and CNG Blends

    NASA Astrophysics Data System (ADS)

    Nitnaware, Pravin Tukaram; Suryawanshi, Jiwak G.

    2018-01-01

    This paper shows exhaust gas recirculation (EGR) effects on multi-cylinder bi-fuel SI engine using blends of 0, 5, 10 and 15% hydrogen by energy with CNG. All trials are performed at a speed of 3000, 3500 and 4000 rpm with EGR rate of 0, 5, 10 and 15%, with equal spark timing and injection pressure of 2.6 bar. At specific hydrogen percentage with increase in EGR rate NOx emission reduces drastically and increases with increase in hydrogen addition. Hydrocarbon (HC) and carbon monoxide (CO) emission decreases with increase in speed and hydrogen addition. There is considerable improvement in brake thermal efficiency (BTE) and brake specific energy consumption (BSEC) at 15% EGR rate. At 3000 rpm, 5% EGR rate with 5% hydrogen had shown maximum cylinder pressure. Brake specific fuel consumption (b.s.f.c) increased with increase in EGR rate and decreased with increase in hydrogen addition for all speeds.

  18. Increase in the thermodynamic efficiency of the working process of spark-ignited engines on natural gas with the addition of hydrogen

    NASA Astrophysics Data System (ADS)

    Mikhailovna Smolenskaya, Natalia; Vladimirovich Smolenskii, Victor; Vladimirovich Korneev, Nicholas

    2018-02-01

    The work is devoted to the substantiation and practical implementation of a new approach for estimating the change in internal energy by pressure and volume. The pressure is measured with a calibrated sensor. The change in volume inside the cylinder is determined by changing the position of the piston. The position of the piston is precisely determined by the angle of rotation of the crankshaft. On the basis of the proposed approach, the thermodynamic efficiency of the working process of spark ignition engines on natural gas with the addition of hydrogen was estimated. Experimental studies were carried out on a single-cylinder unit UIT-85. Their analysis showed an increase in the thermodynamic efficiency of the working process with the addition of hydrogen in a compressed natural gas (CNG).The results obtained make it possible to determine the characteristic of heat release from the analysis of experimental data. The effect of hydrogen addition on the CNG combustion process is estimated.

  19. CNGA3 is expressed in inner ear hair cells and binds to an intracellular C-terminus domain of EMILIN1.

    PubMed

    Selvakumar, Dakshnamurthy; Drescher, Marian J; Dowdall, Jayme R; Khan, Khalid M; Hatfield, James S; Ramakrishnan, Neeliyath A; Drescher, Dennis G

    2012-04-15

    The molecular characteristics of CNG (cyclic nucleotide-gated) channels in auditory/vestibular hair cells are largely unknown, unlike those of CNG mediating sensory transduction in vision and olfaction. In the present study we report the full-length sequence for three CNGA3 variants in a hair cell preparation from the trout saccule with high identity to CNGA3 in olfactory receptor neurons/cone photoreceptors. A custom antibody targeting the N-terminal sequence immunolocalized CNGA3 to the stereocilia and subcuticular plate region of saccular hair cells. The cytoplasmic C-terminus of CNGA3 was found by yeast two-hybrid analysis to bind the C-terminus of EMILIN1 (elastin microfibril interface-located protein 1) in both the vestibular hair cell model and rat organ of Corti. Specific binding between CNGA3 and EMILIN1 was confirmed with surface plasmon resonance analysis, predicting dependence on Ca2+ with Kd=1.6×10-6 M for trout hair cell proteins and Kd=2.7×10-7 M for organ of Corti proteins at 68 μM Ca2+. Pull-down assays indicated that the binding to organ of Corti CNGA3 was attributable to the EMILIN1 intracellular sequence that follows a predicted transmembrane domain in the C-terminus. Saccular hair cells also express the transcript for PDE6C (phosphodiesterase 6C), which in cone photoreceptors regulates the degradation of cGMP used to gate CNGA3 in phototransduction. Taken together, the evidence supports the existence in saccular hair cells of a molecular pathway linking CNGA3, its binding partner EMILIN1 (and β1 integrin) and cGMP-specific PDE6C, which is potentially replicated in cochlear outer hair cells, given stereociliary immunolocalizations of CNGA3, EMILIN1 and PDE6C.

  20. A reevaluation of the literature regarding the health assessment of diesel engine exhaust.

    PubMed

    Bunn, William B; Hesterberg, Thomas W; Valberg, Peter A; Slavin, Thomas J; Hart, Georgia; Lapin, Charles A

    2004-12-15

    While the International Agency for Research on Cancer (IARC) classified diesel exhaust (DE) as a"probable"carcinogen in 1989 based primarily on"sufficient"animal data, other investigators have since concluded that the lung tumors found in the rat studies were a result of particle overloading. Subsequent health risk assessments of DE have not used the rat cancer data. The U.S. Environmental Protection Agency (EPA), in developing its 2002 Health Assessment Document (HAD) for DE, primarily considered the epidemiology studies of railroad workers and truck drivers to develop health risk assessments of DE. However, both sets of epidemiology studies have serious weaknesses that make them unsuitable for cancer risk assessment. Major shortcomings were the lack of contemporaneous measurements of exposures to DE, difficulties with exposure history reconstruction, and adequately accounting for other exposures such as gasoline exhaust and cigarette smoke. To compound these problems, there was not, and there is still not, a specific exposure marker for DE. Interestingly, in the underground mining industry, where diesel exposures are much higher than observed in railroad workers and truck drivers, there was no increase in lung cancer. These problems and concerns led the U.S. EPA to conclude that while DE was a"likely"carcinogen, a unit risk value or range of risk cannot be calculated from existing data and that the risk could be zero. In addition, the DE emissions have changed and continue to change with the implementation of new emission control technologies. The HAD recognized this fact and noted that further studies are needed to assess new diesel engine emissions. Recent chemical characterization studies on low-emitting diesel engines with catalyzed particulate filters have shown emissions rates for several chemicals of concern that are even lower than comparable compressed natural gas (CNG)-fueled engines. With lower emissions, better fire safety, and improved cost-effectiveness of new low-emitting diesels compared to CNG, current efforts to restrict use of low-emitting diesels seems misguided.

  1. Mechanisms of Regulation of Olfactory Transduction and Adaptation in the Olfactory Cilium

    PubMed Central

    Antunes, Gabriela; Sebastião, Ana Maria; Simoes de Souza, Fabio Marques

    2014-01-01

    Olfactory adaptation is a fundamental process for the functioning of the olfactory system, but the underlying mechanisms regulating its occurrence in intact olfactory sensory neurons (OSNs) are not fully understood. In this work, we have combined stochastic computational modeling and a systematic pharmacological study of different signaling pathways to investigate their impact during short-term adaptation (STA). We used odorant stimulation and electroolfactogram (EOG) recordings of the olfactory epithelium treated with pharmacological blockers to study the molecular mechanisms regulating the occurrence of adaptation in OSNs. EOG responses to paired-pulses of odorants showed that inhibition of phosphodiesterases (PDEs) and phosphatases enhanced the levels of STA in the olfactory epithelium, and this effect was mimicked by blocking vesicle exocytosis and reduced by blocking cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) and vesicle endocytosis. These results suggest that G-coupled receptors (GPCRs) cycling is involved with the occurrence of STA. To gain insights on the dynamical aspects of this process, we developed a stochastic computational model. The model consists of the olfactory transduction currents mediated by the cyclic nucleotide gated (CNG) channels and calcium ion (Ca2+)-activated chloride (CAC) channels, and the dynamics of their respective ligands, cAMP and Ca2+, and it simulates the EOG results obtained under different experimental conditions through changes in the amplitude and duration of cAMP and Ca2+ response, two second messengers implicated with STA occurrence. The model reproduced the experimental data for each pharmacological treatment and provided a mechanistic explanation for the action of GPCR cycling in the levels of second messengers modulating the levels of STA. All together, these experimental and theoretical results indicate the existence of a mechanism of regulation of STA by signaling pathways that control GPCR cycling and tune the levels of second messengers in OSNs, and not only by CNG channel desensitization as previously thought. PMID:25144232

  2. Clean Air Program : Design Guidelines for Bus Transit Systems Using Liquefied Natural Gas (LNG) as an Alternative Fuel

    DOT National Transportation Integrated Search

    1997-03-01

    The use of alternative fuels to power transit buses is steadily increasing. Several fuels, including Liquefied Natural Gas (LNG), Compressed Natural Gas (CNG), Liquefied Petroleum Gas (LPG), and Methanol/Ethanol, are already being used. At present, t...

  3. Clean air program : design guidelines for bus transit systems using compressed natural gas as an alternative fuel

    DOT National Transportation Integrated Search

    1996-06-01

    This report documents design guidelines for the safe use of Compressed Natural Gas (CNG). The report is designed to provide guidance, information on safe industry practices, applicable national codes and standards, and reference data that transit age...

  4. Clean air program : design guidelines for bus transit systems using electric and hybrid electric propulsion as an alternative fuel

    DOT National Transportation Integrated Search

    2003-03-01

    The use of alternative fuels to power transit buses is steadily increasing. Several fuels, including : Compressed Natural Gas (CNG), Liquefied Natural Gas (LNG), Liquefied Petroleum Gas (LPG), and : Methanol/Ethanol, are already being used. At presen...

  5. Alternative Fuels Data Center

    Science.gov Websites

    ), propane, electricity, and renewable diesel. For taxation purposes, one GGE of CNG is equal to 5.66 pounds (lbs.), one DGE of LNG is equal to 6.06 lbs., one GGE of propane is equal to 1.35 gallons, and one GGE

  6. Cow Power: A Case Study of Renewable Compressed Natural Gas as a Transportation Fuel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mintz, Marianne; Tomich, Matthew

    This case study explores the production and use of renewable compressed natural gas (R-CNG)—derived from the anaerobic digestion (AD) of dairy manure—to fuel 42 heavy-duty milk tanker trucks operating in Indiana, Michigan, Tennessee, and Kentucky.

  7. Creating a Road Map for Planetary Data Spatial Infrastructure

    NASA Astrophysics Data System (ADS)

    Naß, A.; Archinal, B.; Beyer, R.; DellaGiustina, D.; Fassett, C.; Gaddis, L.; Hagerty, J.; Hare, T.; Laura, J.; Lawrence, S.; Mazarico, E.; Patthoff, A.; Radebaugh, J.; Skinner, J.; Sutton, S.; Thomson, B. J.; Williams, D.

    2017-09-01

    There currently exists a clear need for long-range planning in regard to planetary spatial data and the development of infrastructure to support its use. Planetary data are the hard-earned fruits of planetary exploration, and the Mapping and Planetary Spatial Infrastructure Team (MAPSIT) mission is to ensure their availability for any conceivable investigation, now or in the future.

  8. Development of a lunar infrastructure

    NASA Astrophysics Data System (ADS)

    Burke, J. D.

    If humans are to reside continuously and productively on the Moon, they must be surrounded and supported there by an infrastructure having some attributes of the support systems that have made advanced civilization possible on Earth. Building this lunar infrastructure will, in a sense, be an investment. Creating it will require large resources from Earth, but once it exists it can do much to limit the further demands of a lunar base for Earthside support. What is needed for a viable lunar infrastructure? This question can be approached from two directions. The first is to examine history, which is essentially a record of growing information structures among humans on Earth (tribes, agriculture, specialization of work, education, ethics, arts and sciences, cities and states, technology). The second approach is much less secure but may provide useful insights: it is to examine the minimal needs of a small human community - not just for physical survival but for a stable existence with a net product output. This paper presents a summary, based on present knowledge of the Moon and of the likely functions of a human community there, of some of these infrastructure requirements, and also discusses possible ways to proceed toward meeting early infrastructure needs.

  9. Environmental engineering of navigation infrastructure: a survey of existing practices, challenges, and potential opportunities.

    PubMed

    Fredette, Thomas J; Foran, Christy M; Brasfield, Sandra M; Suedel, Burton C

    2012-01-01

    Navigation infrastructure such as channels, jetties, river training structures, and lock-and-dam facilities are primary components of a safe and efficient water transportation system. Planning for such infrastructure has until recently involved efforts to minimize impacts on the environment through a standardized environmental assessment process. More recently, consistent with environmental sustainability concepts, planners have begun to consider how such projects can also be constructed with environmental enhancements. This study examined the existing institutional conditions within the US Army Corps of Engineers and cooperating federal agencies relative to incorporating environmental enhancements into navigation infrastructure projects. The study sought to (1) investigate institutional attitudes towards the environmental enhancement of navigation infrastructure (EENI) concept, (2) identify potential impediments to implementation and solutions to such impediments, (3) identify existing navigation projects designed with the express intent of enhancing environmental benefit in addition to the primary project purpose, (4) identify innovative ideas for increasing environmental benefits for navigation projects, (5) identify needs for additional technical information or research, and (6) identify laws, regulations, and policies that both support and hinder such design features. The principal investigation tool was an Internet-based survey with 53 questions. The survey captured a wide range of perspectives on the EENI concept including ideas, concerns, research needs, and relevant laws and policies. Study recommendations included further promotion of the concept of EENI to planners and designers, documentation of existing projects, initiation of pilot studies on some of the innovative ideas provided through the survey, and development of national goals and interagency agreements to facilitate implementation. Copyright © 2011 SETAC.

  10. Waste-to-Fuel: A Case Study of Converting Food Waste to Renewable Natural Gas as a Transportation Fuel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mintz, Marianne; Tomich, Matthew

    This case study explores the production and use of renewable compressed natural gas (R-CNG)—derived from the anaerobic digestion (AD) of organic waste—to fuel heavy-duty refuse trucks and other natural gas vehicles in Sacramento, California.

  11. 49 CFR 393.68 - Compressed natural gas fuel containers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Compressed natural gas fuel containers. 393.68... AND ACCESSORIES NECESSARY FOR SAFE OPERATION Fuel Systems § 393.68 Compressed natural gas fuel containers. (a) Applicability. The rules in this section apply to compressed natural gas (CNG) fuel...

  12. Finding the Future That Fits.

    ERIC Educational Resources Information Center

    Taylor, Alison

    In 2000, a government-supported foundation called Careers the Next Generation (CNG) in Alberta, Canada, began coordinating summer internships for high school students in information and computer technology (ICT). The participating firms represented a mix of large and small private and public organizations in high-tech and other industries in the…

  13. Fleet DNA: Commercial Fleet Vehicle Operating Data | Transportation

    Science.gov Websites

    and Vehicle Dynamometer Evaluation and Comparison of Class 7 Hybrid Electric and Conventional Diesel Gasoline-Electric Hybrid Transit Buses In-Use Performance Comparison of Hybrid Electric, CNG, and Diesel Diesel Electric Hybrid Tractor Evaluation: 13-Month Final Report Project Startup: Evaluating Coca-Cola's

  14. 49 CFR 393.68 - Compressed natural gas fuel containers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Compressed natural gas fuel containers. 393.68... AND ACCESSORIES NECESSARY FOR SAFE OPERATION Fuel Systems § 393.68 Compressed natural gas fuel containers. (a) Applicability. The rules in this section apply to compressed natural gas (CNG) fuel...

  15. 78 FR 70394 - Buy America Waiver Notification

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... regarding the FHWA's finding that a Buy America waiver is appropriate for the use of non-domestic iron and.../nara . Background The FHWA's Buy America policy in 23 CFR 635.410 requires a domestic manufacturing... the FHWA's finding that a Buy America waiver is appropriate to use non-domestic CNG Compressor...

  16. Wireless intelligent network: infrastructure before services?

    NASA Astrophysics Data System (ADS)

    Chu, Narisa N.

    1996-01-01

    The Wireless Intelligent Network (WIN) intends to take advantage of the Advanced Intelligent Network (AIN) concepts and products developed from wireline communications. However, progress of the AIN deployment has been slow due to the many barriers that exist in the traditional wireline carriers' deployment procedures and infrastructure. The success of AIN has not been truly demonstrated. The AIN objectives and directions are applicable to the wireless industry although the plans and implementations could be significantly different. This paper points out WIN characteristics in architecture, flexibility, deployment, and value to customers. In order to succeed, the technology driven AIN concept has to be reinforced by the market driven WIN services. An infrastructure suitable for the WIN will contain elements that are foreign to the wireline network. The deployment process is expected to seed with the revenue generated services. Standardization will be achieved by simplifying and incorporating the IS-41C, AIN, and Intelligent Network CS-1 recommendations. Integration of the existing and future systems impose the biggest challenge of all. Service creation has to be complemented with service deployment process which heavily impact the carriers' infrastructure. WIN deployment will likely start from an Intelligent Peripheral, a Service Control Point and migrate to a Service Node when sufficient triggers are implemented in the mobile switch for distributed call control. The struggle to move forward will not be based on technology, but rather on the impact to existing infrastructure.

  17. Real-time Identification System using Mobile Hand-held Devices: Mobile Biometrics Evaluation Framework

    DTIC Science & Technology

    2014-04-01

    must be done to determine current infrastructure and capabilities so that necessary updates and changes can be addressed up front. Mobile biometric...with existing satellite communications infrastructure . 20 PSTP 03-427BIOM 4 State of Mobile Biometric Device Market 4.1 Fingerprint...is a wireless information system highlighted by Real-time wireless data collection mobile device independence, wireless infrastructure independence

  18. Advanced space-based InSAR risk analysis of planned and existing transportation infrastructure.

    DOT National Transportation Integrated Search

    2017-03-21

    The purpose of this document is to summarize activities by Stanford University and : MDA Geospatial Services Inc. (MDA) to estimate surface deformation and associated : risk to transportation infrastructure using SAR Interferometric methods for the :...

  19. Potential impacts of solar arrays on highway environment, safety and operations.

    DOT National Transportation Integrated Search

    2015-10-01

    The advent of solar energy utilization in highway infrastructure around the country has been increasing in : recent years. Right of Ways (ROWs) have several advantages for energy development such as the existing : electrical infrastructure aligned wi...

  20. Expanded Transportation Performance Measures to Supplement Level of Service (LOS) for Growth Management and Transportation Impact Analysis

    DOT National Transportation Integrated Search

    2012-10-01

    Floridas transportation infrastructure must continually evolve to meet the demands of its growing population. Many jurisdictions are moving toward multimodal transportation systems that utilize existing infrastructure more efficiently, providing u...

  1. Adapting to climate change : the public policy response - public infrastructure

    DOT National Transportation Integrated Search

    2009-06-01

    This paper assesses the threats and needs that multidimensional climate change imposes for : public infrastructure, reviews the existing adaptive capacity that could be applied to respond : to these threats and needs, and presents options for enhanci...

  2. Green Infrastructure Models and Tools

    EPA Science Inventory

    The objective of this project is to modify and refine existing models and develop new tools to support decision making for the complete green infrastructure (GI) project lifecycle, including the planning and implementation of stormwater control in urban and agricultural settings,...

  3. User-level framework for performance monitoring of HPC applications

    NASA Astrophysics Data System (ADS)

    Hristova, R.; Goranov, G.

