Effects of acidic deposition on the erosion of carbonate stone - experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

USGS Publications Warehouse

Baedecker, P.A.; Reddy, M.M.; Reimann, K.J.; Sciammarella, C.A.

1992-01-01

One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30?? to horizontal at the five NAPAP materials exposure sites range from ~15 to ~30?? ??m yr-1 for marble, and from ~25 to ~45 ??m yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ~30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ~70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ('clean rain'). These results are for marble and limestone slabs exposed at an angle of 30?? from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60?? or 85??. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at Washington, DC

Acid deposition in east Asia

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

Phadnis, M.J.; Carmichael, G.R.; Ichikawa, Y.

1996-12-31

A comparison between transport models was done to study the acid deposition in east Asia. The two models in question were different in the way the treated the pollutant species and the way simulation was carried out. A single-layer, trajectory model with simple (developed by the Central Research Institute of Electric Power Industry (CRIEPI), Japan) was compared with a multi-layered, eulerian type model (Sulfur Transport Eulerian Model - II [STEM-II]) treating the chemical processes in detail. The acidic species used in the simulation were sulfur dioxide and sulfate. The comparison was done for two episodes: each a month long inmore » winter (February) and summer (August) of 1989. The predicted results from STEM-II were compared with the predicted results from the CRIEPI model as well as the observed data at twenty-one stations in Japan. The predicted values from STEM-II were similar to the ones from the CRIEPI results and the observed values in regards to the transport features. The average monthly values of SO{sub 2} in air, sulfate in air and sulfate in precipitation were in good agreement. Sensitivity studies were carried out under different scenarios of emissions, dry depositions velocities and mixing heights. The predicted values in these sensitivity studies showed a strong dependence on the mixing heights. The predicted wet deposition of sulfur for the two months is 0.7 gS/m2.mon, while the observed deposition is around 1.1 gS/m2.mon. It was also observed that the wet deposition on the Japan sea side of the islands is more than those on the Pacific side and the Okhotsk sea, mainly because of the continental outflow of pollutant air masses from mainland China and Korea. The effects of emissions from Russia and volcanoes were also evaluated.« less

Effects of acidic deposition on the erosion of carbonate stone — experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

NASA Astrophysics Data System (ADS)

Baedecker, Philip A.; Reddy, Michael M.; Reimann, Karl J.; Sciammarella, Cesar A.

One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30° to horizontal at the five NAPAP materials exposure sites range from ˜ 15 to ˜ 30 μm yr -1 for marble, and from ˜ 25 to ˜ 45 μm yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ˜ 30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ˜ 70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ("clean rain"). These results are for marble and limestone slabs exposed at an angle of 30° from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60° or 85°. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at

Expanding atmospheric acid deposition in China from the 1990s to the 2010s

NASA Astrophysics Data System (ADS)

Yu, Haili; Wang, Qiufeng

2017-04-01

Atmospheric acid deposition is considered a global environmental issue. China has been experiencing serious acid deposition, which is anticipated to be more serious with the country's economic development and increasing consumption of fossil fuels in recent decades. By collecting nationwide data on pH and concentrations of sulfate (SO42-) and nitrate (NO3-) in precipitation between 1980 and 2014 in China, we explored the spatiotemporal variations of precipitation acid deposition (bulk deposition) and their influencing factors. Our results showed that average precipitation pH values were 4.86 and 4.84 in the 1990s and 2010s, respectively. This suggests that precipitation acid deposition in China has not seriously changes. Average SO42- deposition declined from 30.73 to 28.61 kg S ha-1 yr-1 but average NO3- deposition increased from 4.02 to 6.79 kg N ha-1 yr-1. Specifically, the area of severe precipitation acid deposition in southern China has shrunk to some extent as a result of decreasing pollutant emissions, whereas the area of moderate precipitation acid deposition has expanded in northern China, associated with rapid industrial and transportation development. Significant positive correlations have been found between precipitation acid deposition, energy consumption, and rainfall. Our findings provide a comprehensive evaluation of the spatiotemporal dynamics of precipitation acid deposition in China over past three decades, and confirm the idea that strategies implemented to save energy and reduce pollutant emissions in China have been effective in alleviating precipitation acid deposition. These findings might be used to demonstrate how developing countries could achieve economic development and environmental protection through the implementation of advanced technologies to reduce pollutant emissions.

Effects of acidic deposition and soil acidification on sugar maple trees in the Adirondack Mountains, New York

USGS Publications Warehouse

Sullivan, Timothy J.; Lawrence, Gregory B.; Bailey, Scott W.; McDonnell, Todd C.; Beier, Colin M.; Weathers, K.C.; McPherson, G.T.; Bishop, Daniel A.

2013-01-01

We documented the effects of acidic atmospheric deposition and soil acidification on the canopy health, basal area increment, and regeneration of sugar maple (SM) trees across the Adirondack region of New York State, in the northeastern United States, where SM are plentiful but not well studied and where widespread depletion of soil calcium (Ca) has been documented. Sugar maple is a dominant canopy species in the Adirondack Mountain ecoregion, and it has a high demand for Ca. Trees in this region growing on soils with poor acid–base chemistry (low exchangeable Ca and % base saturation [BS]) that receive relatively high levels of atmospheric sulfur and nitrogen deposition exhibited a near absence of SM seedling regeneration and lower crown vigor compared with study plots with relatively high exchangeable Ca and BS and lower levels of acidic deposition. Basal area increment averaged over the 20th century was correlated (p < 0.1) with acid–base chemistry of the Oa, A, and upper B soil horizons. A lack of Adirondack SM regeneration, reduced canopy condition, and possibly decreased basal area growth over recent decades are associated with low concentrations of nutrient base cations in this region that has undergone soil Ca depletion from acidic deposition.

Acid deposition and water use efficiency in Appalachian forests

NASA Astrophysics Data System (ADS)

Malcomb, J.

2017-12-01

Multiple studies have reported increases in forest water use efficiency in recent decades, but the drivers of these trends remain uncertain. While acid deposition has profoundly altered the biogeochemistry of Appalachian forests in the past century, its impacts on forest water use efficiency have been largely overlooked. Plant ecophysiology literature suggests that plants up-regulate transpiration in response to soil nutrient limitation in order to maintain sufficient mass flow of nutrients. To test the impacts of acid deposition on forest eco-hydrology in central Appalachia, we integrated dendrochronological techniques, including tree ring δ13C analysis, with catchment water balance data from the Fernow Experimental Forest in West Virginia. Tree cores from four species were collected in Fernow Watershed 3, which has received experimental ammonium sulfate additions since 1989, and Watershed 7, an adjacent control catchment. Initial results suggest that acidification treatments have not significantly influenced tree productivity compared to a control watershed, but the effect varies by species, with tulip poplar showing greatest sensitivity to acidification. Climatic water balance, defined as the difference between growing season precipitation and evapotranspiration, is significantly related to annual tree ring growth, suggesting that climate may be driving tree growth trends in chronically acidified Appalachian forests. Tree ring 13C analysis from Fernow cores is underway and these data will be integrated with catchment hydrology data from five other sites in central Appalachia and the U.S. Northeast, representing a range of forest types, soil base saturations, and acid deposition histories. This work will advance understanding of how climate and acid deposition interact to influence forest productivity and water use efficiency, and improve our ability to model carbon and water cycling in forested ecosystems impacted by acid deposition.

Development of atmospheric acid deposition in China from the 1990s to the 2010s.

PubMed

Yu, Haili; He, Nianpeng; Wang, Qiufeng; Zhu, Jianxing; Gao, Yang; Zhang, Yunhai; Jia, Yanlong; Yu, Guirui

2017-12-01

Atmospheric acid deposition is a global environmental issue. China has been experiencing serious acid deposition, which is anticipated to become more severe with the country's economic development and increasing consumption of fossil fuels in recent decades. We explored the spatiotemporal variations of acid deposition (wet acid deposition) and its influencing factors by collecting nationwide data on pH and concentrations of sulfate (SO 4 2- ) and nitrate (NO 3 - ) in precipitation between 1980 and 2014 in China. Our results showed that average precipitation pH values were 4.59 and 4.70 in the 1990s and 2010s, respectively, suggesting that precipitation acid deposition in China has not seriously worsened. Average SO 4 2- deposition declined from 40.54 to 34.87 kg S ha -1 yr -1 but average NO 3 - deposition increased from 4.44 to 7.73 kg N ha -1 yr -1 . Specifically, the area of severe precipitation acid deposition in southern China has shrunk to some extent as a result of controlling the pollutant emissions; but the area of moderate precipitation acid deposition has expanded in northern China, associated with rapid industrial and transportation development. Furthermore, we found significant positive correlations between precipitation acid deposition, energy consumption, and rainfall. Our findings provide a relatively comprehensive evaluation of the spatiotemporal dynamics of precipitation acid deposition in China over past three decades, and confirm the idea that strategies implemented to save energy and control pollutant emissions in China have been effective in alleviating precipitation acid deposition. These findings might be used to demonstrate how developing countries could achieve economic development and environmental protection through the implementation of advanced technologies to reduce pollutant emissions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Acidic deposition on Taiwan and associated precipitation patterns

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

Lin, N.H.; Chen, C.S.; Peng, C.M.

1996-12-31

The acidic deposition on Taiwan is assessed based on precipitation chemistry observed through a nationwide monitoring network of acid rain. Ten sites have been operated since 1990. These sites were further categorized into five categories, namely, the northern (A), middle (B), southern (C), and eastern (D) Taiwan, and background (E), according to their geographical consideration. As a result, the averages (1990-1994) of pH values for the northern sites were between 4.46-4.63, whereas, the rest sites, excluding a southern site near the industrial area, had their averages greater than 5.0. The average concentrations of sulfate ions for these sites of meanmore » pH < 5.0, ranged between 103 and 148 {mu}eq {ell}{sup -1}. The mean concentrations of nitrate ions for urban sites were about 30-50% of sulfate concentrations. Using these sulfate and nitrate concentrations and rainfall data, the deposition fluxes for these sites were calculated. The overall averages of annual sulfate deposition for five areas (categories A-E) were 118, 60, 64, 60 and 25 kg ha{sup -1}, respectively, which were generally greater than those of 20-40 kg ha{sup -1} observed in the eastern USA. For the nitrate deposition, these five areas had the averages of 59, 38, 33, 40 and 16 kg ha{sup -1}, respectively. One of the important reasons why Taiwan had received higher sulfate and nitrate deposition was due to a great amount of precipitation over this subtropical island. For the northern Taiwan, more than 70% of precipitation events were stratiform and frontal precipitation associated with the northeastern monsoons, and frontal systems during the winter and spring (especially, the Mei-Yu) seasons, respectively. In addition to local effects, the long-range transport of acid substances are thought to play an important role.« less

Low-Vacuum Deposition of Glutamic Acid and Pyroglutamic Acid: A Facile Methodology for Depositing Organic Materials beyond Amino Acids

PubMed Central

Sugimoto, Iwao; Maeda, Shunsaku; Suda, Yoriko; Makihara, Kenji; Takahashi, Kazuhiko

2014-01-01

Thin layers of pyroglutamic acid (Pygl) have been deposited by thermal evaporation of the molten L-glutamic acid (L-Glu) through intramolecular lactamization. This deposition was carried out with the versatile handmade low-vacuum coater, which was simply composed of a soldering iron placed in a vacuum degassing resin chamber evacuated by an oil-free diaphragm pump. Molecular structural analyses have revealed that thin solid film evaporated from the molten L-Glu is mainly composed of L-Pygl due to intramolecular lactamization. The major component of the L-Pygl was in β-phase and the minor component was in γ-phase, which would have been generated from partial racemization to DL-Pygl. Electron microscopy revealed that the L-Glu-evaporated film generally consisted of the 20 nm particulates of Pygl, which contained a periodic pattern spacing of 0.2 nm intervals indicating the formation of the single-molecular interval of the crystallized molecular networks. The DL-Pygl-evaporated film was composed of the original DL-Pygl preserving its crystal structures. This methodology is promising for depositing a wide range of the evaporable organic materials beyond amino acids. The quartz crystal resonator coated with the L-Glu-evaporated film exhibited the pressure-sensing capability based on the adsorption-desorption of the surrounding gas at the film surface. PMID:25254114

Low-Vacuum Deposition of Glutamic Acid and Pyroglutamic Acid: A Facile Methodology for Depositing Organic Materials beyond Amino Acids.

PubMed

Sugimoto, Iwao; Maeda, Shunsaku; Suda, Yoriko; Makihara, Kenji; Takahashi, Kazuhiko

2014-01-01

Thin layers of pyroglutamic acid (Pygl) have been deposited by thermal evaporation of the molten L-glutamic acid (L-Glu) through intramolecular lactamization. This deposition was carried out with the versatile handmade low-vacuum coater, which was simply composed of a soldering iron placed in a vacuum degassing resin chamber evacuated by an oil-free diaphragm pump. Molecular structural analyses have revealed that thin solid film evaporated from the molten L-Glu is mainly composed of L-Pygl due to intramolecular lactamization. The major component of the L-Pygl was in β-phase and the minor component was in γ-phase, which would have been generated from partial racemization to DL-Pygl. Electron microscopy revealed that the L-Glu-evaporated film generally consisted of the 20 nm particulates of Pygl, which contained a periodic pattern spacing of 0.2 nm intervals indicating the formation of the single-molecular interval of the crystallized molecular networks. The DL-Pygl-evaporated film was composed of the original DL-Pygl preserving its crystal structures. This methodology is promising for depositing a wide range of the evaporable organic materials beyond amino acids. The quartz crystal resonator coated with the L-Glu-evaporated film exhibited the pressure-sensing capability based on the adsorption-desorption of the surrounding gas at the film surface.

Chapter 5: Acid deposition

Treesearch

Cliff F. Hunt; Warren E. Heilman

1999-01-01

This publication provides information about the atmospheric conditions in and near the national forest in the Ozark-Ouachita Highlands: the Mark Twain in Missouri, the Ouachita in Arkansas and Oklahoma, and the Ozark and St. Francis in Arkansas. This report includes information about particulate matter, visibility, ozone concentrations, and acid deposition in the Ozark...

Effects of multiple stresses hydropower, acid deposition and climate change on water chemistry and salmon populations in the River Otra, Norway.

PubMed

Wright, Richard F; Couture, Raoul-Marie; Christiansen, Anne B; Guerrero, José-Luis; Kaste, Øyvind; Barlaup, Bjørn T

2017-01-01

Many surface waters in Europe suffer from the adverse effects of multiple stresses. The Otra River, southernmost Norway, is impacted by acid deposition, hydropower development and increasingly by climate change. The river holds a unique population of land-locked salmon and anadromous salmon in the lower reaches. Both populations have been severely affected by acidification. The decrease in acid deposition since the 1980s has led to partial recovery of both populations. Climate change with higher temperatures and altered precipitation can potentially further impact fish populations. We used a linked set of process-oriented models to simulate future climate, discharge, and water chemistry at five sub-catchments in the Otra river basin. Projections to year 2100 indicate that future climate change will give a small but measureable improvement in water quality, but that additional reductions in acid deposition are needed to promote full restoration of the fish communities. These results can help guide management decisions to sustain key salmon habitats and carry out effective long-term mitigation strategies such as liming. The Otra River is typical of many rivers in Europe in that it fails to achieve the good ecological status target of the EU Water Framework Directive. The programme of measures needed in the river basin management plan necessarily must consider the multiple stressors of acid deposition, hydropower, and climate change. This is difficult, however, as the synergistic and antagonistic effects are complex and challenging to address with modelling tools currently available. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental negotiation: an organizational framework for solving the acid deposition puzzle

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

Briassoulis, H.

In spite of the considerable amount of research on acid deposition and its control in the fields of natural, social, and applied sciences, the problem of devising appropriate control solutions remains a highly controversial political issue. In this paper, the thesis advanced is that environmental dispute resolution procedures are needed in order to deal effectively with acid deposition control. In this way, science, economics, and technology are bound to be used more meaningfully and serve the social and political needs of the affected interests. An organizational framework to be used in conducting environmental negotiation is suggested and briefly discussed.

Estimating lake susceptibility to acidification due to acid deposition.

Treesearch

Dale S. Nichols

1990-01-01

Presents a graphical procedure for evaluating the same sensitivity of lakes to acidification due to acid deposition. The procedure is based on empirical relationships between sulfur (and in some cases nitrogen) deposition rates and lake pH, acid-neutralizing capacity, base cation concentrations, and the amount of runoff.

Effects of acid deposition on calcium nutrition and health of Southern Appalachian spruce fir forests

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

McLaughlin, S.B.; Wullschleger, S.; Stone, A.

The role of acid deposition in the health of spruce fir forests in the Southern Appalachian Mountains has been investigated by a wide variety of experimental approaches during the past 10 years. These studies have proceeded from initial dendroecological documentation of altered growth patterns of mature trees to increasingly more focused ecophysiological research on the causes and characteristics of changes in system function associated with increased acidic deposition. Field studies across gradients in deposition and soil chemistry have been located on four mountains spanning 85 km of latitude within the Southern Appalachians. The conclusion that calcium nutrition is an importantmore » component regulating health of red spruce in the Southern Appalachians and that acid deposition significantly reduces calcium availability in several ways has emerged as a consistent result from multiple lines or research. These have included analysis of trends in wood chemistry, soil solution chemistry, foliar nutrition, gas exchange physiology, root histochemistry, and controlled laboratory and field studies in which acid deposition and/or calcium nutrition has been manipulated and growth and nutritional status of saplings or mature red spruce trees measured. This earlier research has led us to investigate the broader implications and consequences of calcium deficiency for changing resistance of spruce-fir forests to natural stresses. Current research is exploring possible relationships between altered calcium nutrition and shifts in response of Fraser fir to insect attack by the balsam wooly adelgid. In addition, changes in wood ultrastructural properties in relation to altered wood chemistry is being examined to evaluate its possible role in canopy deterioration, under wind and ice stresses typical of high elevation forests.« less

Declining acidic deposition begins reversal of forest-soil acidification in the northeastern U.S. and eastern Canada

USGS Publications Warehouse

Lawrence, Gregory B.; Hazlett, Paul W.; Fernandez, Ivan J.; Ouimet, Rock; Bailey, Scott W.; Shortle, Walter C.; Smith, Kevin T.; Antidormi, Michael

2015-01-01

Decreasing trends in acidic deposition levels over the past several decades have led to partial chemical recovery of surface waters. However, depletion of soil Ca from acidic deposition has slowed surface water recovery and led to the impairment of both aquatic and terrestrial ecosystems. Nevertheless, documentation of acidic deposition effects on soils has been limited, and little is known regarding soil responses to ongoing acidic deposition decreases. In this study, resampling of soils in eastern Canada and the northeastern U.S. was done at 27 sites exposed to reductions in wet SO42– deposition of 5.7–76%, over intervals of 8–24 y. Decreases of exchangeable Al in the O horizon and increases in pH in the O and B horizons were seen at most sites. Among all sites, reductions in SO42– deposition were positively correlated with ratios (final sampling/initial sampling) of base saturation (P < 0.01) and negatively correlated with exchangeable Al ratios (P < 0.05) in the O horizon. However, base saturation in the B horizon decreased at one-third of the sites, with no increases. These results are unique in showing that the effects of acidic deposition on North American soils have begun to reverse.

Declining Acidic Deposition Begins Reversal of Forest-Soil Acidification in the Northeastern U.S. and Eastern Canada.

PubMed

Lawrence, Gregory B; Hazlett, Paul W; Fernandez, Ivan J; Ouimet, Rock; Bailey, Scott W; Shortle, Walter C; Smith, Kevin T; Antidormi, Michael R

2015-11-17

Decreasing trends in acidic deposition levels over the past several decades have led to partial chemical recovery of surface waters. However, depletion of soil Ca from acidic deposition has slowed surface water recovery and led to the impairment of both aquatic and terrestrial ecosystems. Nevertheless, documentation of acidic deposition effects on soils has been limited, and little is known regarding soil responses to ongoing acidic deposition decreases. In this study, resampling of soils in eastern Canada and the northeastern U.S. was done at 27 sites exposed to reductions in wet SO4(2-) deposition of 5.7-76%, over intervals of 8-24 y. Decreases of exchangeable Al in the O horizon and increases in pH in the O and B horizons were seen at most sites. Among all sites, reductions in SO4(2-) deposition were positively correlated with ratios (final sampling/initial sampling) of base saturation (P < 0.01) and negatively correlated with exchangeable Al ratios (P < 0.05) in the O horizon. However, base saturation in the B horizon decreased at one-third of the sites, with no increases. These results are unique in showing that the effects of acidic deposition on North American soils have begun to reverse.

Chemical and biological status of lakes and streams in the upper midwest: assessment of acidic deposition effects

USGS Publications Warehouse

Wiener, J.G.; Eilers, J.M.

1987-01-01

Many lakes in three areas in the Upper Midwest - northeastern Minnesota, northern Wisconsin, and the Upper Peninsula of Michigan - have low acid neutralizing capacity (ANC) and may be susceptible to change by acidic deposition. Northcentral Wisconsin and the Upper Peninsula of Michigan together contain about 150-300 acidic lakes (ANC ≤ 0), whereas none have been found in Minnesota. These acidic lakes are precipitation-dominated, Clearwater seepage lakes having small surface area, shallow depth, and low concentrations of dissolved organic carbon. The spatial distribution of these acidic lakes parallels a west to east gradient of increasing sulfate and hydrogen ion deposition. Several of these acidic lakes exhibit chemical characteristics and biological changes consistent with those observed elsewhere in waters reported to be acidified by acidic deposition. However, an hypothesis of recent lake acidification is not supported by analyses of either historical chemical data or diatom remains in lake sediments, and natural sources of acidity and alternative ecological processes have not been conclusively eliminated as causative factors. Streams in this three-state region have high ANC and appear to be insensitive to acidic deposition. The species richness and composition of lacustrine fish communities in the region are partly related to pH and associated chemical factors. Sport fishes considered acid-sensitive and of primary concern with regard to acidification include walleye, smallmouth bass, and black crappie. The fishery in at least one lake, Morgan Lake in Wisconsin (pH 4.6), may have declined because of acidification. Given the general lack of quantitative fishery data for acidic Wisconsin and Michigan lakes, however, more general conclusions concerning impacts or the absence of impacts of acidification on the region's fishery resources are not possible.

Deposition of dietary fatty acids in young Zucker rats fed a cafeteria diet.

PubMed

Rafecas, I; Esteve, M; Fernández-López, J A; Remesar, X; Alemany, M

1992-10-01

The content and accretion of fatty acids in 30, 45 and 60-day-old Zucker lean Fa/? and obese fa/fa rats fed either reference chow or a cafeteria diet has been studied, together with their actual fatty acid intake during each period. Diet had little overall effect on the pattern of deposition of fatty acids, but quantitatively the deposition of fat was much higher in cafeteria-fed rats. The fat-rich cafeteria diet allowed the direct incorporation of most fatty acids into the rat lipids, whilst chow feeding activated lipogenesis and the deposition of a shorter chain and more saturated pattern of fatty acids. Genetic, obesity induced a significant expansion of net lipogenesis when compared with lean controls. Cafeteria-fed obese rats accrued a high proportion of fatty acids, which was close to that ingested, but nevertheless showed a net de novo synthesis of fatty acids. It is postulated that the combined effects of genetic obesity and a fat-rich diet result in high rates of fat accretion with limited net lipogenesis. Lean Zucker rats show a progressive impairment of their delta 5-desaturase system, a situation also observed in obese rats fed a reference diet. In Zucker obese rats, cafeteria feeding resulted in an alteration of the conversion of C18:2 into C20:3. The cafeteria diet fully compensated for these drawbacks by supplying very high amounts of polyunsaturated fatty acids.

PROJECTION OF RESPONSE OF TREES AND FORESTS TO ACIDIC DEPOSITION AND ASSOCIATED POLLUTANTS

EPA Science Inventory

In 1986 the National, Acid Precipitation Assessment Program (NAPAP) established the Forest Response Program (FRP) to assess the effects of acidic deposition and associated pollutants on forests. Modeling studies were developed in parallel with both field studies on the pattern an...

Effects of Acidic Deposition and Soil Acidification on Sugar Maple Trees in the Adirondack Mountains, New York

Treesearch

T. J. Sullivan; G. B. Lawrence; S. W. Bailey; T. C. McDonnell; C. M. Beier; K. C. Weathers; G. T. McPherson; D. A. Bishop

2013-01-01

We documented the effects of acidic atmospheric deposition and soil acidification on the canopy health, basal area increment, and regeneration of sugar maple (SM) trees across the Adirondack region of New York State, in the northeastern United States, where SM are plentiful but not well studied and where widespread depletion of soil calcium (Ca) has been...

Detecting and monitoring acidic deposition effects on soil chemistry and forest growth on the Monongahela National Forest

Treesearch

Patricia Elias; James Burger; Stephanie Connolly; Mary Beth. Adams

2010-01-01

The Monongahela National Forest (MNF) lies downwind from many sources of acid deposition (AD) pollution. Therefore, managers are concerned about the possible deleterious effects of AD on the forest ecosystem. To address the needs of MNF managers, we used Forest Inventory and Analysis (FIA) sites to evaluate forest growth patterns on the MNF to determine the...

ESTIMATES OF CLOUD WATER DEPOSITION AT MOUNTAIN DEPOSITION AT MOUNTAIN ACID DEPOSITION PROGRAM SITES IN THE APPALACHIAN MOUNTAINS

EPA Science Inventory

Cloud water deposition was estimated at three high elevation sites in the Appalachian Mountains of the eastern United States (Whiteface Mountain, NY, Whitetop Mountain, VA, and Clingrnan's Dome, TN) from 1994 through 1999 as part of the Mountain Acid Deposition Program (MADPro). ...

An overview of a 5-year research program on acid deposition in China

NASA Astrophysics Data System (ADS)

Wang, T.; He, K.; Xu, X.; Zhang, P.; Bai, Y.; Wang, Z.; Zhang, X.; Duan, L.; Li, W.; Chai, F.

2011-12-01

Despite concerted research and regulative control of sulfur dioxide in China, acid rain remained a serious environmental issue, due to a sharp increase in the combustion of fossil fuel in the 2000s. In 2005, the Ministry of Science and Technology of China funded a five-year comprehensive research program on acid deposition. This talk will give an overview of the activities and the key findings from this study, covering emission, atmospheric processes, and deposition, effects on soil and stream waters, and impact on typical trees/plants in China. The main results include (1) China still experiences acidic rainfalls in southern and eastern regions, although the situation has stabilized after 2006 due to stringent control of SO2 by the Chinese Government; (2) Sulfate is the dominant acidic compound, but the contribution of nitrate has increased; (3) cloud-water composition in eastern China is strongly influenced by anthropogenic emissions; (4) the persistent fall of acid rain in the 30 years has lead to acidification of some streams/rivers and soils in southern China; (5) the studied plants have shown varying response to acid rain; (6) some new insights have been obtained on atmospheric chemistry, atmospheric transport, soil chemistry, and ecological impacts, some of which will be discussed in this talk. Compared to the situation in North America and Europe, China's acid deposition is still serious, and continued control of sulfur and nitrogen emission is required. There is an urgent need to establish a long-term observation network/program to monitor the impact of acid deposition on soil, streams/rivers/lakes, and forests.

Microbial activity in an acid resin deposit: biodegradation potential and ecotoxicology in an extremely acidic hydrocarbon contamination.

PubMed

Kloos, Karin; Schloter, Michael; Meyer, Ortwin

2006-11-01

Acid resins are residues produced in a recycling process for used oils that was in use in the forties and fifties of the last century. The resin-like material is highly contaminated with mineral oil hydrocarbons, extremely acidic and co-contaminated with substituted and aromatic hydrocarbons, and heavy metals. To determine the potential for microbial biodegradation the acid resin deposit and its surroundings were screened for microbial activity by soil respiration measurements. No microbial activity was found in the core deposit. However, biodegradation of hydrocarbons was possible in zones with a lower degree of contamination surrounding the deposit. An extreme acidophilic microbial community was detected close to the core deposit. With a simple ecotoxicological approach it could be shown that the pure acid resin that formed the major part of the core deposit, was toxic to the indigenous microflora due to its extremely low pH of 0-1.

Phenolic acids as bioindicators of fly ash deposit revegetation.

PubMed

Djurdjević, L; Mitrović, M; Pavlović, P; Gajić, G; Kostić, O

2006-05-01

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

High frequency and large deposition of acid fog on high elevation forest.

