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Ian E Woodrow - One of the best experts on this subject based on the ideXlab platform.
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intra plant variation in Cyanogenesis and the continuum of foliar plant defense traits in the rainforest tree ryparosa kurrangii achariaceae
Tree Physiology, 2008Co-Authors: Bruce L Webber, Ian E WoodrowAbstract:Summary At the intra-plant level, temporal and spatial variations in plant defense traits can be influenced by resource requirements, defensive priorities and storage opportunities. Across a leaf age gradient, Cyanogenic glycoside concentrations in the rainforest understory tree Ryparosa kurrangii B.L. Webber were higher in young expanding leaves than in mature leaves (2.58 and 1.38 mg g –1 , respectively). Moreover, Cyanogens, as an effective chemical defense against generalist herbivores, contributed to a defense continuum protecting foliar tissue during leaf development. Chemical (Cyanogens and phenolic compounds) and phenological (delayed greening) defense traits protected young leaves, whereas mature leaves were largely protected by physical defense mechanisms (lamina toughness; explained primarily by leaf mass per area). Cyanogen concentration was considerably higher in floral tissue than in foliar tissue and decreased in floral tissue during development. Across contrasting tropical seasons, foliar Cyanogenic concentration varied significantly, being highest in the late wet season and lowest during the pre-wet season, the latter coinciding with fruiting and leaf flushing. Cyanogens in R. kurrangii appear to be differentially allocated in a way that maximizes plant fitness but may also act as a store of reduced nitrogen that is remobilized during flowering and leaf flushing.
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constitutive polymorphic Cyanogenesis in the australian rainforest tree ryparosa kurrangii achariaceae
Phytochemistry, 2007Co-Authors: Bruce L Webber, Rebecca Elizabeth Miller, Ian E WoodrowAbstract:Abstract Cyanogenesis, the liberation of volatile hydrogen cyanide from endogenous cyanide-containing compounds, is a proven plant defence mechanism and the particular Cyanogens involved have taxonomic utility. The cyclopentenoncyanhydrin glycoside gynocardin was the only Cyanogen isolated from foliar tissue of the rare Australian rainforest tree, Ryparosa kurrangii (Achariaceae). Mechanical damage simulating foliar herbivory did not induce a significant increase in the expression of Cyanogenesis over a 24 h period, indicating Cyanogenic herbivore defence in R. kurrangii is constitutive. The Cyanogenic potential of mature leaves was quantitatively polymorphic between trees in a natural population, ranging from 0.54 to 4.77 mg CN g −1 dry wt leaf tissue.
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A galloylated Cyanogenic glycoside from the Australian endemic rainforest tree Elaeocarpus sericopetalus (Elaeocarpaceae).
Phytochemistry, 2006Co-Authors: Rebecca E. Miller, Michael Stewart, Robert J. Capon, Ian E WoodrowAbstract:A Cyanogenic glycoside -6'-O-galloylsambunigrin - has been isolated from the foliage of the Australian tropical rainforest tree species Elaeocarpus sericopetalus F. Muell. (Elaeocarpaceae). This is the first formal characterisation of a Cyanogenic constituent in the Elaeocarpaceae family, and only the second in the order Malvales. 6'-O-galloylsambunigrin was identified as the principal glycoside, accounting for 91% of total Cyanogen in a leaf methanol extract. Preliminary analyses indicated that the remaining Cyanogen content may comprise small quantities of sambunigrin, as well as di- and tri-gallates of sambunigrin. E. sericopetalus was found to have foliar concentrations of Cyanogenic glycosides among the highest reported for tree leaves, up to 5.2 mg CN g(-1) dry wt. (c) 2006 Elsevier Ltd. All rights reserved.
Bruce L Webber - One of the best experts on this subject based on the ideXlab platform.
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intra plant variation in Cyanogenesis and the continuum of foliar plant defense traits in the rainforest tree ryparosa kurrangii achariaceae
Tree Physiology, 2008Co-Authors: Bruce L Webber, Ian E WoodrowAbstract:Summary At the intra-plant level, temporal and spatial variations in plant defense traits can be influenced by resource requirements, defensive priorities and storage opportunities. Across a leaf age gradient, Cyanogenic glycoside concentrations in the rainforest understory tree Ryparosa kurrangii B.L. Webber were higher in young expanding leaves than in mature leaves (2.58 and 1.38 mg g –1 , respectively). Moreover, Cyanogens, as an effective chemical defense against generalist herbivores, contributed to a defense continuum protecting foliar tissue during leaf development. Chemical (Cyanogens and phenolic compounds) and phenological (delayed greening) defense traits protected young leaves, whereas mature leaves were largely protected by physical defense mechanisms (lamina toughness; explained primarily by leaf mass per area). Cyanogen concentration was considerably higher in floral tissue than in foliar tissue and decreased in floral tissue during development. Across contrasting tropical seasons, foliar Cyanogenic concentration varied significantly, being highest in the late wet season and lowest during the pre-wet season, the latter coinciding with fruiting and leaf flushing. Cyanogens in R. kurrangii appear to be differentially allocated in a way that maximizes plant fitness but may also act as a store of reduced nitrogen that is remobilized during flowering and leaf flushing.