    2013-10-01

    HP-SEE is an infrastructure that links the existing HPC facilities in South East Europe in a common infrastructure. The analysis of the performance monitoring of the High-Performance Computing (HPC) applications in the infrastructure can be useful for the end user as diagnostic for the overall performance of his applications. The existing monitoring tools for HP-SEE provide to the end user only aggregated information for all applications. Usually, the user does not have permissions to select only the relevant information for him and for his applications. In this article we present a framework for performance monitoring of the HPC applications in the HP-SEE infrastructure. The framework provides standardized performance metrics, which every user can use in order to monitor his applications. Furthermore as a part of the framework a program interface is developed. The interface allows the user to publish metrics data from his application and to read and analyze gathered information. Publishing and reading through the framework is possible only with grid certificate valid for the infrastructure. Therefore the user is authorized to access only the data for his applications.

  4. Integrating smart container technology into existing shipping and law enforcement infrastructure

    NASA Astrophysics Data System (ADS)

    Ferriere, Dale; Pysareva, Khrystyna; Rucinski, Andrzej

    2006-05-01

    While there has been important research and development in the area of smart container technologies, no system design methodologies have yet emerged for integrating this technology into the existing shipping and law enforcement infrastructure. A successful deployment of smart containers requires a precise understanding of how to integrate this new technology into the existing shipping and law enforcement infrastructure, how to establish communication interoperability, and how to establish procedures and protocols related to the operation of smart containers. In addition, this integration needs to be seamless, unobtrusive to commerce, and cost-effective. In order to address these issues, we need to answer the following series of questions: 1) Who will own and operate the smart container technology; 2) Who will be responsible for monitoring the smart container data and notifying first responders; 3) What communication technologies currently used by first responders might be adopted for smart container data transmission; and 4) How will existing cargo manifest data be integrated into smart container data. In short, we need to identify the best practices for smart container ownership and operation. In order to help provide answers to these questions, we have surveyed a sample group of representatives from law enforcement, first responder, regulatory, and private sector organizations. This paper presents smart container infrastructure best practices recommendations obtained from the results of the survey.

  5. Cloud Infrastructure & Applications - CloudIA

    NASA Astrophysics Data System (ADS)

    Sulistio, Anthony; Reich, Christoph; Doelitzscher, Frank

    The idea behind Cloud Computing is to deliver Infrastructure-as-a-Services and Software-as-a-Service over the Internet on an easy pay-per-use business model. To harness the potentials of Cloud Computing for e-Learning and research purposes, and to small- and medium-sized enterprises, the Hochschule Furtwangen University establishes a new project, called Cloud Infrastructure & Applications (CloudIA). The CloudIA project is a market-oriented cloud infrastructure that leverages different virtualization technologies, by supporting Service-Level Agreements for various service offerings. This paper describes the CloudIA project in details and mentions our early experiences in building a private cloud using an existing infrastructure.

  6. Geotechnical Engineering Circular No. 3. Design Guidance: Geotechnical Earthquake Engineering for Highways. Volume II - Design Examples

    DOT National Transportation Integrated Search

    1994-02-01

    The report contains an assessment of existing port infrastructure related to United States-Mexico trade, planned infrastructure improvements, an identification of current trade and transportation flows, and an assessment of emerging trade corridors. ...

  7. Public-private partnerships in transportation infrastructure : survey of experiences and perceptions.

    DOT National Transportation Integrated Search

    2013-09-01

    The use of public-private partnerships (PPPs) for transportation infrastructure delivery has increased in : the U.S. However, concerns about and opposition to these agreements exist due to a variety of factors. : This paper explores the perceptions t...

  8. Integration of bicycling and walking facilities into the infrastructure of urban communities : [research brief].

    DOT National Transportation Integrated Search

    2012-02-01

    Many manuals, handbooks and web resources exist that provide guidance on planning for and designing bicycle and pedestrian facilities. However few of these resources emphasize program and infrastructure characteristics most desired by current (and po...

  9. A Framework For Analysis Of Coastal Infrastructure Vunerabilty To Global Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Obrien, P. S.; White, K. D.; Veatch, W.; Marzion, R.; Moritz, H.; Moritz, H. R.

    2017-12-01

    Recorded impacts of global sea rise on coastal water levels have been documented over the past 100 to 150 years. In the recent 40 years the assumption of hydrologic stationarity has been recognized as invalid. New coastal infrastructure designs must recognize the paradigm shift from hydrologic stationarity to non-stationarity in coastal hydrology. A framework for the evaluation of existing coastal infrastructure is proposed to effectively assess design vulnerability. Two data sets developed from existing structures are chosen to test a proposed framework for vunerabilty to global sea level rise, with the proposed name Climate Preparedness and Resilience Register (CPRR). The CPRR framework consists of four major elements; Datum Adjustment, Coastal Water Levels, Scenario Projections and Performance Thresholds.

  10. Alternative Fuels Data Center

    Science.gov Websites

    Natural Gas Tax Compressed natural gas (CNG) and liquefied natural gas (LNG) used as motor fuel of using natural gas must pay an annual flat rate privilege tax if the vehicle has a gross vehicle equivalent of LNG; operators must prepay a portion of this tax annually. The Mississippi Department of

  11. Alternative Fuels Data Center: Reliable Temperature Compensation is

    Science.gov Websites

    Technical Bulletin addresses the potential hazards created by failure of compressed natural gas (CNG ) dispensers that do not accurately compensate for the temperature of the natural gas in vehicle storage containers as they are filled and the history of serious incidents as a result. Accurate temperature

  12. 77 FR 66601 - Northern Natural Gas Company; Notice of Availability of the Environmental Assessment for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... Ochiltree, Hansford, Hutchinson, and Carson Counties, Texas; Beaver County, Oklahoma; and Kiowa and Clark... Station, Ochiltree County, Texas, MP 38.47; Beaver Compressor Station, Beaver County, Oklahoma, MP 0.00; Northern/CNG Interconnect, Beaver County, Oklahoma, MP 10.35; Englewood Branch Line, Clark County, Kansas...

  13. DOE Office of Scientific and Technical Information (OSTI.GOV)

    none,

    The home that won a Production Builder award in the 2014 Housing Innovation Awards serves as a model for this builder, showcasing high-tech features including an electric car charging station; a compressed natural gas (CNG) car fueling station; a greywater recycling system that filters shower, sink, and clothes washer water for yard irrigation; smart appliances; and an electronic energy management system.

  14. Review and analysis of potential safety impacts of and regulatory barriers to fuel efficiency technologies and alternative fuels in medium- and heavy-duty vehicles

    DOT National Transportation Integrated Search

    2015-06-01

    This report summarizes a safety analysis of medium- and heavy-duty vehicles (MD/HDVs) equipped with fuel efficiency (FE) technologies and/or using alternative fuels (natural gas-CNG and LNG, propane, biodiesel and power train electrification). The st...

  15. Alternative Fuels Data Center

    Science.gov Websites

    , certain buses, or commercial vehicles that are powered by an alternative fuel, if the vehicles obtain an (GVW) Type of Vehicle Decal Fee 18,000 pounds (lbs.) or less Passenger, School Bus, or Commercial $75 vehicles, buses, or commercial motor vehicles that are powered by compressed natural gas (CNG), liquefied

  16. Alternative Fuels Data Center: North Carolina Transportation Data for

    Science.gov Websites

    ) 2,115 Source: BioFuels Atlas from the National Renewable Energy Laboratory Case Studies Video thumbnail CNG Installation a Boost Aug. 19, 2015 Video thumbnail for Biodiesel Offers an Easy Alternative for Fleets Biodiesel Offers an Easy Alternative for Fleets Aug. 18, 2015 Video thumbnail for Blue Skies

  17. Alternative Fuels Data Center: Idaho Transportation Data for Alternative

    Science.gov Websites

    the National Renewable Energy Laboratory Case Studies Video thumbnail for Idaho National Laboratory Operating Costs and Emissions May 16, 2014 Video thumbnail for Republic Services Reduces Waste with 87 CNG Videos on YouTube Video thumbnail for Idaho Surges Ahead with Electric Vehicle Charging Idaho Surges

  18. Alternative Fuels Data Center: Arkansas Launches Natural Gas-Powered Buses

    Science.gov Websites

    and Refueling StationA> Arkansas Launches Natural Gas-Powered Buses and Refueling Station to a great opportunity for [Rock Region METRO] to continue to meet the needs of our customers with the Cities Coalition (ACCC). Before RRM's board of directors would approve the CNG transition project, they

  19. In-vehicle measurement of ultrafine particles on compressed natural gas, conventional diesel, and oxidation-catalyst diesel heavy-duty transit buses.

    PubMed

    Hammond, Davyda; Jones, Steven; Lalor, Melinda

    2007-02-01

    Many metropolitan transit authorities are considering upgrading transit bus fleets to decrease ambient criteria pollutant levels. Advancements in engine and fuel technology have lead to a generation of lower-emission buses in a variety of fuel types. Dynamometer tests show substantial reductions in particulate mass emissions for younger buses (<10 years) over older models, but particle number reduction has not been verified in the research. Recent studies suggest that particle number is a more important factor than particle mass in determining health effects. In-vehicle particle number concentration measurements on conventional diesel, oxidation-catalyst diesel and compressed natural gas transit buses are compared to estimate relative in-vehicle particulate exposures. Two primary consistencies are observed from the data: the CNG buses have average particle count concentrations near the average concentrations for the oxidation-catalyst diesel buses, and the conventional diesel buses have average particle count concentrations approximately three to four times greater than the CNG buses. Particle number concentrations are also noticeably affected by bus idling behavior and ventilation options, such as, window position and air conditioning.

  20. Atmospheric levels of aldehydes and BTEX and their relationship with vehicular fleet changes in Rio de Janeiro urban area.

    PubMed

    Martins, Eduardo Monteiro; Arbilla, Graciela; Bauerfeldt, Glauco Favilla; de Paula, Murilo

    2007-05-01

    A comprehensive monitoring campaign to assess aldehydes and BTEX concentrations was performed during 12 months, in the Tijuca district (Rio de Janeiro), an area with commercial activities and a high flux of vehicles. The mean concentrations of formaldehyde and acetaldehyde were 151 and 30 ppb, respectively. The high formaldehyde/acetaldehyde ratio was attributed to extensive use of compressed natural gas (CNG). The number of CNG vehicles in the metropolitan Region of Rio de Janeiro increased from 23000 in January 2001 to 161000 in January 2005. Monitoring data show that, for the same period, methane and formaldehyde concentrations increased while NO(x) and CO levels diminished. Mean concentrations for benzene, toluene, ethylbenzene, m,p-xylene and o-xylene, were 1.1, 4.8, 3.6, 10.4 and 3.0 micro gm(-3), respectively. Benzene and toluene concentrations were lower than the values determined in 1996, for the same location. The levels of ethylbenzene and xylenes determined in this work are similar to values obtained in 1996. This fact may be explained as a consequence of changes in the gasoline composition.

  1. State-dependent block of CNG channels by dequalinium.

    PubMed

    Rosenbaum, Tamara; Gordon-Shaag, Ariela; Islas, León D; Cooper, Jeremy; Munari, Mika; Gordon, Sharona E

    2004-03-01

    Cyclic nucleotide-gated (CNG) ion channels are nonselective cation channels with a high permeability for Ca(2+). Not surprisingly, they are blocked by a number of Ca(2+) channel blockers including tetracaine, pimozide, and diltiazem. We studied the effects of dequalinium, an extracellular blocker of the small conductance Ca(2+)-activated K(+) channel. We previously noted that dequalinium is a high-affinity blocker of CNGA1 channels from the intracellular side, with little or no state dependence at 0 mV. Here we examined block by dequalinium at a broad range of voltages in both CNGA1 and CNGA2 channels. We found that dequalinium block was mildly state dependent for both channels, with the affinity for closed channels 3-5 times higher than that for open channels. Mutations in the S4-S5 linker did not alter the affinity of open channels for dequalinium, but increased the affinity of closed channels by 10-20-fold. The state-specific effect of these mutations raises the question of whether/how the S4-S5 linker alters the binding of a blocker within the ion permeation pathway.

  2. Cyclic GMP-gated CNG channels function in Sema3A-induced growth cone repulsion.

    PubMed

    Togashi, Kazunobu; von Schimmelmann, Melanie J; Nishiyama, Makoto; Lim, Chae-Seok; Yoshida, Norihiro; Yun, Bokyoung; Molday, Robert S; Goshima, Yoshio; Hong, Kyonsoo

    2008-06-12

    Cyclic nucleotide-gated channels (CNGCs) transduce external signals required for sensory processes, e.g., photoreception, olfaction, and taste. Nerve growth cone guidance by diffusible attractive and repulsive molecules is regulated by differential growth cone Ca2+ signaling. However, the Ca2+-conducting ion channels that transduce guidance molecule signals are largely unknown. We show that rod-type CNGC-like channels function in the repulsion of cultured Xenopus spinal neuron growth cones by Sema3A, which triggers the production of the cGMP that activates the Xenopus CNGA1 (xCNGA1) subunit-containing channels in interneurons. Downregulation of xCNGA1 or overexpression of a mutant xCNGA1 incapable of binding cGMP abolished CNG currents and converted growth cone repulsion to attraction in response to Sema3A. We also show that Ca2+ entry through xCNGCs is required to mediate the repulsive Sema3A signal. These studies extend our knowledge of the function of CNGCs by demonstrating their requirement for signal transduction in growth cone guidance.

  3. Pump-to-Wheels Methane Emissions from the Heavy-Duty Transportation Sector.

    PubMed

    Clark, Nigel N; McKain, David L; Johnson, Derek R; Wayne, W Scott; Li, Hailin; Akkerman, Vyacheslav; Sandoval, Cesar; Covington, April N; Mongold, Ronald A; Hailer, John T; Ugarte, Orlando J

    2017-01-17

    Pump-to-wheels (PTW) methane emissions from the heavy-duty (HD) transportation sector, which have climate change implications, are poorly documented. In this study, methane emissions from HD natural gas fueled vehicles and the compressed natural gas (CNG) and liquefied natural gas (LNG) fueling stations that serve them were characterized. A novel measurement system was developed to quantify methane leaks and losses. Engine related emissions were characterized from twenty-two natural gas fueled transit buses, refuse trucks, and over-the-road (OTR) tractors. Losses from six LNG and eight CNG stations were characterized during compression, fuel delivery, storage, and from leaks. Cryogenic boil-off pressure rise and pressure control venting from LNG storage tanks were characterized using theoretical and empirical modeling. Field and laboratory observations of LNG storage tanks were used for model development and evaluation. PTW emissions were combined with a specific scenario to view emissions as a percent of throughput. Vehicle tailpipe and crankcase emissions were the highest sources of methane. Data from this research are being applied by the authors to develop models to forecast methane emissions from the future HD transportation sector.

  4. Analysis of application of alternative drive systems for international heavy-duty transport on Wroclaw-Dresden-Prague routes

    NASA Astrophysics Data System (ADS)

    Skrętowicz, Maria; Sroka, Zbigniew

    2017-11-01

    The depletion of the fossil fuels resources, significant increase of the air pollution caused by the use of internal combustion engines, and emission of carbon dioxide which is responsible for the greenhouse effect escalates the development of vehicle's alternative drive systems. Generally, the emphasis is given to the alternative fuels (natural gas CNG, mixture of propane-butane gases LPG, hydrogen, alcohol fuels, biofuels) and hybrid or electric vehicles. Roads between large industrial and commercial centres, i.e. Wroclaw - Dresden - Prague, are used mainly by heavy-duty vehicles. Consequently, the contribution of the road transport to the ecological threat in this realm is significant. The objectives of this research were the assessment of the traffic volume and emission rate of exhaust gases caused by heavy-duty vehicles on the analysed roads and evaluation of the possibility of using existing and alternative drive systems in vehicles driving on the roads in the analysed region.

  5. The use of sustainable materials for quick repair of aging bridges : phase II final report.

    DOT National Transportation Integrated Search

    2012-02-01

    "During the last decade fiber reinforced polymer (FRP) materials have gained wide acceptance for repair and strengthening of existing infrastructures or to design new infrastructures due to their desirable properties (high strength to weight ratio, l...

  6. Broad roads in a thin country : infrastructure concessions in Chile

    DOT National Transportation Integrated Search

    2000-01-01

    Chile has experienced rapid economic growth for more than a decade. Demand for basic infrastructure services has grown in tandem with the economic expansion, quickly outstripping the supply capacity of existing assets. In the early 90's a policy deci...

  7. Characteristics of the auto users and non-users of central Texas toll roads.

    DOT National Transportation Integrated Search

    2009-08-01

    As toll road usage increases to finance new road infrastructure or add capacity to existing road infrastructure, the : question of who does and does not use toll roads becomes increasingly important to toll road developers, financiers, : Traffic and ...

  8. Reshoring and its impact on transportation infrastructure & US economy.

    DOT National Transportation Integrated Search

    2016-12-01

    Reshoring is expected to have a tremendous impact on the United States (US) economy and on the utilization of the existing : transportation infrastructures of the country. It is an immense need to identify the potential companies in the US that will ...

  9. Gefitinib and EGFR Gene Copy Number Aberrations in Esophageal Cancer.

    PubMed

    Petty, Russell D; Dahle-Smith, Asa; Stevenson, David A J; Osborne, Aileen; Massie, Doreen; Clark, Caroline; Murray, Graeme I; Dutton, Susan J; Roberts, Corran; Chong, Irene Y; Mansoor, Wasat; Thompson, Joyce; Harrison, Mark; Chatterjee, Anirban; Falk, Stephen J; Elyan, Sean; Garcia-Alonso, Angel; Fyfe, David Walter; Wadsley, Jonathan; Chau, Ian; Ferry, David R; Miedzybrodzka, Zosia

    2017-07-10

    Purpose The Cancer Esophagus Gefitinib trial demonstrated improved progression-free survival with the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor gefitinib relative to placebo in patients with advanced esophageal cancer who had disease progression after chemotherapy. Rapid and durable responses were observed in a minority of patients. We hypothesized that genetic aberration of the EGFR pathway would identify patients benefitting from gefitinib. Methods A prespecified, blinded molecular analysis of Cancer Esophagus Gefitinib trial tumors was conducted to compare efficacy of gefitinib with that of placebo according to EGFR copy number gain (CNG) and EGFR, KRAS, BRAF, and PIK3CA mutation status. EGFR CNG was determined by fluorescent in situ hybridization (FISH) using prespecified criteria and EGFR FISH-positive status was defined as high polysomy or amplification. Results Biomarker data were available for 340 patients. In EGFR FISH-positive tumors (20.2%), overall survival was improved with gefitinib compared with placebo (hazard ratio [HR] for death, 0.59; 95% CI, 0.35 to 1.00; P = .05). In EGFR FISH-negative tumors, there was no difference in overall survival with gefitinib compared with placebo (HR for death, 0.90; 95% CI, 0.69 to 1.18; P = .46). Patients with EGFR amplification (7.2%) gained greatest benefit from gefitinib (HR for death, 0.21; 95% CI, 0.07 to 0.64; P = .006). There was no difference in overall survival for gefitinib versus placebo for patients with EGFR, KRAS, BRAF, and PIK3CA mutations, or for any mutation versus none. Conclusion EGFR CNG assessed by FISH appears to identify a subgroup of patients with esophageal cancer who may benefit from gefitinib as a second-line treatment. Results of this study suggest that anti-EGFR therapies should be investigated in prospective clinical trials in different settings in EGFR FISH-positive and, in particular, EGFR-amplified esophageal cancer.