PubMed

Igawa, Manabu; Matsumura, Ko; Okochi, Hiroshi

2002-01-01

We have collected and analyzed fogwater on the mountainside of Mt. Oyama (1252 m) in the Tanzawa Mountains of Japan and observed the fog event frequency from the base of the mountain with a video camera. The fog event frequency increased with elevation and was observed to be present 46% of the year at the summit. The water deposition via throughfall increased with elevation because of the increase in fogwater interception and was about twice that via rain at the summit, where the air pollutant deposition via throughfall was several times that via rainwater. The dry deposition and the deposition via fogwater were dominant factors in the total ion deposition at high elevation sites. In a fog event, nitric acid, the major acid component on the mountain, is formed during the transport of the air mass from the base of the mountain along the mountainside, where gases including nitric acid deposit and are scavenged by fogwater. Therefore, high acidity caused by nitric acid and relatively low ion strength are observed in the fogwater at high elevation sites.

Wet acid deposition in Chinese natural and agricultural ecosystems: Evidence from national-scale monitoring

NASA Astrophysics Data System (ADS)

Yu, Haili; He, Nianpeng; Wang, Qiufeng; Zhu, Jianxing; Xu, Li; Zhu, Zhilin; Yu, Guirui

2016-09-01

Acid deposition in precipitation has received widespread attention. However, it is necessary to monitor the acid deposition in Chinese agricultural and natural ecosystems because data derived from traditional urban/suburban observations might overestimate it to some extent. In this study, we continuously measured the acid deposition through precipitation (pH, sulfate (SO42-), and nitrate (NO3-)) in 43 field stations from 2009 to 2014 to explore the spatial patterns and the main influencing factors of acid deposition in Chinese agricultural and natural ecosystems. The results showed that the average precipitation pH at the 43 stations varied between 4.10 and 8.25 (average: 6.2) with nearly 20% of the observation sites being subjected to acid precipitation (pH < 5.6). The average deposition of SO42- and NO3- was 115.99 and 32.93 kg ha-1 yr-1, respectively. An apparent regional difference of acid deposition in Chinese agricultural and natural ecosystems was observed, which was most serious in south and central China and less serious in northwest China, Inner Mongolia, and Qinghai-Tibet. The level of economic development and amount of precipitation could explain most of the spatial variations of pH, SO42-, and NO3- depositions. It is anticipated that acid deposition might increase further, although the current level of acid deposition in these Chinese agricultural and natural ecosystems was found to be less serious than projected from urban/suburban data. The control of energy consumption should be strengthened in future to prevent an increase of acid deposition in China.

Wet acid deposition of Chinese natural and agricultural ecosystems: Evidence from national-scale monitoring

NASA Astrophysics Data System (ADS)

Yu, H.; He, N.; Wang, Q.; Zhu, J.; Xu, L.; Zhu, Z.; Yu, G.

2016-12-01

Acid deposition in precipitation has received widespread attention. However, it is necessary to monitor the acid deposition in Chinese agricultural and natural ecosystems because data derived from traditional urban/suburban observations might overestimate it to some extent. In this study, we continuously measured the acid deposition through precipitation [pH, sulfate (SO42-), and nitrate (NO3-)] in 43 field stations from 2009 to 2014 to explore the spatial patterns of acid deposition in Chinese agricultural and natural ecosystems and to explore the main influencing factors. The results showed that the average precipitation pH at the 43 stations varied between 4.10 and 8.25 (average: 6.2) with nearly 20% of the observation sites being subjected to acid precipitation (pH < 5.6). The average deposition of SO42- and NO3- was 115.99 and 32.93 kg ha-1 yr-1, respectively. An apparent regional difference in acid deposition in Chinese agricultural and natural ecosystems was observed, which was most serious in South and Central China and less serious in North-west China, Inner Mongolia, and Qinghai-Tibet. The level of economic development and amount of precipitation could explain most of the spatial variations of pH and of SO42-, and NO3- depositions. It is anticipated that acid deposition might increase further, although the current level of acid deposition in these Chinese agricultural and natural ecosystems was found to be less serious than projected from urban/suburban data. The control of energy consumption should be strengthened in future to prevent an increase of acid deposition in China.

[Correlation between acidic materials and acid deposition in Beijing during 1997-2011].

PubMed

Chen, Yuan-yuan; Tian, He-zhong; Yang, Dong-yan; Zou, Ben-dong; Lu, Hai-feng; Lin, An-guo

2013-05-01

Based on the environment monitoring data and the ambient air quality data during the period of 1997-2011 from Beijing municipal environmental monitoring center, the correlations between primary pre-cursors of acid deposition, acidic materials and precipitation in Beijing area were analyzed in detail by taking economic development and energy mix into account. These results will be helpful for assessing the performance of environment quality improvement, as well as supplying scientific supporting information to make policies for national and local environment protection authorities. The main findings included as follows: there are significant correlations between the concentrations of NO2, NOx, and SO2 in the atmosphere, which indicated that both N and S in ambient air of Beijing came from fossil fuels combustion; acidic pollutants in the air are mainly discharged from local emission sources in Beijing, while there is no obvious correlation between S and N in wet deposition and concentrations of SO2, NO2 and NOx in the atmosphere, which demonstrated that concentrations of different ions in the acid deposition were influenced by both local sources as well as the inputs from other surrounding districts. Besides, the concentration of NO3- appeared to be correlative with the amount of motor vehicles, implying that the NOx from motor vehicles have contributed the increase of NO3- concentration of substantially.

Estimates of cloud water deposition at Mountain Acid Deposition Program sites in the Appalachian Mountains.

PubMed

Baumgardner, Ralph E; Isil, Selma S; Lavery, Thomas F; Rogers, Christopher M; Mohnen, Volker A

2003-03-01

Cloud water deposition was estimated at three high-elevation sites in the Appalachian Mountains of the eastern United States (Whiteface Mountain, NY; Whitetop Mountain, VA; and Clingman's Dome, TN) from 1994 through 1999 as part of the Mountain Acid Deposition Program (MADPro). This paper provides a summary of cloud water chemistry, cloud liquid water content, cloud frequency, estimates of cloud water deposition of sulfur and nitrogen species, and estimates of total deposition of sulfur and nitrogen at these sites. Other cloud studies in the Appalachians and their comparison to MADPro are also summarized. Whiteface Mountain exhibited the lowest mean and median concentrations of sulfur and nitrogen ions in cloud water, while Clingman's Dome exhibited the highest mean and median concentrations. This geographic gradient is partly an effect of the different meteorological conditions experienced at northern versus southern sites in addition to the difference in pollution content of air masses reaching the sites. All sites measured seasonal cloud water deposition rates of SO4(2-) greater than 50 kg/ha and NO3(-) rates of greater than 25 kg/ha. These high-elevation sites experienced additional deposition loading of SO4(2-) and NO3(-) on the order of 6-20 times greater compared with lower elevation Clean Air Status and Trends Network (CASTNet) sites. Approximately 80-90% of this extra loading is from cloud deposition.

Differences in functional traits between invasive and native Amaranthus species under simulated acid deposition with a gradient of pH levels

NASA Astrophysics Data System (ADS)

Wang, Congyan; Wu, Bingde; Jiang, Kun; Zhou, Jiawei

2018-05-01

Co-occurring invasive plant species (invaders hereafter) and natives receive similar or even the same environmental selection pressures. Thus, the differences in functional traits between natives and invaders have become widely recognized as a major driving force of the success of plant invasion. Meanwhile, increasing amounts of acid are deposited into ecosystems. Thus, it is important to elucidate the potential effects of acid deposition on the functional traits of invaders in order to better understand the potential mechanisms for the successful invasion. This study aims to address the differences in functional traits between native red amaranth (Amaranthus tricolor L.; amaranth hereafter) and invasive redroot pigweed (A. retroflexus L.; pigweed hereafter) under simulated acid deposition with a gradient of pH levels. Pigweed was significantly taller than amaranth under most treatments. The greater height of pigweed can lead to greater competitive ability for resource acquisition, particularly for sunlight. Leaf shape index of pigweed was also significantly greater than that of amaranth under all treatments. The greater leaf shape index of pigweed can enhance the efficiency of resource capture (especially sunlight capture) via adjustments to leaf shape and size. Thus, the greater height and leaf shape index of pigweed can significantly enhance its competitive ability, especially under acid deposition. Acid deposition of pH 5.6 significantly increased amaranth leaf width in the co-cultivation due to added nutrients. The pH 4.5 acid deposition treatment significantly increased the specific leaf area of amaranth in the monoculture compared with the pH 5.6 acid deposition treatment and the control. The main mechanism explaining this pattern may be due to acid deposition mediating a hormesis effect on plants, promoting plant growth. The values of the relative competition intensity between amaranth and pigweed for most functional traits were lower than zero under most

Use of stream chemistry for monitoring acidic deposition effects in the Adirondack region of New York

USGS Publications Warehouse

Lawrence, G.B.; Momen, B.; Roy, K.M.

2004-01-01

Acid-neutralizing capacity (ANC) and pH were measured weekly from October 1991 through September 2001 in three streams in the western Adirondack Mountain region of New York to identify trends in stream chemistry that might be related to changes in acidic deposition. A decreasing trend in atmospheric deposition of SO42- was observed within the region over the 10-yr period, although most of the decrease occurred between 1991 and 1995. Both ANC and pH were inversely related to flow in all streams; therefore, a trend analysis was conducted on (i) the measured values of ANC and pH and (ii) the residuals of the concentration-discharge relations. In Buck Creek, ANC increased significantly (p 0.10). In Bald Mountain Brook, ANC and residuals of ANC increased significantly (p < 0.01), although the trend was diatonic-a distinct decrease from 1991 to 1996 was followed by a distinct increase from 1996 to 2001. In Fly Pond outlet, ANC and residuals of ANC increased over the study period (p < 0.01), although the trend of the residuals resulted largely from an abrupt increase in 1997. In general, the trends observed in the three streams are similar to results presented for Adirondack lakes in a previous study, and are consistent with the declining trend in atmospheric deposition for this region, although the observed trends in ANC and pH in streams could not be directly attributed to the trends in acidic deposition.

Patterns of Forest invertebrates Along an Acidic Deposition Gradient in the Midwestern United States

Treesearch

Robert A. Haack

1996-01-01

The Ohio Corridor Study (OCS) was designed to detect possible effects of acidic deposition on oak-hickory (Quercus-Carya) forests in the midwestem United States. There was one study site in Arkansas, and two each in Illinois, Indiana, and Ohio. Estimates of total sulfate deposition have generally increased about two-fold from west (Arkansas) to east (Ohio) during the...

Do Uric Acid Deposits in Zooxanthellae Function as Eye-Spots?

PubMed Central

Yamashita, Hiroshi; Kobiyama, Atsushi; Koike, Kazuhiko

2009-01-01

The symbiosis between zooxanthellae (dinoflagellate genus Symbiodinium) and corals is a fundamental basis of tropical marine ecosystems. However the physiological interactions of the hosts and symbionts are poorly understood. Recently, intracellular crystalline deposits in Symbiodinium were revealed to be uric acid functioning for nutrient storage. This is the first exploration of these enigmatic crystalline materials that had previously been misidentified as oxalic acid, providing new insights into the nutritional strategies of Symbiodinium in oligotrophic tropical waters. However, we believe these deposits also function as eye-spots on the basis of light and electron microscopic observations of motile cells of cultured Symbiodinium. The cells possessed crystalline deposit clusters in rows with each row 100–150 nm thick corresponding to 1/4 the wavelength of light and making them suitable for maximum wave interference and reflection of light. Crystalline clusters in cells observed with a light microscope strongly refracted and polarized light, and reflected or absorbed short wavelength light. The facts that purines, including uric acid, have been identified as the main constituents of light reflectors in many organisms, and that the photoreceptor protein, opsin, was detected in our Symbiodinium strain, support the idea that uric acid deposits in Symbiodinium motile cells may function as a component of an eye-spot. PMID:19609449

Do uric acid deposits in zooxanthellae function as eye-spots?

PubMed

Yamashita, Hiroshi; Kobiyama, Atsushi; Koike, Kazuhiko

2009-07-17

The symbiosis between zooxanthellae (dinoflagellate genus Symbiodinium) and corals is a fundamental basis of tropical marine ecosystems. However the physiological interactions of the hosts and symbionts are poorly understood. Recently, intracellular crystalline deposits in Symbiodinium were revealed to be uric acid functioning for nutrient storage. This is the first exploration of these enigmatic crystalline materials that had previously been misidentified as oxalic acid, providing new insights into the nutritional strategies of Symbiodinium in oligotrophic tropical waters. However, we believe these deposits also function as eye-spots on the basis of light and electron microscopic observations of motile cells of cultured Symbiodinium. The cells possessed crystalline deposit clusters in rows with each row 100-150 nm thick corresponding to 1/4 the wavelength of light and making them suitable for maximum wave interference and reflection of light. Crystalline clusters in cells observed with a light microscope strongly refracted and polarized light, and reflected or absorbed short wavelength light. The facts that purines, including uric acid, have been identified as the main constituents of light reflectors in many organisms, and that the photoreceptor protein, opsin, was detected in our Symbiodinium strain, support the idea that uric acid deposits in Symbiodinium motile cells may function as a component of an eye-spot.

Enhanced acid rain and atmospheric deposition of nitrogen, sulfur and heavy metals in Northern China

NASA Astrophysics Data System (ADS)

Pan, Y.; Wang, Y.

2013-12-01

Atmospheric deposition is known to be important mechanism reducing air pollution. In response to the growing concern on the potential effects of the deposited material entering terrestrial and aquatic environments as well as their subsequent health effects, since 2007 we have established a 10-site monitoring network in Northern China, where particularly susceptible to severe air pollution. Wet and dry deposition was collected using an automatic wet-dry sampler. The presentation will focus on the new results of atmospheric deposition flux for a number of chemical species, such as nutrients (e.g. nitrogen and phosphorus), acidic matters (e.g. sulfur and proton), heavy metals and Polycyclic Aromatic Hydrocarbons, etc. This is to our knowledge the first detailed element budget study in the atmosphere across Northern China. We find that: (1) Over the 3 year period, 26% of precipitation events in the target area were more acid than pH 5.60 and these acidic events occurred in summer and autumn. The annual volume-weighted mean (VWM) pH value of precipitation was lower than 5.60 at most sites, which indicated the acidification of precipitation was not optimistic. The primary ions in precipitation were NH4+, Ca2+, SO42- and NO3-, with 10-sites-average concentrations of 221, 216, 216 and 80 μeq L-1, respectively. The ratio of SO42- to NO3- was 2.7; suggesting SO42- was the dominant acid component. (2) The deposited particles were neutral in general and the pH value increased from rural area to industrial and coastal sites. It is not surprising to note that the annual VWM pH value of precipitation was higher than 5.60 at three urban sites (Beijing and Tianjin mega cities) and one coastal site near the Bohai Bay, considering the fact that high buffer capacity of alkaline component, gas NH3 and mineral aerosols, at these sites compared to other places. (3) The 10-sites annual total deposition amounts for sulfur and nitrogen compounds were 60 and 65 kg N/S ha-1 yr-1

Electrophoretic deposition and electrochemical behavior of novel graphene oxide-hyaluronic acid-hydroxyapatite nanocomposite coatings

NASA Astrophysics Data System (ADS)

Li, Ming; Liu, Qian; Jia, Zhaojun; Xu, Xuchen; Shi, Yuying; Cheng, Yan; Zheng, Yufeng; Xi, Tingfei; Wei, Shicheng

2013-11-01

Novel ternary graphene oxide-hyaluronic acid-hydroxyapatite (GO-HY-HA) nanocomposite coatings were prepared on Ti substrate using anodic electrophoretic deposition (EPD). Hyaluronic acid was employed as charging additive and dispersion agent during EPD. The kinetics and mechanism of the deposition, and the microstructure of the coated samples were investigated using scanning electron microscopy, X-ray diffraction, Raman spectrum, thermo-gravimetric analysis, and microscopic Fourier transform infrared analysis. The results showed that the addition of GO sheets into the HY-HA suspensions could increase the deposition rate and inhibit cracks creation and propagation in the coatings. The corrosion resistant of the resulting samples were evaluated using potentiodynamic polarization method in simulated body fluid, and the GO-HY-HA coatings could effectively improve the anti-corrosion property of the Ti substrate.

Comparison among model estimates of critical loads of acidic deposition using different sources and scales of input data

Treesearch

T.C. McDonnell; B.J. Cosby; T.J. Sullivan; S.G. McNulty; E.C. Cohen

2010-01-01

The critical load (CL) of acidic atmospheric deposition represents the load of acidity deposited from the atmosphere to the earth’s surface at which harmful acidification effects on sensitive biological receptors are thought to occur. In this study, the CL for forest soils was estimated for 27 watersheds throughout the United States using a steady-state mass balance...

Effects of glycolic acid chemical peeling on facial pigment deposition: evaluation using novel computer analysis of digital-camera-captured images.

PubMed

Kakudo, Natsuko; Kushida, Satoshi; Suzuki, Kenji; Kusumoto, Kenji

2013-12-01

Chemical peeling is becoming increasingly popular for skin rejuvenation in dermatological cosmetic medicine. However, the improvements seen with chemical peeling are often very minor, and it is difficult to conduct a quantitative assessment of pre- and post-treatment appearance. We report the pre- and postpeeling effects for facial pigment deposition using a novel computer analysis method for digital-camera-captured images. Glycolic acid chemical peeling was performed a total of 5 times at 2-week intervals in 23 healthy women. We conducted a computer image analysis by utilizing Robo Skin Analyzer CS 50 and Clinical Suite 2.1 and then reviewed each parameter for the area of facial pigment deposition pre- and post-treatment. Parameters were pigmentation size and four pigmentation categories: little pigmentation and three levels of marked pigmentation (Lv1, 2, and 3) based on detection threshold. Each parameter was measured, and the total area of facial pigmentation was calculated. The total area of little pigmentation and marked pigmentation (Lv1) was significantly reduced. On the other hand, a significant difference was not observed for the total area of marked pigmentation Lv2 and Lv3. This suggests that glycolic acid chemical peeling has an effect on small facial pigment disposition or has an effect on light pigment deposition. As the Robo Skin Analyzer is useful for objectively quantifying and analyzing minor changes in facial skin, it is considered to be an effective tool for accumulating treatment evidence in the cosmetic and esthetic skin field. © 2013 Wiley Periodicals, Inc.

Phenolic acids as bioindicators of fly ash deposit revegetation

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

L. Djurdjevic; M. Mitrovic; P. Pavlovic

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the 'Nikola Tesla-A' thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central partmore » of the deposit towards its edges. Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.« less

Hatching success in salamanders and chorus frogs at two sites in Colorado, USA: Effects of acidic deposition and climate

USGS Publications Warehouse

Muths, E.; Campbell, D.H.; Corn, P.S.

2003-01-01

The snowpack in the vicinity of the Mount Zirkel Wilderness Area is among the most acidic in the western United States. We analyzed water chemistry and examined hatching success in tiger salamanders and chorus frogs at ponds there and at nearby Rabbit Ears Pass (Dumont) to determine whether acid deposition affects amphibians or their breeding habitats at these potentially sensitive locations. We found a wide range of acid neutralizing capacity among ponds within sites; the minimum pH recorded during the experiment was 5.4 at one of 12 ponds with all others at pH ??? 5.7. At Dumont, hatching success for chorus frogs was greater in ponds with low acid neutralizing capacity; however, lowest pHs were >5.8. At current levels of acid deposition, weather and pond characteristics are likely more important than acidity in influencing hatching success in amphibian larvae at these sites.

[Current situation and impact factors of acid deposition in main cites of Shandong Province].

PubMed

Jia, Hong-yu; Zhang, Qiao-xian; Deng, Hong-bing; Zhao, Jing-zhu; Mu, Jin-bo; Zhang, De-zhi

2006-12-01

Based on the monitoring data for years in Shandong Province, current situation of acid rain in every city was assessed, and the temporal distribution of the dry, wet and total sulfur deposition in Jinan and Qingdao were studied. The results showed that Qingdao which had the largest precipitation acidity was the single city whose annul average precipitation pH was below 5. 60. The precipitation acidities in the main cities of Shandong Province were in a descent tendency. The total sulfur desposition in Jinan and Qingdao was basically stable or in a descent tendency, but also reached 10 t/(km(2)x a) or so. Among the total sulfur deposition flux, the dry deposition of sulfur had the greater contribution, and the contribution of SO2 dry deposition was higher than that of SO42- dry deposition. By analyzing the relation between the precipitation acidity and the SO2 discharge intensity, soil acidity and meteorological condition, the impact factors of acid precipitation in the cities of Shandong Province were revealed.

Soil calcium status and the response of stream chemistry to changing acidic deposition rates

USGS Publications Warehouse

Lawrence, G.B.; David, M.B.; Lovett, Gary M.; Murdoch, Peter S.; Burns, Douglas A.; Stoddard, J.L.; Baldigo, Barry P.; Porter, J.H.; Thompson, A.W.

1999-01-01

Despite a decreasing trend in acidic deposition rates over the past two to three decades, acidified surface waters in the northeastern United States have shown minimal changes. Depletion of soil Ca pools has been suggested as a cause, although changes in soil Ca pools have not been directly related to long-term records of stream chemistry. To investigate this problem, a comprehensive watershed study was conducted in the Neversink River Basin, in the Catskill Mountains of New York, during 1991-1996. Spatial variations of atmospheric deposition, soil chemistry, and stream chemistry were evaluated over an elevation range of 817-1234 m to determine whether these factors exhibited elevational patterns. An increase in atmospheric deposition of SO4 with increasing elevation corresponded with upslope decreases of exchangeable soil base concentrations and acid-neutralizing capacity of stream water. Exchangeable base concentrations in homogeneous soil incubated within the soil profile for one year also decreased with increasing elevation. An elevational gradient in precipitation was not observed, and effects of a temperature gradient on soil properties were not detected. Laboratory leaching experiments with soils from this watershed showed that (1) concentrations of Ca in leachate increased as the concentrations of acid anions in added solution increased, and (2) the slope of this relationship was positively correlated with base saturation. Field and laboratory soil analyses are consistent with the interpretation that decreasing trends in acid-neutralizing capacity in stream water in the Neversink Basin, dating back to 1984, are the result of decreases in soil base saturation caused by acidic deposition.

RESULTS FROM THE MOUNTAIN ACID DEPOSITION PROGRAM

EPA Science Inventory

The Mountain Acid Deposition Program (MADPro) was initiated in 1993 as part of the research necessary to support the objectives of the Clean Air Status and Trends Network (CASTNet), which was created to address the. requirements of the Clean Air Act Amendments (CAAA). The main ob...

A decade of monitoring at Swiss Long-Term Forest Ecosystem Research (LWF) sites: can we observe trends in atmospheric acid deposition and in soil solution acidity?

PubMed

Pannatier, Elisabeth Graf; Thimonier, Anne; Schmitt, Maria; Walthert, Lorenz; Waldner, Peter

2011-03-01

Trends in atmospheric acid deposition and in soil solution acidity from 1995 or later until 2007 were investigated at several forest sites throughout Switzerland to assess the effects of air pollution abatements on deposition and the response of the soil solution chemistry. Deposition of the major elements was estimated from throughfall and bulk deposition measurements at nine sites of the Swiss Long-Term Forest Ecosystem Research network (LWF) since 1995 or later. Soil solution was measured at seven plots at four soil depths since 1998 or later. Trends in the molar ratio of base cations to aluminum (BC/Al) in soil solutions and in concentrations and fluxes of inorganic N (NO(3)-N + NH(4)-N), sulfate (SO(4)-S), and base cations (BC) were used to detect changes in soil solution chemistry. Acid deposition significantly decreased at three out of the nine study sites due to a decrease in total N deposition. Total SO(4)-S deposition decreased at the nine sites, but due to the relatively low amount of SO(4)-S load compared to N deposition, it did not contribute to decrease acid deposition significantly. No trend in total BC deposition was detected. In the soil solution, no trend in concentrations and fluxes of BC, SO(4)-S, and inorganic N were found at most soil depths at five out of the seven sites. This suggests that the soil solution reacted very little to the changes in atmospheric deposition. A stronger reduction in base cations compared to aluminum was detected at two sites, which might indicate that acidification of the soil solution was proceeding faster at these sites.

Acidic deposition, cation mobilization, and biochemical indicators of stress in healthy red spruce

Treesearch

Walter C. Shortle; Kevin T. Smith; Rakesh Minocha; Gregory B. Lawrence; Mark B. David

1997-01-01

Dendrochemical and biochemical markers link stress in apparently healthy red spruce trees (Picea rubens) to acidic deposition. Acidic deposition to spruce forests of the northeastern USA increased sharply during the 1960s. Previous reports related visible damage of trees at high elevations to root and soil processes. In this report, dendrochemical...

Image analysis of epicuticular damage to foliage caused by dry deposition of the air pollutant nitric acid.

PubMed

Padgett, Pamela E; Parry, Sally D; Bytnerowicz, Andrzej; Heath, Robert L

2009-01-01

Nitric acid vapor is produced by the same photochemical processes that produce ozone. In the laboratory, concentrated nitric acid is a strong acid and a powerful oxidant. In the environment, where the concentrations are much lower, it is an innocuous source of plant nitrogen. As an air pollutant, which mode of action does dry deposition of nitric acid follow? We investigated the effects of dry deposition of nitric acid on the foliage of four tree species native to the western United States. A novel controlled environment, fumigation system enabled a four-week exposure at concentrations consistent with ambient diurnal patterns. Scanning electron microscopy and automated image analysis revealed changes in the epicuticular wax layer during fumigation. Exposure to nitric acid resulted in a reproducible suite of damage symptoms that increased with increasing dose. Each tree species tested exhibited a unique set of damage features, including cracks, lesions, and conformation changes to epicuticular crystallite structures. Dry deposition of atmospheric nitric acid caused substantial perturbation to the epicuticular surface of all four tree species investigated, consistent with the chemical oxidation of epicuticular waxes. Automated image analysis eliminated many biases that can trouble microscopy studies. Trade names and commercial enterprises or products are mentioned solely for information. No endorsements by the U.S. Department of Agriculture are implied.

Acid deposition and assessment of its critical load for the environmental health of waterbodies in a subtropical watershed, China

NASA Astrophysics Data System (ADS)

Jia, Junjie; Gao, Yang

2017-12-01

Atmospheric acidic deposition in subtropical watersheds poses an environmental risk of causing acidification of aquatic ecosystems. In this study, we evaluated the frequency of acid deposition in a subtropical forest ecosystem and the associated critical loads of acidity for a sensitive aquatic ecosystem. We found that out of 132 rainfall events, 33(25%) were acidic rainfall occurrences. Estimated wet acid deposition (2282.78 eq·ha-1·yr-1), consistent with SO42- and NH4+ deposition, was high in spring and summer and low in autumn and winter. Waterbodies surrounded by mixed wood and citrus orchard experience severe acidification, mostly from S deposition because acidic deposition exceeds the corresponding critical loads of acidity. Modifications that take acid rain deposition into consideration are needed for land-use and agricultural management strategies to improve the environmental health of waterbodies in subtropical watersheds.

Effects and quantification of acid runoff from sulfide-bearing rock deposited during construction of Highway E18, Norway

USGS Publications Warehouse

Hindar, Atle; Nordstrom, D. Kirk

2015-01-01

The Highway E18 between the cities of Grimstad and Kristiansand, southern Norway, constructed in the period 2006–2009, cuts through sulfide-bearing rock. The geology of this area is dominated by slowly-weathering gneiss and granites, and oxidation of fresh rock surfaces can result in acidification of surface water. Sulfide-containing rock waste from excavations during construction work was therefore deposited in three waste rock deposits off-site. The deposits consist of 630,000–2,360,000 metric tons of waste rock material. Shell sand and limestone gravel were added in layers in adequate amounts to mitigate initial acid runoff in one of the deposits. The shell sand addition was not adequate in the two others. The pH in the effluents from these two was reduced from 4.9–6.5 to 4.0–4.6, and Al concentrations increased from below 0.4 mg/L to 10–20 mg/L. Stream concentrations of trace metals increased by a factor of 25–400, highest for Ni, and then in decreasing order for Co, Mn, Cd, Zn and Cu. Concentrations of As, Cr and Fe remained unchanged. Ratios of Co/Ni and Cd/Zn indicate that the metal sources for these pair of metals are sphalerite and pyrite, respectively. Based on surveys and established critical limits for Al, surface waters downstream became toxic to fish and invertebrates. The sulfur release rates were remarkably stable in the monitoring period at all three sites. Annual sulfur release was 0.1–0.4% of the total amount of sulfur in the deposit, indicating release periods of 250–800 years. Precipitates of Al-hydroxysulfates, well-known from mining sites, were found at the base of the deposits, in streams and also along the ocean shore-line. The effects of added neutralization agents in the deposits and in treatment areas downstream gradually decreased, as indicated by reduced stream pH over time. Active measures are needed to avoid harmful ecological effects in the future.