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constitutive polymorphic Cyanogenesis in the australian rainforest tree ryparosa kurrangii achariaceae
Phytochemistry, 2007Co-Authors: Bruce L Webber, Rebecca Elizabeth Miller, Ian E WoodrowAbstract:Abstract Cyanogenesis, the liberation of volatile hydrogen cyanide from endogenous cyanide-containing compounds, is a proven plant defence mechanism and the particular Cyanogens involved have taxonomic utility. The cyclopentenoncyanhydrin glycoside gynocardin was the only Cyanogen isolated from foliar tissue of the rare Australian rainforest tree, Ryparosa kurrangii (Achariaceae). Mechanical damage simulating foliar herbivory did not induce a significant increase in the expression of Cyanogenesis over a 24 h period, indicating Cyanogenic herbivore defence in R. kurrangii is constitutive. The Cyanogenic potential of mature leaves was quantitatively polymorphic between trees in a natural population, ranging from 0.54 to 4.77 mg CN g −1 dry wt leaf tissue.
Gregory W Peterson - One of the best experts on this subject based on the ideXlab platform.
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Zirconium Hydroxide–Metal–Organic Framework Composites for Toxic Chemical Removal
2016Co-Authors: Gregory W Peterson, Joseph A. Rossin, Jared B. Decoste, Kato L. Killops, Matthew Browe, Erica Valdes, Paulette JonesAbstract:Composite materials comprising the metal–organic framework CuBTC (HKUST-1 or Cu3(BTC)2) and zirconium hydroxide were made to develop a material capable of broad spectrum toxic chemical removal. Materials were physically mixed at varying percentages, followed by pressing into pellets to set the structure. Mixtures were confirmed using powder X-ray diffraction, attenuated total reflectance–Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Nitrogen isotherm data were collected on the composite media, followed by breakthrough testing against ammonia, Cyanogen chloride, and sulfur dioxide. All samples exhibited substantial porosity. As the percentage of CuBTC increased, ammonia performance increased while sulfur dioxide removal generally decreased. Cyanogen chloride removal increased with increased CuBTC percentage under dry conditions, but failed to provide any significant removal under humid conditions. Adding triethylenediamine to the composites resulted in a substantial increase in Cyanogen chloride removal capacity under humid conditions. In all, the composite structures resulted in some synergistic effects for ammonia and Cyanogen chloride, with removal capacities higher than weighted averages based on performance of pure components. Data indicate that composites comprising CuBTC and zirconium hydroxide may be viable for broad spectrum toxic chemical filtration
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engineering uio 66 nh2 for toxic gas removal
Industrial & Engineering Chemistry Research, 2014Co-Authors: Gregory W Peterson, Jared B Decoste, Farzin Fatollahifard, David K BrittAbstract:The metal–organic framework UiO-66-NH2 was synthesized in a scaled batch of approximately 100 g. The material was then pressed into small pellets at pressures ranging from 5000 to 100000 psi to determine the effects on porosity and crystal structure. Nitrogen isotherm data and powder X-ray diffraction data indicate that the structure remains intact up to 25000 psi, with only a slight decrease in surface area. The structure exhibits significant degradation at pressures above 25000 psi. Subsequently, the powder was pressed at 5000 psi and then crushed and sieved into 20 × 40 mesh granules for evaluation against ammonia and Cyanogen chloride in a breakthrough system simulating individual protection filters and respirator cartridges. The MOF showed capacity similar to that of a broad-spectrum carbon for both ammonia and Cyanogen chloride; however, the breakthrough times, especially for Cyanogen chloride, were dramatically reduced, likely as a result of mass-transfer limitations from the completely microporous...