  10. Winter-time size distribution and source apportionment of total suspended particulate matter and associated metals in Delhi

    NASA Astrophysics Data System (ADS)

    Srivastava, Arun; Gupta, Sandeep; Jain, V. K.

    2009-03-01

    A study of the winter time size distribution and source apportionment of total suspended particulate matter (TSPM) and associated heavy metal concentrations have been carried out for the city of Delhi. This study is important from the point of view of implementation of compressed natural gas (CNG) as alternate of diesel fuel in the public transport system in 2001 to reduce the pollution level. TSPM were collected using a five-stage cascade impactor at six sites in the winters of 2005-06. The results of size distribution indicate that a major portion (~ 40%) of TSPM concentration is in the form of PM0.7 (< 0.7 μm). Similar trends were observed with most of the heavy metals associated with various size fractions of TSPM. A very good correlation between coarse and fine size fraction of TSPM was observed. It was also observed that the metals associated with coarse particles have more chances of correlation with other metals; rather they are associated with fine particles. Source apportionment was carried out separately in coarse and fine size modes of TSPM by Chemical Mass Balance Receptor Model (CMB8) as well as by Principle Component Analysis (PCA) of SPSS. Source apportionment by PCA reveals that there are two major sources (possibly vehicular and crustal re-suspension) in both coarse and fine size fractions. Results obtained by CMB8 show the dominance of vehicular pollutants and crustal dust in fine and coarse size mode respectively. Noticeably the dominance of vehicular pollutants are now confined to fine size only whilst during pre CNG era it dominated both coarse and fine size mode. An increase of 42.5, 44.4, 48.2, 38.6 and 38.9% in the concentrations of TSPM, PM10.9, coarse particles, fine particles and lead respectively was observed during pre (2001) to post CNG (2005-06) period.

  11. Gas Phase Emission Ratios From In-Use Diesel and CNG Curbside Passenger Buses in New York City

    NASA Astrophysics Data System (ADS)

    Herndon, S. C.; Shorter, J.; Canagaratna, M.; Jayne, J.; Nelson, D. D.; Wormhoudt, J. C.; Williams, P.; Silva, P. J.; Shi, Q.; Ghertner, A.; Zahniser, M.; Worsnop, D.; Kolb, C.; Lanni, T.; Drewnick, F.; Demerjian, K. L.

    2002-12-01

    The Aerodyne Mobile Laboratory simultaneously measured gas phase and particulate emissions from in use vehicles during two campaigns in New York City. The campaigns took place during two weeks in October, 2000 and four weeks in July-August, 2001. Passenger curbside buses were the primary focus of the study, but school buses and several other heavy duty diesel vehicles were also characterized. This paper describes the methodologies used to measure individual in use vehicles and presents the results of the gas phase measurements. Emission ratios for NO, NO2, SO2, N2O, CO, CH4 and H2CO relative to CO2 have been determined across several classes of buses. The gas phase concentrations were measured each second, using Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS). Some of the categories of buses into which the data has been sorted are; diesel (both 6V92 and Series 50) with and without the Continuous Regenerative Technology (CRT) retrofit, compressed natural gas powered(CNG) and hybrid diesel-electric buses. The New York Metropolitan Transit Authority (MTA) cooperated with this work, providing details about each of their buses followed. In addition to MTA buses, other New York City passenger bus operators were also measured. In September 2000, MTA began to switch to 30 ppm sulfur diesel fuel while it is believed the non MTA operators did not. The measured emission ratios show that low sulfur fuel greatly reduces the amount of SO2 per CO2. Roughly one third of the MTA fleet of diesel buses have been equipped with the CRT retrofit. The gas phase results of interest in this category show increased direct emission of NO2 and companion work (also submitted to the 12th CRC) show the impact the CRT refit has on particulate emissions. CNG buses show increased H2CO and CH4 emission ratios relative to diesel powered motors.

  12. Choice of precipitant and calcination temperature of precursor for synthesis of NiCo2O4 for control of CO-CH4 emissions from CNG vehicles.

    PubMed

    Trivedi, Suverna; Prasad, Ram

    2018-03-01

    Compressed natural gas (CNG) is most appropriate an alternative of conventional fuel for automobiles. However, emissions of carbon-monoxide and methane from such vehicles adversely affect human health and environment. Consequently, to abate emissions from CNG vehicles, development of highly efficient and inexpensive catalysts is necessary. Thus, the present work attempts to scan the effects of precipitants (Na 2 CO 3 , KOH and urea) for nickel cobaltite (NiCo 2 O 4 ) catalysts prepared by co-precipitation from nitrate solutions and calcined in a lean CO-air mixture at 400°C. The catalysts were used for oxidation of a mixture of CO and CH 4 (1:1). The catalysts were characterized by X-ray diffractometer, Brunauer-Emmett-Teller surface-area, X-ray photoelectron spectroscopy; temperature programmed reduction and Scanning electron microscopy coupled with Energy-Dispersive X-Ray Spectroscopy. The Na 2 CO 3 was adjudged as the best precipitant for production of catalyst, which completely oxidized CO-CH 4 mixture at the lowest temperature (T 100 =350°C). Whereas, for catalyst prepared using urea, T 100 =362°C. On the other hand the conversion of CO-CH 4 mixture over the catalyst synthesized by KOH limited to 97% even beyond 400°C. Further, the effect of higher calcination temperatures of 500 and 600°C was examined for the best catalyst. The total oxidation of the mixture was attained at higher temperatures of 375 and 410°C over catalysts calcined at 500 and 600°C respectively. Thus, the best precipitant established was Na 2 CO 3 and the optimum calcination temperature of 400°C was found to synthesize the NiCo 2 O 4 catalyst for the best performance in CO-CH 4 oxidation. Copyright © 2017. Published by Elsevier B.V.

  13. Greenhouse gas emissions from heavy-duty natural gas, hybrid, and conventional diesel on-road trucks during freight transport

    NASA Astrophysics Data System (ADS)

    Quiros, David C.; Smith, Jeremy; Thiruvengadam, Arvind; Huai, Tao; Hu, Shaohua

    2017-11-01

    Heavy-duty on-road vehicles account for 70% of all freight transport and 20% of transportation-sector greenhouse gas (GHG) emissions in the United States. This study measured three prevalent GHG emissions - carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) - from seven heavy-duty vehicles, fueled by diesel and compressed natural gas (CNG), and compliant to the MY 2007 or 2010 U.S. EPA emission standards, while operated over six routes used for freight movement in California. Total combined (tractor, trailer, and payload) weights were 68,000 ± 1000 lbs. for the seven vehicles. Using the International Panel on Climate Change (IPCC) radiative forcing values for a 100-year time horizon, N2O emissions accounted for 2.6-8.3% of total tailpipe CO2 equivalent emissions (CO2-eq) for diesel vehicles equipped with Diesel Oxidation Catalyst, Diesel Particulate Filter, and Selective Catalytic Reduction system (DOC + DPF + SCR), and CH4 emissions accounted for 1.4-5.9% of CO2-eq emissions from the CNG-powered vehicle with a three-way catalyst (TWC). N2O emissions from diesel vehicles equipped with SCR (0.17-0.30 g/mi) were an order of magnitude higher than diesel vehicles without SCR (0.013-0.023 g/mi) during highway operation. For the vehicles selected in this test program, we measured 11-22% lower CO2-eq emissions from a hybrid compared to conventional diesel vehicles during transport over lower-speed routes of the freight transport system, but 20-27% higher CO2-eq emissions during higher-speed routes. Similarly, a CNG vehicle emitted up to 15% lower CO2-eq compared to conventional diesel vehicles over more neutral-grade highway routes, but emitted up to 12% greater CO2-eq emissions over routes with higher engine loads.

  14. Chemical and optical properties of PM2.5 from on-road operation of light duty vehicles in Delhi city.

    PubMed

    Jaiprakash; Habib, Gazala

    2017-05-15

    This study reports emission factors of PM 2.5 , elemental carbon (EC), organic carbon (OC), ions, trace elements and mass absorption cross-sections (MAC) of aerosol emitted from the on-road operation of light duty vehicles of different vintages. A portable dilution system was used to achieve complete quenching of aerosol at near ambient condition. The particles were collected on the filters and analyzed for chemical and light absorbing properties of aerosol. The diesel-powered passenger cars emitted higher PM 2.5 (56-356mgkm -1 ) with a large fraction of EC (37-65%), while emissions from gasoline (46-78mgkm -1 ), and CNG vehicles (33-34mgkm -1 ) were low and contained low EC (5-15%) and remarkably high OC (46-91%). The MAC of aerosols for diesel vehicles (32-208m 2 g -1 of PM 2.5 ) were well explained by EC content (31-62%) and showed similarity with MAC values reported for wood fuel combustion in cooking stoves indicating the two sources cannot be resolved on the basis of light absorption properties in source apportionment studies. Ionic contributions to PM 2.5 were highest for 4W-gasoline (11-19%) compared to 4W-diesel (7-11%), and CNG (9-10%). The abundance of ions such as Na + , Ca 2+ , SO 4 2- , NO 3 - , and NH 4 + could be due to use of lubricant oil and abrasive nature of engine of old vehicles. Trace elements (Al, Fe, Zn, Pb, and Cu) emitted from after-treatment devices, additives in lube oil, and wearing of engine components, were found to be 2-14%, 3-8% and 11-12% of total PM 2.5 for 4W of diesel, gasoline, and CNG respectively. This study indicates that aerosol emissions from on-road vehicles show a strong dependency on vehicle maintenance, engine type and after-treatment techniques. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A Model for the Fast Synchronous Oscillations of Firing Rate in Rat Suprachiasmatic Nucleus Neurons Cultured in a Multielectrode Array Dish

    PubMed Central

    Stepanyuk, Andrey R.; Belan, Pavel V.; Kononenko, Nikolai I.

    2014-01-01

    When dispersed and cultured in a multielectrode dish (MED), suprachiasmatic nucleus (SCN) neurons express fast oscillations of firing rate (FOFR; fast relative to the circadian cycle), with burst duration ∼10 min, and interburst interval varying from 20 to 60 min in different cells but remaining nevertheless rather regular in individual cells. In many cases, separate neurons in distant parts of the 1 mm recording area of a MED exhibited correlated FOFR. Neither the mechanism of FOFR nor the mechanism of their synchronization among neurons is known. Based on recent data implicating vasoactive intestinal polypeptide (VIP) as a key intercellular synchronizing agent, we built a model in which VIP acts as both a feedback regulator to generate FOFR in individual neurons, and a diffusible synchronizing agent to produce coherent electrical output of a neuronal network. In our model, VIP binding to its (VPAC2) receptors acts through Gs G-proteins to activate adenylyl cyclase (AC), increase intracellular cAMP, and open cyclic-nucleotide-gated (CNG) cation channels, thus depolarizing the cell and generating neuronal firing to release VIP. In parallel, slowly developing homologous desensitization and internalization of VPAC2 receptors terminates elevation of cAMP and thereby provides an interpulse silent interval. Through mathematical modeling, we show that this VIP/VPAC2/AC/cAMP/CNG-channel mechanism is sufficient for generating reliable FOFR in single neurons. When our model for FOFR is combined with a published model of synchronization of circadian rhythms based on VIP/VPAC2 and Per gene regulation synchronization of circadian rhythms is significantly accelerated. These results suggest that (a) auto/paracrine regulation by VIP/VPAC2 and intracellular AC/cAMP/CNG-channels are sufficient to provide robust FOFR and synchrony among neurons in a heterogeneous network, and (b) this system may also participate in synchronization of circadian rhythms. PMID:25192180

  16. Inherited macular degeneration-associated mutations in CNGB3 increase the ligand sensitivity and spontaneous open probability of cone cyclic nucleotide-gated channels

    PubMed Central

    Meighan, Peter C.; Peng, Changhong; Varnum, Michael D.

    2015-01-01

    Cyclic nucleotide gated (CNG) channels are a critical component of the visual transduction cascade in the vertebrate retina. Mutations in the genes encoding these channels have been associated with a spectrum of inherited retinal disorders. To gain insight into their pathophysiological mechanisms, we have investigated the functional consequences of several CNGB3 mutations, previously associated with macular degeneration (Y469D and L595F) or complete achromatopsia (S156F, P309L, and G558C), by expressing these subunits in combination with wild-type CNGA3 in Xenopus oocytes and characterizing them using patch-clamp recordings in the inside-out configuration. These mutations did not prevent the formation of functional heteromeric channels, as indicated by sensitivity to block by L-cis-diltiazem. With the exception of S156F, each of the mutant channels displayed electrophysiological properties reflecting enhanced channel activity at physiological concentrations of cGMP (i.e., a gain-of-function phenotype). The increased channel activity produced by these mutations resulted from either increased functional expression levels, or increased sensitivity to cyclic nucleotides. Furthermore, L595F increased the spontaneous open probability in the absence of activating ligand, signifying a ligand independent gain-of-function change. In addition to the CNGB3 disease-associate mutations, we characterized the effects of several common CNGB3 and CNGA3 single-nucleotide polymorphisms (SNPs) on heteromeric CNGA3+CNGB3 channel function. Two of the SNPs examined (A3-T153M, and B3-W234C) produced decreased ligand sensitivity for heteromeric CNG channels. These changes may contribute to background disease susceptibility when combined with other genetic or non-genetic factors. Together, these studies help to define the underlying molecular phenotype for mutations relating to CNG channel disease pathogenesis. PMID:26106334

  17. Climate Change Impacts on Runoff Generation for the Design of Sustainable Stormwater Infrastructure

    DOT National Transportation Integrated Search

    2011-06-01

    Climate change over the Pacific Northwest is expected to alter the hydrological cycle, such as an increase in winter flooding potential due to more precipitation falling as snow and more frequent rain on snow events. Existing infrastructure for storm...

  18. Characteristics of the truck users and non-users of Texas toll roads.

    DOT National Transportation Integrated Search

    2009-08-01

    As the use of toll roads increase to finance new road infrastructure or add capacity to existing road infrastructure, the : question of who use and do not use toll roads becomes increasingly important to toll road developers, financiers, : Traffic an...

  19. Minimizing Overhead for Secure Computation and Fully Homomorphic Encryption: Overhead

    DTIC Science & Technology

    2015-11-01

    many inputs. We also improved our compiler infrastructure to handle very large circuits in a more scalable way. In Jan’13, we employed the AESNI and...Amazon’s elastic compute infrastructure , and is running under a Xen hypervisor. Since we do not have direct access to the bare metal, we cannot...creating novel opportunities for compressing au- thentication overhead. It is especially compelling that existing public key infrastructures can be used

  20. Silicon Valley as an Early Adopter for On-Demand Civil VTOL Operations

    NASA Technical Reports Server (NTRS)

    Antcliff, Kevin R.; Moore, Mark D.; Goodrich, Kenneth H.

    2016-01-01

    With high incomes, long commutes, severe ground geographic constraints, severe highway congestion during peak commute times, high housing costs, and near perfect year-round weather, the Silicon Valley is positioned to be an excellent early adopter market for emerging aviation On-Demand Mobility transportation solutions. Prior efforts have attempted to use existing aviation platforms (helicopters or General Aviation aircraft) with existing infrastructure solutions, or only investigated new vehicle platforms without understanding how to incorporate new vehicle types into existing built-up communities. Research has been performed with the objective of minimizing door-to-door time for "Hyper Commuters" (frequent, long-distance commuters) in the Silicon Valley through the development of new helipad infrastructure for ultra-low noise Vertical Takeoff and Landing (VTOL) aircraft. Current travel times for chosen city-pairs across urban and suburban commutes are compared to future mobility concepts that provide significantly higher utilization and productivity to yield competitive operating costs compared to existing transportation choices. Helipads are introduced near current modes of transportation and infrastructure for ease-of-access, and maximizing proximity. Strategies for both private and public infrastructure development are presented that require no new land purchase while minimizing community noise exposure. New VTOL concepts are introduced with cruise speeds of 200 mph, which yield a greater than three times improvement in overall door-to-door time when compared to current automobiles, and in some cases, improvements of up to 6 times lower trip times.

  1. Characterizing pediatric surgical capacity in the Eastern Democratic Republic of Congo: results of a pilot study.

    PubMed

    Cairo, Sarah B; Kalisya, Luc Malemo; Bigabwa, Richard; Rothstein, David H

    2018-03-01

    Characterize pediatric surgical capacity in the eastern Democratic Republic of Congo (DRC) to identify areas of potential improvement. The Pediatric Personnel, Infrastructure, Procedures, Equipment, and Supplies (PediPIPES) survey was used in two representative eastern DRC provinces to assess existing surgical infrastructure and capacity. We compared our results to previously published reports from other sub-Saharan African countries. Fourteen hospitals in the eastern DRC and 37 in 19 sub-Saharan African (SSA) countries were compared. The average PediPIPES index for the DRC was 7.7 compared to 13.5 for SSAs. The greatest disparities existed in the areas of personnel and infrastructure. Running water was reportedly available to 57.1% of the hospitals in the DRC, and the majority of hospitals (78.6%) were dependent on generators and solar panels for electricity. Only two hospitals in the DRC (14.3%) reported a pediatric surgeon equivalent on staff, compared to 86.5% of facilities sampled in SSA reporting ≥ 1 pediatric surgeon. Significant barriers in personnel, infrastructure, procedures, equipment, and supplies impede the provision of adequate surgical care to children. Further work is needed to assess allocation and utilization of existing resources, and to enhance training of personnel with specific attention to pediatric surgery.

  2. Strengthening of bridge columns subjected to an impact lateral load caused by vehicle collision : phase I final report.

    DOT National Transportation Integrated Search

    2011-08-01

    "Fiber reinforced polymer (FRP) materials have gained wide acceptance for repair and retrofit of existing infrastructures or to design new infrastructures due to their desirable properties (high strength to weight ratio, light weight and consequent e...

  3. 75 FR 30460 - Notice of Funding Availability for the Department of Transportation's National Infrastructure...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ... provide quantitative information regarding expected reductions in emissions of CO 2 or fuel consumption as... provide quantitative information that validates the existence of substantial transportation-related costs... infrastructure investments on systematic analysis of expected benefits and costs, including both quantitative and...