Acid deposition effects on forest composition and growth on the Monongahela National Forest, West Virginia

Treesearch

P.E. Elias; J.A. Burger; M.B. Adams

2009-01-01

The northern and central Appalachian forests are subject to high levels of atmospheric acid deposition (AD), which has been shown in some forests to negatively impact forest growth as well as predispose the forest system to damage from secondary stresses. The purpose of this study was to evaluate the possible contribution of AD to changes in composition and...

Basal area growth of sugar maple in relation to acid deposition, stand health, and soil nutrients.

PubMed

Duchesne, Louis; Ouimet, Rock; Houle, Daniel

2002-01-01

Previous studies have shown in noncalcareous soils that acid deposition may have increased soil leaching of basic cations above the input rate from soil weathering and atmospheric depositions. This phenomenon may have increased soil acidity levels, and, as a consequence, may have reduced the availability of these essential nutrients for forest growth. Fourteen plots of the Forest Ecosystem Research and Monitoring Network in Québec were used to examine the relation between post-industrial growth trends of sugar maple (Acer saccharum Marsh.) and acid deposition (N and S), stand decline rate, and soil exchangeable nutrient concentrations. Atmospheric N and S deposition and soil exchangeable acidity were positively associated with stand decline rate, and negatively with the average tree basal area increment trend. The growth rate reduction reached on average 17% in declining stands compared with healthy ones. The results showed a significant sugar maple growth rate reduction since 1960 on acid soils. The appearance of the forest decline phenomenon in Québec can be attributed, at least partially, to soil acidification and acid deposition levels.

MOUNTAIN ACID DEPOSITION PROGRAM (MADPRO): CLOUD DEPOSITION TO THE APPALACHIAN MOUNTAINS, 1994 THROUGH 1999

EPA Science Inventory

The mountain Acid Deposition Program (MADPro) was initiated in 1993 as part of the research necessary to support the objectives of the Clean Air Status and Trends Network (CASTNet), which was created to address the requirements of the Clean Air Act Amendments (CAAA). The two ma...

Precipitation-chemistry measurements from the California Acid Deposition Monitoring Program, 1985-1990

USGS Publications Warehouse

Blanchard, Charles L.; Tonnessen, Kathy A.

1993-01-01

The configuration of the California Acid Deposition Monitoring Program (CADMP) precipitation network is described and quality assurance results summarized. Comparison of CADMP and the National Acid Deposition Program/National Trends Network (NADP/NTN) data at four parallel sites indicated that mean depth-weighted differences were less than 3 μeq ℓ−1 for all ions, being statistically significant for ammonium, sulfate and hydrogen ion. These apparently small differences were 15–30% of the mean concentrations of ammonium, sulfate and hydrogen ion. Mean depth-weighted concentrations and mass deposition rates for the period 1985–1990 are summarized; the latter were highest either where concentrations or precipitation depths were relatively high.

Influence of boric acid (H3BO3) concentration on the physical properties of electrochemical deposited nickel (Ni) nanowires

NASA Astrophysics Data System (ADS)

Kananathan, J.; Sofiah, A. G. N.; Samykano, M.; Ulakanathan, S.; Lah, N. A. C.; Harun, W. S. W.; Sudhakar, K.; Kadirgama, K.; Ngui, W. K.; Siregar, J. P.

2017-10-01

Authors have investigated the influence of the stabilizer (Boric Acid) concentration during the template-assisted electrochemical deposition of Nickel (Ni) nanowires in Anodic Alumina Oxide (AAO) templates. The synthesis was performed using Ni Sulfate Hexahydrate (NiSO4.6H2O) as metal salts and Boric Acid (H3BO3) as a stabilizer. The mixture of both solutions creates electrolyte and utilized for the electrochemical deposition of Ni nanowires. During the experiment, the boric acid concentration varied between 5 g/L, 37.5 g/L and 60 g/L with a deposition temperature of 80 °C (constant). After the electrochemical deposition process, AAO templates were cleaned with distilled water before dissolution in Sodium Hydroxide (NaOH) solution to obtain the freestanding Ni nanowires. Physical properties of the synthesized Ni nanowires were analyzed using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDX) and X-ray Diffraction (XRD). The physical properties of obtained Ni nanowires has eloborated by taking into account the effect of boric acid concentration on the surface morphology, growth length, elemental composition and crystal orientation crystal of the synthesized nickel nanowires. The finding exposes that the boric acid concentration does not influence all aspects in the physicals properties of the synthesized Ni nanowires. The boric acid concentration did not affect the surface texture and crystal orientation. However, shorter Ni nanowires obtained as the concentration of boric acid increased.

EVALUATION OF ACID DEPOSITION MODELS USING PRINCIPAL COMPONENT SPACES

EPA Science Inventory

An analytical technique involving principal components analysis is proposed for use in the evaluation of acid deposition models. elationships among model predictions are compared to those among measured data, rather than the more common one-to-one comparison of predictions to mea...

Long-term temporal trends and spatial patterns in the acid-base chemistry of lakes in the Adirondack region of New York in response to decreases in acidic deposition

NASA Astrophysics Data System (ADS)

Driscoll, Charles T.; Driscoll, Kimberley M.; Fakhraei, Habibollah; Civerolo, Kevin

2016-12-01

We examined the response of lake water chemistry in the Adirondack Mountains of New York State, USA to decreases in acid deposition. Striking declines in the concentrations and fluxes of sulfate and hydrogen ion in wet deposition have been observed since the late 1970s, while significant decreases in nitrate have been evident since the early 2000s. Decreases in estimated dry sulfur and nitrate deposition have also occurred in the Adirondacks, but with no change in dry to wet deposition ratios. These patterns follow long-term decreases in anthropogenic emissions of sulfur dioxide and nitrogen oxides in the U.S. over the same interval. All of the 48 lakes monitored through the Adirondack Long-Term Monitoring program since 1992 have exhibited significant declines in sulfate concentrations, consistent with reductions in atmospheric deposition of sulfur. Nitrate concentrations have also significantly diminished at variable rates in many (33 of 48) lakes. Decreases in concentrations of sulfate plus nitrate (48 of 48) in lakes have driven widespread increases in acid neutralizing capacity (ANC; 42 of 48) and lab pH (33 of 48), and decreases in the toxic fraction, inorganic monomeric Al (45 of 48). Coincident with decreases in acid deposition, concentrations of dissolved organic carbon (DOC) have also increased in some (29 of 48) lakes. While recovery from elevated acid deposition is evident across Adirondack lakes, highly sensitive and impacted mounded seepages lakes and thin till drainage lakes are recovering most rapidly. Future research might focus on how much additional recovery could be achieved given the current deposition relative to future deposition anticipated under the Clean Power Plan, ecosystem effects of increased mobilization of dissolved organic matter, and the influence of changing climate on recovery from acidification.

Effect of Enhancers on in vitro and in vivo Skin Permeation and Deposition of S-Methyl-L-Methionine.

PubMed

Kim, Ki Taek; Kim, Ji Su; Kim, Min-Hwan; Park, Ju-Hwan; Lee, Jae-Young; Lee, WooIn; Min, Kyung Kuk; Song, Min Gyu; Choi, Choon-Young; Kim, Won-Serk; Oh, Hee Kyung; Kim, Dae-Duk

2017-07-01

S-methyl- L -methionine (SMM), also known as vitamin U, is commercially available as skin care cosmetic products for its wound healing and photoprotective effects. However, the low skin permeation expected of SMM due to its hydrophilic nature with a log P value of -3.3, has not been thoroughly addressed. The purpose of this study thus was to evaluate the effect of skin permeation enhancers on the skin permeation/deposition of SMM. Among the enhancers tested for the in vitro skin permeation and deposition of SMM, oleic acid showed the most significant enhancing effect. Moreover, the combination of oleic acid and ethanol further enhanced in vitro permeation and deposition of SMM through hairless mouse skin. Furthermore, the combination of oleic acid and ethanol significantly increased the in vivo deposition of SMM in the epidermis/dermis for 12 hr, which was high enough to exert a therapeutic effect. Therefore, based on the in vitro and in vivo studies, the combination of oleic acid and ethanol was shown to be effective in improving the topical skin delivery of SMM, which may be applied in the cosmetic production process for SMM.

Effect of Enhancers on in vitro and in vivo Skin Permeation and Deposition of S-Methyl-l-Methionine

PubMed Central

Kim, Ki Taek; Kim, Ji Su; Kim, Min-Hwan; Park, Ju-Hwan; Lee, Jae-Young; Lee, WooIn; Min, Kyung Kuk; Song, Min Gyu; Choi, Choon-Young; Kim, Won-Serk; Oh, Hee Kyung; Kim, Dae-Duk

2017-01-01

S-methyl-l-methionine (SMM), also known as vitamin U, is commercially available as skin care cosmetic products for its wound healing and photoprotective effects. However, the low skin permeation expected of SMM due to its hydrophilic nature with a log P value of −3.3, has not been thoroughly addressed. The purpose of this study thus was to evaluate the effect of skin permeation enhancers on the skin permeation/deposition of SMM. Among the enhancers tested for the in vitro skin permeation and deposition of SMM, oleic acid showed the most significant enhancing effect. Moreover, the combination of oleic acid and ethanol further enhanced in vitro permeation and deposition of SMM through hairless mouse skin. Furthermore, the combination of oleic acid and ethanol significantly increased the in vivo deposition of SMM in the epidermis/dermis for 12 hr, which was high enough to exert a therapeutic effect. Therefore, based on the in vitro and in vivo studies, the combination of oleic acid and ethanol was shown to be effective in improving the topical skin delivery of SMM, which may be applied in the cosmetic production process for SMM. PMID:28274096

Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids.

PubMed

Lawrence, G B; Sutherland, J W; Boylen, C W; Nierzwicki-Bauer, S W; Momen, B; Baldigo, B P; Simonin, H A

2007-01-01

Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is toxic to many forms of aquatic biota, are also altered by organic acids. However, when inorganic Al concentrations are plotted against ANC (the sum of Ca2+, Mg2+, Na+, and K+, minus S042-, N03-, and Cl-), a distinct threshold for Al mobilization becomes apparent. If the concentration of strong organic anions is included as a negative component of ANC, the threshold occurs at an ANC value of approximately zero, the value expected from theoretical charge balance constraints. This adjusted ANC is termed the base-cation surplus. The threshold relationship between the base-cation surplus and Al was shown with data from approximately 200 streams in the Adirondack region of New York, during periods with low and high dissolved organic carbon concentrations, and for an additional stream from the Catskill region of New York. These results indicate that (1) strong organic anions can contribute to the mobilization of inorganic Al in combination with SO42- and N03-, and (2) the presence of inorganic Al in surface waters is an unambiguous indication of acidic deposition effects.

The effect of pomegranate seed oil and grapeseed oil on cis-9, trans-11 CLA (rumenic acid), n-3 and n-6 fatty acids deposition in selected tissues of chickens.

PubMed

Białek, A; Białek, M; Lepionka, T; Kaszperuk, K; Banaszkiewicz, T; Tokarz, A

2018-04-23

The aim of this study was to determine whether diet modification with different doses of grapeseed oil or pomegranate seed oil will improve the nutritive value of poultry meat in terms of n-3 and n-6 fatty acids, as well as rumenic acid (cis-9, trans-11 conjugated linoleic acid) content in tissues diversified in lipid composition and roles in lipid metabolism. To evaluate the influence of applied diet modification comprehensively, two chemometric methods were used. Results of cluster analysis demonstrated that pomegranate seed oil modifies fatty acids profile in the most potent way, mainly by an increase in rumenic acid content. Principal component analysis showed that regardless of type of tissue first principal component is strongly associated with type of deposited fatty acid, while second principal component enables identification of place of deposition-type of tissue. Pomegranate seed oil seems to be a valuable feed additive in chickens' feeding. © 2018 Blackwell Verlag GmbH.

Aluminum toxicity risk reduction as a result of reduced acid deposition in Adirondack lakes and ponds.

PubMed

Michelena, Toby M; Farrell, Jeremy L; Winkler, David A; Goodrich, Christine A; Boylen, Charles W; Sutherland, James W; Nierzwicki-Bauer, Sandra A

2016-11-01

In 1990, the US Congress amended the Clean Air Act (CAA) to reduce regional-scale ecosystem degradation from SO x and NO x emissions which have been responsible for acid deposition in regions such as the Adirondack Mountains of New York State. An ecosystem assessment project was conducted from 1994 to 2012 by the Darrin Fresh Water Institute to determine the effect of these emission reduction policies on aquatic systems. The project investigated water chemistry and biota in 30 Adirondack lakes and ponded waters. Although regulatory changes made in response to the 1990 CAA amendments resulted in a reduction of acid deposition within the Adirondacks, the ecosystem response to these reductions is complicated. A statistical analysis of SO 4 , pH, Al, and DOC data collected during this project demonstrates positive change in response to decreased deposition. The changes in water chemistry also have lowered the risk of Al toxicity to brook trout (Salvelinus fontinalis [Mitchill]), which allowed the re-introduction of this species to Brooktrout Lake from which it had been extirpated. However, pH and labile aluminum (Al im ) fluctuate and are not strongly correlated to changes in acid deposition. As such, toxicity to S. fontinalis also is cyclic and provides rationale for the difficulties inherent in re-establishing resident populations in impacted aquatic environments. Overall, aquatic ecosystems of the Adirondacks show a positive response to reduced deposition driven by changes in environmental policy, but the response is more complex and indicates an ecosystem-wide interaction between aquatic and watershed components of the ecosystem.

3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid

PubMed Central

Assaud, Loïc; Monyoncho, Evans; Pitzschel, Kristina; Allagui, Anis; Petit, Matthieu; Hanbücken, Margrit

2014-01-01

Summary Three-dimensionally (3D) nanoarchitectured palladium/nickel (Pd/Ni) catalysts, which were prepared by atomic layer deposition (ALD) on high-aspect-ratio nanoporous alumina templates are investigated with regard to the electrooxidation of formic acid in an acidic medium (0.5 M H2SO4). Both deposition processes, Ni and Pd, with various mass content ratios have been continuously monitored by using a quartz crystal microbalance. The morphology of the Pd/Ni systems has been studied by electron microscopy and shows a homogeneous deposition of granularly structured Pd onto the Ni substrate. X-ray diffraction analysis performed on Ni and NiO substrates revealed an amorphous structure, while the Pd coating crystallized into a fcc lattice with a preferential orientation along the [220]-direction. Surface chemistry analysis by X-ray photoelectron spectroscopy showed both metallic and oxide contributions for the Ni and Pd deposits. Cyclic voltammetry of the Pd/Ni nanocatalysts revealed that the electrooxidation of HCOOH proceeds through the direct dehydrogenation mechanism with the formation of active intermediates. High catalytic activities are measured for low masses of Pd coatings that were generated by a low number of ALD cycles, probably because of the cluster size effect, electronic interactions between Pd and Ni, or diffusion effects. PMID:24605281

Wetlands serve as natural sources for improvement of stream ecosystem health in regions affected by acid deposition

USGS Publications Warehouse

Pound, Katrina L; Lawrence, Gregory B.; Passy, Sophia I.

2013-01-01

For over 40 years, acid deposition has been recognized as a serious international environmental problem, but efforts to restore acidified streams and biota have had limited success. The need to better understand the effects of different sources of acidity on streams has become more pressing with the recent increases in surface water organic acids, or 'brownification' associated with climate change and decreased inorganic acid deposition. Here, we carried out a large scale multi-seasonal investigation in the Adirondacks, one of the most acid-impacted regions in the United States, to assess how acid stream producers respond to local and watershed influences and whether these influences can be used in acidification remediation. We explored the pathways of wetland control on aluminum chemistry and diatom taxonomic and functional composition. We demonstrate that streams with larger watershed wetlands have higher organic content, lower concentrations of acidic anions, and lower ratios of inorganic to organic monomeric aluminum, all beneficial for diatom biodiversity and guilds producing high biomass. Although brownification has been viewed as a form of pollution, our results indicate that it may be a stimulating force for biofilm producers with potentially positive consequences for higher trophic levels. Our research also reveals that the mechanism of watershed control of local stream diatom biodiversity through wetland export of organic matter is universal in running waters, operating not only in hard streams, as previously reported, but also in acid streams. Our findings that the negative impacts of acid deposition on Adirondack stream chemistry and biota can be mitigated by wetlands have important implications for biodiversity conservation and stream ecosystem management. Future acidification research should focus on the potential for wetlands to improve stream ecosystem health in acid-impacted regions and their direct use in stream restoration, for example, through

Responses of soil N-fixing bacteria communities to invasive plant species under different types of simulated acid deposition

NASA Astrophysics Data System (ADS)

Wang, Congyan; Zhou, Jiawei; Jiang, Kun; Liu, Jun; Du, Daolin

2017-06-01

Biological invasions have incurred serious threats to native ecosystems in China, and soil N-fixing bacteria communities (SNB) may play a vital role in the successful plant invasion. Meanwhile, anthropogenic acid deposition is increasing in China, which may modify or upgrade the effects that invasive plant species can cause on SNB. We analyzed the structure and diversity of SNB by means of new generation sequencing technology in soils with different simulated acid deposition (SAD), i.e., different SO4 2- to NO3 - ratios, and where the invasive ( Amaranthus retroflexus L.) and the native species ( Amaranthus tricolor L.) grew mixed or isolated for 3 months. A. retroflexus itself did not exert significant effects on the diversity and richness of SNB but did it under certain SO4 2- to NO3 - ratios. Compared to soils where the native species grew isolated, the soils where the invasive A. retroflexus grew isolated showed lower relative abundance of some SNB classes under certain SAD treatments. Some types of SAD can alter soil nutrient content which in turn could affect SNB diversity and abundance. Specifically, greater SO4 2- to NO3 - ratios tended to have more toxic effects on SNB likely due to the higher exchange capacity of hydroxyl groups (OH-) between SO4 2- and NO3 -. As a conclusion, it can be expected a change in the structure of SNB after A. retroflexus invasion under acid deposition rich in sulfuric acid. This change may create a plant soil feedback favoring future A. retroflexus invasions.

Responses of soil N-fixing bacteria communities to invasive plant species under different types of simulated acid deposition.

PubMed

Wang, Congyan; Zhou, Jiawei; Jiang, Kun; Liu, Jun; Du, Daolin

2017-06-01

Biological invasions have incurred serious threats to native ecosystems in China, and soil N-fixing bacteria communities (SNB) may play a vital role in the successful plant invasion. Meanwhile, anthropogenic acid deposition is increasing in China, which may modify or upgrade the effects that invasive plant species can cause on SNB. We analyzed the structure and diversity of SNB by means of new generation sequencing technology in soils with different simulated acid deposition (SAD), i.e., different SO 4 2- to NO 3 - ratios, and where the invasive (Amaranthus retroflexus L.) and the native species (Amaranthus tricolor L.) grew mixed or isolated for 3 months. A. retroflexus itself did not exert significant effects on the diversity and richness of SNB but did it under certain SO 4 2- to NO 3 - ratios. Compared to soils where the native species grew isolated, the soils where the invasive A. retroflexus grew isolated showed lower relative abundance of some SNB classes under certain SAD treatments. Some types of SAD can alter soil nutrient content which in turn could affect SNB diversity and abundance. Specifically, greater SO 4 2- to NO 3 - ratios tended to have more toxic effects on SNB likely due to the higher exchange capacity of hydroxyl groups (OH - ) between SO 4 2- and NO 3 - . As a conclusion, it can be expected a change in the structure of SNB after A. retroflexus invasion under acid deposition rich in sulfuric acid. This change may create a plant soil feedback favoring future A. retroflexus invasions.

Intensified Vegetation Water Use due to Soil Calcium Leaching under Acid Deposition

NASA Astrophysics Data System (ADS)

Lanning, M.; Wang, L.; Scanlon, T. M.; Vadeboncoeur, M. A.; Adams, M. B.; Epstein, H. E.; Druckenbrod, D.

2017-12-01

Despite the important role vegetation plays in the global water cycle, the exact controls of vegetation water use, especially the role of soil biogeochemistry, remain elusive. Nitrate and sulfate deposition from fossil fuel burning has caused significant soil acidification, leading to the leaching of soil base cations. From a physiological perspective, plants require various soil cations as signaling and regulatory ions as well as integral parts of structural molecules; a depletion of soil cations can cause reduced productivity and abnormal responses to environmental change. A deficiency in calcium could also potentially prolong stomatal opening, leading to increased transpiration until enough calcium had been acquired to stimulate stomatal closure. Based on the plant physiology and the nature of acidic deposition, we hypothesize that depletion of the soil calcium supply, induced by acid deposition, would intensify vegetation water use at the watershed scale. We tested this hypothesis by analyzing a long-term and unique data set (1989-2012) of soil lysimeter data along with stream flow and evapotranspiration data at the Fernow Experimental Forest. We show that depletion of soil calcium by acid deposition can intensify vegetation water use ( 10% increase in evapotranspiration and depletion in soil water) for the first time. These results are critical to understanding future water availability, biogeochemical cycles, and surficial energy flux and may help reduce uncertainties in terrestrial biosphere models.

Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids

USGS Publications Warehouse

Lawrence, G.B.; Sutherland, J.W.; Boylen, C.W.; Nierzwicki-Bauer, S. W.; Momen, B.; Baldigo, Barry P.; Simonin, H.A.

2007-01-01

Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is toxic to many forms of aquatic biota, are also altered by organic acids. However, when inorganic Al concentrations are plotted against ANC (the sum of Ca2+, Mg 2+, Na+, and K+, minus SO42-, NO3-, and Cl-), a distinct threshold for Al mobilization becomes apparent. If the concentration of strong organic anions is included as a negative component of ANC, the threshold occurs at an ANC value of approximately zero, the value expected from theoretical charge balance constraints. This adjusted ANC is termed the base-cation surplus. The threshold relationship between the base-cation surplus and Al was shown with data from approximately 200 streams in the Adirondack region of New York, during periods with low and high dissolved organic carbon concentrations, and for an additional stream from the Catskill region of New York. These results indicate that (1) strong organic anions can contribute to the mobilization of inorganic Al in combination with SO42- and NO 3-, and (2) the presence of inorganic Al in surface waters is an unambiguous indication of acidic deposition effects. ?? 2007 American Chemical Society.

Amino acid geochemistry of fossil bones from the Rancho La Brea asphalt deposit, California

USGS Publications Warehouse

McMenamin, M.A.S.; Blunt, D.J.; Kvenvolden, K.A.; Miller, S.E.; Marcus, L.F.; Pardi, R.R.

1982-01-01

Low aspartic acid d:l ratios and modern collagenlike concentration values indicate that amino acids in bones from the Rancho La Brea asphalt deposit, Los Angeles, California are better preserved than amino acids in bones of equivalent age that have not been preserved in asphalt. Amino acids were recovered from 10 Rancho La Brea bone samples which range in age from less than 200 to greater than 36,000 yr. The calibrated rates of aspartic acid racemization range from 2.1 to 5.0 ?? 10-6yr-1. Although this wide range of rate constants decreases the level of confidence for age estimates, use of the larger rate constant of 5.0 ?? 10-6yr-1 provides minimum age estimates which fit the known stratigraphic and chronologic records of the Rancho La Brea deposits. ?? 1982.

Salicylic acid deposition from wash-off products: comparison of in vivo and porcine deposition models.

PubMed

Davies, M A

2015-10-01

Salicylic acid (SA) is a widely used active in anti-acne face wash products. Only about 1-2% of the total dose is actually deposited on skin during washing, and more efficient deposition systems are sought. The objective of this work was to develop an improved method, including data analysis, to measure deposition of SA from wash-off formulae. Full fluorescence excitation-emission matrices (EEMs) were acquired for non-invasive measurement of deposition of SA from wash-off products. Multivariate data analysis methods - parallel factor analysis and N-way partial least-squares regression - were used to develop and compare deposition models on human volunteers and porcine skin. Although both models are useful, there are differences between them. First, the range of linear response to dosages of SA was 60 μg cm(-2) in vivo compared to 25 μg cm(-2) on porcine skin. Second, the actual shape of the SA band was different between substrates. The methods employed in this work highlight the utility of the use of EEMs, in conjunction with multivariate analysis tools such as parallel factor analysis and multiway partial least-squares calibration, in determining sources of spectral variability in skin and quantification of exogenous species deposited on skin. The human model exhibited the widest range of linearity, but porcine model is still useful up to deposition levels of 25 μg cm(-2) or used with nonlinear calibration models. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Acid rain and its environmental effects: Recent scientific advances

NASA Astrophysics Data System (ADS)

Burns, Douglas A.; Aherne, Julian; Gay, David A.; Lehmann, Christopher M. B.

2016-12-01

The term 'acid rain' refers to atmospheric deposition of acidic constituents that impact the earth as rain, snow, particulates, gases, and vapor. Acid rain was first recognized by Ducros (1845) and subsequently described by the English chemist Robert Angus Smith (Smith, 1852) whose pioneering studies linked the sources to industrial emissions and included early observations of deleterious environmental effects (Smith, 1872). Smith's work was largely forgotten until the mid-20th century when observations began to link air pollution to the deposition of atmospheric sulfate (SO42-) and other chemical constituents, first near the metal smelter at Sudbury, Ontario, Canada, and later at locations in Europe, North America, and Australia (Gorham, 1961). Our modern understanding of acid rain as an environmental problem caused largely by regional emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) stems from observations in the 1960s and early 1970s in Sweden by Svante Odén (Odén, 1976), and in North America by Gene Likens and colleagues (Likens and Bormann, 1974). These scientists and many who followed showed the link to emissions from coal-fired power plants and other industrial sources, and documented the environmental effects of acid rain such as the acidification of surface waters and toxic effects on vegetation, fish, and other biota.

Acid deposition sensitivity map of the Southern Appalachian Assessment area; Virginia, North Carolina, South Carolina, Tennessee, Georgia, and Alabama

USGS Publications Warehouse

Pepper, John D.; Grosz, Andrew E.; Kress, Thomas H.; Collins, Thomas K.; Kappesser, Gary B.; Huber, Cindy M.; Webb, James R.

1995-01-01

Project Summary: The following digital product represents the Acid Deposition Sensitivity of the Southern Appalachian Assessment Area. Areas having various susceptibilities to acid deposition from air pollution are designated on a three tier ranking in the region of the Southern Appalachian Assessment (SAA). The assessment is being conducted by Federal agencies that are members of the Southern Appalachian Man and Biosphere (SAMAB) Cooperative. Sensitivities to acid deposition, ranked high, medium, and low are assigned on the basis of bedrock compositions and their associated soils, and their capacities to neutralize acid precipitation.

A modified approach for estimating the aquatic critical load of acid deposition in northern Saskatchewan, Canada

NASA Astrophysics Data System (ADS)

Whitfield, Colin J.; Mowat, Aidan C.; Scott, Kenneth A.; Watmough, Shaun A.

2016-12-01

Acid-sensitive ecosystems are found in northern Saskatchewan, which lies downwind of major sulphur (S) and nitrogen (N) emissions sources associated with the oil sands extraction industry. In order to protect these ecosystems against acidification, tolerance to acid deposition must be quantified. The suitability of the central empirical relationship used in the Steady-State Water Chemistry (SSWC) model to predict historical sulphate (SO4) concentrations was investigated, and an alternate approach for determining aquatic critical loads of acidity (CL(A)) was employed for the study lakes (n = 260). Critical loads of acidity were often low, with median values of 12-16 mmolc m-2 yr-1, with the lower value reflecting a region-specific limit for acid-neutralizing capacity identified in this study. Uncertain levels of atmospheric deposition in the region, however, are problematic for characterizing acidification risk. Accurate S and chloride (Cl) deposition are needed to identify catchment sources (and sinks) of these elements in the new approach for CL(A) calculation. Likewise, accurate depiction of atmospheric deposition levels can prove useful for evaluation of lake runoff estimates on which estimates of CL(A) are contingent. While CL(A) are low and exceedance may occur according to projected increases in S deposition in the near-term, S retention appears to be an important feature in many catchments and risk of acidification may be overstated should long-term S retention be occurring in peatlands.

Quantitation of total protein deposits on contact lenses by means of amino acid analysis.