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Engineering UiO-66-NH2 for Toxic Gas Removal
2014Co-Authors: Gregory W Peterson, Jared B. Decoste, Farzin Fatollahi-fard, David K BrittAbstract:The metal–organic framework UiO-66-NH2 was synthesized in a scaled batch of approximately 100 g. The material was then pressed into small pellets at pressures ranging from 5000 to 100000 psi to determine the effects on porosity and crystal structure. Nitrogen isotherm data and powder X-ray diffraction data indicate that the structure remains intact up to 25000 psi, with only a slight decrease in surface area. The structure exhibits significant degradation at pressures above 25000 psi. Subsequently, the powder was pressed at 5000 psi and then crushed and sieved into 20 × 40 mesh granules for evaluation against ammonia and Cyanogen chloride in a breakthrough system simulating individual protection filters and respirator cartridges. The MOF showed capacity similar to that of a broad-spectrum carbon for both ammonia and Cyanogen chloride; however, the breakthrough times, especially for Cyanogen chloride, were dramatically reduced, likely as a result of mass-transfer limitations from the completely microporous MOF
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mof 74 building unit has a direct impact on toxic gas adsorption
Chemical Engineering Science, 2011Co-Authors: Grant T Glover, Gregory W Peterson, David K Britt, Bryan J Schindler, Omar M YaghiAbstract:Metal organic framework (MOF-74) analogs have been synthesized using cobalt, magnesium, nickel, and zinc metal centers. The capability of these materials to remove ammonia, Cyanogen chloride, and sulfur dioxide from air has been evaluated via fixed-bed breakthrough testing in both dry and humid conditions. Octane breakthrough tests were performed to determine the physisorption capacities of the materials. All materials were stored in air prior to use. Dynamic breakthrough capacities of the analogs were compared to 13X zeolite and BPL activated carbon. The impact of the metal center on the adsorption behavior is illustrated with each analog providing different ammonia and Cyanogen chloride adsorption capacities. The results provide an important step in the assessment of the potential of MOFs to function as porous adsorbent materials.
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Enhanced Cyanogen Chloride Removal by the Reactive Zirconium Hydroxide Substrate
Industrial & Engineering Chemistry Research, 2010Co-Authors: Gregory W Peterson, George W. Wagner, Jennifer H. Keller, Joseph A. RossinAbstract:A novel microporous sorbent consisting of zirconium hydroxide impregnated with triethylenediamine (TEDA) was evaluated for the removal of Cyanogen chloride. Breakthrough data were collected on packed beds, illustrating the efficacious nature of TEDA and the enhanced Cyanogen chloride removal from the basic zirconium hydroxide structure. NMR and XPS analyses revealed the fate of Cyanogen chloride, with inorganic chloride byproducts deposited on the surface of the material and polymerized urea condensates physically adsorbed in the pore structure. The zirconium hydroxide media were found to provide significantly enhanced removal capabilities as compared to traditionally impregnated activated carbons, allowing for the development of respirators with reduced encumbrance.
David K Britt - One of the best experts on this subject based on the ideXlab platform.
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engineering uio 66 nh2 for toxic gas removal
Industrial & Engineering Chemistry Research, 2014Co-Authors: Gregory W Peterson, Jared B Decoste, Farzin Fatollahifard, David K BrittAbstract:The metal–organic framework UiO-66-NH2 was synthesized in a scaled batch of approximately 100 g. The material was then pressed into small pellets at pressures ranging from 5000 to 100000 psi to determine the effects on porosity and crystal structure. Nitrogen isotherm data and powder X-ray diffraction data indicate that the structure remains intact up to 25000 psi, with only a slight decrease in surface area. The structure exhibits significant degradation at pressures above 25000 psi. Subsequently, the powder was pressed at 5000 psi and then crushed and sieved into 20 × 40 mesh granules for evaluation against ammonia and Cyanogen chloride in a breakthrough system simulating individual protection filters and respirator cartridges. The MOF showed capacity similar to that of a broad-spectrum carbon for both ammonia and Cyanogen chloride; however, the breakthrough times, especially for Cyanogen chloride, were dramatically reduced, likely as a result of mass-transfer limitations from the completely microporous...