  4. Complex Networks and Critical Infrastructures

    NASA Astrophysics Data System (ADS)

    Setola, Roberto; de Porcellinis, Stefano

    The term “Critical Infrastructures” indicates all those technological infrastructures such as: electric grids, telecommunication networks, railways, healthcare systems, financial circuits, etc. that are more and more relevant for the welfare of our countries. Each one of these infrastructures is a complex, highly non-linear, geographically dispersed cluster of systems, that interact with their human owners, operators, users and with the other infrastructures. Their augmented relevance and the actual political and technological scenarios, which have increased their exposition to accidental failure and deliberate attacks, demand for different and innovative protection strategies (generally indicate as CIP - Critical Infrastructure Protection). To this end it is mandatory to understand the mechanisms that regulate the dynamic of these infrastructures. In this framework, an interesting approach is those provided by the complex networks. In this paper we illustrate some results achieved considering structural and functional properties of the corresponding topological networks both when each infrastructure is assumed as an autonomous system and when we take into account also the dependencies existing among the different infrastructures.

  5. Alternative Fuels Data Center: Publications

    Science.gov Websites

    ;According to Table 3, CNG is $.33 less than gasoline on an energy-equivalent basis, while E85 is $0.18 more than gasoline on an energy-equivalent basis. Charging Electric Vehicles in Smart Cities: An EVI-Pro 350 Level 2 plugs at non-residential locations are required to support Columbus' primary PEV goal of

  6. 49 CFR 579.21 - Reporting requirements for manufacturers of 5,000 or more light vehicles annually.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., 05 parking brake, 06 engine and engine cooling system, 07 fuel system, 10 power train, 11 electrical... model, the model year, the type, the platform, the fuel and/or propulsion system type coded as follows: CNG (compressed natural gas), CIF (compression ignition fuel), EBP (electric battery power), FCP (fuel...

  7. New Report Compares Performance of Compressed Natural Gas Refuse Haulers to

    Science.gov Websites

    Diesel-Powered Trucks Report Compares Performance of Compressed Natural Gas Refuse Haulers to Diesel-Powered Trucks For more information contact: e:mail: Public Affairs A new report that compares the performance of compressed natural gas (CNG) refuse haulers in New York City to similar diesel-powered trucks

  8. 49 CFR 571.304 - Standard No. 304; Compressed natural gas fuel container integrity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 304; Compressed natural gas fuel... natural gas fuel container integrity. S1. Scope. This standard specifies requirements for the integrity of compressed natural gas (CNG), motor vehicle fuel containers. S2. Purpose. The purpose of this standard is to...

  9. Alternative Fuels Data Center: Indiana Beverage Company Invests in

    Science.gov Websites

    fleet of compressed natural gas (CNG) tractors. For information about this project, contact Greater Nov. 4, 2017 Photo of a truck Natural Gas Vehicles Make a Difference in Tennessee Oct. 28, 2017 Image Natural Gas Trucks June 23, 2017 Photo of a transit bus America's Largest Home Runs on Biodiesel in North

  10. 49 CFR 571.304 - Standard No. 304; Compressed natural gas fuel container integrity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... system over the entire liner, including the domes. Hoop wrapped means winding of filament in a....3Number and placement of thermocouples. To monitor flame temperature, place three thermocouples so that... average ambient wind velocity at the CNG fuel container during the period specified in S8.3.6 of this...

  11. 49 CFR 571.304 - Standard No. 304; Compressed natural gas fuel container integrity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... system over the entire liner, including the domes. Hoop wrapped means winding of filament in a....3Number and placement of thermocouples. To monitor flame temperature, place three thermocouples so that... average ambient wind velocity at the CNG fuel container during the period specified in S8.3.6 of this...

  12. 49 CFR 571.304 - Standard No. 304; Compressed natural gas fuel container integrity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... system over the entire liner, including the domes. Hoop wrapped means winding of filament in a....3Number and placement of thermocouples. To monitor flame temperature, place three thermocouples so that... average ambient wind velocity at the CNG fuel container during the period specified in S8.3.6 of this...

  13. Alternative Fuels Data Center: Filling CNG Fuel Tanks

    Science.gov Websites

    , therefore containing less energy by volume when the fuel system reaches the rated pressure. For this reason because when gas molecules are compressed, they create heat. The faster they are compressed, the more they heat up and expand. So when the gas is compressed rapidly through a fast-fill process, the molecules

  14. Alternative Fuels Data Center: CNG Shuttles Save Fuel Costs for R&R

    Science.gov Websites

    Go Electric in Florida Feb. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels Vehicles With Natural Gas Oct. 1, 2011 Hybrid Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Fisher Coachworks Develops Plug

  15. Alternative Fuels Data Center: Atlanta Airport Converts Shuttles to CNG

    Science.gov Websites

    company saves money and conserves fuel with compressed natural gas airport shuttles. For information about . Rental Cars Go Electric in Florida Feb. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1 Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels Vehicles With Natural Gas Oct. 1, 2011

  16. Alternative Fuels Data Center: Wisconsin Transportation Data for

    Science.gov Websites

    Compressed Natural Gas (CNG) 41 15 Electric 249 36 Ethanol (E85) 189 1 Hydrogen 0 0 Liquefied Natural Gas Natural Gas Electricity Transportation Fuel Consumption Source: State Energy Data System based on beta ) 68,820 Natural Gas (million cubic feet) 400,877 Conventional Power Plants 76 Generating Capacity

  17. Alternative Fuels Data Center: Natural Gas Stations Abound on Oklahoma's

    Science.gov Websites

    " Our stakeholders are proud to have built a first-of-its-kind CNG corridor that's helping local Pollard of Central Oklahoma Clean Cities (OKCC). "Our stakeholders are proud to have built a first-of Fallin presented her Oklahoma First Energy Plan, the state's first comprehensive energy plan. The plan

  18. Alternative Fuels Data Center: Vehicle Search

    Science.gov Websites

    ZeroTruck Search Engines and Hybrid Systems For medium- and heavy-duty vehicles: Engine & Power Sources Hydraulic hybrid Hybrid - CNG Hybrid - Diesel Electric Hybrid - LNG Hybrid Search x Pick Engine Fuel Natural Gas Propane Electric Plug-in Hybrid Electric Hydraulic hybrid Hybrid Search x Pick Engine Fuel

  19. 49 CFR 571.304 - Standard No. 304; Compressed natural gas fuel container integrity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Standard No. 304; Compressed natural gas fuel... natural gas fuel container integrity. S1. Scope. This standard specifies requirements for the integrity of compressed natural gas (CNG), motor vehicle fuel containers. S2. Purpose. The purpose of this standard is to...

  20. Policy and Policy Formulation Considerations for Incorporation of Secure Mobile Devices in USMC Ground Combat Units

    DTIC Science & Technology

    2014-09-01

    power. The wireless infrastructure is an expansion of the current DOD IE which can be leveraged to connect mobile capabilities and technologies. The...DOD must focus on three critical areas central to mobility : the wireless infrastructure , the devices themselves, and the applications the devices use... infrastructure to support mobile devices. – The intent behind this goal is to improve the existing wireless backbone to support secure voice, data, and video

  1. Green infrastructure development at European Union's eastern border: Effects of road infrastructure and forest habitat loss.

    PubMed

    Angelstam, Per; Khaulyak, Olha; Yamelynets, Taras; Mozgeris, Gintautas; Naumov, Vladimir; Chmielewski, Tadeusz J; Elbakidze, Marine; Manton, Michael; Prots, Bohdan; Valasiuk, Sviataslau

    2017-05-15

    The functionality of forest patches and networks as green infrastructure may be affected negatively both by expanding road networks and forestry intensification. We assessed the effects of (1) the current and planned road infrastructure, and (2) forest loss and gain, on the remaining large forest landscape massifs as green infrastructure at the EU's eastern border region in post-socialistic transition. First, habitat patch and network functionality in 1996-98 was assessed using habitat suitability index modelling. Second, we made expert interviews about road development with planners in 10 administrative regions in Poland, Belarus and Ukraine. Third, forest loss and gain inside the forest massifs, and gain outside them during the period 2001-14 were measured. This EU cross-border region hosts four remaining forest massifs as regional green infrastructure hotspots. While Poland's road network is developing fast in terms of new freeways, city bypasses and upgrades of road quality, in Belarus and Ukraine the focus is on maintenance of existing roads, and no new corridors. We conclude that economic support from the EU, and thus rapid development of roads in Poland, is likely to reduce the permeability for wildlife of the urban and agricultural matrix around existing forest massifs. However, the four identified forest massifs themselves, forming the forest landscape green infrastructure at the EU's east border, were little affected by road development plans. In contrast, forest loss inside massifs was high, especially in Ukraine. Only in Poland forest loss was balanced by gain. Forest gain outside forest massifs was low. To conclude, pro-active and collaborative spatial planning across different sectors and countries is needed to secure functional forest green infrastructure as base for biodiversity conservation and human well-being. Copyright © 2017. Published by Elsevier Ltd.

  2. 47 CFR 54.504 - Requests for services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... pricing and technology infrastructure information submitted as part of an FCC Form 471 shall be treated as... disclosure of pricing or technology infrastructure information. (ii) The exemption for existing contract... school” as defined in § 54.500 of this subpart, do not operate as for-profit businesses, and do not have...

  3. Perspectives on the use of green infrastructure for stormwater management in Cleveland and Milwaukee.

    PubMed

    Keeley, Melissa; Koburger, Althea; Dolowitz, David P; Medearis, Dale; Nickel, Darla; Shuster, William

    2013-06-01

    Green infrastructure is a general term referring to the management of landscapes in ways that generate human and ecosystem benefits. Many municipalities have begun to utilize green infrastructure in efforts to meet stormwater management goals. This study examines challenges to integrating gray and green infrastructure for stormwater management, informed by interviews with practitioners in Cleveland, OH and Milwaukee WI. Green infrastructure in these cities is utilized under conditions of extreme fiscal austerity and its use presents opportunities to connect stormwater management with urban revitalization and economic recovery while planning for the effects of negative- or zero-population growth. In this context, specific challenges in capturing the multiple benefits of green infrastructure exist because the projects required to meet federally mandated stormwater management targets and the needs of urban redevelopment frequently differ in scale and location.

  4. Perspectives on the Use of Green Infrastructure for Stormwater Management in Cleveland and Milwaukee

    NASA Astrophysics Data System (ADS)

    Keeley, Melissa; Koburger, Althea; Dolowitz, David P.; Medearis, Dale; Nickel, Darla; Shuster, William

    2013-06-01

    Green infrastructure is a general term referring to the management of landscapes in ways that generate human and ecosystem benefits. Many municipalities have begun to utilize green infrastructure in efforts to meet stormwater management goals. This study examines challenges to integrating gray and green infrastructure for stormwater management, informed by interviews with practitioners in Cleveland, OH and Milwaukee WI. Green infrastructure in these cities is utilized under conditions of extreme fiscal austerity and its use presents opportunities to connect stormwater management with urban revitalization and economic recovery while planning for the effects of negative- or zero-population growth. In this context, specific challenges in capturing the multiple benefits of green infrastructure exist because the projects required to meet federally mandated stormwater management targets and the needs of urban redevelopment frequently differ in scale and location.

  5. The development of Korea's new long-term care service infrastructure and its results: focusing on the market-friendly policy used for expansion of the numbers of service providers and personal care workers.

    PubMed

    Chon, Yongho

    2013-01-01

    One of the main reasons for reforming long-term care systems is a deficient existing service infrastructure for the elderly. This article provides an overview of why and how the Korean government expanded long-term care infrastructure through the introduction of a new compulsory insurance system, with a particular focus on the market-friendly policies used to expand the infrastructure. Then, the positive results of the expansion of the long-term care infrastructure and the challenges that have emerged are examined. Finally, it is argued that the Korean government should actively implement a range of practical policies and interventions within the new system.

  6. The Information Technology Infrastructure for the Translational Genomics Core and the Partners Biobank at Partners Personalized Medicine

    PubMed Central

    Boutin, Natalie; Holzbach, Ana; Mahanta, Lisa; Aldama, Jackie; Cerretani, Xander; Embree, Kevin; Leon, Irene; Rathi, Neeta; Vickers, Matilde

    2016-01-01

    The Biobank and Translational Genomics core at Partners Personalized Medicine requires robust software and hardware. This Information Technology (IT) infrastructure enables the storage and transfer of large amounts of data, drives efficiencies in the laboratory, maintains data integrity from the time of consent to the time that genomic data is distributed for research, and enables the management of complex genetic data. Here, we describe the functional components of the research IT infrastructure at Partners Personalized Medicine and how they integrate with existing clinical and research systems, review some of the ways in which this IT infrastructure maintains data integrity and security, and discuss some of the challenges inherent to building and maintaining such infrastructure. PMID:26805892

  7. DOE Office of Scientific and Technical Information (OSTI.GOV)

    McCaskey, Alexander J.

    Hybrid programming models for beyond-CMOS technologies will prove critical for integrating new computing technologies alongside our existing infrastructure. Unfortunately the software infrastructure required to enable this is lacking or not available. XACC is a programming framework for extreme-scale, post-exascale accelerator architectures that integrates alongside existing conventional applications. It is a pluggable framework for programming languages developed for next-gen computing hardware architectures like quantum and neuromorphic computing. It lets computational scientists efficiently off-load classically intractable work to attached accelerators through user-friendly Kernel definitions. XACC makes post-exascale hybrid programming approachable for domain computational scientists.

  8. Collaborative Access Control For Critical Infrastructures

    NASA Astrophysics Data System (ADS)

    Baina, Amine; El Kalam, Anas Abou; Deswarte, Yves; Kaaniche, Mohamed

    A critical infrastructure (CI) can fail with various degrees of severity due to physical and logical vulnerabilities. Since many interdependencies exist between CIs, failures can have dramatic consequences on the entire infrastructure. This paper focuses on threats that affect information and communication systems that constitute the critical information infrastructure (CII). A new collaborative access control framework called PolyOrBAC is proposed to address security problems that are specific to CIIs. The framework offers each organization participating in a CII the ability to collaborate with other organizations while maintaining control of its resources and internal security policy. The approach is demonstrated on a practical scenario involving the electrical power grid.

  9. The Resilient Infrastructure Initiative

    DOE PAGES

    Clifford, Megan

    2016-10-01

    Infrastructure is, by design, largely unnoticed until it breaks down and services fail. This includes water supplies, gas pipelines, bridges and dams, phone lines and cell towers, roads and culverts, railways, and the electric grid—all of the complex systems that keep our societies and economies running. Climate change, population growth, increased urbanization, system aging, and outdated design standards stress existing infrastructure and its ability to satisfy the rapidly changing demands from users. Here, the resilience of both physical and cyber infrastructure systems, however, is critical to a community as it prepares for, responds to, and recovers from a disaster, whethermore » natural or man-made.« less

  10. Proposed Requirements-driven User-scenario Development Protocol for the Belmont Forum E-Infrastructure and Data Management Cooperative Research Agreement

    NASA Astrophysics Data System (ADS)

    Wee, B.; Car, N.; Percivall, G.; Allen, D.; Fitch, P. G.; Baumann, P.; Waldmann, H. C.

    2014-12-01

    The Belmont Forum E-Infrastructure and Data Management Cooperative Research Agreement (CRA) is designed to foster a global community to collaborate on e-infrastructure challenges. One of the deliverables is an implementation plan to address global data infrastructure interoperability challenges and align existing domestic and international capabilities. Work package three (WP3) of the CRA focuses on the harmonization of global data infrastructure for sharing environmental data. One of the subtasks under WP3 is the development of user scenarios that guide the development of applicable deliverables. This paper describes the proposed protocol for user scenario development. It enables the solicitation of user scenarios from a broad constituency, and exposes the mechanisms by which those solicitations are evaluated against requirements that map to the Belmont Challenge. The underlying principle of traceability forms the basis for a structured, requirements-driven approach resulting in work products amenable to trade-off analyses and objective prioritization. The protocol adopts the ISO Reference Model for Open Distributed Processing (RM-ODP) as a top level framework. User scenarios are developed within RM-ODP's "Enterprise Viewpoint". To harmonize with existing frameworks, the protocol utilizes the conceptual constructs of "scenarios", "use cases", "use case categories", and use case templates as adopted by recent GEOSS Architecture Implementation Project (AIP) deliverables and CSIRO's eReefs project. These constructs are encapsulated under the larger construct of "user scenarios". Once user scenarios are ranked by goodness-of-fit to the Belmont Challenge, secondary scoring metrics may be generated, like goodness-of-fit to FutureEarth science themes. The protocol also facilitates an assessment of the ease of implementing given user scenario using existing GEOSS AIP deliverables. In summary, the protocol results in a traceability graph that can be extended to coordinate across research programmes. If implemented using appropriate technologies and harmonized with existing ontologies, this approach enables queries, sensitivity analyses, and visualization of complex relationships.

  11. Alternative Fuels Data Center: Maps and Data

    Science.gov Websites

    -24960-10gn0o4 Annual Percent Growth of Vehicles in Operation Generated_thumb20160914-24960-10gn0o4 Last Annual Percent Growth of Vehicles in Operation 2010-2011 2011-2012 2012-2013 2013-2014 2014-2015 CNG States of America. Electric drive trains (EVs, Hydrogen, PHEVs and HEVs) experienced the greatest growth

  12. Alternative Fuels Data Center

    Science.gov Websites

    Alternative Fuel Tax Rates A special excise tax rate of 2% is imposed on the sale of propane and an excise tax of $0.23 per gallon is imposed on all special fuels sales and deliveries, including compressed of CNG or 1.7 gallons of LNG. Retailers must obtain a license from the Office of the State Tax

  13. Alternative Fuels Data Center

    Science.gov Websites

    Natural Gas and Propane Tax Effective January 1, 2019, propane, compressed natural gas (CNG), and liquefied natural gas (LNG) will be subject to an excise tax at a rate of $0.04 per gasoline gallon equivalent (GGE), plus a $0.01 ninth-cent fuel tax, a $0.01 local option fuel tax, and an additional variable

  14. Alternative Fuels Data Center: Wyoming Transportation Data for Alternative

    Science.gov Websites

    Biodiesel (B20 and above) 0 4 Compressed Natural Gas (CNG) 7 7 Electric 37 1 Ethanol (E85) 8 4 Hydrogen 0 0 of nearly 100 coalitions. Wyoming has 1 coalition: Yellowstone-Teton Clean Cities Coalition Contact a . Gasoline Diesel Natural Gas Transportation Fuel Consumption Source: State Energy Data System based on beta

  15. Optogenetic manipulation of cGMP in cells and animals by the tightly light-regulated guanylyl-cyclase opsin CyclOp

    PubMed Central

    Gao, Shiqiang; Nagpal, Jatin; Schneider, Martin W.; Kozjak-Pavlovic, Vera; Nagel, Georg; Gottschalk, Alexander

    2015-01-01

    Cyclic GMP (cGMP) signalling regulates multiple biological functions through activation of protein kinase G and cyclic nucleotide-gated (CNG) channels. In sensory neurons, cGMP permits signal modulation, amplification and encoding, before depolarization. Here we implement a guanylyl cyclase rhodopsin from Blastocladiella emersonii as a new optogenetic tool (BeCyclOp), enabling rapid light-triggered cGMP increase in heterologous cells (Xenopus oocytes, HEK293T cells) and in Caenorhabditis elegans. Among five different fungal CyclOps, exhibiting unusual eight transmembrane topologies and cytosolic N-termini, BeCyclOp is the superior optogenetic tool (light/dark activity ratio: 5,000; no cAMP production; turnover (20 °C) ∼17 cGMP s−1). Via co-expressed CNG channels (OLF in oocytes, TAX-2/4 in C. elegans muscle), BeCyclOp photoactivation induces a rapid conductance increase and depolarization at very low light intensities. In O2/CO2 sensory neurons of C. elegans, BeCyclOp activation evokes behavioural responses consistent with their normal sensory function. BeCyclOp therefore enables precise and rapid optogenetic manipulation of cGMP levels in cells and animals. PMID:26345128

  16. Optogenetic manipulation of cGMP in cells and animals by the tightly light-regulated guanylyl-cyclase opsin CyclOp.

    PubMed

    Gao, Shiqiang; Nagpal, Jatin; Schneider, Martin W; Kozjak-Pavlovic, Vera; Nagel, Georg; Gottschalk, Alexander

    2015-09-08

    Cyclic GMP (cGMP) signalling regulates multiple biological functions through activation of protein kinase G and cyclic nucleotide-gated (CNG) channels. In sensory neurons, cGMP permits signal modulation, amplification and encoding, before depolarization. Here we implement a guanylyl cyclase rhodopsin from Blastocladiella emersonii as a new optogenetic tool (BeCyclOp), enabling rapid light-triggered cGMP increase in heterologous cells (Xenopus oocytes, HEK293T cells) and in Caenorhabditis elegans. Among five different fungal CyclOps, exhibiting unusual eight transmembrane topologies and cytosolic N-termini, BeCyclOp is the superior optogenetic tool (light/dark activity ratio: 5,000; no cAMP production; turnover (20 °C) ∼17 cGMP s(-1)). Via co-expressed CNG channels (OLF in oocytes, TAX-2/4 in C. elegans muscle), BeCyclOp photoactivation induces a rapid conductance increase and depolarization at very low light intensities. In O2/CO2 sensory neurons of C. elegans, BeCyclOp activation evokes behavioural responses consistent with their normal sensory function. BeCyclOp therefore enables precise and rapid optogenetic manipulation of cGMP levels in cells and animals.