PubMed

Yan, G; Nyquist, G; Caldwell, K D; Payor, R; McCraw, E C

1993-04-01

This study was done to characterize and quantify the protein deposits on worn contact lenses and to measure the residual deposits after extraction in 2% sodium dodecyl sulfate and the total protein deposits on worn vifilcon, atlafilcon, and tefilcon lenses (Food and Drug Administration Types IV, II, and I, respectively). Contact lens extracts were separated with gel electrophoresis, and the amount of protein was estimated after silver staining and densitometry. To determine the residual deposits, the contact lenses were hydrolyzed, and amino acid analysis was carried out by reverse-phase high-performance liquid chromatography after precolumn derivatization with phenylisothiocyanate. Refinement of the hydrolysis conditions was undertaken to minimize interference by the lens polymers. The extraction removed only approximately 25% of the protein deposits. Mild hydrolytic conditions, 20 hr in 6 N HCl at 105 degrees C, were found to cause minimal polymer interference. Of the 350, 10, and 20 micrograms of protein typically determined on whole vifilcon, atlafilcon, and tefilcon lenses, the polymers were estimated to account for 4, 0.5, and less than 0.4 micrograms, respectively. Hydrolysis of worn contact lenses with subsequent amino acid separation can be applied to determine the total protein deposits without the uncertainty inherent in extraction of the deposits.

The effects of acid deposition on sulfate reduction and methane production in peatlands

NASA Technical Reports Server (NTRS)

Murray, Georgia L.; Hines, Mark E.; Bayley, Suzanne E.

1992-01-01

Peatlands, as fens and bods, make up a large percentage of northern latitude terrestrial environments. They are organic rich and support an active community of anaerobic bacteria, such as methanogenic and sulfate-reducing bacteria. The end products of these microbial activities, methane and hydrogen sulfide, are important components in the global biogeochemical cycles of carbon and sulfur. Since these two bacterial groups compete for nutritional substrates, increases in sulfate deposition due to acid rain potentially can disrupt the balance between these processes leading to a decrease in methane production and emission. This is significant because methane is a potent greenhouse gas that effects the global heat balance. A section of Mire 239 in the Experimental Lakes Area, in Northwestern Ontario, was artificially acidified and rates of sulfate reduction and methane production were measured with depth. Preliminary results suggested that methane production was not affected immediately after acidification. However, concentrations of dissolved methane decreased and dissolved sulfide increased greatly after acidification and both took several days to recover. The exact mechanism for the decrease in methane was not determined. Analyses are under way which will be used to determine rates of sulfate reduction. These results will be available by Spring and will be discussed.

A deposit model for carbonatite and peralkaline intrusion-related rare earth element deposits: Chapter J in Mineral deposit models for resource assessment

USGS Publications Warehouse

Verplanck, Philip L.; Van Gosen, Bradley S.; Seal, Robert R.; McCafferty, Anne E.

2014-01-01

The greatest environmental challenges associated with carbonatite and peralkaline intrusion-related rare earth element deposits center on the associated uranium and thorium. Considerable uncertainty exists around the toxicity of rare earth elements and warrants further investigation. The acid-generating potential of carbonatites and peralkaline intrusion-related deposits is low due to the dominance of carbonate minerals in carbonatite deposits, the presence of feldspars and minor calcite within the alkaline intrusion deposits, and only minor quantities of potentially acid-generating sulfides. Therefore, acid-drainage issues are not likely to be a major concern associated with these deposits. Uranium has the potential to be recovered as a byproduct, which would mitigate some of its environmental effects. However, thorium will likely remain a waste-stream product that will require management since progress is not being made towards the development of thorium-based nuclear reactors in the United States or other large scale commercial uses. Because some deposits are rich in fluorine and beryllium, these elements may be of environmental concern in certain locations.

Kriging Direct and Indirect Estimates of Sulfate Deposition: A Comparison

Treesearch

Gregory A. Reams; Manuela M.P. Huso; Richard J. Vong; Joseph M. McCollum

1997-01-01

Due to logistical and cost constraints, acidic deposition is rarely measured at forest research or sampling locations. A crucial first step to assessing the effects of acid rain on forests is an accurate estimate of acidic deposition at forest sample sites. We examine two methods (direct and indirect) for estimating sulfate deposition at atmospherically unmonitored...

SOM Stability under Long-term Recovery from Acidic Deposition in a Northern Hardwood Forest

NASA Astrophysics Data System (ADS)

Marinos, R.; Bernhardt, E. S.; Groffman, P. M.; Likens, G.; Rosi-Marshall, E. J.

2016-12-01

Forested ecosystems in the Northeast U.S.A. are currently recovering from decades of acidic deposition that decreased soil pH, leached base cations, and increased soluble aluminum (Al) in soils. Because most research examining SOM dynamics in these ecosystems has taken place against a background of acidic deposition, it remains poorly understood how SOM pools will change as a result of the long-term trajectory of recovery from acidic deposition throughout the region. These potential changes may alter soil fertility status as well as the chemistry of receiving freshwater bodies. Watershed-scale experiments that increase soil pH and base cation status may provide insight into how SOM pools in these recovering ecosystems will respond on timescales of decades to centuries, but results from these experiments have been equivocal. At Hubbard Brook Experimental Forest in New Hampshire, a watershed-scale acid remediation treatment of calcium silicate caused a 40% decline of SOM pools in the humic (Oa) soil horizon, in addition to increasing soil pH and base saturation. We sought to understand the mechanisms driving this substantial loss of SOM. We found that, in the Oa horizon of the treatment watershed, respiration and nitrogen (N) mineralization were significantly, positively correlated with exchangeable calcium (Ca) and uncorrelated with soil pH; in a linear regression, exchangeable Ca explained 76% of the variation in respiration and 74% of the variation in nitrogen mineralization in the treatment soils. These metrics were uncorrelated in soils from a nearby reference watershed, where Ca is uniformly low. This suggests that the rate and magnitude of soil Ca changes during recovery from acid deposition may provide an important long-term control on the stability of SOM in these ecosystems. Additionally, we found substantially enhanced in-stream biotic uptake of the inorganic N released from this enhanced SOM decomposition, with growing-season N flux from the treatment

Acid rain and its environmental effects: Recent scientific advances

USGS Publications Warehouse

Burns, Douglas A.; Aherne, Julian; Gay, David A.; Lehmann, Christopher M.B.

2016-01-01

The term ‘acid rain’ refers to atmospheric deposition of acidic constituents that impact the earth as rain, snow, particulates, gases, and vapor. Acid rain was first recognized by Ducros (1845) and subsequently described by the English chemist Robert Angus Smith (Smith, 1852) whose pioneering studies linked the sources to industrial emissions and included early observations of deleterious environmental effects (Smith, 1872). Smith's work was largely forgotten until the mid-20th century when observations began to link air pollution to the deposition of atmospheric sulfate (SO42−) and other chemical constituents, first near the metal smelter at Sudbury, Ontario, Canada, and later at locations in Europe, North America, and Australia (Gorham, 1961). Our modern understanding of acid rain as an environmental problem caused largely by regional emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) stems from observations in the 1960s and early 1970s in Sweden by Svante Odén (Odén, 1976), and in North America by Gene Likens and colleagues (Likens and Bormann, 1974). These scientists and many who followed showed the link to emissions from coal-fired power plants and other industrial sources, and documented the environmental effects of acid rain such as the acidification of surface waters and toxic effects on vegetation, fish, and other biota.

Acid Rain.

ERIC Educational Resources Information Center

Openshaw, Peter

1987-01-01

Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

Geology and geochemistry of Summitville, Colorado: an epithermal acid sulfate deposit in a volcanic dome

USGS Publications Warehouse

Gray, J.E.; Coolbaugh, M.F.

1994-01-01

Geologic studies during recent open-pit mining at Summitville, Colorado, have provided new information on an epithermal acid sulfate Au-Ag-Cu deposit formed in a volcanic dome. Geologic mapping, geochemical studies of whole-rock samples from blast holes, and geologic and geochemical traverse studies refine the details of the evolution of the Summitville deposit. Six distinct events followed emplacement of the quartz latite volcanic dome and define the development of the Summitville deposit: 1) an early stage of acid sulfate alteration, 2) subsequent Cu sulfide and gold mineralization, 3) widespread hydrothermal brecciation, 4) volumetrically minor, base metal sulfide-bearing barite veining, 5) volumetrically minor, kaolinite matrix brecciation, and finally, 6) supergene oxidation. -from Authors

Critical loads of acidity for 90,000 lakes in northern Saskatchewan: A novel approach for mapping regional sensitivity to acidic deposition

NASA Astrophysics Data System (ADS)

Cathcart, H.; Aherne, J.; Jeffries, D. S.; Scott, K. A.

2016-12-01

Atmospheric emissions of sulphur dioxide (SO2) from large point sources are the primary concern for acidic deposition in western Canada, particularly in the Athabasca Oil Sands Region (AOSR) where prevailing winds may potentially carry SO2 over acid-sensitive lakes in northern Saskatchewan. A novel catchment-scale regression kriging approach was used to assess regional sensitivity and critical loads of acidity for the total lake population of northern Saskatchewan (89,947 lakes). Lake catchments were delineated using Thiessen polygons, and surface water chemistry was predicted for sensitivity indicators (calcium, pH, alkalinity, and acid neutralizing capacity). Critical loads were calculated with the steady state water chemistry model using regression-kriged base cations, sulphate, and dissolved organic carbon concentrations modelled from surface water observations (n > 800) and digital landscape-scale characteristics, e.g., climate, soil, vegetation, landcover, and geology maps. A large region (>13,726 km2) of two or more indicators of acid sensitivity (pH < 6 and acid neutralizing capacity, alkalinity, calcium < 50 μeq L-1) and low critical loads < 5 meq m-2 yr-1 were predicted on the Athabasca Basin. Exceedance of critical loads under 2006 modelled total sulphate deposition was predicted for 12% of the lakes (covering an area of 3742 km2), primarily located on the Athabasca Basin, within 100 km of the AOSR. There have been conflicting scientific reports of impacts from atmospheric emissions from the AOSR; the results of this study suggest that catchments in the Athabasca Basin within 100 km of the AOSR have received acidic deposition in excess of their critical loads and many of them may be at risk of ecosystem damage owing to their sensitivity.

Responses of 20 lake-watersheds in the Adirondack region of New York to historical and potential future acidic deposition.

PubMed

Zhou, Qingtao; Driscoll, Charles T; Sullivan, Timothy J

2015-04-01

Critical loads (CLs) and dynamic critical loads (DCLs) are important tools to guide the protection of ecosystems from air pollution. In order to quantify decreases in acidic deposition necessary to protect sensitive aquatic species, we calculated CLs and DCLs of sulfate (SO4(2-))+nitrate (NO3-) for 20 lake-watersheds from the Adirondack region of New York using the dynamic model, PnET-BGC. We evaluated lake water chemistry and fish and total zooplankton species richness in response to historical acidic deposition and under future deposition scenarios. The model performed well in simulating measured chemistry of Adirondack lakes. Current deposition of SO4(2-)+NO3-, calcium (Ca2+) weathering rate and lake acid neutralizing capacity (ANC) in 1850 were related to the extent of historical acidification (1850-2008). Changes in lake Al3+ concentrations since the onset of acidic deposition were also related to Ca2+ weathering rate and ANC in 1850. Lake ANC and fish and total zooplankton species richness were projected to increase under hypothetical decreases in future deposition. However, model projections suggest that lake ecosystems will not achieve complete chemical and biological recovery in the future. Copyright © 2014. Published by Elsevier B.V.

Acidic deposition, plant pests, and the fate of forest ecosystems.

PubMed

Gragnani, A; Gatto, M; Rinaldi, S

1998-12-01

We present and analyze a nonlinear dynamical system modelling forest-pests interactions and the way they are affected by acidic deposition. The model includes mechanisms of carbon and nitrogen exchange between soil and vegetation, biomass decomposition and microbial mineralization, and defoliation by pest grazers, which are partially controlled by avian or mammalian predators. Acidic deposition is assumed to directly damage vegetation, to decrease soil pH, which in turn damages roots and inhibits microbial activity, and to predispose trees to increased pest attack. All the model parameters are set to realistic values except the inflow of protons to soil and the predation mortality inflicted to the pest which are allowed to vary inside reasonable ranges. A numerical bifurcation analysis with respect to these two parameters is carried out. Five functioning modes are uncovered: (i) pest-free equilibrium; (ii) pest persisting at endemic equilibrium; (iii) forest-pest permanent oscillations; (iv) bistable behavior with the system converging either to pest-free equilibrium or endemic pest presence in accordance with initial conditions; (v) bistable behavior with convergence to endemic pest presence or permanent oscillations depending on initial conditions. Catastrophic bifurcations between the different behavior modes are possible, provided the abundance of predators is not too small. Numerical simulation shows that increasing acidic load can lead the forest to collapse in a short time period without important warning signals. Copyright 1998 Academic Press.

Modeling wet deposition of acid substances over the PRD region in China

NASA Astrophysics Data System (ADS)

Lu, Xingcheng; Fung, Jimmy Chi Hung; Wu, Dongwei

2015-12-01

The Pearl River Delta (PRD) region in southern China has suffered heavily from acid rain in the last 10 years due to the anthropogenic emission of sulfur dioxide and nitrogen dioxide. Several measurement-based studies about this issue have been conducted to analyze the chemical composition of precipitation in this area. However, no detailed, high resolution numerical simulation regarding this topic has ever been done in this region. In this study, the WRF-SMOKE-CMAQ system was applied to simulate the wet deposition of acid substances (SO42- and NO3-) in the PRD region from 2009 to 2011 with a resolution of 3 km. The simulation output agreed well with the observation data. Our results showed that Guangzhou was the city most affected by acid rain in this region. The ratio of non-sea-salt sulfate to nitrate indicated that the acid rain in this region belonged to the sulfate-nitrate mixed type. The source apportionment result suggests that point source and super regional source are the ones that contribute the pollutants most in the rain water over PRD Region. The sulfate and nitrate input to some reservoirs via wet deposition was also estimated based on the model simulation. Our results suggest that further cross-city cooperation and emission reduction are needed to further curb acid rain in this region.

Ascorbic acid induces alkaline phosphatase, type X collagen, and calcium deposition in cultured chick chondrocytes.

PubMed

Leboy, P S; Vaias, L; Uschmann, B; Golub, E; Adams, S L; Pacifici, M

1989-10-15

During the process of endochondral bone formation, proliferating chondrocytes give rise to hypertrophic chondrocytes, which then deposit a mineralized matrix to form calcified cartilage. Chondrocyte hypertrophy and matrix mineralization are associated with expression of type X collagen and the induction of high levels of the bone/liver/kidney isozyme of alkaline phosphatase. To determine what role vitamin C plays in these processes, chondrocytes derived from the cephalic portion of 14-day chick embryo sternae were grown in the absence or presence of exogenous ascorbic acid. Control untreated cells displayed low levels of type X collagen and alkaline phosphatase activity throughout the culture period. However, cells grown in the presence of ascorbic acid produced increasing levels of alkaline phosphatase activity and type X collagen mRNA and protein. Both alkaline phosphatase activity and type X collagen mRNA levels began to increase within 24 h of ascorbate treatment; by 9 days, the levels of both alkaline phosphatase activity and type X collagen mRNA were 15-20-fold higher than in non-ascorbate-treated cells. Ascorbate treatment also increased calcium deposition in the cell layer and decreased the levels of types II and IX collagen mRNAs; these effects lagged significantly behind the elevation of alkaline phosphatase and type X collagen. Addition of beta-glycerophosphate to the medium increased calcium deposition in the presence of ascorbate but had no effect on levels of collagen mRNAs or alkaline phosphatase. The results suggest that vitamin C may play an important role in endochondral bone formation by modulating gene expression in hypertrophic chondrocytes.

Foliar loading and metabolic assimilation of dry deposited nitric acid air pollutants by trees

Treesearch

Pamela E. Padgett; Hillary Cook; Andrzej Bytnerowicz; Robert L. Heath

2009-01-01

Dry deposition of nitric acid vapor (HNO(3)) is a major contributor to eutrophication of natural ecosystems. Although soil fertilization by nitrogen deposition is considered to be the primary pathway for changes in plant nutrient status and shifts in ecological structure, the aerial portion of plants offer many times the surface area in which to...

Forest ecosystems and the changing patterns of nitrogen input and acid deposition today and in the future based on a scenario.

PubMed

Busch, G; Lammel, G; Beese, F O; Feichter, J; Dentener, F J; Roelofs, G J

2001-01-01

A global assessment of the impact of the anthropogenic perturbation of the nitrogen and sulfur cycles on forest ecosystems is carried out for both the present-day [1980-1990] and for a projection into the future [2040-2050] under a scenario of economic development which represents a medium path of development according to expert guess [IPCC IS92a]. Results show that forest soils will receive considerably increasing loads of nitrogen and acid deposition and that deposition patterns are likely to change. The regions which are most prone to depletion of soils buffering capacity and supercritical nitrogen deposition are identified in the subtropical and tropical regions of South America and Southeast Asia apart from the well known 'hotspots' North-Eastern America and Central Europe. The forest areas likely to meet these two risks are still a minor fraction of the global forest ecosystems, though. But the bias between eutrophication and acidification will become greater and an enhanced growth triggered by the fertilizing effects of increasing nitrogen input cannot be balanced by the forest soils nutrient pools. Results show increasing loads into forest ecosystems which are likely to account for 46% higher acid loads and 36% higher nitrogen loads in relation to the 1980-1990 situation. Global background deposition of up to 5 kg N ha-1 a-1 will be exceeded at more than 25% of global forest ecosystems and at more than 50% of forest ecosystems on acid sensitive soils. More than 33% of forest ecosystems on acid sensitive soils will receive acid loads which exceeds their buffering capacity. About 25% of forest areas with exceeded acid loads will receive critical nitrogen loads.

In-vitro evaluation of Polylactic acid (PLA) manufactured by fused deposition modeling.

PubMed

Wurm, Matthias C; Möst, Tobias; Bergauer, Bastian; Rietzel, Dominik; Neukam, Friedrich Wilhelm; Cifuentes, Sandra C; Wilmowsky, Cornelius von

2017-01-01

With additive manufacturing (AM) individual and biocompatible implants can be generated by using suitable materials. The aim of this study was to investigate the biological effects of polylactic acid (PLA) manufactured by Fused Deposition Modeling (FDM) on osteoblasts in vitro according to European Norm / International Organization for Standardization 10,993-5. Human osteoblasts (hFOB 1.19) were seeded onto PLA samples produced by FDM and investigated for cell viability by fluorescence staining after 24 h. Cell proliferation was measured after 1, 3, 7 and 10 days by cell-counting and cell morphology was evaluated by scanning electron microscopy. For control, we used titanium samples and polystyrene (PS). Cell viability showed higher viability on PLA (95,3% ± 2.1%) than in control (91,7% ±2,7%). Cell proliferation was highest in the control group (polystyrene) and higher on PLA samples compared to the titanium samples. Scanning electron microscopy revealed homogenous covering of sample surface with regularly spread cells on PLA as well as on titanium. The manufacturing of PLA discs from polylactic acid using FDM was successful. The in vitro investigation with human fetal osteoblasts showed no cytotoxic effects. Furthermore, FDM does not seem to alter biocompatibility of PLA. Nonetheless osteoblasts showed reduced growth on PLA compared to the polystyrene control within the cell experiments. This could be attributed to surface roughness and possible release of residual monomers. Those influences could be investigated in further studies and thus lead to improvement in the additive manufacturing process. In addition, further research focused on the effect of PLA on bone growth should follow. In summary, PLA processed in Fused Deposition Modelling seems to be an attractive material and method for reconstructive surgery because of their biocompatibility and the possibility to produce individually shaped scaffolds.

Influence of acid deposition on regeneration dynamics along a disturbance intensity gradient

Treesearch

Sarah E. Stehn; Christopher R. Webster; Michael A. Jenkins; Shibu Jose

2010-01-01

Now considered one of the most threatened vegetation communities in North America, spruce-fir forests of the southern Appalachians have been devastated by the combined impacts of the exotic balsam woolly adelgid (Adelges piceae, BWA) and chronic acid deposition.

Investigation of Gas-Sensing Property of Acid-Deposited Polyaniline Thin-Film Sensors for Detecting H2S and SO2

PubMed Central

Dong, Xingchen; Zhang, Xiaoxing; Wu, Xiaoqing; Cui, Hao; Chen, Dachang

2016-01-01

Latent insulation defects introduced in manufacturing process of gas-insulated switchgears can lead to partial discharge during long-time operation, even to insulation fault if partial discharge develops further. Monitoring of decomposed components of SF6, insulating medium of gas-insulated switchgear, is a feasible method of early-warning to avoid the occurrence of sudden fault. Polyaniline thin-film with protonic acid deposited possesses wide application prospects in the gas-sensing field. Polyaniline thin-film sensors with only sulfosalicylic acid deposited and with both hydrochloric acid and sulfosalicylic acid deposited were prepared by chemical oxidative polymerization method. Gas-sensing experiment was carried out to test properties of new sensors when exposed to H2S and SO2, two decomposed products of SF6 under discharge. The gas-sensing properties of these two sensors were compared with that of a hydrochloric acid deposited sensor. Results show that the hydrochloric acid and sulfosalicylic acid deposited polyaniline thin-film sensor shows the most outstanding sensitivity and selectivity to H2S and SO2 when concentration of gases range from 10 to 100 μL/L, with sensitivity changing linearly with concentration of gases. The sensor also possesses excellent long-time and thermal stability. This research lays the foundation for preparing practical gas-sensing devices to detect H2S and SO2 in gas-insulated switchgears at room temperature. PMID:27834895

The surprising recovery of red spruce growth shows links to decreased acid deposition and elevated temperature.

PubMed

Kosiba, Alexandra M; Schaberg, Paul G; Rayback, Shelly A; Hawley, Gary J

2018-10-01

Following growth declines and increased mortality linked to acid deposition-induced calcium depletion, red spruce (Picea rubens Sarg.) in the northeastern United States are experiencing a recovery. We found that more than 75% of red spruce trees and 90% of the plots examined in this study exhibited increasing growth since 2001. To understand this change, we assessed the relationship between red spruce radial growth and factors that may influence growth: tree age and diameter, stand dynamics, plot characteristics (elevation, slope, aspect, geographical position), and a suite of environmental variables (temperature, precipitation, climate and precipitation indices (degree days, SPEI [standardized precipitation evapotranspiration index], and acid deposition [SO 4 2- , NO 3 - , pH of rainfall, cation:anion ratio of rainfall]) for 52 plots (658 trees) from five states (spanning 2.5°N × 5°W). Examining the growth relationships from 1925 to 2012, we found that while there was variability in response to climate and acid deposition (limited to 1980-2012) by elevation and location, plot and tree factors did not adequately explain growth. Higher temperatures outside the traditional growing season (e.g., fall, winter, and spring) were related to increased growth. Nitrogen deposition (1980-2012) was associated with lower growth, but the strength of this relationship has lessened over time. Overall, we predict sustained favorable conditions for red spruce in the near term as acid deposition continues to decline and non-traditional growing season (fall through spring) temperatures moderate, provided that overall temperatures and precipitation remain adequate for growth. Copyright © 2018 Elsevier B.V. All rights reserved.

Physical characteristics of study plots across the Lake States acidic deposition gradient.

Treesearch

Lewis F. Ohmann; David F. Grigal; Sandra Brovold

1989-01-01

Describes the location and physical setting of the 171 plots that were remeasured and sampled for a study of the relation between various aspects of forest conditions and atmospheric position across the northwestern Minnesota to southeastern Michigan acidic deposition gradient.

Assessment of lake sensitivity to acidic deposition in national parks of the Rocky Mountains.

PubMed

Nanus, L; Williams, M W; Campbell, D H; Tonnessen, K A; Blett, T; Clow, D W

2009-06-01

The sensitivity of high-elevation lakes to acidic deposition was evaluated in five national parks of the Rocky Mountains based on statistical relations between lake acid-neutralizing capacity concentrations and basin characteristics. Acid-neutralizing capacity (ANC) of 151 lakes sampled during synoptic surveys and basin-characteristic information derived from geographic information system (GIS) data sets were used to calibrate the statistical models. The explanatory basin variables that were considered included topographic parameters, bedrock type, and vegetation type. A logistic regression model was developed, and modeling results were cross-validated through lake sampling during fall 2004 at 58 lakes. The model was applied to lake basins greater than 1 ha in area in Glacier National Park (n = 244 lakes), Grand Teton National Park (n = 106 lakes), Great Sand Dunes National Park and Preserve (n = 11 lakes), Rocky Mountain National Park (n = 114 lakes), and Yellowstone National Park (n = 294 lakes). Lakes that had a high probability of having an ANC concentration <100 microeq/L, and therefore sensitive to acidic deposition, are located in basins with elevations >3000 m, with <30% of the catchment having northeast aspect and with >80% of the catchment bedrock having low buffering capacity. The modeling results indicate that the most sensitive lakes are located in Rocky Mountain National Park and Grand Teton National Park. This technique for evaluating the lake sensitivity to acidic deposition is useful for designing long-term monitoring plans and is potentially transferable to other remote mountain areas of the United States and the world.

Impacts of acidic deposition: context and case studies of forest soils in the southeastern US

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

Binkley, D.; Driscoll, C.T.; Allen, H.L.

1988-12-01

The authors designed their assessment to include both the basic foundation needed by non-experts and the detailed information needed by experts. Their assessment includes background information on acidic deposition (Chap. 1), an in-depth discussion of the nature of soil acidity and ecosystem H(1+) budgets (Chap. 2), and a summary of rates of deposition in the Southeastern U.S. (Chap. 3). A discussion of the nature of forest soils in the region (Chap. 4) is followed by an overview of previous assessments of soil sensitivity to acidification (Chap. 5). The potential impacts of acidic deposition on forest nutrition are described in themore » context of the degree of current nutrient limitation on forest productivity (Chap. 6). The results of simulations with the MAGIC model provided evaluations of the likely sensitivity of a variety of soils representative of forest soils in the South (Chap. 7), as well as a test of soil sensitivity criteria. The authors' synthesis and recommendations for research (Chap. 8) also serve as an executive summary.« less

Critical loads of atmospheric deposition to Adirondack lake watersheds: A guide for policymakers

USGS Publications Warehouse

Burns, Douglas A.; Sullivan, Timothy J.

2015-01-01

Acid deposition is sometimes referred to as “acid rain,” although part of the acid load reaches the surface by means other than rainfall. In the eastern U.S., acid deposition consists of several forms of sulfur and nitrogen that largely originate as emissions to the atmosphere from sources such as electricity-generating facilities (coal, oil, and natural gas), diesel- and gasoline-burning vehicles, some agricultural activities, and smokestack industries. Acid deposition is known to cause deleterious effects to sensitive ecosystems of which the Adirondack region of New York State provides several well-known and well-studied examples. This largely forested region includes abundant lakes, streams, and wetlands and possesses several landscape features that result in high ecosystem sensitivity to acid deposition. These features include bedrock that weathers slowly, steep slopes, and thin, naturally acidic soils. An ecosystem is described as sensitive to, or affected by, acid deposition if prolonged exposure to acid deposition has resulted in detrimental ecosystem effects. Soils, streams, and lakes that are less sensitive are better able to buffer acid deposition. A principal reason that acidification is a concern for resource managers is because of the changes induced in native biota and their habitat on land and in water. As the chemistry of soils and surface waters in sensitive landscapes changes in response to prolonged exposure to acid deposition, organisms that cannot tolerate high acidity, such as sugar maple trees and many species of fish and aquatic insects, may be gradually eliminated from the ecosystem. Other biota such as red spruce may experience increased stress and reduced growth rates as a result of acidification, exposing these species to increased susceptibility to disease and other natural stressors and perhaps increased mortality. The ecological effects of acid deposition have been documented by extensive research that began in the U.S. in the

Acetic acid effects on enhancement of growth rate and reduction of amorphous carbon deposition on CNT arrays along a growth window in a floating catalyst reactor

NASA Astrophysics Data System (ADS)

Maghrebi, Morteza; Khodadadi, Abbas Ali; Mortazavi, Yadollah; Sane, Ali; Rahimi, Mohsen; Shirazi, Yaser; Tsakadze, Zviad; Mhaisalkar, Subodh

2009-11-01

The mm-long carbon nanotube (CNT) arrays were grown in a floating catalyst reactor, using xylene-ferrocene and a small amount of acetic acid as the feed. The CNT arrays deposited on a quartz substrate at several positions along the reactor were extensively characterized using Raman spectroscopy, scanning electron microscopy, X-ray diffraction, high-resolution transmission electron microscopy, and optical microscopy. Various characterization methods consistently reveal that the acetic acid additive to the feed alleviates deposition of amorphous carbon layer, which gradually thickens CNTs along the reactor. The acetic acid also resulted in a higher growth rate along the so-called growth window, where CNT arrays are deposited on the quartz substrate. High-performance liquid chromatography of extracted byproducts (PAHs) confirmed the presence of some polycyclic aromatic hydrocarbons. The solid weight of PAHs decreased upon addition of ferrocene as the catalyst precursor, as well as of acetic acid to xylene feed. The results suggest that primary light products of xylene pyrolysis can be competitive reactants for both catalytic and subsequent pyrolytic reactions. They may also be more efficient feeds for CNT growth than xylene itself.