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Engineering UiO-66-NH2 for Toxic Gas Removal
2014Co-Authors: Gregory W Peterson, Jared B. Decoste, Farzin Fatollahi-fard, David K BrittAbstract:The metal–organic framework UiO-66-NH2 was synthesized in a scaled batch of approximately 100 g. The material was then pressed into small pellets at pressures ranging from 5000 to 100000 psi to determine the effects on porosity and crystal structure. Nitrogen isotherm data and powder X-ray diffraction data indicate that the structure remains intact up to 25000 psi, with only a slight decrease in surface area. The structure exhibits significant degradation at pressures above 25000 psi. Subsequently, the powder was pressed at 5000 psi and then crushed and sieved into 20 × 40 mesh granules for evaluation against ammonia and Cyanogen chloride in a breakthrough system simulating individual protection filters and respirator cartridges. The MOF showed capacity similar to that of a broad-spectrum carbon for both ammonia and Cyanogen chloride; however, the breakthrough times, especially for Cyanogen chloride, were dramatically reduced, likely as a result of mass-transfer limitations from the completely microporous MOF
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mof 74 building unit has a direct impact on toxic gas adsorption
Chemical Engineering Science, 2011Co-Authors: Grant T Glover, Gregory W Peterson, David K Britt, Bryan J Schindler, Omar M YaghiAbstract:Metal organic framework (MOF-74) analogs have been synthesized using cobalt, magnesium, nickel, and zinc metal centers. The capability of these materials to remove ammonia, Cyanogen chloride, and sulfur dioxide from air has been evaluated via fixed-bed breakthrough testing in both dry and humid conditions. Octane breakthrough tests were performed to determine the physisorption capacities of the materials. All materials were stored in air prior to use. Dynamic breakthrough capacities of the analogs were compared to 13X zeolite and BPL activated carbon. The impact of the metal center on the adsorption behavior is illustrated with each analog providing different ammonia and Cyanogen chloride adsorption capacities. The results provide an important step in the assessment of the potential of MOFs to function as porous adsorbent materials.
A Barcia - One of the best experts on this subject based on the ideXlab platform.
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probing non polar interstellar molecules through their protonated form detection of protonated Cyanogen nccnh
Astronomy and Astrophysics, 2015Co-Authors: M Agundez, J Cernicharo, P De Vicente, N Marcelino, E Roueff, A Fuente, M Gerin, M Guelin, C Albo, A BarciaAbstract:Cyanogen (NCCN) is the simplest member of the series of dicyanopolyynes. It has been hypothesized that this family of molecules can be important constituents of interstellar and circumstellar media, although the lack of a permanent electric dipole moment prevents its detection through radioastronomical techniques. Here we present the first solid evidence of the presence of Cyanogen in interstellar clouds through the detection of its protonated form toward the cold dark clouds TMC-1 and L483. Protonated Cyanogen (NCCNH+) has been identified through the J = 5 – 4 and J = 10 – 9 rotational transitions using the 40m radiotelescope of Yebes and the IRAM 30m telescope. We derive beam averaged column densities for NCCNH+ of (8.6 ± 4.4) × 1010 cm−2 in TMC-1 and (3.9 ± 1.8) × 1010 cm−2 in L483, which translate to fairly low fractional abundances relative to H2, in the range (1-10) × 10−12. The chemistry of protonated molecules in dark clouds is discussed, and it is found that, in general terms, the abundance ratio between the protonated and non protonated forms of a molecule increases with increasing proton affinity. Our chemical model predicts an abundance ratio NCCNH+/NCCN of ~ 10−4, which implies that the abundance of Cyanogen in dark clouds could be as high as (1-10) × 10−8 relative to H2, i.e., comparable to that of other abundant nitriles such as HCN, HNC, and HC3N.
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probing non polar interstellar molecules through their protonated form detection of protonated Cyanogen nccnh
arXiv: Astrophysics of Galaxies, 2015Co-Authors: M Agundez, J Cernicharo, P De Vicente, N Marcelino, E Roueff, A Fuente, M Gerin, M Guelin, C Albo, A BarciaAbstract:Cyanogen (NCCN) is the simplest member of the series of dicyanopolyynes. It has been hypothesized that this family of molecules can be important constituents of interstellar and circumstellar media, although the lack of a permanent electric dipole moment prevents its detection through radioastronomical techniques. Here we present the first solid evidence of the presence of Cyanogen in interstellar clouds through the detection of its protonated form toward the cold dark clouds TMC-1 and L483. Protonated Cyanogen (NCCNH+) has been identified through the J=5-4 and J=10-9 rotational transitions using the 40m radiotelescope of Yebes and the IRAM 30m telescope. We derive beam averaged column densities for NCCNH+ of (8.6+/-4.4)e10 cm-2 in TMC-1 and (3.9+/-1.8)e10 cm-2 in L483, which translate to fairly low fractional abundances relative to H2, in the range (1-10)e-12. The chemistry of protonated molecules in dark clouds is discussed, and it is found that, in general terms, the abundance ratio between the protonated and non protonated forms of a molecule increases with increasing proton affinity. Our chemical model predicts an abundance ratio NCCNH+/NCCN of 1e-4, which implies that the abundance of Cyanogen in dark clouds could be as high as (1-10)e-8 relative to H2, i.e., comparable to that of other abundant nitriles such as HCN, HNC, and HC3N.