  17. Spatial distribution of calcium-gated chloride channels in olfactory cilia.

    PubMed

    French, Donald A; Badamdorj, Dorjsuren; Kleene, Steven J

    2010-12-30

    In vertebrate olfactory receptor neurons, sensory cilia transduce odor stimuli into changes in neuronal membrane potential. The voltage changes are primarily caused by the sequential openings of two types of channel: a cyclic-nucleotide-gated (CNG) cationic channel and a calcium-gated chloride channel. In frog, the cilia are 25 to 200 µm in length, so the spatial distributions of the channels may be an important determinant of odor sensitivity. To determine the spatial distribution of the chloride channels, we recorded from single cilia as calcium was allowed to diffuse down the length of the cilium and activate the channels. A computational model of this experiment allowed an estimate of the spatial distribution of the chloride channels. On average, the channels were concentrated in a narrow band centered at a distance of 29% of the ciliary length, measured from the base of the cilium. This matches the location of the CNG channels determined previously. This non-uniform distribution of transduction proteins is consistent with similar findings in other cilia. On average, the two types of olfactory transduction channel are concentrated in the same region of the cilium. This may contribute to the efficient detection of weak stimuli.

  18. Dual fuel injection piggyback controller system

    NASA Astrophysics Data System (ADS)

    Muji, Siti Zarina Mohd.; Hassanal, Muhammad Amirul Hafeez; Lee, Chua King; Fawzi, Mas; Zulkifli, Fathul Hakim

    2017-09-01

    Dual-fuel injection is an effort to reduce the dependency on diesel and gasoline fuel. Generally, there are two approaches to implement the dual-fuel injection in car system. The first approach is changing the whole injector of the car engine, the consequence is excessive high cost. Alternatively, it also can be achieved by manipulating the system's control signal especially the Electronic Control Unit (ECU) signal. Hence, the study focuses to develop a dual injection timing controller system that likely adopted to control injection time and quantity of compressed natural gas (CNG) and diesel fuel. In this system, Raspberry Pi 3 reacts as main controller unit to receive ECU signal, analyze it and then manipulate its duty cycle to be fed into the Electronic Driver Unit (EDU). The manipulation has changed the duty cycle to two pulses instead of single pulse. A particular pulse mainly used to control injection of diesel fuel and another pulse controls injection of Compressed Natural Gas (CNG). The test indicated promising results that the system can be implemented in the car as piggyback system. This article, which was originally published online on 14 September 2017, contained an error in the acknowledgment section. The corrected acknowledgment appears in the Corrigendum attached to the pdf.

  19. Reducing transit bus emissions: Alternative fuels or traffic operations?

    NASA Astrophysics Data System (ADS)

    Alam, Ahsan; Hatzopoulou, Marianne

    2014-06-01

    In this study, we simulated the operations and greenhouse gas (GHG) emissions of transit buses along a busy corridor and quantified the effects of two different fuels (conventional diesel and compressed natural gas) as well as a set of driving conditions on emissions. Results indicate that compressed natural gas (CNG) reduces GHG emissions by 8-12% compared to conventional diesel, this reduction could increase to 16% with high levels of traffic congestion. However, the benefits of switching from conventional diesel to CNG are less apparent when the road network is uncongested. We also investigated the effects of bus operations on emissions by applying several strategies such as transit signal priority (TSP), queue jumper lanes, and relocation of bus stops. Results show that in congested conditions, TSP alone can reduce GHG emissions by 14% and when combined with improved technology; a reduction of 23% is achieved. The reduction benefits are even more apparent when other transit operational improvements are combined with TSP. Finally a sensitivity analysis was performed to investigate the effect of operational improvements on emissions under varying levels of network congestion. We observe that under “extreme congestion”, the benefits of TSP decrease.

  20. Exposure of smoke solutions from CNG-powered four-stroke auto-rickshaws induces distressed embryonic movements, embryonic hemorrhaging and ectopia cordis.

    PubMed

    Ejaz, Sohail; Ejaz, Ahmed; Sohail, Amara; Ahmed, Mukthar; Nasir, Amar; Lim, Chae Woong

    2009-07-01

    In south Asian countries, a campaign has launched to promote CNG-powered four-stroke auto-rickshaws (CNFAR) to decrease emission load in the environment. Even though, CNFAR are considered environmentally safe, emissions of some other toxic chemicals would amplify, which may effect the development of growing fetus and may result in different growth defects. By utilizing the in vivo chicken embryo model, this report analyzes the toxic potential of CNFAR smoke solutions (CNFARSS) on embryonic movements (EM) and cardiovascular development. Application of CNFARSS to embryos caused profound decline (p<0.001) in all four types of EMs. Several recovery attempts of all EMs were observed in oscillating fashion, however, EMs did not recover by the end of experiment. Exposure of CNFARSS escorted intense decline (p<0.001) with temperate recovery phases in the EM of tail. Macroscopic evaluation of all CNFARSS treated chicken embryos revealed several widespread hemorrhaging throughout the whole body. Moreover, four different types of ectopia cordis were prominently observed among all CNFARSS treated embryos, namely; incomplete ectopia cordis, complete ectopia cordis, cervico-thoracic ectopia cordis and thoraco-abdominal ectopia cordis.

  1. Evaluation of Green Infrastructure on Peak Flow Mitigation Focusing on the Connectivity of Impervious Areas

    NASA Astrophysics Data System (ADS)

    Seo, Y.; Hwang, J.; Kwon, Y.

    2017-12-01

    The existence of impervious areas is one of the most distinguishing characteristics of urban catchments. It decreases infiltration and increases direct runoff in urban catchments. The recent introduction of green infrastructure in urban catchments for the purpose of sustainable development contributes to the decrease of the directly connected impervious areas (DCIA) by isolating existing impervious areas and consequently, to the flood risk mitigation. This study coupled the width function-based instantaneous hydrograph (WFIUH), which is able to handle the spatial distribution of the impervious areas, with the concept of the DCIA to assess the impact of decreasing DCIA on the shape of direct runoff hydrographs. Using several scenarios for typical green infrastructure and corresponding changes of DCIA in a test catchment, this study evaluated the effect of green infrastructure on the shape of the resulting direct runoff hydrographs and peak flows. The results showed that the changes in the DCIA immediately affects the shape of the direct runoff hydrograph and decreases peak flows depending on spatial implementation scenarios. The quantitative assessment of the spatial distribution of impervious areas and also the changes to the DCIA suggests effective and well-planned green infrastructure can be introduced in urban environments for flood risk management.

  2. The "New Guy": "Good Management Begins with Good People"

    ERIC Educational Resources Information Center

    Vicars, Dennis

    2011-01-01

    The author believes the two most valuable employees in an organization are the valued person(s) that has been there forever and helped build the infrastructure and processes and a "new guy" who questions why they exist. The seasoned professionals not only understand the processes, infrastructure, culture, educational programs, and vision, but were…

  3. Evolution of A Distributed Live, Virtual, Constructive Environment for Human in the Loop Unmanned Aircraft Testing

    NASA Technical Reports Server (NTRS)

    Murphy, James R.; Otto, Neil M.

    2017-01-01

    NASA's Unmanned Aircraft Systems Integration in the National Airspace System Project is conducting human in the loop simulations and flight testing intended to reduce barriers associated with enabling routine airspace access for unmanned aircraft. The primary focus of these tests is interaction of the unmanned aircraft pilot with the display of detect and avoid alerting and guidance information. The project's integrated test and evaluation team was charged with developing the test infrastructure. As with any development effort, compromises in the underlying system architecture and design were made to allow for the rapid prototyping and open-ended nature of the research. In order to accommodate these design choices, a distributed test environment was developed incorporating Live, Virtual, Constructive, (LVC) concepts. The LVC components form the core infrastructure support simulation of UAS operations by integrating live and virtual aircraft in a realistic air traffic environment. This LVC infrastructure enables efficient testing by leveraging the use of existing assets distributed across multiple NASA Centers. Using standard LVC concepts enable future integration with existing simulation infrastructure.

  4. Evolution of A Distributed Live, Virtual, Constructive Environment for Human in the Loop Unmanned Aircraft Testing

    NASA Technical Reports Server (NTRS)

    Murphy, Jim; Otto, Neil

    2017-01-01

    NASA's Unmanned Aircraft Systems Integration in the National Airspace System Project is conducting human in the loop simulations and flight testing intended to reduce barriers associated with enabling routine airspace access for unmanned aircraft. The primary focus of these tests is interaction of the unmanned aircraft pilot with the display of detect and avoid alerting and guidance information. The projects integrated test and evaluation team was charged with developing the test infrastructure. As with any development effort, compromises in the underlying system architecture and design were made to allow for the rapid prototyping and open-ended nature of the research. In order to accommodate these design choices, a distributed test environment was developed incorporating Live, Virtual, Constructive, (LVC) concepts. The LVC components form the core infrastructure support simulation of UAS operations by integrating live and virtual aircraft in a realistic air traffic environment. This LVC infrastructure enables efficient testing by leveraging the use of existing assets distributed across multiple NASA Centers. Using standard LVC concepts enable future integration with existing simulation infrastructure.

  5. Preliminary Identification of Urban Park Infrastructure Resilience in Semarang Central Java

    NASA Astrophysics Data System (ADS)

    Muzdalifah, Aji Uhfatun; Maryono

    2018-02-01

    Park is one of the spot green infrastructure. There are two major characteristic of park, first Active parks and second passive park. Those of two open spaces have been significant on the fulfillment of urban environment. To maintenance the urban park, it is very importance to identify the characteristic of active and passive park. The identification also needs to fostering stakeholder effort to increase quality of urban park infrastructure. This study aims to explore and assess the characteristic of urban park infrastructure in Semarang City, Central Java. Data collection methods conduct by review formal document, field observation and interview with key government officer. The study founded that urban active parks infrastructure resilience could be defined by; Park Location, Garden Shape, Vegetation, Support Element, Park Function, and Expected Benefit from Park Existence. Moreover, the vegetation aspect and the supporting elements are the most importance urban park infrastructure in Semarang.

  6. Critical Infrastructure Interdependencies Assessment

    DOE PAGES

    Petit, Frederic; Verner, Duane

    2016-11-01

    Throughout the world there is strong recognition that critical infrastructure security and resilience needs to be improved. In the United States, the National Infrastructure Protection Plan (NIPP) provides the strategic vision to guide the national effort to manage risk to the Nation’s critical infrastructure.”1 The achievement of this vision is challenged by the complexity of critical infrastructure systems and their inherent interdependencies. The update to the NIPP presents an opportunity to advance the nation’s efforts to further understand and analyze interdependencies. Such an important undertaking requires the involvement of public and private sector stakeholders and the reinforcement of existing partnershipsmore » and collaborations within the U.S. Department of Homeland Security (DHS) and other Federal agencies, including national laboratories; State, local, tribal, and territorial governments; and nongovernmental organizations.« less

  7. The Impact of Airport Performance towards Construction and Infrastructure Expansion in Indonesia

    NASA Astrophysics Data System (ADS)

    Laksono, T. D.; Kurniasih, N.; Hasyim, C.; Setiawan, M. I.; Ahmar, A. S.

    2018-01-01

    Development that is generated from airport areas includes construction and infrastructure development. This research reviews about how the implementation of material management in certain construction project and the relationship between development especially construction and infrastructure development with Airport Performance. The method that is used in this research is mixed method. The population in this research is 297 airports that are existed in Indonesia. From those 297 airports then it is chosen airports that have the most completed data about construction project and it is obtained 148 airports. Based on the coefficient correlation (R) test it is known that construction and infrastructure development has relatively strong relation with airport performance variable, but there are still other factors that influence construction and infrastructure development become bigger effect.

  8. The impact of natural hazard on critical infrastructure systems: definition of an ontology

    NASA Astrophysics Data System (ADS)

    Dimauro, Carmelo; Bouchon, Sara; Frattini, Paolo; Giusto, Claudia

    2013-04-01

    According to the Council of the European Union Directive (2008), 'critical infrastructure' means an asset, system or part thereof which is essential for the maintenance of vital societal functions, health, safety, security, economic or social well-being of people, and the disruption or destruction of which would have a significant impact as a result of the failure to maintain those functions. Critical infrastructure networks are exposed to natural events, such as floods, storms, landslides, earthquakes, etc. Recent natural disasters show that socio-economic consequences can be very much aggravated by the impact on these infrastructures. Though, there is still a lack of a recognized approach or methodology to assess the vulnerability of critical infrastructure assets against natural threats. The difficulty to define such an approach is increased by the need to consider a very high number of natural events, which differ in nature, magnitude and probability, as well as the need to assess the vulnerability of a high variety of infrastructure assets (e.g. bridges, roads, tunnels, pipelines, etc.) To meet this challenge, the objective of the THREVI2 EU-CIPS project is to create a database linking the relationships between natural hazards and critical infrastructure assets. The query of the database will allow the end-users (critical infrastructure protection authorities and operators) to identify the relevant scenarios according to the own priorities and criteria. The database builds on an ontology optimized for the assessment of the impact of threats on critical infrastructures. The ontology aims at capturing the existing knowledge on natural hazards, critical infrastructures assets and their related vulnerabilities. Natural phenomena that can threaten critical infrastructures are classified as "events", and organized in a genetic-oriented hierarchy. The main attributes associated to each event are the probability, the magnitude and the "modus". The modus refers to the physical-chemical process by means the event (e.g., a pyroclastic flow) can interact and damage a critical infrastructure asset (e.g., a pipe). Each event can be characterized by several modi (e.g., impact load, heating, burying) that can cause damages to the asset. Hence, the damage is linked to the modus and not directly to the event. The advantage of using the "modus" approach is to allow reducing the number of interactions (natural hazard/Critical infrastructure assets) to be addressed. All different events exert their impact on infrastructures by means of a limited number of different modus. This allows adapting existing vulnerability or fragility laws to events that have not been studied yet, and for which these laws are not available.

  9. Deployment strategies of managed lanes on arterials : [summary].

    DOT National Transportation Integrated Search

    2015-02-01

    Floridas continuing growth has often been attracted to areas where good highway : infrastructure already exists. Traffic loads have developed to the point where widening existing : highways is not sufficient, or perhaps impossible, to accommodate ...

  10. Human-Technology Centric In Cyber Security Maintenance For Digital Transformation Era

    NASA Astrophysics Data System (ADS)

    Ali, Firkhan Ali Bin Hamid; Zalisham Jali, Mohd, Dr

    2018-05-01

    The development of the digital transformation in the organizations has become more expanding in these present and future years. This is because of the active demand to use the ICT services among all the organizations whether in the government agencies or private sectors. While digital transformation has led manufacturers to incorporate sensors and software analytics into their offerings, the same innovation has also brought pressure to offer clients more accommodating appliance deployment options. So, their needs a well plan to implement the cyber infrastructures and equipment. The cyber security play important role to ensure that the ICT components or infrastructures execute well along the organization’s business successful. This paper will present a study of security management models to guideline the security maintenance on existing cyber infrastructures. In order to perform security model for the currently existing cyber infrastructures, combination of the some security workforces and security process of extracting the security maintenance in cyber infrastructures. In the assessment, the focused on the cyber security maintenance within security models in cyber infrastructures and presented a way for the theoretical and practical analysis based on the selected security management models. Then, the proposed model does evaluation for the analysis which can be used to obtain insights into the configuration and to specify desired and undesired configurations. The implemented cyber security maintenance within security management model in a prototype and evaluated it for practical and theoretical scenarios. Furthermore, a framework model is presented which allows the evaluation of configuration changes in the agile and dynamic cyber infrastructure environments with regard to properties like vulnerabilities or expected availability. In case of a security perspective, this evaluation can be used to monitor the security levels of the configuration over its lifetime and to indicate degradations.

  11. Synergizing green and gray infrastructures to increase water supply resilience in the Brazos River basin in Texas

    NASA Astrophysics Data System (ADS)

    Gao, H.; Yamazaki, D.; Finley, T.; Bohn, T. J.; Low, G.; Sabo, J. L.

    2017-12-01

    Water infrastructure lies at the heart of the challenges and opportunities of Integrated Water Resource Management (IWRM). Green infrastructure (e.g., wetlands restoration) presents an alternative to its hard-path counterpart - gray infrastructure, which often has external, economic and unmeasured ecological costs. But the science framework to prioritize green infrastructure buildout is nascent. In this study, we addressed this gap in Brazos River basin in Texas, in the context of corporate decisions to secure water supplies for various water stewardship objectives. We developed a physically-based tool to quantify the potential for wetland restoration to restore desired flows (hydrology), and a financial framework for comparing its cost-benefit with heightening an existing dam (conservation finance). Our framework has three components. First, we harnessed a topographic index (HAND) to identify the potential wetlands sites. Second, we coupled a land surface model (VIC) with a hydrodynamic model (CaMa-Flood) to investigate the effects of wetland size, location, and vegetation on hydrology. Finally, we estimated the net present value, indirect rate of return and payback period for green (wetlands) vs. gray (reservoir expansion) infrastructure. We found wetlands have more substantial impact on peak flow than baseflow. Interestingly, wetlands can improve baseflow reliability but not directly except with the largest (>400 km2) projects. Peak flow reduction volumes of wetlands if used as credits towards reservoir flood-control storage provide adequate conservation storage to deliver guaranteed reliability of baseflow. Hence, the synergy of existing dams with newly created wetlands offers a promising natural solution to increase water supply resilience, while green projects also generate revenue compared to their gray counterparts. This study demonstrates the possibility of using innovative engineering design to synergize green and gray infrastructures to convert water conflict to opportunities.