Stress assessment and spectral characterization of suspected acid deposition damage in red spruce (Picea Rubens) from Vermont

NASA Technical Reports Server (NTRS)

Rock, B. N.; Vogelmann, J. E.

1985-01-01

The effects of acid deposition on Picea rubens are studied. The Picea rubens located at Camels Hump Mt., Mt. Ascutney, and Ripton, VT were analyzed using stress level evaluations, in situ spectral data, pressure bomb analysis, and aircraft sensors. Spruce stress per circular plot and percent spruce mortality are calculated. The relation between stress levels and elevation and exposure and weather patterns is examined. It is observed that variations in the reflectance curves of the foliage and branches are related to cellular health, the type of cellular arrangement, and the degree of leaf tissue hydration; the leaf and twig specimens from high stress sites are more reflective in the red portion of the visible and less reflective in the NIR portion of the spectrum. The pressure bomb data reveal that the xylem water tension is higher in specimens from high stress sites. It is noted that remote sensing permits discrimination and mapping of suspected acid deposition damage.

Mesoscale acid deposition modeling studies

NASA Technical Reports Server (NTRS)

Kaplan, Michael L.; Proctor, F. H.; Zack, John W.; Karyampudi, V. Mohan; Price, P. E.; Bousquet, M. D.; Coats, G. D.

1989-01-01

The work performed in support of the EPA/DOE MADS (Mesoscale Acid Deposition) Project included the development of meteorological data bases for the initialization of chemistry models, the testing and implementation of new planetary boundary layer parameterization schemes in the MASS model, the simulation of transport and precipitation for MADS case studies employing the MASS model, and the use of the TASS model in the simulation of cloud statistics and the complex transport of conservative tracers within simulated cumuloform clouds. The work performed in support of the NASA/FAA Wind Shear Program included the use of the TASS model in the simulation of the dynamical processes within convective cloud systems, the analyses of the sensitivity of microburst intensity and general characteristics as a function of the atmospheric environment within which they are formed, comparisons of TASS model microburst simulation results to observed data sets, and the generation of simulated wind shear data bases for use by the aviation meteorological community in the evaluation of flight hazards caused by microbursts.

Sensitivity of high-elevation streams in the Southern Blue Ridge Province to acidic deposition

USGS Publications Warehouse

Winger, P.V.; Lasier, P.J.; Hudy, M.; Fowler, D.; Van Den Avyle, M.J.

1987-01-01

The Southern Blue Ridge Province, which encompasses parts of northern Georgia, eastern Tennessee, and western North Carolina, has been predicted to be sensitive to impacts from acidic deposition, owing to the chemical composition of the bedrock geology and soils. This study confirms the predicted potential sensitivity, quantifies the level of total alkalinity and describes the chemical characteristics of 30 headwater streams of this area. Water chemistry was measured five times between April 1983 and June 1984 at first and third order reaches of each stream during baseflow conditions. Sensitivity based on total alkalinity and the Calcite Saturation Index indicates that the headwater streams of the Province are vulnerable to acidification. Total alkalinity and p11 were generally higher in third order reaches (mean, 72 ?eq/? and 6.7) than in first order reaches (64 ?eq/? and 6.4). Ionic concentrations were low, averaging 310 and 340 ?eq/? in first and third order reaches, respectively. A single sampling appears adequate for evaluating sensitivity based on total alkalinity, but large temporal variability requires multiple sampling for the detection of changes in pH and alkalinity over time. Monitoring of stream water should continue in order to detect any subtle effects of acidic deposition on these unique resource systems.

The response of soil solution chemistry in European forests to decreasing acid deposition.

PubMed

Johnson, James; Graf Pannatier, Elisabeth; Carnicelli, Stefano; Cecchini, Guia; Clarke, Nicholas; Cools, Nathalie; Hansen, Karin; Meesenburg, Henning; Nieminen, Tiina M; Pihl-Karlsson, Gunilla; Titeux, Hugues; Vanguelova, Elena; Verstraeten, Arne; Vesterdal, Lars; Waldner, Peter; Jonard, Mathieu

2018-03-31

Acid deposition arising from sulphur (S) and nitrogen (N) emissions from fossil fuel combustion and agriculture has contributed to the acidification of terrestrial ecosystems in many regions globally. However, in Europe and North America, S deposition has greatly decreased in recent decades due to emissions controls. In this study, we assessed the response of soil solution chemistry in mineral horizons of European forests to these changes. Trends in pH, acid neutralizing capacity (ANC), major ions, total aluminium (Al tot ) and dissolved organic carbon were determined for the period 1995-2012. Plots with at least 10 years of observations from the ICP Forests monitoring network were used. Trends were assessed for the upper mineral soil (10-20 cm, 104 plots) and subsoil (40-80 cm, 162 plots). There was a large decrease in the concentration of sulphate (SO42-) in soil solution; over a 10-year period (2000-2010), SO42- decreased by 52% at 10-20 cm and 40% at 40-80 cm. Nitrate was unchanged at 10-20 cm but decreased at 40-80 cm. The decrease in acid anions was accompanied by a large and significant decrease in the concentration of the nutrient base cations: calcium, magnesium and potassium (Bc = Ca 2+  + Mg 2+  + K + ) and Al tot over the entire dataset. The response of soil solution acidity was nonuniform. At 10-20 cm, ANC increased in acid-sensitive soils (base saturation ≤10%) indicating a recovery, but ANC decreased in soils with base saturation >10%. At 40-80 cm, ANC remained unchanged in acid-sensitive soils (base saturation ≤20%, pHCaCl2 ≤ 4.5) and decreased in better-buffered soils (base saturation >20%, pHCaCl2 > 4.5). In addition, the molar ratio of Bc to Al tot either did not change or decreased. The results suggest a long-time lag between emission abatement and changes in soil solution acidity and underline the importance of long-term monitoring in evaluating ecosystem response to decreases in deposition. © 2018 John Wiley & Sons

The distribution of common construction materials at risk to acid deposition in the United States

NASA Astrophysics Data System (ADS)

Lipfert, Frederick W.; Daum, Mary L.

Information on the geographic distribution of various types of exposed materials is required to estimate the economic costs of damage to construction materials from acid deposition. This paper focuses on the identification, evaluation and interpretation of data describing the distributions of exterior construction materials, primarily in the United States. This information could provide guidance on how data needed for future economic assessments might be acquired in the most cost-effective ways. Materials distribution surveys from 16 cities in the U.S. and Canada and five related databases from government agencies and trade organizations were examined. Data on residential buildings are more commonly available than on nonresidential buildings; little geographically resolved information on distributions of materials in infrastructure was found. Survey results generally agree with the appropriate ancillary databases, but the usefulness of the databases is often limited by their coarse spatial resolution. Information on those materials which are most sensitive to acid deposition is especially scarce. Since a comprehensive error analysis has never been performed on the data required for an economic assessment, it is not possible to specify the corresponding detailed requirements for data on the distributions of materials.

Long-term response of surface water acid neutralizing capacity in a central Appalachian (USA) river basin to declining acid deposition

NASA Astrophysics Data System (ADS)

Kline, Kathleen M.; Eshleman, Keith N.; Garlitz, James E.; U'Ren, Sarah H.

2016-12-01

Long-term changes in acid-base chemistry resulting from declining regional acid deposition were examined using data from repeating synoptic surveys conducted within the 275 km2 Upper Savage River Watershed (USRW) in western Maryland (USA); a randomly-selected set of 40 stream reaches was sampled 36 times between 1999 and 2014 to: (1) repeatedly characterize the acid-base status of the entire river basin; (2) determine whether an extensive network of streams of varying order has shown signs of recovery in acid neutralizing capacity (ANC); and (3) understand the key factors controlling the rate of ANC recovery across the river network. Several non-parametric analyses of trends (i.e., Mann Kendall Trend: MKT tests; and Regional Kendall Trend: RKT) in streamwater acid-base chemistry suggest that USRW has significantly responded to declining acid deposition during the study period; the two most robust, statistically significant trends were decreasing surface water SO42- (∼1.5 μeq L-1 yr-1) and NO3- (∼1 μeq L-1 yr-1) concentrations-consistent with observed downward trends in regional wet S and N deposition. Basin-wide decreasing trends in K+, Mg2+, and Ca2+ were also observed, while Na+ concentrations increased. Significant ANC recovery was observed in 10-20% of USRW stream reaches (depending on the p level used), but the magnitude of the trend relative to natural variability was apparently insufficient to allow detection of a basin-wide ANC trend using the RKT test. Watershed factors, such as forest disturbances and increased application of road deicing salts, appeared to contribute to substantial variability in concentrations of NO3- and Na+ in streams across the basin, but these factors did not affect our overall interpretation of the results as a systematic recovery of USRW from regional acidification. Methodologically, RKT appears to be a robust method for identifying basin-wide trends using synoptic data, but MKT results for individual systems should be

Potential human health effects of acid rain: report of a workshop

PubMed Central

Goyer, Robert A.; Bachmann, John; Clarkson, Thomas W.; Ferris, Benjamin G.; Graham, Judith; Mushak, Paul; Perl, Daniel P.; Rall, David P.; Schlesinger, Richard; Sharpe, William; Wood, John M.

1985-01-01

This report summarizes the potential impact of the acid precipitation phenomenon on human health. There are two major components to this phenomenon: the predepositional phase, during which there is direct human exposure to acidic substances from ambient air, and the post-depositional phase, in which the deposition of acid materials on water and soil results in the mobilization, transport, and even chemical transformation of toxic metals. Acidification increases bioconversion of mercury to methylmercury, which accumulates in fish, increasing the risk to toxicity in people who eat fish. Increase in water and soil content of lead and cadmium increases human exposure to these metals which become additive to other sources presently under regulatory control. The potential adverse health effects of increased human exposure to aluminum is not known at the present time. PMID:3896772

[Effects of low molecular weight organic acids on speciation of exogenous Cu in an acid soil].

PubMed

Huang, Guo-Yong; Fu, Qing-Ling; Zhu, Jun; Wan, Tian-Ying; Hu, Hong-Qing

2014-08-01

In order to ascertain the effect of LMWOA (citric acid, tartaric acid, oxalic acid) on Cu-contaminated soils and to investigate the change of Cu species, a red soil derived from quartz sandstone deposit was added by Cu (copper) in the form of CuSO4 x 5H2O so as to simulate soil Cu pollution, keeping the additional Cu concentrations were 0, 100, 200, 400 mg x kg(-1) respectively. After 9 months, different LMWOA was also added into the simulated soil, keeping the additional LMWOAs in soil were 0, 5, 10, 20 mmol x kg(-1) respectively. After 2 weeks incubation, the modified sequential extraction method on BCR (European Communities Bureau of Reference) was used to evaluate the effects of these LMWOAs on the changes of copper forms in soil. The result showed that the percentage of weak acid dissolved Cu, the most effective form in the soil increased with three organic acids increase in quantity in the simulated polluted soil. And there was a good activation effect on Cu in the soil when organic acid added. Activation effects on Cu increased with concentration of citric acid increasing, but it showed a rise trend before they are basically remained unchanged in the case of tartaric acid and oxalic acid added in the soil. On the contrary, the state of the reduction of copper which was regarded as a complement for effective state decreased with the increased concentration of organic acid in the soil, especially with citric acid. When 20 mmol x kg(-1) oxalic acid and citric acid were added into the soil, the activation effect was the best; whereas for tartaric, the concentration was 10 mmol x kg(-1). In general, the effect on the changes of Cu forms in the soil is citric acid > tartaric acid > oxalic acid.

Effects of dietary conjugated linoleic acid and linoleic:linolenic acid ratio on polyunsaturated fatty acid status in laying hens.

PubMed

Du, M; Ahn, D U; Sell, J L

2000-12-01

A study was conducted to determine the effects of dietary conjugated linoleic acid (CLA) and the ratio of linoleic:linolenic acid on long-chain polyunsaturated fatty acid status. Thirty-two 31-wk-old White Leghorn hens were randomly assigned to four diets containing 8.2% soy oil, 4.1% soy oil + 2.5% CLA (4.1% CLA source), 4.1% flax oil + 2.5% CLA, or 4.1% soy oil + 4.1% flax oil. Hens were fed the diets for 3 wk before eggs and tissues were collected for the study. Lipids were extracted from egg yolk and tissues, classes of egg yolk lipids were separated, and fatty acid concentrations of total lipids, triglyceride, phosphatidylethanolamine, and phosphatidylcholine were analyzed by gas chromatography. The concentrations of monounsaturated fatty acids and non-CLA polyunsaturated fatty acids were reduced after CLA feeding. The amount of arachidonic acid was decreased after CLA feeding in linoleic acid- and linolenic acid-rich diets, but amounts of eicosapentaenoic acid and docosahexaenoic acid were increased in the linolenic-rich diet, indicating that the synthesis or deposition of long-chain n-3 fatty acids was accelerated after CLA feeding. The increased docosahexaenoic acid and eicosapentaenoic acid contents in lipid may be compensation for the decreased arachidonic acid content. Dietary supplementation of linoleic acid increased n-6 fatty acid levels in lipids, whereas linolenic acid increased n-3 fatty acid levels. Results also suggest that CLA might not be elongated to synthesize long-chain fatty acids in significant amounts. The effect of CLA in reducing the level of n-6 fatty acids and promoting the level of n-3 fatty acids could be related to the biological effects of CLA.

Calcium phosphates deposited on titanium electrode surface--part 1: Effect of the electrode polarity and oxide film on the deposited materials.

PubMed

Okawa, Seigo; Watanabe, Kouichi; Kanatani, Mitsugu

2013-01-01

We report experimental results about the effect of polarity of electrode and anodized titanium oxide film on the deposited materials by electrolysis of an acidic calcium phosphate solution. Mirror-polished titanium and anodized titanium were used as anode or cathode, and a Pt plate was used as a counter electrode. The load voltage was held constant at 20 VDC. No deposited materials were found on the anode surface. On the other hand, dicalcium phosphate dihydrate (DCPD) was deposited on the cathode surface at the beginning of the electrolysis. After the electrolysis time 600 s, the non-stoichiometric hydroxyapatite (HAp) with several hundred nanometers was formed on the specimen surface. Based on X-ray photoelectron spectroscopy data, the anodized oxide film contained both P(5+) and P(3+) ions. This characteristic of the oxide film and the electrolysis conditions were related to the behavior of the deposition of ultra fine HAp with high crystallinity.

Influence of acidic atmospheric deposition on soil solution composition in the Daniel Boone National Forest, Kentucky, USA

Treesearch

C.D. Barton; A.D. Karathanasis; G. Chalfant

2002-01-01

Acid atmosperic depositoin may enter an environmental ecosystem in a variety of forms and pathways, but the most common components include sulfuric and nitric acids formed when rainwater interacts with sulfur (SO3) and nitrogen (NO3) emmissions. For many soils and watersheds sensitive to acid deposition, the predominant...

The effect of acid precipitation on tree growth in eastern North America

Treesearch

Charles V. Cogbill

1976-01-01

Detailed study of the history of forest tree growth by tree-ring analysis is used to assess the effect of acid precipitation. The pattern and historical trends of acid precipitation deposition are compared with growth trends from mature forest stands in New Hampshire and Tennessee. No clear indication of a regional, synchronized decrease in tree growth was found. The...

Effect of forage energy intake and supplementation on marbling deposition in growing beef cattle.

USDA-ARS?s Scientific Manuscript database

Glucose is the primary carbon source for fatty acid synthesis in intramuscular fat, whereas, acetate is primarily utilized by subcutaneous fat. Our objective was to examine the effect of forage energy intake and type of fermentation on marbling deposition by stocker cattle grazing dormant native ra...

Long-term changes in soil and stream chemistry across an acid deposition gradient in the northeastern United States

USGS Publications Warehouse

Siemion, Jason; McHale, Michael; Lawrence, Gregory B.; Burns, Douglas A.; Antidormi, Michael

2018-01-01

Declines in acidic deposition across Europe and North America have led to decreases in surface water acidity and signs of chemical recovery of soils from acidification. To better understand the link between recovery of soils and surface waters, chemical trends in precipitation, soils, and streamwater were investigated in three watersheds representing a depositional gradient from high to low across the northeastern United States. Significant declines in concentrations of H+ (ranging from −1.2 to −2.74 microequivalents [μeq] L−1 yr−1), NO3− (ranging from −0.6 to −0.84 μeq L−1 yr−1), and SO42− (ranging from −0.95 to −2.13 μeq L−1 yr−1) were detected in precipitation in the three watersheds during the period 1999 to 2013. Soil chemistry in the A horizon of the watershed with the greatest decrease in deposition showed significant decreases in exchangeable Al and increases in exchangeable bases. Soil chemistry did not significantly improve during the study in the other watersheds, and base saturation in the Oa and upper B horizons significantly declined in the watershed with the smallest decrease in deposition. Streamwater SO42−concentrations significantly declined in all three streams (ranging from −2.01 to −2.87 μeq L−1 yr−1) and acid neutralizing capacity increased (ranging from 1.38 to 1.60 μeq L−1 yr−1) in the two streams with the greatest decreases in deposition. Recovery of soils has likely been limited by decades of acid deposition that have leached base cations from soils with base-poor parent material.

Image analysis of epicuticular damage to foliage caused by dry deposition of the air pollutant nitric acid

Treesearch

Pamela E. Padgett; Sally D. Parry; Andrzej Bytnerowicz; Robert L. Heath

2009-01-01

Nitric acid vapor is produced by the same photochemical processes that produce ozone. In the laboratory, concentrated nitric acid is a strong acid and a powerful oxidant. In the environment, where the concentrations are much lower, it is an innocuous source of plant nitrogen. As an air pollutant, which mode of action does dry deposition of nitric...

Application of a Depositional Facies Model to an Acid Mine Drainage Site▿ †

PubMed Central

Brown, Juliana F.; Jones, Daniel S.; Mills, Daniel B.; Macalady, Jennifer L.; Burgos, William D.

2011-01-01

Lower Red Eyes is an acid mine drainage site in Pennsylvania where low-pH Fe(II) oxidation has created a large, terraced iron mound downstream of an anoxic, acidic, metal-rich spring. Aqueous chemistry, mineral precipitates, microbial communities, and laboratory-based Fe(II) oxidation rates for this site were analyzed in the context of a depositional facies model. Depositional facies were defined as pools, terraces, or microterracettes based on cm-scale sediment morphology, irrespective of the distance downstream from the spring. The sediments were composed entirely of Fe precipitates and cemented organic matter. The Fe precipitates were identified as schwertmannite at all locations, regardless of facies. Microbial composition was studied with fluorescence in situ hybridization (FISH) and transitioned from a microaerophilic, Euglena-dominated community at the spring, to a Betaproteobacteria (primarily Ferrovum spp.)-dominated community at the upstream end of the iron mound, to a Gammaproteobacteria (primarily Acidithiobacillus)-dominated community at the downstream end of the iron mound. Microbial community structure was more strongly correlated with pH and geochemical conditions than depositional facies. Intact pieces of terrace and pool sediments from upstream and downstream locations were used in flowthrough laboratory reactors to measure the rate and extent of low-pH Fe(II) oxidation. No change in Fe(II) concentration was observed with 60Co-irradiated sediments or with no-sediment controls, indicating that abiotic Fe(II) oxidation was negligible. Upstream sediments attained lower effluent Fe(II) concentrations compared to downstream sediments, regardless of depositional facies. PMID:21097582

Use of soil-streamwater relationships to assess regional patterns of acidic deposition effects in the northeastern USA

USGS Publications Warehouse

Siemion, Jason; Lawrence, Gregory B.; Murdoch, Peter S.

2013-01-01

Declines of acidic deposition levels by as much as 50% since 1990 have led to partial recovery of surface waters in the northeastern USA but continued depletion of soil calcium through this same period suggests a disconnection between soil and surface water chemistry. To investigate the role of soil-surface water interactions in recovery from acidification, the first regional survey to directly relate soil chemistry to stream chemistry during high flow was implemented in a 4144-km2 area of the Catskill region of New York, where acidic deposition levels are among the highest in the East.More than 40% of 95 streams sampled in the southern Catskill Mountains were determined to be acidified and had inorganic monomeric aluminum concentrations that exceeded a threshold that is toxic to aquatic biota. More than 80% likely exceeded this threshold during the highest flows, but less than 10% of more than 100 streams sampled were acidified in the northwestern portion of the region. Median Oa horizon soil base saturation ranged from 50% to 80% at 200 sites across the region, but median base saturation in the upper 10 cm of the B horizon was less than 20% across the region and was only 2% in the southern area. Aluminum is likely to be interfering with root uptake of calcium in the mineral horizon in approximately half the sampled watersheds. Stream chemistry was highly variable over the Catskill region and, therefore, did not always reflect the calcium depletion of the B horizon that our sampling suggested was nearly ubiquitous throughout the region. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Titania Deposition on PMR-15

NASA Technical Reports Server (NTRS)

Meador, Mary B.; Sutter, James K.; Pizem, Hillel; Gershevitz, Olga; Goffer, Yossi; Frimer, Aryeh A.; Sukenik, Chaim N.; Sampathkumaran, Uma; Milhet, Xavier; McIlwain, Alan

2005-01-01

The formation, degree of crystallinity and adherence of dense titania (TiO2) thin film coatings on a high-temperature polyimide resin (PMR-15) can be influenced by the chemical composition of the polymer surface. Furthermore, solution deposition conditions can be adjusted to provide additional control over the morphology and crystallinity of the titania films. Recipes for solution-based titania deposition that used a slowly-hydrolyzing titanium fluoride salt in the presence of boric acid as a fluoride scavenger allowed growth of films up to 750 nm thick in 22 h. By adjusting solution pH and temperature, either amorphous titania or oriented crystalline anatase films could be formed. Surface sulfonate groups enhance the adhesion of solution-deposited oxide thin film coatings. While most sulfonation procedures severely damaged the PMR-15 surface, the use of chlorosulfonic acid followed by hydrolysis of the installed chlorosulfonyl groups provided effective surface sulfonation without significant surface damage. In some cases, the oxide deposition solution caused partial hydrolysis of the polymer surface, which itself was sufficient to allow adhesion of the titania film through chelation of titanium ions by exposed benzoic acid groups on the polymer surface.

An Assessment of Student Knowledge in Fourth, Eighth and Eleventh Grades of Science and Natural Resource Concepts Related to Acidic Deposition.

ERIC Educational Resources Information Center

Brody, Michael; And Others

This study assessed the level of scientific and natural resource knowledge that 4th, 8th, and 11th grade students in Maine possessed concerning acidic deposition. A representative sample of public school students (n=175) was interviewed on 12 concept principles considered critical to a full understanding of the acidic deposition problem. These…

Geology-based method of assessing sensitivity of streams to acidic deposition in Charles and Anne Arundel Counties, Maryland

USGS Publications Warehouse

Rice, Karen C.; Bricker, Owen P.

1991-01-01

The report describes the results of a study to assess the sensitivity of streams to acidic deposition in Charles and Anne Arundel Counties, Maryland using a geology-based method. Water samples were collected from streams in July and August 1988 when streams were at base-flow conditions. Eighteen water samples collected from streams in Charles County, and 17 water samples from streams in Anne Arundel County were analyzed in the field for pH, specific conductance, and acid-neutralizing capacity (ANC); 8 water samples from streams in Charles County were analyzed in the laboratory for chloride and sulfate concentrations. The assessment revealed that streams in these counties are sensitive to acidification by acidic deposition.

Deposition of lignin droplets produced during dilute acid pretreatment of maize stems retards enzymatic hydrolysis of cellulose.

PubMed

Selig, Michael J; Viamajala, Sridhar; Decker, Stephen R; Tucker, Melvin P; Himmel, Michael E; Vinzant, Todd B

2007-01-01

Electron microscopy of lignocellulosic biomass following high-temperature pretreatment revealed the presence of spherical formations on the surface of the residual biomass. The hypothesis that these droplet formations are composed of lignins and possible lignin carbohydrate complexes is being explored. Experiments were conducted to better understand the formation of these "lignin" droplets and the possible implications they might have on the enzymatic saccharification of pretreated biomass. It was demonstrated that these droplets are produced from corn stover during pretreatment under neutral and acidic pH at and above 130 degrees C, and that they can deposit back onto the surface of residual biomass. The deposition of droplets produced under certain pretreatment conditions (acidic pH; T > 150 degrees C) and captured onto pure cellulose was shown to have a negative effect (5-20%) on the enzymatic saccharification of this substrate. It was noted that droplet density (per unit area) was greater and droplet size more variable under conditions where the greatest impact on enzymatic cellulose conversion was observed. These results indicate that this phenomenon has the potential to adversely affect the efficiency of enzymatic conversion in a lignocellulosic biorefinery.

Mechanisms of base-cation depletion by acid deposition in forest soils of the northeastern U.S.

Treesearch

Gregory B. Lawrence; Mark B. David; Walter C. Shortle; Scott W. Bailey; Gary M. Lovett

1999-01-01

Several studies have indicated a long-term decrease in exchangeable Ca in forest soils within the northeastern Unrted States, but the regional extent of these decreases and the importance of acid deposition as a cause has not been fully resolved. Results, from two recently completed studies have provided the opportunity to further investigate the role of acid...

Template-directed deposition of amyloid

NASA Astrophysics Data System (ADS)

Ha, Chanki

The formation of amyloid plaques in tissue is a pathological feature of many neurodegenerative diseases. Amyloid deposition, the process of amyloid plaque growth by the association of individual soluble amyloid molecules with a pre-existing amyloid template (i.e. plaque), is known to be critical for amyloid formation in vivo. In order to characterize amyloid deposition, we developed novel, synthetic amyloid templates like amyloid plaques in the human Alzheimer's brain by attaching amyloid seeds covalently onto an N-hydroxysuccinimide-activated surface. Amyloid plaques with a characteristic beta-sheet structure formed through a conformational rearrangement of soluble insulin or Abeta monomers upon interaction with the template. The amyloid deposition rate followed saturation kinetics with respect to insulin concentration in the solution. According to visualization of temporal evolution of Abeta plaque deposition on a template, it was found that mature amyloid plaques serve as a sink of soluble Abeta in a solution as well as a reservoir of small aggregates such as oligomers and protofibrils. Quantitative analysis of seeding efficiencies of three different Abeta species revealed that oligomeric forms of Abeta act more efficiently as seeds than monomers or fibrils do. Furthermore, studies on the interaction between Abeta40 and 42 showed an important role of Abeta42 in amyloid deposition. A slightly acidic condition was found to be unfavorable for amyloid plaque formation. Effects of metal ions on amyloid deposition indicated that Fe3+, but not Cu3 and Zn2+, is important for the deposition of amyloid plaques. The binding of Fe3+ to Abeta42 peptide was confirmed by using SIMS analysis. Zn2+ induced nonfibrillar amorphous aggregates, but the release of Zn2+ from Abeta42 deposits by Fe3+ triggered the formation of amyloid fibers. Effects or metal ion chelators such as ethylenediamine tetraacetic acid, deferoxamine, and clioquinol on amyloid deposition were tested to

The Response of Stream and Soil Chemistry to Decreases in Acid Deposition in the Catskill Mountains, New York, USA

NASA Astrophysics Data System (ADS)

McHale, M. R.; Burns, D. A.; Siemion, J.; Antidormi, M. R.

2016-12-01

The Catskill Mountains have been adversely impacted by decades of acid deposition, however, since the early 1990s, acid deposition levels have decreased sharply as a result of decreases in emissions of sulfur dioxide and nitrogen oxides. The purpose of this study is to provide updated trends in acid deposition and stream-water chemistry in the southeastern Catskill Mountains and to examine whether soil chemistry has shown signs of recovery during the past 2 decades. We measured significant reductions in acid deposition in the region during the 23 year period from 1992 to 2014. The reductions were reflected in significant improvement in stream-water quality in all 5 of the streams included in this study. The largest and most significant trends were for sulfate (SO42-) concentrations (mean trend of -2.5 μeq L-1 yr-1 for 5 sites); hydrogen ion (H+) also decreased significantly as did inorganic monomeric aluminum (Alim) which is toxic to some aquatic biota (mean trends of -0.3 μeq L-1 yr-1 for H+ and -0.1 μeq L-1 yr-1 for Alim for the 3 most acidic sites). Acid neutralizing capacity (ANC) increased a mean of 0.65 μeq L-1 yr-1 for all 5 sites, which was 4 fold less than the decrease in SO42- concentrations. These upward trends in ANC were limited in part by coincident decreases in base cations (-1.3 μeq L-1 yr-1 for calcium + magnesium). No significant trends were detected in stream-water nitrate (NO3-) concentrations despite significant decreasing trends in NO3- deposition. This incongruity is likely caused by the large biological demand and complex cycling processes of nitrogen. Despite the decreases in stream-water acidity, we measured no recovery in soil chemistry which we attributed to soils with low buffering capacity that have been further depleted by decades of acid deposition. Tightly coupled decreasing trends in stream-water silicon (Si) (-0.2 μeq L-1 yr-1) and base cations suggest a decrease in the soil mineral weathering rate. We hypothesize that a

Assessment of lake sensitivity to acidic deposition in national parks of the Rocky Mountains

USGS Publications Warehouse

Nanus, L.; Williams, M.W.; Campbell, D.H.; Tonnessen, K.A.; Blett, T.; Clow, D.W.

2009-01-01

The sensitivity of high-elevation lakes to acidic deposition was evaluated in five national parks of the Rocky Mountains based on statistical relations between lake acid-neutralizing capacity concentrations and basin characteristics. Acid-neutralizing capacity (ANC) of 151 lakes sampled during synoptic surveys and basin-characteristic information derived from geographic information system (GIS) data sets were used to calibrate the statistical models. The explanatory basin variables that were considered included topographic parameters, bedrock type, and vegetation type. A logistic regression model was developed, and modeling results were cross-validated through lake sampling during fall 2004 at 58 lakes. The model was applied to lake basins greater than 1 ha in area in Glacier National Park (n = 244 lakes), Grand Teton National Park (n = 106 lakes), Great Sand Dunes National Park and Preserve (n = 11 lakes), Rocky Mountain National Park (n = 114 lakes), and Yellowstone National Park (n = 294 lakes). Lakes that had a high probability of having an ANC concentration 3000 m, with 80% of the catchment bedrock having low buffering capacity. The modeling results indicate that the most sensitive lakes are located in Rocky Mountain National Park and Grand Teton National Park. This technique for evaluating the lake sensitivity to acidic deposition is useful for designing long-term monitoring plans and is potentially transferable to other remote mountain areas of the United States and the world.

Critical Loads of Acid Deposition for Wilderness Lakes in the Sierra Nevada (California) Estimated by the Steady-State Water Chemistry Model

Treesearch

Glenn D. Shaw; Ricardo Cisneros; Donald Schweizer; James O. Sickman; Mark E. Fenn

2014-01-01

Major ion chemistry (2000-2009) from 208 lakes (342 sample dates and 600 samples) in class I and II wilderness areas of the Sierra Nevada was used in the Steady-State Water Chemistry (SSWC) model to estimate critical loads for acid deposition and investigate the current vulnerability of high elevation lakes to acid deposition. The majority of the lakes were dilute (...

Response of DOC in acid-sensitive Maine lakes to decreasing sulfur deposition (1993 - 2009)

EPA Science Inventory

In response to the Clean Air Act Amendments of 1990, sulfur deposition has decreased across the northeastern United States. As a result, sulfate concentrations in lakes and streams have also decreased and many surface waters have become less acidic. Over the same time period, th...

Acid Rain

USGS Publications Warehouse

Bricker, Owen P.; Rice, Karen C.

1993-01-01

Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

Acid Rain

USGS Publications Warehouse

Bricker, Owen P.; Rice, Karen C.; Dietrich, W.E.; Sposito, Garrison

1997-01-01

Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

Acid rain attack on outdoor sculpture in perspective

NASA Astrophysics Data System (ADS)

Livingston, Richard A.

2016-12-01

A major concern motivating research in acid rain materials effects has been the potential for damage to cultural heritage, particularly outdoor marble and bronze sculpture. However, a combination of field and laboratory studies has failed to show a correlation between rain pH and loss of materials. In order to understand this counterintuitive lack of acid rain effect, an aqueous geochemical modeling approach was used to analyze rain runoff chemistry for the relative importance of acid rain neutralization, dry deposition, and in the case of marble, natural carbonate dissolution. This approach involved the development of pH - SO42- phase diagrams for marble (calcium carbonate) and bronze (copper) under ambient environmental conditions. This then enabled reaction path modeling of the acid neutralization process using the pH range typically found in wet deposition (3.5-6). The results were for marble that the theoretical maximum amount of Ca2+ ion that could be lost due acid rain neutralization would be 0.158 mmol/l compared to 10.5 mmol/l by dry deposition, and for bronze, the Cu2+ ion losses would be 0.21 mmol/l and 47.3 mmol/l respectively. Consequently dry deposition effects on these materials have the potential to dominate over wet deposition effects. To test these predictions the geochemical models were applied to examples of data sets from mass balance (runoff vs rainfall) studies on a marble statue in New York City and some bronze memorial plaques at Gettysburg PA. Although these data sets were collected in the early 1980s they remain valid for demonstrating the mass balance method. For the marble statue, the mean Ca2+ losses by dry deposition was about 69% of the total compared 0.3% for acid rain neutralization, which was less than the natural carbonate dissolution losses of 0.8%. For the bronze, the mean Cu2+ losses were 70.6% by SO42- dry deposition and 23% by NO3- dry deposition compared to 6.4% by acid rain neutralization. Thus for both cases the wet

Effects of acid deposition on dissolution of carbonate stone during summer storms in the Adirondack Mountains, New York, 1987-89

USGS Publications Warehouse

Schuster, Paul F.; Reddy, Michael M.; Sherwood, S.I.

1994-01-01

This study is part of a long-term research program designed to identify and quantify acid rain damage to carbonate stone. Acidic deposition accelerates the dissolution of carbonate-stone monuments and building materials. Sequential sampling of runoff from carbonate-stone (marble) and glass (reference) microcatchments in the Adirondack Mountains in New York State provided a detailed record of the episodic fluctuations in rain rate and runoff chemistry during individual summer storms. Rain rate and chemical concentrations from carbonate-stone and glass runoff fluctuated three to tenfold during storms. Net calcium-ion concentrations from the carbonatestone runoff, a measure of stone dissolution, typically fluctuated twofold during these storms. High net sulfate and net calcium concentrations in the first effective runoff at the start of a storm indicated that atmospheric pollutants deposited on the stone surface during dry periods formed calcium sulfate minerals, an important process in carbonate stone dissolution. Dissolution of the carbonate stone generally increased up to twofold during coincident episodes of low rain rate (less than 5 millimeters per hour) and decreased rainfall (glass runoff) pH (less than 4.0); episodes of high rain rate (cloudbursts) were coincident with a rapid increase in rainfall pH and also a rapid decrease in the dissolution of carbonate-stone. During a storm, it seems the most important factors causing increased dissolution of carbonate stone are coincident periods of low rain rate and decreased rainfall pH. Dissolution of the carbonate stone decreased slightly as the rain rate exceeded about 5 millimeters per hour, probably in response to rapidly increasing rainfall pH during episodes of high rain rate and shorter contact time between the runoff and the stone surface. High runoff rates resulting from cloudbursts remove calcium sulfate minerals formed during dry periods prior to storms and also remove dissolution products formed in large

Contemporaneous deposition of phyllosilicates and sulfates: Using Australian acidic saline lake deposits to describe geochemical variability on Mars

USGS Publications Warehouse

Baldridge, A.M.; Hook, S.J.; Crowley, J.K.; Marion, G.M.; Kargel, J.S.; Michalski, J.L.; Thomson, B.J.; de Souza, Filho C.R.; Bridges, N.T.; Brown, A.J.

2009-01-01

Studies of the origin of the Martian sulfate and phyllosilicate deposits have led to the hypothesis that there was a marked, global-scale change in the Mars environment from circum-neutral pH aqueous alteration in the Noachian to an acidic evaporitic system in the late Noachian to Hesperian. However, terrestrial studies suggest that two different geochemical systems need not be invoked to explain such geochemical variation.Western Australian acidic playa lakes have large pH differences separated vertically and laterally by only a few tens of meters, demonstrating how highly variable chemistries can coexist over short distances in natural environments. We suggest diverse and variable Martian aqueous environments where the coetaneous formation of phyllosilicates and sulfates at the Australian sites are analogs for regions where phyllosilicates and sulfates coexist on Mars. In these systems, Fe and alkali earth phyllosilicates represent deep facies associated with upwelling neutral to alkaline groundwater, whereas aluminous phyllosilicates and sulfates represent near-surface evaporitic facies formed from more acidic brines. Copyright 2009 by the American Geophysical Union.

Effects of simulated deposition of acid mist and iron ore particulate matter on photosynthesis and the generation of oxidative stress in Schinus terebinthifolius Radii and Sophora tomentosa L.

PubMed

Kuki, Kacilda Naomi; Oliva, Marco Antônio; Pereira, Eduardo Gusmão; Costa, Alan Carlos; Cambraia, José

2008-09-15

Particulate matter is a natural occurrence in the environment, but some industries, such as the iron ore sector, can raise the total amount of particles in the atmosphere. This industry is primarily a source of iron and sulfur dioxide particulates. The effects of the pollutants from the iron ore industries on representatives of restinga vegetation in a Brazilian coastal ecosystem were investigated using physiological and biochemical measures. Two species, Schinus terebinthifolius and Sophora tomentosa, were exposed to simulated deposition of acid mist and iron ore particulate matter in acrylic chambers in a greenhouse. Parameters such as gas exchange, fluorescence emission, chlorophyll content, total iron content, antioxidant enzyme activity and malondialdehyde content were assessed in order to evaluate the responses of the two species. Neither treatment was capable of inducing oxidative stress in S. terebinthifolius. Nevertheless, the deposition of iron ore particulates on this species increased chlorophyll content, the maximum quantum efficiency of photosystem II and the electron transport rate, while iron content was unaltered. On the other hand, S. tomentosa showed a greater sensitivity to the treatments. Plants of S. tomentosa that were exposed to acid mist had a decrease in photosynthesis, while the deposition of iron particulate matter led to an increase in iron content and membrane permeability of the leaves. The activities of antioxidant enzymes, such as catalases and superoxide dismutase, were enhanced by both treatments. The results suggested that the two restinga species use different strategies to overcome the stressful conditions created by the deposition of particulate matter, either solid or wet. It seems that while S. terebinthifolius avoided stress, S. tomentosa used antioxidant enzyme systems to partially neutralize oxidative stress. The findings also point to the potential use of S. tomentosa as a biomarker species under field conditions.

PERSISTENT EPISODIC ACIDIFICATION OF STREAMS LINKED TO ACID RAIN EFFECTS ON SOIL

EPA Science Inventory

Episodic acidification of streams, identified in the late 1980s as one of the most significant environmental problems caused by acidic deposition, had not been evaluated since the early 1990s despite decreasing levels of acidic deposition over the past decade. This analysis indic...

Adsorptive removal of sulfate from acid mine drainage by polypyrrole modified activated carbons: Effects of polypyrrole deposition protocols and activated carbon source.

PubMed

Hong, Siqi; Cannon, Fred S; Hou, Pin; Byrne, Tim; Nieto-Delgado, Cesar

2017-10-01

Polypyrrole modified activated carbon was used to remove sulfate from acid mine drainage water. The polypyrrole modified activated carbon created positively charged functionality that offered elevated sorption capacity for sulfate. The effects of the activated carbon type, approach of polymerization, preparation temperature, solvent, and concentration of oxidant solution over the sulfate adsorption capacity were studied at an array of initial sulfate concentrations. A hardwood based activated carbon was the more favorable activated carbon template, and this offered better sulfate removal than when using bituminous based activated carbon or oak wood activated carbon as the template. The hardwood-based activated carbon modified with polypyrrole removed 44.7 mg/g sulfate, and this was five times higher than for the pristine hardwood-based activated carbon. Various protocols for depositing the polypyrrole onto the activated carbon were investigated. When ferric chloride was used as an oxidant, the deposition protocol that achieved the most N + atomic percent (3.35%) while also maintaining the least oxygen atomic percent (6.22%) offered the most favorable sulfate removal. For the rapid small scale column tests, when processing the AMD water, hardwood-based activated carbon modified with poly pyrrole exhibited 33 bed volume compared to the 5 bed volume of pristine activated carbons. Copyright © 2017 Elsevier Ltd. All rights reserved.

Insights from the metagenome of an acid salt lake: the role of biology in an extreme depositional environment.

PubMed

Johnson, Sarah Stewart; Chevrette, Marc Gerard; Ehlmann, Bethany L; Benison, Kathleen Counter

2015-01-01

The extremely acidic brine lakes of the Yilgarn Craton of Western Australia are home to some of the most biologically challenging waters on Earth. In this study, we employed metagenomic shotgun sequencing to generate a microbial profile of the depositional environment associated with the sulfur-rich sediments of one such lake. Of the 1.5 M high-quality reads generated, 0.25 M were mapped to protein features, which in turn provide new insights into the metabolic function of this community. In particular, 45 diverse genes associated with sulfur metabolism were identified, the majority of which were linked to either the conversion of sulfate to adenylylsulfate and the subsequent production of sulfide from sulfite or the oxidation of sulfide, elemental sulfur, and thiosulfate via the sulfur oxidation (Sox) system. This is the first metagenomic study of an acidic, hypersaline depositional environment, and we present evidence for a surprisingly high level of microbial diversity. Our findings also illuminate the possibility that we may be meaningfully underestimating the effects of biology on the chemistry of these sulfur-rich sediments, thereby influencing our understanding of past geobiological conditions that may have been present on Earth as well as early Mars.

Insights from the Metagenome of an Acid Salt Lake: The Role of Biology in an Extreme Depositional Environment

PubMed Central

Johnson, Sarah Stewart; Chevrette, Marc Gerard; Ehlmann, Bethany L.; Benison, Kathleen Counter

2015-01-01

The extremely acidic brine lakes of the Yilgarn Craton of Western Australia are home to some of the most biologically challenging waters on Earth. In this study, we employed metagenomic shotgun sequencing to generate a microbial profile of the depositional environment associated with the sulfur-rich sediments of one such lake. Of the 1.5 M high-quality reads generated, 0.25 M were mapped to protein features, which in turn provide new insights into the metabolic function of this community. In particular, 45 diverse genes associated with sulfur metabolism were identified, the majority of which were linked to either the conversion of sulfate to adenylylsulfate and the subsequent production of sulfide from sulfite or the oxidation of sulfide, elemental sulfur, and thiosulfate via the sulfur oxidation (Sox) system. This is the first metagenomic study of an acidic, hypersaline depositional environment, and we present evidence for a surprisingly high level of microbial diversity. Our findings also illuminate the possibility that we may be meaningfully underestimating the effects of biology on the chemistry of these sulfur-rich sediments, thereby influencing our understanding of past geobiological conditions that may have been present on Earth as well as early Mars. PMID:25923206

The response of soil and stream chemistry to decreases in acid deposition in the Catskill Mountains, New York, USA

USGS Publications Warehouse

McHale, Michael; Burns, Douglas A.; Siemion, Jason; Antidormi, Michael

2017-01-01

The Catskill Mountains have been adversely impacted by decades of acid deposition, however, since the early 1990s, levels have decreased sharply as a result of decreases in emissions of sulfur dioxide and nitrogen oxides. This study examines trends in acid deposition, stream-water chemistry, and soil chemistry in the southeastern Catskill Mountains. We measured significant reductions in acid deposition and improvement in stream-water quality in 5 streams included in this study from 1992 to 2014. The largest, most significant trends were for sulfate (SO42−) concentrations (mean trend of −2.5 μeq L−1 yr−1); hydrogen ion (H+) and inorganic monomeric aluminum (Alim) also decreased significantly (mean trends of −0.3 μeq L−1 yr−1 for H+ and −0.1 μeq L−1 yr−1 for Alim for the 3 most acidic sites). Acid neutralizing capacity (ANC) increased by a mean of 0.65 μeq L−1 yr−1 for all 5 sites, which was 4 fold less than the decrease in SO42−concentrations. These upward trends in ANC were limited by coincident decreases in base cations (−1.3 μeq L−1 yr−1 for calcium + magnesium). No significant trends were detected in stream-water nitrate (NO3−) concentrations despite significant decreasing trends in NO3− wet deposition. We measured no recovery in soil chemistry which we attributed to an initially low soil buffering capacity that has been further depleted by decades of acid deposition. Tightly coupled decreasing trends in stream-water silicon (Si) (−0.2 μeq L−1 yr−1) and base cations suggest a decrease in the soil mineral weathering rate. We hypothesize that a decrease in the ionic strength of soil water and shallow groundwater may be the principal driver of this apparent decrease in the weathering rate. A decreasing weathering rate would help to explain the slow recovery of stream pH and ANC as well as that of soil base cations.

Persistent episodic acidification of streams linked to acid rain effects on soil

USGS Publications Warehouse

Lawrence, G.B.

2002-01-01

Episodic acidification of streams, identified in the late 1980s as one of the most significant environmental problems caused by acidic deposition, had not been evaluated since the early 1990s despite decreasing levels of acidic deposition over the past decade. This analysis indicates that episodic acidification of streams in upland regions in the northeastern United States persists, and is likely to be much more widespread than chronic acidification. Depletion of exchangeable Ca in the mineral soil has decreased the neutralization capacity of soils and increased the role of the surface organic horizon in the neutralization of acidic soil water during episodes. Increased accumulation of N and S in the forest floor from decades of acidic deposition will delay the recovery of soil base status, and therefore, the elimination of acidic episodes, which is anticipated from decreasing emissions.

A deposit model for Mississippi Valley-Type lead-zinc ores: Chapter A in Mineral deposit models for resource assessment

USGS Publications Warehouse

Leach, David L.; Taylor, Ryan D.; Fey, David L.; Diehl, Sharon F.; Saltus, Richard W.

2010-01-01

This report also describes the geoenvironmental characteristic of MVT deposits. The response of MVT ores in the supergene environment is buffered by their placement in carbonate host rocks which commonly results in near-neutral associated drainage water. The geoenvironmental features and anthropogenic mining effects presented in this report illustrates this important environmental aspect of MVT deposits which separates them from other deposit types (especially coal, VHMS, Cu-porphyry, SEDEX, acid-sulfate polymetallic vein).

Hexanoic Acid Treatment Prevents Systemic MNSV Movement in Cucumis melo Plants by Priming Callose Deposition Correlating SA and OPDA Accumulation.

PubMed

Fernández-Crespo, Emma; Navarro, Jose A; Serra-Soriano, Marta; Finiti, Iván; García-Agustín, Pilar; Pallás, Vicente; González-Bosch, Carmen

2017-01-01

Unlike fungal and bacterial diseases, no direct method is available to control viral diseases. The use of resistance-inducing compounds can be an alternative strategy for plant viruses. Here we studied the basal response of melon to Melon necrotic spot virus (MNSV) and demonstrated the efficacy of hexanoic acid (Hx) priming, which prevents the virus from systemically spreading. We analysed callose deposition and the hormonal profile and gene expression at the whole plant level. This allowed us to determine hormonal homeostasis in the melon roots, cotyledons, hypocotyls, stems and leaves involved in basal and hexanoic acid-induced resistance (Hx-IR) to MNSV. Our data indicate important roles of salicylic acid (SA), 12-oxo-phytodienoic acid (OPDA), jasmonic-isoleucine, and ferulic acid in both responses to MNSV. The hormonal and metabolites balance, depending on the time and location associated with basal and Hx-IR, demonstrated the reprogramming of plant metabolism in MNSV-inoculated plants. The treatment with both SA and OPDA prior to virus infection significantly reduced MNSV systemic movement by inducing callose deposition. This demonstrates their relevance in Hx-IR against MNSV and a high correlation with callose deposition. Our data also provide valuable evidence to unravel priming mechanisms by natural compounds.

Hexanoic Acid Treatment Prevents Systemic MNSV Movement in Cucumis melo Plants by Priming Callose Deposition Correlating SA and OPDA Accumulation

PubMed Central

Fernández-Crespo, Emma; Navarro, Jose A.; Serra-Soriano, Marta; Finiti, Iván; García-Agustín, Pilar; Pallás, Vicente; González-Bosch, Carmen

2017-01-01

Unlike fungal and bacterial diseases, no direct method is available to control viral diseases. The use of resistance-inducing compounds can be an alternative strategy for plant viruses. Here we studied the basal response of melon to Melon necrotic spot virus (MNSV) and demonstrated the efficacy of hexanoic acid (Hx) priming, which prevents the virus from systemically spreading. We analysed callose deposition and the hormonal profile and gene expression at the whole plant level. This allowed us to determine hormonal homeostasis in the melon roots, cotyledons, hypocotyls, stems and leaves involved in basal and hexanoic acid-induced resistance (Hx-IR) to MNSV. Our data indicate important roles of salicylic acid (SA), 12-oxo-phytodienoic acid (OPDA), jasmonic-isoleucine, and ferulic acid in both responses to MNSV. The hormonal and metabolites balance, depending on the time and location associated with basal and Hx-IR, demonstrated the reprogramming of plant metabolism in MNSV-inoculated plants. The treatment with both SA and OPDA prior to virus infection significantly reduced MNSV systemic movement by inducing callose deposition. This demonstrates their relevance in Hx-IR against MNSV and a high correlation with callose deposition. Our data also provide valuable evidence to unravel priming mechanisms by natural compounds. PMID:29104580

Red herring in acid rain research

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

Havas, M.; Hutchinson, T.C.; Likens, G.E.

1984-06-01

Five common misconceptions, red herrings, regarding the effects of acid deposition on aquatic ecosystems are described in an attempt to clarify some of the confusion they have created. These misconceptions are the following: Bog lakes have been acidic for thousands of years; thus the acidification of lakes is not a recent phenomenon. The early methods for measuring pH are in error; therfore, no statements can be made regarding historical trends. Acidification of lakes and streams results from changed land use practices (forestry, agriculture, animal husbandry) and not acid deposition. The decrease in fish populations is caused by overfishing, disease, andmore » water pollution, not acidification. Because lakes that receive identical rainfall can have considerable different pHs, regional lake acidification cannot be due to acid precipitation. It is easy to suggest a whole series of alternative, and often unlikely, explanations of the causes and consequences of acid deposition. These keep scientists busy for years assembling and examining data only to conclude that the explanation is not valid. These tactics cause, and perhaps are designed to cause, continuous delay in remedial action. They fail to take into account the large body of information that deals with the sources of the acid deposition and the seriousness of its effects.« less

Simulation of acid mine drainage generation around Küre VMS Deposits, Northern Turkey

NASA Astrophysics Data System (ADS)

Demirel, Cansu; Kurt, Mehmet Ali; Çelik Balci, Nurgül

2015-04-01

This study investigated comparative leaching characteristics of acidophilic bacterial strains under shifting environmental conditions at proposed two stages as formation stage or post acidic mine drainage (AMD) generation. At the first stage, initial reactions associated with AMD generation was simulated in shaking flasks containing massive pyritic chalcopyrite ore by using a pure strain Acidithiobacillus ferrooxidans and a mixed culture of Acidithiobacillus sp. mostly dominated by A. ferrooxidans and A. thiooxidans at 26oC. At the second stage, long term bioleaching experiments were carried out with the same strains at 26oC and 40oC to investigate the leaching characteristics of pyritic chalcopyrite ore under elevated heavy metal and temperature conditions. During the experiments, physicochemical characteristics (e.i. Eh, pH, EC) metal (Fe, Co, Cu, Zn) and sulfate concentration of the experimental solution were monitored during 180 days. Significant acid generation and sulfate release were determined during bioleaching of the ore by mixed acidophilic cultures containing both iron and sulfur oxidizers. In the early stage of the experiments, heavy metal release from the ore was caused by generation of acid due to accelerated bacterial oxidation of the ore. Generally high concentrations of Co and Cu were released into the solution from the experiments conducted by pure cultures of Acidithiobacillus ferrooxidans whereas high Zn and Fe was released into the solution from the mixed culture experiments. In the later stage of AMD generation and post AMD, chemical oxidation is accelerated causing excessive amounts of contamination, even exceeding the amounts resulted from bacterial oxidation by mixed cultures. Acidithibacillus ferrooxidans was found to be more effective in leaching Cu, Fe and Co at higher temperatures in contrary to mixed acidophiles that are more prone to operate at optimal moderate conditions. Moreover, decreasing Fe values are noted in bioleaching

Maternal docosahexaenoic acid increases adiponectin and normalizes IUGR-induced changes in rat adipose deposition.

PubMed

Bagley, Heidi N; Wang, Yan; Campbell, Michael S; Yu, Xing; Lane, Robert H; Joss-Moore, Lisa A

2013-01-01

Intrauterine growth restriction (IUGR) predisposes to obesity and adipose dysfunction. We previously demonstrated IUGR-induced increased visceral adipose deposition and dysregulated expression of peroxisome proliferator activated receptor- γ 2 (PPAR γ 2) in male adolescent rats, prior to the onset of obesity. In other studies, activation of PPAR γ increases subcutaneous adiponectin expression and normalizes visceral adipose deposition. We hypothesized that maternal supplementation with docosahexaenoic acid (DHA), a PPAR γ agonist, would normalize IUGR adipose deposition in association with increased PPAR γ , adiponectin, and adiponectin receptor expression in subcutaneous adipose. To test these hypotheses, we used a well-characterized model of uteroplacental-insufficiency-(UPI-) induced IUGR in the rat with maternal DHA supplementation. Our primary findings were that maternal DHA supplementation during rat pregnancy and lactation (1) normalizes IUGR-induced changes in adipose deposition and visceral PPAR γ expression in male rats and (2) increases serum adiponectin, as well as adipose expression of adiponectin and adiponectin receptors in former IUGR rats. Our novel findings suggest that maternal DHA supplementation may normalize adipose dysfunction and promote adiponectin-induced improvements in metabolic function in IUGR.

A case study on the influences of long-range transport to Taiwan`s acid deposition using Taiwan air quality model

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

Ken-Hui Chang; Fu-Tien Jeng

1996-12-31

The long-range and transboundary transport of precursors of add deposition in East Asia became important due to the industrial development around this area. We started to develop Taiwan Air Quality Model (TAQM) system since 1992, which is based on regional Acid Deposition Model (RADM) system. A typical episode in Mei-Yu season has been selected to study. A case considering all emissions within simulated domain has been run as a reference case, and another perturbed case, not including Taiwan`s emission, has been also run for analyzing quantitatively the influence of long-range transport to Taiwan`s wet deposition during the episode are 31%more » and 24% for total sulfur compounds and total nitrogen compounds respectively; but for dry deposition, only 6% is contributed by long range transport for sulfur compounds and 29% for total nitrogen compounds. Therefore, the percentages of total acid deposition contributed by long-range transport are 27% and 25% for total sulfur compounds and total nitrogen compounds, respectively.« less

Acidic deposition and red spruce in the central and southern Appalachians, past and present

Treesearch

Mary Beth. Adams

2010-01-01

During the 1980s, the Spruce-Fir Research Program, part of the Congressionally mandated National Atmospheric Precipitation Assessment Program (NAPAP), investigated the links between acidic deposition and decline and mortality of red spruce forests in the eastern United States. The Spruce-Fir Research Program was highly successful in advancing the state of knowledge on...

Effect of titanium oxide compact layer in dye-sensitized solar cell prepared by liquid-phase deposition

NASA Astrophysics Data System (ADS)

Huang, Jung-Jie; Chiu, Shih-Ping; Wu, Menq-Jion; Hsu, Chun-Fa

2016-11-01

In this study, titanium dioxide films were deposited on indium tin oxide glass substrates by liquid-phase deposition (LPD) for application as the compact layer in dye-sensitized solar cells (DSSCs). A deposition solution of ammonium hexafluorotitanate and boric acid was used for TiO2 deposition. Compact layer passivation can improve DSSC performance by decreasing carrier losses from recombination at the ITO/electrolyte interface and improving the electrical contact between the ITO and the TiO2 photo-electrode. The optimum thickness of the compact layer was found to be 48 nm, which resulted in a 50 % increase in the conversion efficiency compared with cells without compact layers. The conversion efficiency can be increased from 3.55 to 5.26 %. Therefore, the LPD-TiO2 compact layer inhibits the dark current and increases the short-circuit current density effectively.