  12. The Contribution of the Geodetic Community (WG4) to EPOS

    NASA Astrophysics Data System (ADS)

    Fernandes, R. M. S.; Bastos, L. C.; Bruyninx, C.; D'Agostino, N.; Dousa, J.; Ganas, A.; Lidberg, M.; Nocquet, J.-M.

    2012-04-01

    WG4 - "EPOS Geodetic Data and Infrastructure" is the Working Group of the EPOS project responsible to define and prepare the integration of the existing Pan-European Geodetic Infrastructures into a unique future consistent infrastructure that supports the European Geosciences, which is the ultimate goal of the EPOS project. The WG4 is formed by representatives of the participating EPOS countries and from EUREF (European Reference Frame), which also ensures the inclusion and the contact with countries that formally are not part of the current phase of EPOS. In reality, the fact that Europe is formed by many countries (having different laws and policies) lacking an infrastructure similar to UNAVCO (which concentrates the effort of the local geo-science community) raises the difficulties to create a common geodetic infrastructure serving not only the entire geo-science community, but also many other areas of great social-economic impact. The benefits of the creation of such infrastructure (shared and easily accessed by all) are evident in order to optimize the existing and future geodetic resources. This presentation intends to detail the work being produced within the working group WG4 related with the definition of strategies towards the implementation of the best solutions that will permit to the end-users, and in particular geo-scientists, to access the geodetic data, derived solutions, and associated metadata using transparent and uniform processes. Discussed issues include the access to high-rate data in near real-time, storage and backup of historical and future data, the sustainability of the networks in order to achieve long-term stability in the observation infrastructure, seamless access to the data, open data policies, and processing tools.

  13. Developing Istanbul into a Regional Business Hub

    DTIC Science & Technology

    2004-12-01

    infrastructure, industrial concentration, availability of work force, political stability and cultural affinity. (Galan, Gonzalez-Benito, 2001...and transportation costs, infrastructure, political stability , and quality of labor, appear with a certain degree of relevance on a second level...degree of political stability and government intervention in the economy; the existence of property rights legislation determining the legal rights

  14. Integrating Cost Engineering and Project Management in a Junior Engineering Economics Course and a Senior Capstone Project Design Course

    ERIC Educational Resources Information Center

    Tickles, Virginia C.; Li, Yadong; Walters, Wilbur L.

    2013-01-01

    Much criticism exists concerning a lack of focus on real-world problem-solving in the science, technology, engineering and mathematics (STEM) infrastructures. Many of these critics say that current educational infrastructures are incapable in preparing future scientists and engineers to solve the complex and multidisciplinary problems this society…

  15. Communication: Essential for Leadership to a Public Good--an Information Infrastructure.

    ERIC Educational Resources Information Center

    Moran, Robert F., Jr.

    This paper discusses the central role of effective communication in library leadership and how a leadership role in the library and information community can define and help establish an information infrastructure in our society. The opportunity for this leadership to exist in the convergence of libraries and computer centers is examined in a…

  16. Developing an Information Infrastructure To Support Information Retrieval: Towards a Theory of Clustering Based in Classification.

    ERIC Educational Resources Information Center

    Micco, Mary; Popp, Rich

    Techniques for building a world-wide information infrastructure by reverse engineering existing databases to link them in a hierarchical system of subject clusters to create an integrated database are explored. The controlled vocabulary of the Library of Congress Subject Headings is used to ensure consistency and group similar items. Each database…

  17. Technography and Design-Actuality Gap-Analysis of Internet Computer Technologies-Assisted Education: Western Expectations and Global Education

    ERIC Educational Resources Information Center

    Greenhalgh-Spencer, Heather; Jerbi, Moja

    2017-01-01

    In this paper, we provide a design-actuality gap-analysis of the internet infrastructure that exists in developing nations and nations in the global South with the deployed internet computer technologies (ICT)-assisted programs that are designed to use internet infrastructure to provide educational opportunities. Programs that specifically…

  18. Youth and Lifelong Education: After-School Programmes as a Vital Component of Lifelong Education Infrastructure

    ERIC Educational Resources Information Center

    Lauzon, Allan C.

    2013-01-01

    This paper argues that after-school programmes need to be considered an essential part of lifelong learning infrastructure, particularly in light of the dominance of the economic discourse in both lifelong learning literature and the initial schooling literature. The paper, which is based upon existing literature, begins by providing an overview…

  19. Permeability of existing structures for terrestrial wildlife : a passage assessment system.

    DOT National Transportation Integrated Search

    2011-07-01

    "A Passage Assessment System (PAS) was developed to help the Washington Department of : Transportation (WSDOT) evaluate existing transportation infrastructure for its ability to facilitate : terrestrial wildlife movement from one side of a roadway to...

  20. Traffic prediction using wireless cellular networks : final report.

    DOT National Transportation Integrated Search

    2016-03-01

    The major objective of this project is to obtain traffic information from existing wireless : infrastructure. : In this project freeway traffic is identified and modeled using data obtained from existing : wireless cellular networks. Most of the prev...

  1. On-road and laboratory emissions of NO, NO2, NH3, N2O and CH4 from late-model EU light utility vehicles: Comparison of diesel and CNG.

    PubMed

    Vojtíšek-Lom, Michal; Beránek, Vít; Klír, Vojtěch; Jindra, Petr; Pechout, Martin; Voříšek, Tomáš

    2018-03-01

    Exhaust emissions of eight Euro 6 light duty vehicles - two station wagons and six vans - half powered by diesel fuel and half by compressed natural gas (CNG) were examined using both chassis dynamometer and on-road testing. A portable on-board FTIR analyzer was used to measure concentrations of reactive nitrogen compounds - NO, NO 2 and ammonia, of CO, formaldehyde, acetaldehyde and greenhouse gases CO 2 , methane and N 2 O. Exhaust flow was inferred from engine control unit data. Total emissions per cycle were compared and found to be in good agreement with laboratory measurements of NO X , CO and CO 2 during dynamometer tests. On diesel engines, mean NO X emissions were 136-1070mg/km in the laboratory and 537-615mg/km on the road, in many cases nearly an order of magnitude higher compared to the numerical value of the Euro 6 limit. Mean N 2 O emissions were 3-19mg/km and were equivalent to several g/km CO 2 . The measurements suggest that NO X and N 2 O emissions from late-model European light utility vehicles with diesel engines are non-negligible and should be continuously assessed and scrutinized. High variances in NO X emissions among the tested diesel vehicles suggest that large number of vehicles should be tested to offer at least some insights about distribution of fleet emissions among vehicles. CNG engines exhibited relatively low emissions of NO X (12-186mg/km) and NH 3 (10-24mg/km), while mean emissions of methane were 18-45mg/km, under 1g/km CO 2 equivalent, and N 2 O, CO, formaldehyde and acetaldehyde were negligible. The combination of a relatively clean-burning fuel, modern engine technology and a three-way catalyst has resulted in relatively low emissions under the wide variety of operating conditions encountered during the tests. The on-board FTIR has proven to be a useful instrument capable of covering, with the exception of total hydrocarbons, essentially all gaseous pollutants of interest. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Deleterious impacts of a 900-MHz electromagnetic field on hippocampal pyramidal neurons of 8-week-old Sprague Dawley male rats.

    PubMed

    Şahin, Arzu; Aslan, Ali; Baş, Orhan; İkinci, Ayşe; Özyılmaz, Cansu; Fikret Sönmez, Osman; Çolakoğlu, Serdar; Odacı, Ersan

    2015-10-22

    Children are at potential risk due to their intense use of mobile phones. We examined 8-week-old rats because this age of the rats is comparable with the preadolescent period in humans. The number of pyramidal neurons in the cornu ammonis of the Sprague Dawley male rat (8-weeks old, weighing 180-250 g) hippocampus following exposure to a 900 MHz (MHz) electromagnetic field (EMF) were examined. The study consisted of control (CN-G), sham exposed (SHM-EG) and EMF exposed (EMF-EG) groups with 6 rats in each. The EMF-EG rats were exposed to 900 MHz EMF (1h/day for 30 days) in an EMF jar. The SHM-EG rats were placed in the EMF jar but not exposed to the EMF (1h/day for 30 days). The CN-G rats were not placed into the exposure jar and were not exposed to the EMF during the study period. All animals were sacrificed at the end of the experiment, and their brains were removed for histopathological and stereological analysis. The number of pyramidal neurons in the cornu ammonis of the hippocampus was estimated on Cresyl violet stained sections of the brain using the optical dissector counting technique. Histopathological evaluations were also performed on these sections. Histopathological observation showed abundant cells with abnormal, black or dark blue cytoplasm and shrunken morphology among the normal pyramidal neurons. The largest lateral ventricles were observed in the EMF-EG sections compared to those from the other groups. Stereological analyses showed that the total number of pyramidal neurons in the cornu ammonis of the EMF-EG rats was significantly lower than those in the CN-G (p<0.05) and the SHM-EG (p<0.05). In conclusion, our results suggest that pyramidal neuron loss and histopathological changes in the cornu ammonis of 8-week-old male rats may be due to the 900-MHz EMF exposure. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Uncertainty in particle number modal analysis during transient operation of compressed natural gas, diesel, and trap-equipped diesel transit buses.

    PubMed

    Holmén, Britt A; Qu, Yingge

    2004-04-15

    The relationships between transient vehicle operation and ultrafine particle emissions are not well-known, especially for low-emission alternative bus technologies such as compressed natural gas (CNG) and diesel buses equipped with particulate filters/traps (TRAP). In this study, real-time particle number concentrations measured on a nominal 5 s average basis using an electrical low pressure impactor (ELPI) for these two bus technologies are compared to that of a baseline catalyst-equipped diesel bus operated on ultralow sulfur fuel (BASE) using dynamometer testing. Particle emissions were consistently 2 orders of magnitude lower for the CNG and TRAP compared to BASE on all driving cycles. Time-resolved total particle numbers were examined in terms of sampling factors identified as affecting the ability of ELPI to quantify the particulate matter number emissions for low-emitting vehicles such as CNG and TRAP as a function of vehicle driving mode. Key factors were instrument sensitivity and dilution ratio, alignment of particle and vehicle operating data, sampling train background particles, and cycle-to-cycle variability due to vehicle, engine, after-treatment, or driver behavior. In-cycle variability on the central business district (CBD) cycle was highest for the TRAP configuration, but this could not be attributed to the ELPI sensitivity issues observed for TRAP-IDLE measurements. Elevated TRAP emissions coincided with low exhaust temperature, suggesting on-road real-world particulate filter performance can be evaluated by monitoring exhaust temperature. Nonunique particle emission maps indicate that measures other than vehicle speed and acceleration are necessary to model disaggregated real-time particle emissions. Further testing on a wide variety of test cycles is needed to evaluate the relative importance of the time history of vehicle operation and the hysteresis of the sampling train/dilution tunnel on ultrafine particle emissions. Future studies should monitor particle emissions with high-resolution real-time instruments and account for the operating regime of the vehicle using time-series analysis to develop predictive number emissions models.

  4. Characterizing the range of children's air pollutant exposure during school bus commutes.

    PubMed

    Sabin, Lisa D; Behrentz, Eduardo; Winer, Arthur M; Jeong, Seong; Fitz, Dennis R; Pankratz, David V; Colome, Steven D; Fruin, Scott A

    2005-09-01

    Real-time and integrated measurements of gaseous and particulate pollutants were conducted inside five conventional diesel school buses, a diesel bus with a particulate trap, and a bus powered by compressed natural gas (CNG) to determine the range of children's exposures during school bus commutes and conditions leading to high exposures. Measurements were made during 24 morning and afternoon commutes on two Los Angeles Unified School District bus routes from South to West Los Angeles, with seven additional runs on a rural/suburban route, and three runs to test the effect of window position. For these commutes, the mean concentrations of diesel vehicle-related pollutants ranged from 0.9 to 19 microg/m(3) for black carbon, 23 to 400 ng/m(3) for particle-bound polycyclic aromatic hydrocarbon (PB-PAH), and 64 to 220 microg/m(3) for NO(2). Concentrations of benzene and formaldehyde ranged from 0.1 to 11 microg/m(3) and 0.3 to 5 microg/m(3), respectively. The highest real-time concentrations of black carbon, PB-PAH and NO(2) inside the buses were 52 microg/m(3), 2000 ng/m(3), and 370 microg/m(3), respectively. These pollutants were significantly higher inside conventional diesel buses compared to the CNG bus, although formaldehyde concentrations were higher inside the CNG bus. Mean black carbon, PB-PAH, benzene and formaldehyde concentrations were higher when the windows were closed, compared with partially open, in part, due to intrusion of the bus's own exhaust into the bus cabin, as demonstrated through the use of a tracer gas added to each bus's exhaust. These same pollutants tended to be higher on urban routes compared to the rural/suburban route, and substantially higher inside the bus cabins compared to ambient measurements. Mean concentrations of pollutants with substantial secondary formation, such as PM(2.5), showed smaller differences between open and closed window conditions and between bus routes. Type of bus, traffic congestion levels, and encounters with other diesel vehicles contributed to high exposure variability between runs.

  5. Towards the ecotourism: a decision support model for the assessment of sustainability of mountain huts in the Alps.

    PubMed

    Stubelj Ars, Mojca; Bohanec, Marko

    2010-12-01

    This paper studies mountain hut infrastructure in the Alps as an important element of ecotourism in the Alpine region. To improve the decision-making process regarding the implementation of future infrastructure and improvement of existing infrastructure in the vulnerable natural environment of mountain ecosystems, a new decision support model has been developed. The methodology is based on qualitative multi-attribute modelling supported by the DEXi software. The integrated rule-based model is hierarchical and consists of two submodels that cover the infrastructure of the mountain huts and that of the huts' surroundings. The final goal for the designed tool is to help minimize the ecological footprint of tourists in environmentally sensitive and undeveloped mountain areas and contribute to mountain ecotourism. The model has been tested in the case study of four mountain huts in Triglav National Park in Slovenia. Study findings provide a new empirical approach to evaluating existing mountain infrastructure and predicting improvements for the future. The assessment results are of particular interest for decision makers in protected areas, such as Alpine national parks managers and administrators. In a way, this model proposes an approach to the management assessment of mountain huts with the main aim of increasing the quality of life of mountain environment visitors as well as the satisfaction of tourists who may eventually become ecotourists. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Cooperative Drought Adaptation: Integrating Infrastructure Development, Conservation, and Water Transfers into Adaptive Policy Pathways

    NASA Astrophysics Data System (ADS)

    Zeff, H. B.; Characklis, G. W.; Reed, P. M.; Herman, J. D.

    2015-12-01

    Water supply policies that integrate portfolios of short-term management decisions with long-term infrastructure development enable utilities to adapt to a range of future scenarios. An effective mix of short-term management actions can augment existing infrastructure, potentially forestalling new development. Likewise, coordinated expansion of infrastructure such as regional interconnections and shared treatment capacity can increase the effectiveness of some management actions like water transfers. Highly adaptable decision pathways that mix long-term infrastructure options and short-term management actions require decision triggers capable of incorporating the impact of these time-evolving decisions on growing water supply needs. Here, we adapt risk-based triggers to sequence a set of potential infrastructure options in combination with utility-specific conservation actions and inter-utility water transfers. Individual infrastructure pathways can be augmented with conservation or water transfers to reduce the cost of meeting utility objectives, but they can also include cooperatively developed, shared infrastructure that expands regional capacity to transfer water. This analysis explores the role of cooperation among four water utilities in the 'Research Triangle' region of North Carolina by formulating three distinct categories of adaptive policy pathways: independent action (utility-specific conservation and supply infrastructure only), weak cooperation (utility-specific conservation and infrastructure development with regional transfers), and strong cooperation (utility specific conservation and jointly developed of regional infrastructure that supports transfers). Results suggest that strong cooperation aids the utilities in meeting their individual objections at substantially lower costs and with fewer irreversible infrastructure options.

  7. Strategic behaviors and governance challenges in social-ecological systems

    NASA Astrophysics Data System (ADS)

    Muneepeerakul, Rachata; Anderies, John M.

    2017-08-01

    The resource management and environmental policy literature focuses on devising regulations and incentive structures to achieve desirable goals. It often presumes the existence of public infrastructure that actualizes these incentives and regulations through a process loosely referred to as `governance.' In many cases, it is not clear if and how such governance infrastructure can be created and supported. Here, we take a complex systems view in which `governance' is an emergent phenomenon generated by interactions between social, economic, and environmental (both built and natural) factors. We present a framework and formal stylized model to explore under what circumstances stable governance structures may emerge endogenously in coupled infrastructure systems comprising shared natural, social, and built infrastructures of which social-ecological systems are specific examples. The model allows us to derive general conditions for a sustainable coupled infrastructure system in which critical infrastructure (e.g., canals) is provided by a governing entity that enables resource users (e.g., farmers) to produce outputs from natural infrastructure (e.g., water) to meet their needs while supporting the governing entity.

  8. GEMSS: grid-infrastructure for medical service provision.

    PubMed

    Benkner, S; Berti, G; Engelbrecht, G; Fingberg, J; Kohring, G; Middleton, S E; Schmidt, R

    2005-01-01

    The European GEMSS Project is concerned with the creation of medical Grid service prototypes and their evaluation in a secure service-oriented infrastructure for distributed on demand/supercomputing. Key aspects of the GEMSS Grid middleware include negotiable QoS support for time-critical service provision, flexible support for business models, and security at all levels in order to ensure privacy of patient data as well as compliance to EU law. The GEMSS Grid infrastructure is based on a service-oriented architecture and is being built on top of existing standard Grid and Web technologies. The GEMSS infrastructure offers a generic Grid service provision framework that hides the complexity of transforming existing applications into Grid services. For the development of client-side applications or portals, a pluggable component framework has been developed, providing developers with full control over business processes, service discovery, QoS negotiation, and workflow, while keeping their underlying implementation hidden from view. A first version of the GEMSS Grid infrastructure is operational and has been used for the set-up of a Grid test-bed deploying six medical Grid service prototypes including maxillo-facial surgery simulation, neuro-surgery support, radio-surgery planning, inhaled drug-delivery simulation, cardiovascular simulation and advanced image reconstruction. The GEMSS Grid infrastructure is based on standard Web Services technology with an anticipated future transition path towards the OGSA standard proposed by the Global Grid Forum. GEMSS demonstrates that the Grid can be used to provide medical practitioners and researchers with access to advanced simulation and image processing services for improved preoperative planning and near real-time surgical support.