Acidic deposition, cation mobilization, and biochemical indicators of stress in healthy red spruce

USGS Publications Warehouse

Shortle, W.C.; Smith, K.T.; Minocha, R.; Lawrence, G.B.; David, M.B.

1997-01-01

Dendrochemical and biochemical markers link stress in apparently healthy red spruce trees (Picea rubens) to acidic deposition. Acidic deposition to spruce forests of the northeastern USA increased sharply during the 1960s. Previous reports related visible damage of trees at high elevations to root and soil processes. In this report, dendrochemical and foliar biochemical markers indicate perturbations in biological processes in healthy red spruce trees across the northeastern USA. Previous research on the dendrochemistry of red spruce stemwood indicated that under uniform environmental conditions, stemwood concentrations of Ca and Mg decreased with increasing radial distance from the pith. For nine forest locations, frequency analysis shows that 28 and 52% of samples of red spruce stemwood formed in the 1960s are enriched in Ca and Mg, respectively, relative to wood formed prior to and after the 1960s. This enrichment in trees throughout the northeastern USA may be interpretable as a signal of increased availability of essential cations in forest soils. Such a temporary increase in the availability of Ca and Mg could be caused by cation mobilization, a consequence of increased acidic deposition. During cation mobilization, essential Ca and Mg as well as potentially harmful Al become more available for interaction with binding sites in the soil and absorbing roots. As conditions which favor cation mobilization continue, Ca and Mg can be leached or displaced from the soil. A measure of the interaction between Ca and Al is the Al/Ca binding ratio (molar charge ratio of exchangeable Al to exchangeable Ca). As the Al/Ca binding ratio in the root zone increased from 0.3 to 1.9, the foliar concentration of the biochemical stress marker putrescine also increased from 45 to 145 nm g-1. The correlation of the putrescine concentration to the Al/Ca binding ratio (adj. r2 = 0.68, P < 0.027) suggests that foliar stress may be linked to soil chemistry.

Humic substances and trace metals associated with Fe and Al oxides deposited in an acidic mountain stream

USGS Publications Warehouse

McKnight, Diane M.; Wershaw, R. L.; Bencala, K.E.; Zellweger, G.W.; Feder, G.L.

1992-01-01

Hydrous iron and aluminum oxides are deposited on the streambed in the confluence of the Snake River and Deer Creek, two streams in the Colorado Rocky Mountains. The Snake River is acidic and has high concentrations of dissolved Fe and Al. These metals precipitate at the confluence with the pristine, neutral pH, Deer Creek because of the greater pH (4.5-6.0) in the confluence. The composition of the deposited oxides changes consistently with distance downstream, with the most upstream oxide samples having the greatest Fe and organic carbon content. Fulvic acid accounts for most of the organic content of the oxides. Results indicate that streambed oxides in the confluence are not saturated with respect to their capacity to sorb dissolved humic substances from streamwater. The contents of several trace metals (Mn, Zn, Cu, Pb, Ni and Co) also decrease with distance downstream and are correlated with both the Fe and organic carbon contents. Strong metal-binding sites associated with the sorbed fulvic acid are more than sufficient to account for the trace metal content of the oxides. Complexation of trace metals by sorbed fulvic acid may explain the observed downstream decrease in trace metal content.

Early indications of soil recovery from acidic deposition in U.S. red spruce forests

Treesearch

Gregory B. Lawrence; Walter C. Shortle; Mark B. David; Kevin T. Smith; Richard A. Warby; Andrei G. Lapenis

2012-01-01

Forty to fifty percent decreases in acidic deposition through the 1980s and 1990s led to partial recovery of acidified surface waters in the northeastern United States; however, the limited number of studies that have assessed soil change found increased soil acidification during this period. From existing data, it's not clear whether soils continued to worsen in...

Effects of future sulfate and nitrate deposition scenarios on Linville Gorge and Shining Rock Wildernesses

Treesearch

Katherine J. Elliott; James M. Vose; William A. Jackson

2013-01-01

We used the Nutrient Cycling Model (NuCM) to simulate the effects of various sulfur (S) and nitrogen (N) deposition scenarios on wilderness areas in Western North Carolina. Linville Gorge Wilderness (LGW) and Shining Rock Wilderness (SRW) were chosen because they are high elevation acidic cove forests and are located on geologic parent material known to be low in base...

Interactive effects of elevated CO2 and nitrogen deposition on fatty acid molecular and isotope composition of above- and belowground tree biomass and forest soil fractions.

PubMed

Griepentrog, Marco; Eglinton, Timothy I; Hagedorn, Frank; Schmidt, Michael W I; Wiesenberg, Guido L B

2015-01-01

Atmospheric carbon dioxide (CO2) and reactive nitrogen (N) concentrations have been increasing due to human activities and impact the global carbon (C) cycle by affecting plant photosynthesis and decomposition processes in soil. Large amounts of C are stored in plants and soils, but the mechanisms behind the stabilization of plant- and microbial-derived organic matter (OM) in soils are still under debate and it is not clear how N deposition affects soil OM dynamics. Here, we studied the effects of 4 years of elevated (13C-depleted) CO2 and N deposition in forest ecosystems established in open-top chambers on composition and turnover of fatty acids (FAs) in plants and soils. FAs served as biomarkers for plant- and microbial-derived OM in soil density fractions. We analyzed above- and belowground plant biomass of beech and spruce trees as well as soil density fractions for the total organic C and FA molecular and isotope (δ13C) composition. FAs did not accumulate relative to total organic C in fine mineral fractions, showing that FAs are not effectively stabilized by association with soil minerals. The δ13C values of FAs in plant biomass increased under high N deposition. However, the N effect was only apparent under elevated CO2 suggesting a N limitation of the system. In soil fractions, only isotope compositions of short-chain FAs (C16+18) were affected. Fractions of 'new' (experimental-derived) FAs were calculated using isotope depletion in elevated CO2 plots and decreased from free light to fine mineral fractions. 'New' FAs were higher in short-chain compared to long-chain FAs (C20-30), indicating a faster turnover of short-chain compared to long-chain FAs. Increased N deposition did not significantly affect the quantity of 'new' FAs in soil fractions, but showed a tendency of increased amounts of 'old' (pre-experimental) C suggesting that decomposition of 'old' C is retarded by high N inputs. © 2014 John Wiley & Sons Ltd.

Further emissions cuts needed for speedier acid rain recovery

NASA Astrophysics Data System (ADS)

Showstack, Randy

Some people may have thought that the problem of acid deposition, commonly referred to as acid rain, had been solved in the United States with the passage of the Acid Deposition Control Program under Title IV of the 1990 Clean Air Act Amendments (CAAA).Although that legislation has helped to dramatically limit emissions of sulfur dioxide and nitrogen oxide—gases that can react in the atmosphere and form acidic compounds, including fine particles of sulfates and nitrates— much steeper cuts are needed for a quicker recovery from acid rain in the north-eastern United States, according to a new scientific appraisal of the effectiveness of measures called for in that law. The appraisal was issued on March 26 and is entitled “Acidic Deposition in the Northeastern United States: Sources and Inputs, Ecosystem Effects, and Management Strategies.”

Insights into electrodeposition of an inhibitor film and its inhibitive effects on calcium carbonate deposition.

PubMed

Morizot, Arnaud P; Neville, Anne

2002-01-01

Polycarboxylic acid (PAA), a common scale inhibitor has demonstrated adsorption properties on stainless steel surfaces. An electrochemically based technique has been used to assess the extent of film formation. The presence of calcium and magnesium ions in the solution and the cathodic electrochemical activity at the metal surface have been shown to enhance the inhibitor film formation by promoting the transport of the inhibitor from the solution to the metal surface. The effect of the inhibitor film in retarding scale deposition is assessed using measurement of the deposition onto metal electrodes immersed in a supersaturated solution of CaCO(3). The practical implications of these findings are discussed.

Target loads of atmospheric sulfur and nitrogen deposition for protection of acid sensitive aquatic resources in the Adirondack Mountains, New York

USGS Publications Warehouse

Sullivan, T.J.; Cosby, B.J.; Driscoll, C.T.; McDonnell, T.C.; Herlihy, A.T.; Burns, Douglas A.

2012-01-01

The dynamic watershed acid-base chemistry model of acidification of groundwater in catchments (MAGIC) was used to calculate target loads (TLs) of atmospheric sulfur and nitrogen deposition expected to be protective of aquatic health in lakes in the Adirondack ecoregion of New York. The TLs were calculated for two future dates (2050 and 2100) and three levels of protection against lake acidification (acid neutralizing capacity (ANC) of 0, 20, and 50 eq L -1). Regional sulfur and nitrogen deposition estimates were combined with TLs to calculate exceedances. Target load results, and associated exceedances, were extrapolated to the regional population of Adirondack lakes. About 30% of Adirondack lakes had simulated TL of sulfur deposition less than 50 meq m -2 yr to protect lake ANC to 50 eq L -1. About 600 Adirondack lakes receive ambient sulfur deposition that is above this TL, in some cases by more than a factor of 2. Some critical criteria threshold values were simulated to be unobtainable in some lakes even if sulfur deposition was to be decreased to zero and held at zero until the specified endpoint year. We also summarize important lessons for the use of target loads in the management of acid-impacted aquatic ecosystems, such as those in North America, Europe, and Asia. Copyright 2012 by the American Geophysical Union.

Iron dissolution of dust source materials during simulated acidic processing: the effect of sulfuric, acetic, and oxalic acids.

PubMed

Chen, Haihan; Grassian, Vicki H

2013-09-17

Atmospheric organic acids potentially display different capacities in iron (Fe) mobilization from atmospheric dust compared with inorganic acids, but few measurements have been made on this comparison. We report here a laboratory investigation of Fe mobilization of coal fly ash, a representative Fe-containing anthropogenic aerosol, and Arizona test dust, a reference source material for mineral dust, in pH 2 sulfuric acid, acetic acid, and oxalic acid, respectively. The effects of pH and solar radiation on Fe dissolution have also been explored. The relative capacities of these three acids in Fe dissolution are in the order of oxalic acid > sulfuric acid > acetic acid. Oxalate forms mononuclear bidentate ligand with surface Fe and promotes Fe dissolution to the greatest extent. Photolysis of Fe-oxalate complexes further enhances Fe dissolution with the concomitant degradation of oxalate. These results suggest that ligand-promoted dissolution of Fe may play a more significant role in mobilizing Fe from atmospheric dust compared with proton-assisted processing. The role of atmospheric organic acids should be taken into account in global-biogeochemical modeling to better access dissolved atmospheric Fe deposition flux at the ocean surface.

Water availability drives gas exchange and growth of trees in northeastern US, not elevated CO2 and reduced acid deposition.

PubMed

Levesque, Mathieu; Andreu-Hayles, Laia; Pederson, Neil

2017-04-10

Dynamic global vegetation models (DGVM) exhibit high uncertainty about how climate change, elevated atmospheric CO 2 (atm. CO 2 ) concentration, and atmospheric pollutants will impact carbon sequestration in forested ecosystems. Although the individual roles of these environmental factors on tree growth are understood, analyses examining their simultaneous effects are lacking. We used tree-ring isotopic data and structural equation modeling to examine the concurrent and interacting effects of water availability, atm. CO 2 concentration, and SO 4 and nitrogen deposition on two broadleaf tree species in a temperate mesic forest in the northeastern US. Water availability was the strongest driver of gas exchange and tree growth. Wetter conditions since the 1980s have enhanced stomatal conductance, photosynthetic assimilation rates and, to a lesser extent, tree radial growth. Increased water availability seemingly overrides responses to reduced acid deposition, CO 2 fertilization, and nitrogen deposition. Our results indicate that water availability as a driver of ecosystem productivity in mesic temperate forests is not adequately represented in DGVMs, while CO 2 fertilization is likely overrepresented. This study emphasizes the importance to simultaneously consider interacting climatic and biogeochemical drivers when assessing forest responses to global environmental changes.

Simulated effects of reduced sulfur, nitrogen, and base cation deposition on soils and solutions in Southern Appalachian forests

Treesearch

D.W. Johnson; R.B. Susfalk; P.F. Brewer; W.T. Swank

1999-01-01

Effects of reduced deposition of N, S, and CB on nutrient pools, fluxes, soil, and soil solution chemistry were simulated for two Appalachian forest ecosystems using the nutrient cycling model. In the extremely acidic, N- and S-saturated red spruce (Picea rubens (Sarg.)) forest (Nolan Divide), reducing

Valuation of damages to recreational trout fishing in the Upper Northeast due to acidic deposition

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

Englin, J.E.; Cameron, T.A.; Mendelsohn, R.E.

1991-04-01

This report documents methods used to estimate economic models of changes in recreational fishing due to the acidic deposition. The analysis was conducted by Pacific Northwest Laboratory (PNL) and its subcontractors for the US Environmental Protection Agency (EPA) and the US Department of Energy (DOE) in support of the National Acidic Precipitation Assessment Program (NAPAP). The primary data needed to estimate these models were collected in the 1989 Aquatic Based Recreation Survey (ABRS), which was jointly funded by the DOE and the EPA's Office of Policy Planning and Evaluation. 11 refs., 5 figs., 15 tabs.

Creation of superhydrophobic stainless steel surfaces by acid treatments and hydrophobic film deposition.

PubMed

Li, Lester; Breedveld, Victor; Hess, Dennis W

2012-09-26

In this work, we present a method to render stainless steel surfaces superhydrophobic while maintaining their corrosion resistance. Creation of surface roughness on 304 and 316 grade stainless steels was performed using a hydrofluoric acid bath. New insight into the etch process is developed through a detailed analysis of the chemical and physical changes that occur on the stainless steel surfaces. As a result of intergranular corrosion, along with metallic oxide and fluoride redeposition, surface roughness was generated on the nano- and microscales. Differences in alloy composition between 304 and 316 grades of stainless steel led to variations in etch rate and different levels of surface roughness for similar etch times. After fluorocarbon film deposition to lower the surface energy, etched samples of 304 and 316 stainless steel displayed maximum static water contact angles of 159.9 and 146.6°, respectively. However, etching in HF also caused both grades of stainless steel to be susceptible to corrosion. By passivating the HF-etched samples in a nitric acid bath, the corrosion resistant properties of stainless steels were recovered. When a three step process was used, consisting of etching, passivation and fluorocarbon deposition, 304 and 316 stainless steel samples exhibited maximum contact angles of 157.3 and 134.9°, respectively, while maintaining corrosion resistance.

Acid Rain: What's the Forecast?

ERIC Educational Resources Information Center

Bybee, Rodger

1984-01-01

Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)

Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

USGS Publications Warehouse

Spiker, E. C.; Hosker, R.P.; Weintraub, V.C.; Sherwood, S.I.

1995-01-01

The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3

Dendrochemical evidence for soil recovery from acidic deposition in forests of the northeastern U.S. with comparisons to the southeastern U.S. and Russia

Treesearch

Walter C. Shortle; Kevin T. Smith; Andrei G. Lapenis

2017-01-01

A soil resampling approach has detected an early stage of recovery in the cation chemistry of spruce forest soil due to reductions in acid deposition. That approach is limited by the lack of soil data and archived soil samples prior to major increases in acid deposition during the latter half of the 20th century. An alternative approach is the dendrochemical analysis...

Extreme nitrogen deposition can change methane oxidation rate in moist acidic tundra soil in Arctic regions

NASA Astrophysics Data System (ADS)

Lee, J.; Kim, J.; Kang, H.

2017-12-01

Recently, extreme nitrogen(N) deposition events are observed in Arctic regions where over 90% of the annual N deposition occurred in just a few days. Since Arctic ecosystems are typically N-limited, input of extremely high amount of N could substantially affect ecosystem processes. CH4 is a potent greenhouse gas that has 25 times greater global warming potential than CO2 over a 100-year time frame. Ammonium is known as an inhibitor of methane oxidation and nitrate also shows inhibitory effect on it in temperate ecosystems. However, effects of N addition on Arctic ecosystems are still elusive. We conducted a lab-scale incubation experiment with moist acidic tundra (MAT) soil from Council, Alaska to investigate the effect of extreme N deposition events on methane oxidation. Zero point five % methane was added to the head space to determine the potential methane oxidation rate of MAT soil. Three treatments (NH4NO3-AN, (NH4)2SO4-AS, KNO3-PN) were used to compare effects of ammonium, nitrate and salts. All treatments were added in 3 levels: 10μg N gd.w-1(10), 50μg N gd.w-1(50) and 100μg N gd.w-1(100). AN10 and AN50 increased methane oxidation rate 1.7, 6% respectively. However, AN100 shows -8.5% of inhibitory effect. In AS added samples, all 3 concentrations (AN10, AN50, AN100) stimulated methane oxidation rate with 4.7, 8.9, 4%, respectively. On the contrary, PN50 (-9%) and PN100 (-59.5%) exhibited a significant inhibitory effect. We also analyzed the microbial gene abundance and community structures of methane oxidizing bacteria using a DNA-based fingerprinting method (T-RFLP) Our study results suggest that NH4+ can stimulate methane oxidation in Arctic MAT soil, while NO3- can inhibit methane oxidation significantly.

Target loads of atmospheric sulfur deposition for the protection and recovery of acid-sensitive streams in the Southern Blue Ridge Province.

PubMed

Sullivan, Timothy J; Cosby, Bernard J; Jackson, William A

2011-11-01

An important tool in the evaluation of acidification damage to aquatic and terrestrial ecosystems is the critical load (CL), which represents the steady-state level of acidic deposition below which ecological damage would not be expected to occur, according to current scientific understanding. A deposition load intended to be protective of a specified resource condition at a particular point in time is generally called a target load (TL). The CL or TL for protection of aquatic biota is generally based on maintaining surface water acid neutralizing capacity (ANC) at an acceptable level. This study included calibration and application of the watershed model MAGIC (Model of Acidification of Groundwater in Catchments) to estimate the target sulfur (S) deposition load for the protection of aquatic resources at several future points in time in 66 generally acid-sensitive watersheds in the southern Blue Ridge province of North Carolina and two adjoining states. Potential future change in nitrogen leaching is not considered. Estimated TLs for S deposition ranged from zero (ecological objective not attainable by the specified point in time) to values many times greater than current S deposition depending on the selected site, ANC endpoint, and evaluation year. For some sites, one or more of the selected target ANC critical levels (0, 20, 50, 100μeq/L) could not be achieved by the year 2100 even if S deposition was reduced to zero and maintained at that level throughout the simulation. Many of these highly sensitive streams were simulated by the model to have had preindustrial ANC below some of these target values. For other sites, the watershed soils contained sufficiently large buffering capacity that even very high sustained levels of atmospheric S deposition would not reduce stream ANC below common damage thresholds. Copyright © 2011 Elsevier Ltd. All rights reserved.

Correlation analysis of tree growth, climate, and acid deposition in the Lake States.

Treesearch

Margaret R. Holdaway

1990-01-01

Describes research designed to detect subtle regional tree growth trends related to sulfate (SO4) deposition in the Lake States. Correlation methods were used to analyze climatic and SO4 deposition. Effects of SO4 deposition are greater on climatically stressed trees, especially pine species on dry sites, than on unstressed trees. Jack pine growth shows the...

A biogeochemical comparison of two well-buffered catchments with contrasting histories of acid deposition

USGS Publications Warehouse

Shanley, J.B.; Kram, P.; Hruska, J.; Bullen, T.D.

2004-01-01

Much of the biogeochemical cycling research in catchments in the past 25 years has been driven by acid deposition research funding. This research has focused on vulnerable base-poor systems; catchments on alkaline lithologies have received little attention. In regions of high acid loadings, however, even well-buffered catchments are susceptible to forest decline and episodes of low alkalinity in streamwater. As part of a collaboration between the Czech and U.S. Geological Surveys, we compared biogeochemical patterns in two well-studied, well-buffered catchments: Pluhuv Bor in the western Czech Republic, which has received high loading of atmospheric acidity, and Sleepers River Research Watershed in Vermont, U.S.A., where acid loading has been considerably less. Despite differences in lithology, wetness, forest type, and glacial history, the catchments displayed similar patterns of solute concentrations and flow. At both catchments, base cation and alkalinity diluted with increasing flow, whereas nitrate and dissolved organic carbon increased with increasing flow. Sulfate diluted with increasing flow at Sleepers River, while at Pluhuv Bor the sulfate-flow relation shifted from positive to negative as atmospheric sulfur (S) loadings decreased and soil S pools were depleted during the 1990s. At high flow, alkalinity decreased to near 100 ??eq L-1 at Pluhuv Bor compared to 400 ??eq L-1 at Sleepers River. Despite the large amounts of S flushed from Pluhuv Bor soils, these alkalinity declines were caused solely by dilution, which was greater at Pluhuv Bor relative to Sleepers River due to greater contributions from shallow flow paths at high flow. Although the historical high S loading at Pluhuv Bor has caused soil acidification and possible forest damage, it has had little effect on the acid/base status of streamwater in this well-buffered catchment. ?? 2004 Kluwer Academic Publishers.

Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios.

PubMed

Zhao, Bo; Liu, An; Wu, Guangxue; Li, Dunzhu; Guan, Yuntao

2017-01-01

Road-deposited sediments (RDS) on urban impervious surfaces are important carriers of heavy metals. Dissolved heavy metals that come from RDS influenced by acid rain, are more harmful to urban receiving water than particulate parts. RDS and its associated heavy metals were investigated at typical functional areas, including industrial, commercial and residential sites, in Guangdong, Southern China, which was an acid rain sensitive area. Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios. Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above 3.0, regardless of land use. Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types. Coarse particles (>150μm) that could be efficiently removed by conventional street sweepers, accounted for 55.1%-47.1% of the total dissolved metal loading in runoff with pH3.0-5.6. The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain. Copyright © 2016. Published by Elsevier B.V.

Lysophosphatidic acid enhances collagen deposition and matrix thickening in engineered tissue.

PubMed

Chabaud, Stéphane; Marcoux, Thomas-Louis; Deschênes-Rompré, Marie-Pier; Rousseau, Alexandre; Morissette, Amélie; Bouhout, Sara; Bernard, Geneviève; Bolduc, Stéphane

2015-11-01

The time needed to produce engineered tissue is critical. A self-assembly approach provided excellent results regarding biological functions and cell differentiation because it closely respected the microenvironment of cells. Nevertheless, the technique was time consuming for producing tissue equivalents with enough extracellular matrix to allow manipulations. Unlike L-arginine supplementation that only increased accumulation of collagen in cell culture supernatant in our model, addition of lysophosphatidic acid, a natural bioactive lipid, did not modify the amount of accumulated collagen in the cell culture supernatant; however, it enhanced the matrix deposition rate without inducing fibroblast hyperproliferation and tissue fibrosis. Copyright © 2013 John Wiley & Sons, Ltd.

Deposition kinetics and characterization of stable ionomers from hexamethyldisiloxane and methacrylic acid by plasma enhanced chemical vapor deposition

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

Urstöger, Georg; Resel, Roland; Coclite, Anna Maria, E-mail: anna.coclite@tugraz.at

2016-04-07

A novel ionomer of hexamethyldisiloxane and methacrylic acid was synthesized by plasma enhanced chemical vapor deposition (PECVD). The PECVD process, being solventless, allows mixing of monomers with very different solubilities, and for polymers formed at high deposition rates and with high structural stability (due to the high number of cross-links and covalent bonding to the substrate) to be obtained. A kinetic study over a large set of parameters was run with the aim of determining the optimal conditions for high stability and proton conductivity of the polymer layer. Copolymers with good stability over 6 months' time in air and watermore » were obtained, as demonstrated by ellipsometry, X-Ray reflectivity, and FT-IR spectroscopy. Stable coatings showed also proton conductivity as high as 1.1 ± 0.1 mS cm{sup −1}. Chemical analysis showed that due to the high molecular weight of the chosen precursors, it was possible to keep the plasma energy-input-per-mass low. This allowed limited precursor fragmentation and the functional groups of both monomers to be retained during the plasma polymerization.« less

High elevation watersheds in the southern Appalachians: indicators of sensitivity to acidic deposition and the potential for restoration through liming

Treesearch

Jennifer D. Knoepp; James M. Vose; William A. Jackson; Katherine J. Elliott; Stan Zarnoch

2016-01-01

Southern Appalachian high elevation watersheds have deep rocky soils with high organic matter content, different vegetation communities, and receive greater inputs of acidic deposition compared to low elevation sites within the region. Since the implementation of the Clean Air Act Amendment in the 1990s, concentrations of acidic anions in rainfall have...

Effects of acid rain and sulfur dioxide on marble dissolution

USGS Publications Warehouse

Schuster, Paul F.; Reddy, Michael M.; Sherwood, Susan I.

1994-01-01

Acid precipitation and the dry deposition of sulfur dioxide (SO2) accelerate damage to carbonate-stone monuments and building materials. This study identified and quantified environmental damage to a sample of Vermont marble during storms and their preceding dry periods. Results from field experiments indicated the deposition of SO2 gas to the stone surface during dry periods and a twofold increase in marble dissolution during coincident episodes of low rain rate and decreased rainfall pH. The study is widely applicable to the analysis of carbonate-stone damage at locations affected by acid rain and air pollution.

Simulated effects of sulfur deposition on nutrient cycling in class I wilderness areas

Treesearch

Katherine J. Elliott; James M. Vose; Jennifer D. Knoepp; Dale W. Johnson; William T. Swank; William Jackson

2008-01-01

As a consequence of human land use, population growth, and industrialization, wilderness and other natural areas can be threatened by air pollution, climate change, and exotic diseases or pests. Air pollution in the form of acidic deposition is comprised of sulfuric and nitric acids and ammonium derived from emissions of sulfur dioxide, nitrogen oxides, and ammonia....

Target loads of atmospheric sulfur deposition for the protection and recovery of acid-sensitive streams in the Southern Blue Ridge Province

Treesearch

Timothy Sullivan; Bernard Cosby; William Jackson

2011-01-01

An important tool in the evaluation of acidification damage to aquatic and terrestrial ecosystems is the critical load (CL), which represents the steady-state level of acidic deposition below which ecological damage would not be expected to occur, according to current scientific understanding. A deposition load intended to be protective of a specified resource...

Selective deposition of dietary α-Lipoic acid in mitochondrial fraction and its synergistic effect with α-Tocoperhol acetate on broiler meat oxidative stability

PubMed Central

2013-01-01

The use of bioactive antioxidants in feed of broiler to mitigate reactive oxygen species (ROS) in biological systems is one of promising nutritional strategies. The aim of present study was to alleviate ROS production in mitochondrial fraction (MF) of meat by supplemented dietary antioxidant in feed of broiler. For this purpose, mitochondria specific antioxidant: α-lipoic acid (25 mg, 75 mg and 150 mg) with or without combination of α-tocopherol acetate (200 mg) used in normal and palm olein oxidized oil (4%) supplemented feed. One hundred and eighty one day old broiler birds were randomly divided into six treatments and provided the mentioned feed from third week. Feed intake, feed conversion ratio (FCR) remained statistically same in all groups while body weight decreased in supplemented groups accordingly at the end of study. The broiler meat MF antioxidant potential was significantly improved by feeding supplemented feed estimated as 1,1-di phenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, 2,2-azinobis-(3- ethylbenzothiazoline-6-sulphonic acid) (ABTS+) and thiobarbituric acid reactive substances (TBARS). The maximum antioxidant activity was depicted in group fed on 150 mg/kg α-lipoic acid (ALA) and 200 mg/kg α-tocopherol acetate (ATA) (T4) in both breast and leg MF. Moreover, TBARS were higher in leg as compared to breast MF. Although, oxidized oil containing feed reduced the growth, lipid stability and antioxidant potential of MF whilst these traits were improved by receiving feed containing ALA and ATA. ALA and ATA showed higher deposition in T4 group while least in group received oxidized oil containing feed (T5). Positive correlation exists between DPPH free radical scavenging activity and the ABTS + reducing activity. In conclusion, ALA and ATA supplementation in feed had positive effect on antioxidant status of MF that consequently diminished the oxidative stress in polyunsaturated fatty acid enriched meat. PMID:23617815

Piper sarmentosum is comparable to glycyrrhizic acid in reducing visceral fat deposition in adrenalectomised rats given dexamethasone.