  9. A Cis-Lunar Propellant Infrastructure for Flexible Path Exploration and Space Commerce

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.

    2012-01-01

    This paper describes a space infrastructure concept that exploits lunar water for propellant production and delivers it to users in cis-lunar space. The goal is to provide responsive economical space transportation to destinations beyond low Earth orbit (LEO) and enable in-space commerce. This is a game changing concept that could fundamentally affect future space operations, provide greater access to space beyond LEO, and broaden participation in space exploration. The challenge is to minimize infrastructure development cost while achieving a low operational cost. This study discusses the evolutionary development of the infrastructure from a very modest robotic operation to one that is capable of supporting human operations. The cis-lunar infrastructure involves a mix of technologies including cryogenic propellant production, reusable lunar landers, propellant tankers, orbital transfer vehicles, aerobraking technologies, and electric propulsion. This cislunar propellant infrastructure replaces Earth-launched propellants for missions beyond LEO. It enables users to reach destinations with smaller launchers or effectively multiplies the user s existing payload capacity. Users can exploit the expanded capacity to launch logistics material that can then be traded with the infrastructure for propellants. This mutually beneficial trade between the cis-lunar infrastructure and propellant users forms the basis of in-space commerce.

  10. Assessing equitable access to urban green space: the role of engineered water infrastructure.

    PubMed

    Wendel, Heather E Wright; Downs, Joni A; Mihelcic, James R

    2011-08-15

    Urban green space and water features provide numerous social, environmental, and economic benefits, yet disparities often exist in their distribution and accessibility. This study examines the link between issues of environmental justice and urban water management to evaluate potential improvements in green space and surface water access through the revitalization of existing engineered water infrastructures, namely stormwater ponds. First, relative access to green space and water features were compared for residents of Tampa, Florida, and an inner-city community of Tampa (East Tampa). Although disparities were not found in overall accessibility between Tampa and East Tampa, inequalities were apparent when quality, diversity, and size of green spaces were considered. East Tampa residents had significantly less access to larger, more desirable spaces and water features. Second, this research explored approaches for improving accessibility to green space and natural water using three integrated stormwater management development scenarios. These scenarios highlighted the ability of enhanced water infrastructures to increase access equality at a variety of spatial scales. Ultimately, the "greening" of gray urban water infrastructures is advocated as a way to address environmental justice issues while also reconnecting residents with issues of urban water management.

  11. Assured communications and combat resiliency: the relationship between effective national communications and combat efficiency

    NASA Astrophysics Data System (ADS)

    Allgood, Glenn O.; Kuruganti, Phani Teja; Nutaro, James; Saffold, Jay

    2009-05-01

    Combat resiliency is the ability of a commander to prosecute, control, and consolidate his/her's sphere of influence in adverse and changing conditions. To support this, an infrastructure must exist that allows the commander to view the world in varying degrees of granularity with sufficient levels of detail to permit confidence estimates to be levied against decisions and course of actions. An infrastructure such as this will include the ability to effectively communicate context and relevance within and across the battle space. To achieve this will require careful thought, planning, and understanding of a network and its capacity limitations in post-event command and control. Relevance and impact on any existing infrastructure must be fully understood prior to deployment to exploit the system's full capacity and capabilities. In this view, the combat communication network is considered an integral part of or National communication network and infrastructure. This paper will describe an analytical tool set developed at ORNL and RNI incorporating complexity theory, advanced communications modeling, simulation, and visualization technologies that could be used as a pre-planning tool or post event reasoning application to support response and containment.

  12. Infrastructure of electronic information management

    USGS Publications Warehouse

    Twitchell, G.D.

    2004-01-01

    The information technology infrastructure of an organization, whether it is a private, non-profit, federal, or academic institution, is key to delivering timely and high-quality products and services to its customers and stakeholders. With the evolution of the Internet and the World Wide Web, resources that were once "centralized" in nature are now distributed across the organization in various locations and often remote regions of the country. This presents tremendous challenges to the information technology managers, users, and CEOs of large world-wide corporations who wish to exchange information or get access to resources in today's global marketplace. Several tools and technologies have been developed over recent years that play critical roles in ensuring that the proper information infrastructure exists within the organization to facilitate this global information marketplace Such tools and technologies as JAVA, Proxy Servers, Virtual Private Networks (VPN), multi-platform database management solutions, high-speed telecommunication technologies (ATM, ISDN, etc.), mass storage devices, and firewall technologies most often determine the organization's success through effective and efficient information infrastructure practices. This session will address several of these technologies and provide options related to those that may exist and can be readily applied within Eastern Europe. ?? 2004 - IOS Press and the authors. All rights reserved.

  13. Regional Charging Infrastructure for Plug-In Electric Vehicles: A Case Study of Massachusetts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wood, Eric; Raghavan, Sesha; Rames, Clement

    Given the complex issues associated with plug-in electric vehicle (PEV) charging and options in deploying charging infrastructure, there is interest in exploring scenarios of future charging infrastructure deployment to provide insight and guidance to national and regional stakeholders. The complexity and cost of PEV charging infrastructure pose challenges to decision makers, including individuals, communities, and companies considering infrastructure installations. The value of PEVs to consumers and fleet operators can be increased with well-planned and cost-effective deployment of charging infrastructure. This will increase the number of miles driven electrically and accelerate PEV market penetration, increasing the shared value of charging networksmore » to an expanding consumer base. Given these complexities and challenges, the objective of the present study is to provide additional insight into the role of charging infrastructure in accelerating PEV market growth. To that end, existing studies on PEV infrastructure are summarized in a literature review. Next, an analysis of current markets is conducted with a focus on correlations between PEV adoption and public charging availability. A forward-looking case study is then conducted focused on supporting 300,000 PEVs by 2025 in Massachusetts. The report concludes with a discussion of potential methodology for estimating economic impacts of PEV infrastructure growth.« less

  14. Applications of the INTELSAT system to remote health care

    NASA Technical Reports Server (NTRS)

    Maleter, Andrea

    1991-01-01

    INTELSAT, the International Telecommunications Satellite Organization, is a not-for-profit commercial cooperate of 124 member nations, created on 20 August 1964. It owns and operates a global system of communications satellites that provides international telecommunications services to 180 countries, territories, and dependencies, and domestic telecommunications services to 40 nations. INTELSAT has actively encouraged the use of satellites for both telemedicine and disaster relief. Topics discussed include: INTELSAT domestic/regional services; use of transportable antennas; INTELNET; using the existing telecommunications infrastructure for remote health care applications: Project Access; INTELSAT's role in disaster telecommunications efforts; and how INTELSAT's existing infrastructure can be used for disaster telecommunications.

  15. Simulation and Verification of Synchronous Set Relations in Rewriting Logic

    NASA Technical Reports Server (NTRS)

    Rocha, Camilo; Munoz, Cesar A.

    2011-01-01

    This paper presents a mathematical foundation and a rewriting logic infrastructure for the execution and property veri cation of synchronous set relations. The mathematical foundation is given in the language of abstract set relations. The infrastructure consists of an ordersorted rewrite theory in Maude, a rewriting logic system, that enables the synchronous execution of a set relation provided by the user. By using the infrastructure, existing algorithm veri cation techniques already available in Maude for traditional asynchronous rewriting, such as reachability analysis and model checking, are automatically available to synchronous set rewriting. The use of the infrastructure is illustrated with an executable operational semantics of a simple synchronous language and the veri cation of temporal properties of a synchronous system.

  16. Synthesis Study on Transitions in Signal Infrastructure and Control Algorithms for Connected and Automated Transportation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aziz, H. M. Abdul; Wang, Hong; Young, Stan

    Documenting existing state of practice is an initial step in developing future control infrastructure to be co-deployed for heterogeneous mix of connected and automated vehicles with human drivers while leveraging benefits to safety, congestion, and energy. With advances in information technology and extensive deployment of connected and automated vehicle technology anticipated over the coming decades, cities globally are making efforts to plan and prepare for these transitions. CAVs not only offer opportunities to improve transportation systems through enhanced safety and efficient operations of vehicles. There are also significant needs in terms of exploring how best to leverage vehicle-to-vehicle (V2V) technology,more » vehicle-to-infrastructure (V2I) technology and vehicle-to-everything (V2X) technology. Both Connected Vehicle (CV) and Connected and Automated Vehicle (CAV) paradigms feature bi-directional connectivity and share similar applications in terms of signal control algorithm and infrastructure implementation. The discussion in our synthesis study assumes the CAV/CV context where connectivity exists with or without automated vehicles. Our synthesis study explores the current state of signal control algorithms and infrastructure, reports the completed and newly proposed CV/CAV deployment studies regarding signal control schemes, reviews the deployment costs for CAV/AV signal infrastructure, and concludes with a discussion on the opportunities such as detector free signal control schemes and dynamic performance management for intersections, and challenges such as dependency on market adaptation and the need to build a fault-tolerant signal system deployment in a CAV/CV environment. The study will serve as an initial critical assessment of existing signal control infrastructure (devices, control instruments, and firmware) and control schemes (actuated, adaptive, and coordinated-green wave). Also, the report will help to identify the future needs for the signal infrastructure to act as the nervous system for urban transportation networks, providing not only signaling, but also observability, surveillance, and measurement capacity. The discussion of the opportunities space includes network optimization and control theory perspectives, and the current states of observability for key system parameters (what can be detected, how frequently can it be reported) as well as controllability of dynamic parameters (this includes adjusting not only the signal phase and timing, but also the ability to alter vehicle trajectories through information or direct control). The perspective of observability and controllability of the dynamic systems provides an appropriate lens to discuss future directions as CAV/CV become more prevalent in the future.« less

  17. Alternative Fuels Data Center: AT&T Fleet Reaches Milestone of 8,000 CNG

    Science.gov Websites

    received its 8,000th compressed natural gas vehicle and now has a total of 10,000 various alternative fuel , 2017 Photo of a truck Natural Gas Vehicles Make a Difference in Tennessee Oct. 28, 2017 Image of an Biodiesel Aug. 26, 2017 Photo of a truck Idaho Transports Mail and Reduces Emissions with Natural Gas Trucks

  18. Real-time measurements of nitrogen oxide emissions from in-use New York City transit buses using a chase vehicle.

    PubMed

    Shorter, Joanne H; Herndon, Scott; Zahniser, Mark S; Nelson, David D; Wormhoudt, Joda; Demerjian, Kenneth L; Kolb, Charles E

    2005-10-15

    New diesel engine technologies and alternative fuel engines are being introduced into fleets of mass transit buses to try to meet stricter emission regulations of nitrogen oxides and particulates: Real-time instruments including an Aerodyne Research tunable infrared laser differential absorption spectrometer (TILDAS) were deployed in a mobile laboratory to assess the impact of the implementation of the new technologies on nitrogen oxide emissions in real world driving conditions. Using a "chase" vehicle sampling strategy, the mobile laboratory followed target vehicles, repeatedly sampling their exhaust. Nitrogen oxides from approximately 170 in-use New York City mass transit buses were sampled during the field campaigns. Emissions from conventional diesel buses, diesel buses with continuously regenerating technology (CRT), diesel hybrid electric buses, and compressed natural gas (CNG) buses were compared. The chase vehicle sampling method yields real world emissions that can be included in more realistic emission inventories. The NO, emissions from the diesel and CNG buses were comparable. The hybrid electric buses had approximately one-half the NOx emissions. In CRT diesels, NO2 accounts for about one-third of the NOx emitted in the exhaust, while for non-CRT buses the NO2 fraction is less than 10%.

  19. Simultaneous determination of carbonyls and NO2 in exhausts of heavy-duty diesel trucks and transit buses by HPLC following 2,4-dinitrophenylhydrazine cartridge collection.

    PubMed

    Tang, Shida; Graham, Lisa; Shen, Ling; Zhou, Xianliang; Lanni, Thomas

    2004-11-15

    A method combining 2,4-dinitrophenylhydrazine (DNPH) cartridge sampling and high-performance liquid chromatography (HPLC) analysis has been used for the measurement of carbonyl and NO2 emissions from heavy-duty diesel trucks and transit buses. The reaction of NO2 with DNPH allows for the simultaneous and unambiguous determination of NO2 and carbonyl concentrations in exhaust samples. The potential coelution of the NO2-DNPH derivative with the formaldehyde-DNPH derivative under certain chromatographic conditions was investigated. Successful separation of these two species was achieved allowing for simultaneous determination of carbonyls and NO2 in the exhaust samples collected from heavy-duty diesel (HDD) trucks and diesel, diesel/electric hybrid, diesel equipped with the continuously regenerating technology (CRT) particle traps, and compressed natural gas (CNG) transit buses tested over various drive cycles. Elevated NO2 emissions from CRT-equipped buses were observed. The NO2/NOx volume ratios for HDD trucks and transit buses are discussed. A comparison of the DNPH derivatization with HPLC/UV-visible detection method with a chemiluminescence analyzer method for NO2 measurement is presented for a limited number of diesel/CRT and CNG buses.

  20. Volatile properties of particles emitted by compressed natural gas and diesel buses during steady-state and transient driving modes.

    PubMed

    Jayaratne, E R; Meyer, N K; Ristovski, Z D; Morawska, L

    2012-01-03

    Volatile properties of particle emissions from four compressed natural gas (CNG) and four diesel buses were investigated under steady-state and transient driving modes on a chassis dynamometer. The exhaust was diluted utilizing a full-flow continuous volume sampling system and passed through a thermodenuder at controlled temperature. Particle number concentration and size distribution were measured with a condensation particle counter and a scanning mobility particle sizer, respectively. We show that while almost all the particles emitted by the CNG buses were in the nanoparticle size range, at least 85% and 98% were removed at 100 and 250 °C, respectively. Closer analysis of the volatility of particles emitted during transient cycles showed that volatilization began at around 40 °C, with the majority occurring by 80 °C. Particles produced during hard acceleration from rest exhibited lower volatility than those produced during other times of the cycle. On the basis of our results and the observation of ash deposits on the walls of the tailpipes, we suggest that these nonvolatile particles were composed mostly of ash from lubricating oil. Heating the diesel bus emissions to 100 °C removed ultrafine particle numbers by 69-82% when a nucleation mode was present and just 18% when it was not.

  1. An explosion of a CNG fuel vessel in an urban bus.

    PubMed

    Park, Chan-Seong; Jeon, Seung-Won; Moon, Jung-Eun; Lee, Kyu-Jung

    2010-03-01

    An investigation is presented of the explosion of a CNG (compressed natural gas) fuel vessel, called a liner, in an urban bus. The explosion happened at a gas station 10 min after filling was completed. There were no traces of soot and flames at the failed liner, which would be indicative of explosion by ignition of the gas. The filling process of the station was automatically monitored and recorded in a computer. There was no unusual record of the filling system that indicated excess pressure at the time of the accident. There were cracks on the liner that were initiated at the outer surface of the cylindrical shell located at a point 4 cm above the lower dome where cracks did not originate easily as a result of overload. Chemical analysis was performed on a specimen that was cut from the liner, and there was no peculiarity in the mix. Mechanical analysis was performed on the specimens and showed that the hardness was not in the specified range because of inadequate heat treatment of the metal. The hardness of the liner was strictly controlled in the manufacturing process. All the liners that were manufactured at the same period with the failed liner were recalled for examination.

  2. An atypical CNG channel activated by a single cGMP molecule controls sperm chemotaxis.

    PubMed

    Bönigk, Wolfgang; Loogen, Astrid; Seifert, Reinhard; Kashikar, Nachiket; Klemm, Clementine; Krause, Eberhard; Hagen, Volker; Kremmer, Elisabeth; Strünker, Timo; Kaupp, U Benjamin

    2009-10-27

    Sperm of the sea urchin Arbacia punctulata can respond to a single molecule of chemoattractant released by an egg. The mechanism underlying this extreme sensitivity is unknown. Crucial signaling events in the response of A. punctulata sperm to chemoattractant include the rapid synthesis of the intracellular messenger guanosine 3',5'-monophosphate (cGMP) and the ensuing membrane hyperpolarization that results from the opening of potassium-selective cyclic nucleotide-gated (CNGK) channels. Here, we use calibrated photolysis of caged cGMP to show that approximately 45 cGMP molecules are generated during the response to a single molecule of chemoattractant. The CNGK channel can respond to such small cGMP changes because it is exquisitely sensitive to cGMP and activated in a noncooperative fashion. Like voltage-activated Ca(v) and Na(v) channels, the CNGK polypeptide consists of four homologous repeat sequences. Disabling each of the four cyclic nucleotide-binding sites through mutagenesis revealed that binding of a single cGMP molecule to repeat 3 is necessary and sufficient to activate the CNGK channel. Thus, CNGK has developed a mechanism of activation that is different from the activation of other CNG channels, which requires the cooperative binding of several ligands and operates in the micromolar rather than the nanomolar range.

  3. General Solvent-dependent Strategy toward Enhanced Oxygen Reduction Reaction in Graphene/Metal Oxide Nanohybrids: Effects of Nitrogen-containing Solvent

    NASA Astrophysics Data System (ADS)

    Kao, Wei-Yao; Chen, Wei-Quan; Chiu, Yu-Hsiang; Ho, Yu-Hsuan; Chen, Chun-Hu

    2016-11-01

    A general solvent-dependent protocol directly influencing the oxygen reduction reaction (ORR) in metal oxide/graphene nanohybrids has been demonstrated. We conducted the two-step synthesis of cobalt oxide/N-doped graphene nanohybrids (CNG) with solvents of water, ethanol, and dimethylformamide (DMF), representing tree typical categories of aqueous, polar organic, and organic N-containing solvents commonly adopted for graphene nanocomposites preparation. The superior ORR performance of the DMF-hybrids can be attributed to the high nitrogen-doping, aggregation-free hybridization, and unique graphene porous structures. As DMF is the more effective N-source, the spectroscopic results support a catalytic nitrogenation potentially mediated by cobalt-DMF coordination complexes. The wide-distribution of porosity (covering micro-, meso-, to macro-pore) and micron-void assembly of graphene may further enhance the diffusion kinetics for ORR. As the results, CNG by DMF-synthesis exhibits the high ORR activities close to Pt/C (i.e. only 8 mV difference of half-wave potential with electron transfer number of 3.96) with the better durability in the alkaline condition. Additional graphene hybrids comprised of iron and manganese oxides also show the superior ORR activities by DMF-synthesis, confirming the general solvent-dependent protocol to achieve enhanced ORR activities.

  4. General Solvent-dependent Strategy toward Enhanced Oxygen Reduction Reaction in Graphene/Metal Oxide Nanohybrids: Effects of Nitrogen-containing Solvent

    PubMed Central

    Kao, Wei-Yao; Chen, Wei-Quan; Chiu, Yu-Hsiang; Ho, Yu-Hsuan; Chen, Chun-Hu

    2016-01-01

    A general solvent-dependent protocol directly influencing the oxygen reduction reaction (ORR) in metal oxide/graphene nanohybrids has been demonstrated. We conducted the two-step synthesis of cobalt oxide/N-doped graphene nanohybrids (CNG) with solvents of water, ethanol, and dimethylformamide (DMF), representing tree typical categories of aqueous, polar organic, and organic N-containing solvents commonly adopted for graphene nanocomposites preparation. The superior ORR performance of the DMF-hybrids can be attributed to the high nitrogen-doping, aggregation-free hybridization, and unique graphene porous structures. As DMF is the more effective N-source, the spectroscopic results support a catalytic nitrogenation potentially mediated by cobalt-DMF coordination complexes. The wide-distribution of porosity (covering micro-, meso-, to macro-pore) and micron-void assembly of graphene may further enhance the diffusion kinetics for ORR. As the results, CNG by DMF-synthesis exhibits the high ORR activities close to Pt/C (i.e. only 8 mV difference of half-wave potential with electron transfer number of 3.96) with the better durability in the alkaline condition. Additional graphene hybrids comprised of iron and manganese oxides also show the superior ORR activities by DMF-synthesis, confirming the general solvent-dependent protocol to achieve enhanced ORR activities. PMID:27853187

  5. Elastic Cloud Computing Infrastructures in the Open Cirrus Testbed Implemented via Eucalyptus

    NASA Astrophysics Data System (ADS)

    Baun, Christian; Kunze, Marcel

    Cloud computing realizes the advantages and overcomes some restrictionsof the grid computing paradigm. Elastic infrastructures can easily be createdand managed by cloud users. In order to accelerate the research ondata center management and cloud services the OpenCirrusTM researchtestbed has been started by HP, Intel and Yahoo!. Although commercialcloud offerings are proprietary, Open Source solutions exist in the field ofIaaS with Eucalyptus, PaaS with AppScale and at the applications layerwith Hadoop MapReduce. This paper examines the I/O performance ofcloud computing infrastructures implemented with Eucalyptus in contrastto Amazon S3.

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Clifford, Megan

    Infrastructure is, by design, largely unnoticed until it breaks down and services fail. This includes water supplies, gas pipelines, bridges and dams, phone lines and cell towers, roads and culverts, railways, and the electric grid—all of the complex systems that keep our societies and economies running. Climate change, population growth, increased urbanization, system aging, and outdated design standards stress existing infrastructure and its ability to satisfy the rapidly changing demands from users. Here, the resilience of both physical and cyber infrastructure systems, however, is critical to a community as it prepares for, responds to, and recovers from a disaster, whethermore » natural or man-made.« less

  7. An experimental study of gully sidewall expansion

    USDA-ARS?s Scientific Manuscript database

    Soil erosion, in its myriad forms, devastates arable land and infrastructure and strains the balance between economic stability and viability. Gullies may form in existing channels or where no previous channel drainage existed. Typically, gullies are a result of a disequilibrium between the eroding ...

  8. Abandoned rail corridors in Texas : a policy and infrastructure evaluation.

    DOT National Transportation Integrated Search

    2011-03-01

    The use of existing and abandoned railroad rights-of-way has been a proven method of acquiring linear : corridors for the construction of roadways since the formation of the Texas Highway Department. Either : paralleling existing rail lines or re-usi...

  9. Changes in the Arctic: Background and Issues for Congress

    DTIC Science & Technology

    2016-05-12

    discovery of new oil and gas deposits far from existing storage, pipelines , and shipping facilities cannot be developed until infrastructure is built...markets. Other questions in need of answers include the status of port, pipeline , and liquid natural gas infrastructure; whether methane hydrates...Changes to the Arctic brought about by warming temperatures will likely allow more exploration for oil, gas , and minerals. Warming that causes

  10. Unified messaging solution for biosurveillance and disease surveillance.

    PubMed

    Abellera, John P; Srinivasan, Arunkumar; Danos, C Scott; McNabb, Scott; Rhodes, Barry

    2007-10-11

    Biosurveillance and disease surveillance systems serve different purposes. However, the richness and quality of an existing data stream and infrastructure used in biosurveillance may prove beneficial for any state-based electronic disease surveillance system, especially if an electronic laboratory data feed does not exist between a hospital and state-based system. The use of an Enterprise Application Integration(EAI) engine, such as the BioSense Integrator,will be necessary to map heterogeneous messages into standard representations, then validate and route them [1] to a disparate system. This poster illustrates the use of an existing BioSense Integrator in order to create a unified message to support the exchange of electronic lab messages necessary for reportable disease notification. An evaluation of the infrastructure for data messaging will be examined and presented, along with a cost and benefit analysis between hospital and state-based system.

  11. Co-location and Self-Similar Topologies of Urban Infrastructure Networks

    NASA Astrophysics Data System (ADS)

    Klinkhamer, Christopher; Zhan, Xianyuan; Ukkusuri, Satish; Elisabeth, Krueger; Paik, Kyungrock; Rao, Suresh

    2016-04-01

    The co-location of urban infrastructure is too obvious to be easily ignored. For reasons of practicality, reliability, and eminent domain, the spatial locations of many urban infrastructure networks, including drainage, sanitary sewers, and road networks, are well correlated. However, important questions dealing with correlations in the network topologies of differing infrastructure types remain unanswered. Here, we have extracted randomly distributed, nested subnets from the urban drainage, sanitary sewer, and road networks in two distinctly different cities: Amman, Jordan; and Indianapolis, USA. Network analyses were performed for each randomly chosen subnet (location and size), using a dual-mapping approach (Hierarchical Intersection Continuity Negotiation). Topological metrics for each infrastructure type were calculated and compared for all subnets in a given city. Despite large differences in the climate, governance, and populace of the two cities, and functional properties of the different infrastructure types, these infrastructure networks are shown to be highly spatially homogenous. Furthermore, strong correlations are found between topological metrics of differing types of surface and subsurface infrastructure networks. Also, the network topologies of each infrastructure type for both cities are shown to exhibit self-similar characteristics (i.e., power law node-degree distributions, [p(k) = ak-γ]. These findings can be used to assist city planners and engineers either expanding or retrofitting existing infrastructure, or in the case of developing countries, building new cities from the ground up. In addition, the self-similar nature of these infrastructure networks holds significant implications for the vulnerability of these critical infrastructure networks to external hazards and ways in which network resilience can be improved.

  12. The future of metabolomics in ELIXIR

    PubMed Central

    van Rijswijk, Merlijn; Beirnaert, Charlie; Caron, Christophe; Cascante, Marta; Dominguez, Victoria; Dunn, Warwick B.; Ebbels, Timothy M. D.; Giacomoni, Franck; Gonzalez-Beltran, Alejandra; Hankemeier, Thomas; Haug, Kenneth; Izquierdo-Garcia, Jose L.; Jimenez, Rafael C.; Jourdan, Fabien; Kale, Namrata; Klapa, Maria I.; Kohlbacher, Oliver; Koort, Kairi; Kultima, Kim; Le Corguillé, Gildas; Moreno, Pablo; Moschonas, Nicholas K.; Neumann, Steffen; O’Donovan, Claire; Reczko, Martin; Rocca-Serra, Philippe; Rosato, Antonio; Salek, Reza M.; Sansone, Susanna-Assunta; Satagopam, Venkata; Schober, Daniel; Shimmo, Ruth; Spicer, Rachel A.; Spjuth, Ola; Thévenot, Etienne A.; Viant, Mark R.; Weber, Ralf J. M.; Willighagen, Egon L.; Zanetti, Gianluigi; Steinbeck, Christoph

    2017-01-01

    Metabolomics, the youngest of the major omics technologies, is supported by an active community of researchers and infrastructure developers across Europe. To coordinate and focus efforts around infrastructure building for metabolomics within Europe, a workshop on the “Future of metabolomics in ELIXIR” was organised at Frankfurt Airport in Germany. This one-day strategic workshop involved representatives of ELIXIR Nodes, members of the PhenoMeNal consortium developing an e-infrastructure that supports workflow-based metabolomics analysis pipelines, and experts from the international metabolomics community. The workshop established metabolite identification as the critical area, where a maximal impact of computational metabolomics and data management on other fields could be achieved. In particular, the existing four ELIXIR Use Cases, where the metabolomics community - both industry and academia - would benefit most, and which could be exhaustively mapped onto the current five ELIXIR Platforms were discussed. This opinion article is a call for support for a new ELIXIR metabolomics Use Case, which aligns with and complements the existing and planned ELIXIR Platforms and Use Cases. PMID:29043062

  13. The future of metabolomics in ELIXIR.

    PubMed

    van Rijswijk, Merlijn; Beirnaert, Charlie; Caron, Christophe; Cascante, Marta; Dominguez, Victoria; Dunn, Warwick B; Ebbels, Timothy M D; Giacomoni, Franck; Gonzalez-Beltran, Alejandra; Hankemeier, Thomas; Haug, Kenneth; Izquierdo-Garcia, Jose L; Jimenez, Rafael C; Jourdan, Fabien; Kale, Namrata; Klapa, Maria I; Kohlbacher, Oliver; Koort, Kairi; Kultima, Kim; Le Corguillé, Gildas; Moreno, Pablo; Moschonas, Nicholas K; Neumann, Steffen; O'Donovan, Claire; Reczko, Martin; Rocca-Serra, Philippe; Rosato, Antonio; Salek, Reza M; Sansone, Susanna-Assunta; Satagopam, Venkata; Schober, Daniel; Shimmo, Ruth; Spicer, Rachel A; Spjuth, Ola; Thévenot, Etienne A; Viant, Mark R; Weber, Ralf J M; Willighagen, Egon L; Zanetti, Gianluigi; Steinbeck, Christoph

    2017-01-01

    Metabolomics, the youngest of the major omics technologies, is supported by an active community of researchers and infrastructure developers across Europe. To coordinate and focus efforts around infrastructure building for metabolomics within Europe, a workshop on the "Future of metabolomics in ELIXIR" was organised at Frankfurt Airport in Germany. This one-day strategic workshop involved representatives of ELIXIR Nodes, members of the PhenoMeNal consortium developing an e-infrastructure that supports workflow-based metabolomics analysis pipelines, and experts from the international metabolomics community. The workshop established metabolite identification as the critical area, where a maximal impact of computational metabolomics and data management on other fields could be achieved. In particular, the existing four ELIXIR Use Cases, where the metabolomics community - both industry and academia - would benefit most, and which could be exhaustively mapped onto the current five ELIXIR Platforms were discussed. This opinion article is a call for support for a new ELIXIR metabolomics Use Case, which aligns with and complements the existing and planned ELIXIR Platforms and Use Cases.

  14. Concept of intellectual charging system for electrical and plug-in hybrid vehicles in Russian Federation

    NASA Astrophysics Data System (ADS)

    Kolbasov, A.; Karpukhin, K.; Terenchenko, A.; Kavalchuk, I.

    2018-02-01

    Electric vehicles have become the most common solution to improve sustainability of the transportation systems all around the world. Despite all benefits, wide adaptation of electric vehicles requires major changes in the infrastructure, including grid adaptation to the rapidly increased power demand and development of the Connected Car concept. This paper discusses the approaches to improve usability of electric vehicles, by creating suitable web-services, with possible connections vehicle-to-vehicle, vehicle-to-infrastructure, and vehicle-to-grid. Developed concept combines information about electrical loads on the grid in specific direction, navigation information from the on-board system, existing and empty charging slots and power availability. In addition, this paper presents the universal concept of the photovoltaic integrated charging stations, which are connected to the developed information systems. It helps to achieve rapid adaptation of the overall infrastructure to the needs of the electric vehicles users with minor changes in the existing grid and loads.

  15. Assessing the uptake of persistent identifiers by research infrastructure users

    PubMed Central

    Maull, Keith E.

    2017-01-01

    Significant progress has been made in the past few years in the development of recommendations, policies, and procedures for creating and promoting citations to data sets, software, and other research infrastructures like computing facilities. Open questions remain, however, about the extent to which referencing practices of authors of scholarly publications are changing in ways desired by these initiatives. This paper uses four focused case studies to evaluate whether research infrastructures are being increasingly identified and referenced in the research literature via persistent citable identifiers. The findings of the case studies show that references to such resources are increasing, but that the patterns of these increases are variable. In addition, the study suggests that citation practices for data sets may change more slowly than citation practices for software and research facilities, due to the inertia of existing practices for referencing the use of data. Similarly, existing practices for acknowledging computing support may slow the adoption of formal citations for computing resources. PMID:28394907

  16. SEQADAPT: an adaptable system for the tracking, storage and analysis of high throughput sequencing experiments.

    PubMed

    Burdick, David B; Cavnor, Chris C; Handcock, Jeremy; Killcoyne, Sarah; Lin, Jake; Marzolf, Bruz; Ramsey, Stephen A; Rovira, Hector; Bressler, Ryan; Shmulevich, Ilya; Boyle, John

    2010-07-14

    High throughput sequencing has become an increasingly important tool for biological research. However, the existing software systems for managing and processing these data have not provided the flexible infrastructure that research requires. Existing software solutions provide static and well-established algorithms in a restrictive package. However as high throughput sequencing is a rapidly evolving field, such static approaches lack the ability to readily adopt the latest advances and techniques which are often required by researchers. We have used a loosely coupled, service-oriented infrastructure to develop SeqAdapt. This system streamlines data management and allows for rapid integration of novel algorithms. Our approach also allows computational biologists to focus on developing and applying new methods instead of writing boilerplate infrastructure code. The system is based around the Addama service architecture and is available at our website as a demonstration web application, an installable single download and as a collection of individual customizable services.

  17. SEQADAPT: an adaptable system for the tracking, storage and analysis of high throughput sequencing experiments

    PubMed Central

    2010-01-01

    Background High throughput sequencing has become an increasingly important tool for biological research. However, the existing software systems for managing and processing these data have not provided the flexible infrastructure that research requires. Results Existing software solutions provide static and well-established algorithms in a restrictive package. However as high throughput sequencing is a rapidly evolving field, such static approaches lack the ability to readily adopt the latest advances and techniques which are often required by researchers. We have used a loosely coupled, service-oriented infrastructure to develop SeqAdapt. This system streamlines data management and allows for rapid integration of novel algorithms. Our approach also allows computational biologists to focus on developing and applying new methods instead of writing boilerplate infrastructure code. Conclusion The system is based around the Addama service architecture and is available at our website as a demonstration web application, an installable single download and as a collection of individual customizable services. PMID:20630057

  18. Mitigating and adapting to climate change: multi-functional and multi-scale assessment of green urban infrastructure.

    PubMed

    Demuzere, M; Orru, K; Heidrich, O; Olazabal, E; Geneletti, D; Orru, H; Bhave, A G; Mittal, N; Feliu, E; Faehnle, M

    2014-12-15

    In order to develop climate resilient urban areas and reduce emissions, several opportunities exist starting from conscious planning and design of green (and blue) spaces in these landscapes. Green urban infrastructure has been regarded as beneficial, e.g. by balancing water flows, providing thermal comfort. This article explores the existing evidence on the contribution of green spaces to climate change mitigation and adaptation services. We suggest a framework of ecosystem services for systematizing the evidence on the provision of bio-physical benefits (e.g. CO2 sequestration) as well as social and psychological benefits (e.g. improved health) that enable coping with (adaptation) or reducing the adverse effects (mitigation) of climate change. The multi-functional and multi-scale nature of green urban infrastructure complicates the categorization of services and benefits, since in reality the interactions between various benefits are manifold and appear on different scales. We will show the relevance of the benefits from green urban infrastructures on three spatial scales (i.e. city, neighborhood and site specific scales). We will further report on co-benefits and trade-offs between the various services indicating that a benefit could in turn be detrimental in relation to other functions. The manuscript identifies avenues for further research on the role of green urban infrastructure, in different types of cities, climates and social contexts. Our systematic understanding of the bio-physical and social processes defining various services allows targeting stressors that may hamper the provision of green urban infrastructure services in individual behavior as well as in wider planning and environmental management in urban areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Hydrogeology of the Old Faithful area, Yellowstone National Park, Wyoming, and its relevance to natural resources and infrastructure

    USGS Publications Warehouse

    ,; Foley, Duncan; Fournier, Robert O.; Heasler, Henry P.; Hinckley, Bern; Ingebritsen, Steven E.; Lowenstern, Jacob B.; Susong, David D.

    2014-01-01

    There are many documented examples at YNP and elsewhere where human infrastructure and natural thermal features have negatively affected each other. Unless action is taken, human conflicts with the Old Faithful hydrothermal system are likely to increase over the coming years. This is partly because of the increase in park visitation over the past decades, but also because the interval between eruptions of Old Faithful has increased, lengthening the time spent (and services needed) for each visitor at Old Faithful. To avoid an increase in visitor impacts, the National Park Service should consider 2 alternate strategies to accommodate people, vehicles, and services in the Upper Geyser Basin, such as shuttle services from staging (parking and dining) areas with little or no recent hydrothermal activity. We further suggest that YNP consider a zone system to guide maintenance and development of infrastructure in the immediate Old Faithful area. A “red” zone includes hydrothermally active land where new development is discouraged and existing infrastructure is modified with great care. An outer “green” zone represents areas where cooler temperatures and less hydrothermal flow are thought to exist, and where development and maintenance could proceed as occurs elsewhere in the park. An intermediate “yellow” zone would require preliminary assessment of subsurface temperatures and gas concentrations to assess suitability for infrastructure development. The panel recommends that YNP management follow the lead of the National Park System Advisory Board Science Committee (2012) by applying the “precautionary principle” when making decisions regarding the interaction of hydrothermal phenomena and park infrastructure in the Old Faithful area and other thermal areas within YNP.

  20. Development of Network-based Communications Architectures for Future NASA Missions

    NASA Technical Reports Server (NTRS)

    Slywczak, Richard A.

    2007-01-01

    Since the Vision for Space Exploration (VSE) announcement, NASA has been developing a communications infrastructure that combines existing terrestrial techniques with newer concepts and capabilities. The overall goal is to develop a flexible, modular, and extensible architecture that leverages and enhances terrestrial networking technologies that can either be directly applied or modified for the space regime. In addition, where existing technologies leaves gaps, new technologies must be developed. An example includes dynamic routing that accounts for constrained power and bandwidth environments. Using these enhanced technologies, NASA can develop nodes that provide characteristics, such as routing, store and forward, and access-on-demand capabilities. But with the development of the new infrastructure, challenges and obstacles will arise. The current communications infrastructure has been developed on a mission-by-mission basis rather than an end-to-end approach; this has led to a greater ground infrastructure, but has not encouraged communications between space-based assets. This alone provides one of the key challenges that NASA must encounter. With the development of the new Crew Exploration Vehicle (CEV), NASA has the opportunity to provide an integration path for the new vehicles and provide standards for their development. Some of the newer capabilities these vehicles could include are routing, security, and Software Defined Radios (SDRs). To meet these needs, the NASA/Glenn Research Center s (GRC) Network Emulation Laboratory (NEL) has been using both simulation and emulation to study and evaluate these architectures. These techniques provide options to NASA that directly impact architecture development. This paper identifies components of the infrastructure that play a pivotal role in the new NASA architecture, develops a scheme using simulation and emulation for testing these architectures and demonstrates how NASA can strengthen the new infrastructure by implementing these concepts.

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