PubMed

Fairus, A; Ima Nirwana, S; Elvy Suhana, M R; Tan, M H; Santhana, R; Farihah, H S

2013-01-01

Visceral obesity may be due to the dysregulation of cortisol production or metabolism that lead to metabolic disease. In adipose tissue, the enzyme 11beta-hydroxysteroid dehydrogenase type 1 regulates cortisol metabolism (11beta-HSD1). A previous study showed an increase in the visceral fat deposition in adrenalectomised rats given intramuscular dexamethasone. Glycyrrhizic acid (GCA) has been shown to reduce fat deposition because it is a known potent inhibitor of the 11beta-HSD1 enzyme. Piper sarmentosum (PS) is an edible medicinal plant commonly used in Asia as traditional medicine for treating diabetes, hypertension and joint pains. In this study, we determined the effects of PS extract on the disposition and morphology of perirenal adipocytes of adrenalectomised rats given intramuscular dexamethasone. A total of 21 male Spraque Dawley rats were adrenalectomised and given intramuscular dexamethasone, 120 μg/kg/day. These rats were further divided into three groups: adrenalectomised control (ADR+Dexa; n=7), GCA-treated (ADR+Dexa+GCA; dose=240 mg/kg/day; n=7) and PS-treated (ADR+Dexa+PS; dose=125 mg/kg/day; n=7) groups. The various treatments were given via gastric gavage following 2 weeks of adrenalectomy. Treatment with PS extract for 8 weeks showed decreased deposition of perirenal adipocytes which was similar to the GCA-treated group. However, PS-treated rats had thinner adipocyte membrane compared with that of the GCA-treated group. In conclusion, PS extract decreased perirenal fat deposition and reduced the diameter of the adipocyte membrane. However, the mechanisms of action needed further study.

Effect of Eicosapentaenoic Acid and Docosahexaenoic Acid on Myogenesis and Mitochondrial Biosynthesis during Murine Skeletal Muscle Cell Differentiation.

PubMed

Hsueh, Tun-Yun; Baum, Jamie I; Huang, Yan

2018-01-01

Polyunsaturated fatty acids are important nutrients for human health, especially omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have been found to play positive roles in the prevention of various diseases. However, previous studies have reported that excessive omega-3 fatty acids supplement during pregnancy caused side effects such as slower neural transmission times and postnatal growth restriction. In this study, we investigated the effect of EPA and DHA on mitochondrial function and gene expression in C2C12 myoblasts during skeletal muscle differentiation. C2C12 myoblasts were cultured to confluency and then treated with differentiation medium that contained fatty acids (50-µM EPA and DHA). After 72 h of myogenic differentiation, mRNA was collected, and gene expression was analyzed by real-time PCR. Microscopy was used to examine cell morphology following treatment with fatty acids. The effect of EPA and DHA on cellular oxygen consumption was measured using a Seahorse XF24 Analyzer. Cells treated with fatty acids had fewer myotubes formed ( P ≤ 0.05) compared with control cells. The expression of the genes related to myogenesis was significantly lower ( P ≤ 0.05) in cells treated with fatty acids, compared with control cells. Genes associated with adipogenesis had higher ( P ≤ 0.05) expression after treatment with fatty acids. Also, the mitochondrial biogenesis decreased with lower ( P ≤ 0.05) gene expression and lower ( P ≤ 0.05) mtDNA/nDNA ratio in cells treated with fatty acids compared with control cells. However, the expression of genes related to peroxisome biosynthesis was higher ( P ≤ 0.05) in cells treated with fatty acids. Moreover, fatty-acid treatment reduced ( P ≤ 0.05) oxygen consumption rate under oligomycin-inhibited (reflecting proton leak) and uncoupled conditions. Our data imply that fatty acids might reduce myogenesis and increase adipogenesis in myotube formation. Fatty acids

The surprising recovery of red spruce growth shows links to decreased acid deposition and elevated temperature

Treesearch

Alexandra M. Kosiba; Paul G. Schaberg; Shelly A. Rayback; Gary J. Hawley

2018-01-01

Following growth declines and increased mortality linked to acid deposition-induced calcium depletion, red spruce (Picea rubens Sarg.) in the northeastern United States are experiencing a recovery. We found that more than 75% of red spruce trees and 90% of the plots examined in this study exhibited increasing growth since 2001. To understand this...

Numerical simulation of the effects of dilution level, depth of inhalation, and smoke composition on nicotine vapor deposition during cigarette smoking.

PubMed

Ingebrethsen, Bradley J

2006-12-01

A numerical model of an aerosol containing vaporizable nicotine depositing to the walls of a tube was developed and applied to simulate the vapor deposition of nicotine in a denuder tube and under conditions approximating those in the respiratory tract during mainstream cigarette smoke inhalation. The numerical model was validated by comparison to data for denuder tube collection of nicotine from the smoke of three types of cigarette differing in smoke acidity and nicotine volatility. Simulations predict that the absorption of water by aerosol particles inhibits nicotine vapor deposition to tube walls, and that increased temperature, decreased tube diameter, and increased dilution enhance nicotine vapor deposition rate. The combined effect of changing these four parameters to approximate the transition from conducting to gas exchange regions of the respiratory tract was a significant net increase in predicted nicotine vapor deposition rate. Comparisons of nicotine deposition rates between conditions in the conducting airways and those in the gas exchange region were informative with regard to reported nicotine retention measurements during human smoking. Reports that vaporizable nicotine can penetrate past the conducting airways, that nicotine can be retained at near 100% efficiency from mainstream smoke, and that cigarettes with differing acidity and nicotine volatility have similar nicotine uptake rates are all shown to be consistent with the results of the model simulations.

DEPOSITION OF SULFATE ACID AEROSOLS IN THE DEVELOPING HUMAN LUNG

EPA Science Inventory

Computations of aerosol deposition as affected by (i) aerosol hygroscopicity, (ii) human age, and (iii) respiratory intensity are accomplished using a validated mathematical model. he interactive effects are very complicated but systematic. ew general observations can be made; ra...

High Elevation Lakes of the Western US: Are we Studying Systems Recovering from Excess Atmospheric Deposition of Acids and Nutrients?

NASA Astrophysics Data System (ADS)

Sickman, J. O.

2011-12-01

Instrumental records and monitoring of high elevation lakes began in most areas of the western US in the early 1980s. Much effort has been devoted to detecting changes in these aquatic ecosystems resulting from increased atmospheric deposition of acids and nutrients. However, there is growing evidence that thresholds for atmospheric pollutants were crossed much earlier in the 20th Century and that some of the subsequent hydrochemical and ecological changes observed in these lakes may be the result of recovery from earlier atmospheric forcing. We examine responses of high elevation lakes to atmospheric deposition on annual to century timescales using data from a 29-year study of Emerald Lake (Sequoia National Park) and paleolimnological analyses of other high elevation lakes incorporating diatom species analyses and geochemical proxies for fossil-fuel burning. At Emerald Lake, we have observed multiple transitions between nitrogen and phosphorus limitation of phytoplankton, the earliest of which occurred in the beginning of the 1980s and may be the result of reduction in N deposition due to the Clean Air Act. Critical loads analyses incorporating diatom species in lake sediments suggest that thresholds for N deposition were crossed in the period of 1950-1980 in the Rocky Mountains and likely much earlier, 1900-1920, in the Sierra Nevada. Diatom species composition is strongly controlled by acid neutralizing capacity (ANC) in the Sierra Nevada and we have observed a pronounced decline and recovery of ANC over the period of 1920-1980 in some Sierra Nevada lakes that coincides with the abundance of spheroidal carbonaceous particles (i.e., a diagnostic tracer of fossil fuel combustion) preserved in lake sediments; these patterns appear to be driven by increased emissions of oxidized N and S in the mid-20th Century and reductions in acid precursor levels caused by the Clean Air Act in the 1970s. Thus, when interpreting observational records from western high elevation

Effect of inulin supplementation and dietary fat source on performance, blood serum metabolites, liver lipids, abdominal fat deposition, and tissue fatty acid composition in broiler chickens.

PubMed

Velasco, S; Ortiz, L T; Alzueta, C; Rebolé, A; Treviño, J; Rodríguez, M L

2010-08-01

A study was conducted to evaluate the effect of adding inulin to diets containing 2 different types of fat as energy sources on performance, blood serum metabolites, liver lipids, and fatty acids of abdominal adipose tissue and breast and thigh meat. A total of 240 one-day-old female broiler chicks were randomly allocated into 1 of 6 treatments with 8 replicates per treatment and 5 chicks per pen. The experiment consisted of a 3 x 2 factorial arrangement of treatments including 3 concentrations of inulin (0, 5, and 10 g/kg of diet) and 2 types of fat [palm oil (PO) and sunflower oil (SO)] at an inclusion rate of 90 g/kg of diet. The experimental period lasted from 1 to 34 d. Dietary fat type did not affect BW gain but impaired feed conversion (P < 0.001) in birds fed the PO diets compared with birds fed the SO diets. The diets containing PO increased abdominal fat deposition and serum lipid and glucose concentrations. Triacylglycerol contents in liver were higher in the birds fed PO diets. Dietary fat type also modified fatty acids of abdominal and i.m. fat, resulting in a higher concentration of C16:0 and C18:1n-9 and a lower concentration of C18:2n-6 in the birds fed PO diets. The addition of inulin to diets modified (P = 0.017) BW gain quadratically without affecting feed conversion. Dietary inulin decreased the total lipid concentration in liver (P = 0.003) and that of triacylglycerols and very low density lipoprotein cholesterol (up to 31%) in blood serum compared with the control groups. The polyunsaturated fatty acid:saturated fatty acid ratio increased in abdominal and i.m. fat when inulin was included in the SO-containing diets. The results from the current study suggest that the addition of inulin to broiler diets has a beneficial effect on blood serum lipids by decreasing triacylglyceride concentrations The results also support the use of inulin to increase the capacity of SO for enhancing polyunsaturated fatty acid:saturated fatty acid ratio of i.m. fat

Effects of calcium on seed germination, seedling growth and photosynthesis of six forest tree species under simulated acid rain.

PubMed

Liu, Ting-Wu; Wu, Fei-Hua; Wang, Wen-Hua; Chen, Juan; Li, Zhen-Ji; Dong, Xue-Jun; Patton, Janet; Pei, Zhen-Ming; Zheng, Hai-Lei

2011-04-01

We selected six tree species, Pinus massoniana Lamb., Cryptomeria fortunei Hooibr. ex Otto et Dietr., Cunninghamia lanceolata (Lamb.) Hook., Liquidambar formosana Hance, Pinus armandii Franch. and Castanopsis chinensis Hance, which are widely distributed as dominant species in the forest of southern China where acid deposition is becoming more and more serious in recent years. We investigated the effects and potential interactions between simulated acid rain (SiAR) and three calcium (Ca) levels on seed germination, radicle length, seedling growth, chlorophyll content, photosynthesis and Ca content in leaves of these six species. We found that the six species showed different responses to SiAR and different Ca levels. Pinus armandii and C. chinensis were very tolerant to SiAR, whereas the others were more sensitive. The results of significant SiAR × Ca interactions on different physiological parameters of the six species demonstrate that additional Ca had a dramatic rescue effect on the seed germination and seedling growth for the sensitive species under SiAR. Altogether, we conclude that the negative effects of SiAR on seed germination, seedling growth and photosynthesis of the four sensitive species could be ameliorated by Ca addition. In contrast, the physiological processes of the two tolerant species were much less affected by both SiAR and Ca treatments. This conclusion implies that the degree of forest decline caused by long-term acid deposition may be attributed not only to the sensitivity of tree species to acid deposition, but also to the Ca level in the soil.

Different sources of omega-3 polyunsaturated fatty acids affects apparent digestibility, tissue deposition, and tissue oxidative stability in growing female rats.

PubMed

Tou, Janet C; Altman, Stephanie N; Gigliotti, Joseph C; Benedito, Vagner A; Cordonier, Elizabeth L

2011-10-14

Numerous health benefits associated with increased omega-3 polyunsaturated fatty acid (n-3 PUFA) consumption has lead to an increasing variety of available n-3 PUFA sources. However, sources differ in the type, amount, and structural form of the n-3 PUFAs. Therefore, the objective of this study was to determine the effect of different sources of ω-3 PUFAs on digestibility, tissue deposition, eicosanoid metabolism, and oxidative stability. Female Sprague-Dawley rats (age 28 d) were randomly assigned (n = 10/group) to be fed a high fat 12% (wt) diet consisting of either corn oil (CO) or n-3 PUFA rich flaxseed (FO), krill (KO), menhaden (MO), salmon (SO) or tuna (TO) oil for 8 weeks. Rats were individually housed in metabolic cages to determine fatty acid digestibility. Diet and tissue fatty acid composition was analyzed by gas chromatography and lipid classes using thin layer chromatography. Eicosanoid metabolism was determined by measuring urinary metabolites of 2-series prostaglandins (PGs) and thromoboxanes (TXBs) using enzyme immunoassays. Oxidative stability was assessed by measuring thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) using colorimetric assays. Gene expression of antioxidant defense enzymes was determined by real time quantitative polymerase chain reaction (RT-qPCR). Rats fed KO had significantly lower DHA digestibility and brain DHA incorporation than SO and TO-fed rats. Of the n-3 PUFA sources, rats fed SO and TO had the highest n-3 PUFAs digestibility and in turn, tissue accretion. Higher tissue n-3 LC-PUFAs had no significant effect on 2-series PG and TXB metabolites. Despite higher tissue n-3 LC-PUFA deposition, there was no increase in oxidation susceptibility indicated by no significant increase in TBARS or decrease in TAC and gene expression of antioxidant defense enzymes, in SO or TO-fed rats. On the basis that the optimal n-3 PUFA sources should provide high digestibility and efficient tissue

Acid or N? Disentangling Nutrient- and pH Effects of Nitrogen and Sulfur Deposition to Forest Ecosystems

NASA Astrophysics Data System (ADS)

Goodale, C. L.

2016-12-01

Nitrogen deposition can act as both a nutrient and acidifying agent with sometimes synergistic and sometimes contradictory effects on ecosystem processes. However, these two roles are rarely separated. Similarly, deposition patterns of N and S often covary, making it difficult to correctly attribute their respective roles on the biogeochemistry of downwind ecosystems. In 2011, we initiated a N x pH (S) experiment in six mixed hardwood stands (3 primary, 3 secondary) in Central New York designed to separate nutrient and acidifying impacts of N and S deposition. Three treatments included two 50 N ha-1 yr-1 additions in forms intended to raise (NaNO3) or lower ((NH4)2SO4) soil pH as well as elemental S treatment to acidify without N. Five years of treatment shifted surface soil pH in the expected directions. Treatment effects on soil extract DOC correlated with pH, with lower DOC concentration and aromaticity in the acidifying treatments. Foliar litterfall did not vary by stand age or treatment, but N and S treatments enriched litterfall N and S concentrations, respectively. Wood production did not vary significantly by stand age or treatment but trended toward an increase in response to the N additions in both stand ages. The treatments did not affect early stages of litter decomposition, but both N additions and acidification suppressed decomposition in later stages, with largest effects from acidification alone. Soil respiration responses followed those of litter decomposition, except that the response of respiration to the NaNO3 addition depended on the stand's mycorrhizal composition, with greater suppression in stands with a higher fraction of ectomycorrhizal tree species. Together, these results show that both N addition and acidification can suppress decomposition rates, but likely for different reasons that may be linked to plant carbon allocation (for N) and microbial function (pH). Distinguishing these mechanisms will be important for projecting recovery of

Graphene decorated microelectrodes for simultaneous detection of ascorbic, dopamine, and folic acids by means of chemical vapor deposition

NASA Astrophysics Data System (ADS)

Namdar, N.; Hassanpour Amiri, M.; Dehghan Nayeri, F.; Gholizadeh, A.; Mohajerzadeh, S.

2015-09-01

In this paper, high quality and large area graphene layers were synthesized using thermal chemical vapour deposition on copper foil substrates. We use graphene incorporated electrodes to measure simultaneously ascorbic acid, dopamine and folic acid. Cyclic voltammetry and differential pulse voltammetry methods were used to evaluate electrochemical behaviour of the grown graphene layers. The graphene-modified electrode shows large electrochemical potential difference compared to bare gold electrodes with higher current responses. Also our fabricated electrodes configuration can be used easily for microfluidic analysis.

Identifying calcium sources at an acid deposition-impacted spruce forest: A strontium isotope, alkaline earth element multi-tracer approach

USGS Publications Warehouse

Bullen, T.D.; Bailey, S.W.

2005-01-01

Depletion of calcium from forest soils has important implications for forest productivity and health. Ca is available to fine feeder roots from a number of soil organic and mineral sources, but identifying the primary source or changes of sources in response to environmental change is problematic. We used strontium isotope and alkaline earth element concentration ratios of trees and soils to discern the record of Ca sources for red spruce at a base-poor, acid deposition-impacted watershed. We measured 87Sr/86Sr and chemical compositions of cross-sectional stemwood cores of red spruce, other spruce tissues and sequential extracts of co-located soil samples. 87Sr/86Sr and Sr/Ba ratios together provide a tracer of alkaline earth element sources that distinguishes the plant-available fraction of the shallow organic soils from those of deeper organic and mineral soils. Ca/Sr ratios proved less diagnostic, due to within-tree processes that fractionate these elements from each other. Over the growth period from 1870 to 1960, 87Sr/86Sr and Sr/Ba ratios of stemwood samples became progressively more variable and on average trended toward values that considered together are characteristic of the uppermost forest floor. In detail the stemwood chemistry revealed an episode of simultaneous enhanced uptake of all alkaline earth elements during the growth period from 1930 to 1960, coincident with reported local and regional increases in atmospheric inputs of inorganic acidity. We attribute the temporal trends in stemwood chemistry to progressive shallowing of the effective depth of alkaline earth element uptake by fine roots over this growth period, due to preferential concentration of fine roots in the upper forest floor coupled with reduced nutrient uptake by roots in the lower organic and upper mineral soils in response to acid-induced aluminum toxicity. Although both increased atmospheric deposition and selective weathering of Ca-rich minerals such as apatite provide possible

A case study of the relative effects of power plant nitrogen oxides and sulfur dioxide emission reductions on atmospheric nitrogen deposition.

PubMed

Vijayaraghavan, Krish; Seigneur, Christian; Bronson, Rochelle; Chen, Shu-Yun; Karamchandani, Prakash; Walters, Justin T; Jansen, John J; Brandmeyer, Jo Ellen; Knipping, Eladio M

2010-03-01

The contrasting effects of point source nitrogen oxides (NOx) and sulfur dioxide (SO2) air emission reductions on regional atmospheric nitrogen deposition are analyzed for the case study of a coal-fired power plant in the southeastern United States. The effect of potential emission reductions at the plant on nitrogen deposition to Escambia Bay and its watershed on the Florida-Alabama border is simulated using the three-dimensional Eulerian Community Multiscale Air Quality (CMAQ) model. A method to quantify the relative and individual effects of NOx versus SO2 controls on nitrogen deposition using air quality modeling results obtained from the simultaneous application of NOx and SO2 emission controls is presented and discussed using the results from CMAQ simulations conducted with NOx-only and SO2-only emission reductions; the method applies only to cases in which ambient inorganic nitrate is present mostly in the gas phase; that is, in the form of gaseous nitric acid (HNO3). In such instances, the individual effects of NOx and SO2 controls on nitrogen deposition can be approximated by the effects of combined NOx + SO2 controls on the deposition of NOy, (the sum of oxidized nitrogen species) and reduced nitrogen species (NHx), respectively. The benefit of controls at the plant in terms of the decrease in nitrogen deposition to Escambia Bay and watershed is less than 6% of the overall benefit due to regional Clean Air Interstate Rule (CAIR) controls.

Deposition and rainwater concentrations of trifluoroacetic acid in the United States from the use of HFO-1234yf

NASA Astrophysics Data System (ADS)

Kazil, J.; McKeen, S.; Kim, S.-W.; Ahmadov, R.; Grell, G. A.; Talukdar, R. K.; Ravishankara, A. R.

2014-12-01

Currently, HFC-134a (1,1,1,2-tetrafluoroethane) is the most common refrigerant in automobile air conditioners. This high global warming potential substance (100 year GWP of 1370) will likely be phased out and replaced with HFO-1234yf (2,3,3,3-tetrafluoropropene) that has a 100 year GWP of 4. HFO-1234yf will be oxidized to produce trifluoroacetic acid (TFA) in clouds. TFA, a mildly toxic substance with detrimental effects on some aquatic organisms at high concentrations (≥100μgL-1), would be transported by rain to the surface and enter bodies of water. We investigated the dry and wet deposition of TFA from HFO-1234yf over the contiguous USA using the Advanced Research Weather Research and Forecasting model (ARW) with interactive chemical, aerosol, and cloud processes (WRF/Chem) model. Special focus was placed on emissions from three continental USA regions with different meteorological characteristics. WRF/Chem simulated meteorology, cloud processes, gas and aqueous phase chemistry, and dry and wet deposition between May and September 2006. The model reproduced well the multimonth total sulfate wet deposition (4% bias) and its spatial variability (r = 0.86) observed by the National Atmospheric Deposition Program. HFO-1234yf emissions were obtained by assuming the number of automobile air conditioners to remain unchanged, and substituting HFO-1234yf, mole-per-mole for HFC-134a. Our estimates of current HFC-134a emissions were in agreement with field data. Average TFA rainwater concentration was 0.89μgL-1, with peak values of 7.8μgL-1, for the May-September 2006 period over the contiguous USA. TFA rainwater concentrations over the dry western USA were often significantly higher, but wet-deposited TFA amounts remained relatively low at such locations.

Impact of acid and trace metals deposition on freshwater invertebrates in north-eastern Fennoscandia and Kola Peninsula

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

Yakovlev, V.

1996-12-31

Freshwater invertebrate communities in a total 400 lakes and streams in northeastern Norway, Finnish Lapland and the Kola Peninsula, subjected to the atmospheric deposition were studied. The severe influence of toxic heavy metals, dusts from smelters and mineral enrichment factories were found in the Kola Peninsula. The negative acidification effects on benthic communities were found in the Jarfjord (Norway), Enontekio, Ranua-Posio and Kittila-Kolari (Finnish Lapland) areas and in the Kola Peninsula (Russia). Taxa groups, known to be sensitive to acidification, such as gammarids, snails, mayflies, stone flies, were represented with few species and in a low abundance. Heavy metals accumulationmore » in biota is recorded in areas surrounding nickel smelters in the Kola Peninsula. The metal concentration invertebrates in remote areas is rather wide and depend on an air deposition, characteristics of lake catchment areas, as well as water acidity. The environmental variables, such as lake hydrological type, altitude of lakes, dominant substratum type, abundance of macrophytes and mosses in sampling area, content of pollutants in water also show significant relationships with metal concentration in invertebrates. The most severe negative effects on biota were found in waters with low pH and simultaneously contaminated by heavy metals. The biological method for estimation of simultaneously water acidification and contamination is suggested.« less

Effect of Eicosapentaenoic Acid and Docosahexaenoic Acid on Myogenesis and Mitochondrial Biosynthesis during Murine Skeletal Muscle Cell Differentiation

PubMed Central

Hsueh, Tun-Yun; Baum, Jamie I.; Huang, Yan

2018-01-01

Polyunsaturated fatty acids are important nutrients for human health, especially omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which have been found to play positive roles in the prevention of various diseases. However, previous studies have reported that excessive omega-3 fatty acids supplement during pregnancy caused side effects such as slower neural transmission times and postnatal growth restriction. In this study, we investigated the effect of EPA and DHA on mitochondrial function and gene expression in C2C12 myoblasts during skeletal muscle differentiation. C2C12 myoblasts were cultured to confluency and then treated with differentiation medium that contained fatty acids (50-µM EPA and DHA). After 72 h of myogenic differentiation, mRNA was collected, and gene expression was analyzed by real-time PCR. Microscopy was used to examine cell morphology following treatment with fatty acids. The effect of EPA and DHA on cellular oxygen consumption was measured using a Seahorse XF24 Analyzer. Cells treated with fatty acids had fewer myotubes formed (P ≤ 0.05) compared with control cells. The expression of the genes related to myogenesis was significantly lower (P ≤ 0.05) in cells treated with fatty acids, compared with control cells. Genes associated with adipogenesis had higher (P ≤ 0.05) expression after treatment with fatty acids. Also, the mitochondrial biogenesis decreased with lower (P ≤ 0.05) gene expression and lower (P ≤ 0.05) mtDNA/nDNA ratio in cells treated with fatty acids compared with control cells. However, the expression of genes related to peroxisome biosynthesis was higher (P ≤ 0.05) in cells treated with fatty acids. Moreover, fatty-acid treatment reduced (P ≤ 0.05) oxygen consumption rate under oligomycin-inhibited (reflecting proton leak) and uncoupled conditions. Our data imply that fatty acids might reduce myogenesis and increase adipogenesis in myotube formation. Fatty acids may also

Metal organic chemical vapor deposition of environmental barrier coatings for the inhibition of solid deposit formation from heated jet fuel

NASA Astrophysics Data System (ADS)

Mohan, Arun Ram

for the deposition of metal and metal oxide functional coatings by MOCVD. Alumina was chosen as a candidate for metal oxide coating because of its thermal and phase stability. Platinum was chosen as a candidate to utilize the oxygen spillover process to maintain a self-cleaning surface by oxidizing the deposits formed during thermal stressing. Two metal organic precursors, aluminum trisecondary butoxide and aluminum acetylacetonate, were used as precursors to coat tubes of varying diameters. The morphology and uniformity of the coatings were characterized by electron microscopy and energy-dispersive x-ray spectroscopy. The coating was characterized by x-ray photoelectron spectroscopy to obtain the surface chemical composition. This is the first study conducted to examine the application of MOCVD to coat internal surfaces of tubes with varying diameters. In the third part of the study, the metal oxide coatings, alumina from aluminum acetylacetonate, alumina from aluminum trisecondary butoxide, zirconia from zirconium acetylacetonate, tantalum oxide from tantalum pentaethoxide and the metal coating, platinum from platinum acetylacetonate were deposited by MOCVD on AISI304. The chemical composition and the surface acidity of the coatings were characterized by x-ray photoelectron spectroscopy. The morphology of the coatings was characterized by electron microscopy. The coated substrates were tested in the presence of heated Jet-A in a flow reactor to evaluate their effectiveness in inhibiting the solid deposit formation. All coatings inhibited the formation of metal sulfides and the carbonaceous solid deposits formed by metal catalysis. The coatings also delayed the accumulation of solid carbonaceous deposits. In particular, it has been confirmed that the surface acidity of the metal oxide coatings affects the formation of carbonaceous deposits. Bimolecular addition reactions promoted by the Bronsted acid sites appear to lead to the formation of carbonaceous solid

Spatial distribution and seasonal variations of atmospheric sulfur deposition over Northern China

NASA Astrophysics Data System (ADS)

Pan, Y. P.; Wang, Y. S.; Tang, G. Q.; Wu, D.

2012-09-01

The increasing anthropogenic emissions of acidic compounds have induced acid deposition accompanied by acidification in the aquatic and terrestrial ecosystems worldwide. However, comprehensive assessment of spatial patterns and long-term trends of acid deposition in China remains a challenge due to a paucity of field-based measurement data, in particular for dry deposition. Here we quantify the sulfur (S) deposition on a regional scale via precipitation, particles and gases during a 3-yr observation campaign at ten selected sites in Northern China. Results show that the total S deposition flux in the target area ranged from 35.0 to 100.7 kg S ha-1 yr-1, categorized as high levels compared to those documented in Europe, North America, and East Asia. The ten-site, 3-yr average total S deposition was 64.8 kg S ha-1 yr-1, with 32% attributed to wet deposition, and the rest attributed to dry deposition. Compared with particulate sulfate, gaseous SO2 was the major contributor of dry-deposited S, contributing approximately 49% to the total flux. Wet deposition of sulfate showed pronounced seasonal variations with maximum in summer and minimum in winter, corresponding to precipitation patterns in Northern China. However, the spatial and inter-annual differences in the wet deposition were not significant, which were influenced by the precipitation amount, scavenging ratio and the concentrations of atmospheric S compounds. In contrast, the relatively large dry deposition of SO2 and sulfate during cold season, especially at industrial areas, was reasonably related to the local emissions from home heating. Although seasonal fluctuations were constant, clear spatial differences were observed in the total S deposition flux and higher values were also found in industrial areas with huge emissions of SO2. These findings indicate that human activity has dramatically altered the atmospheric S deposition and thus regional S cycles. To systematically illustrate the potential effects

Soil nutrient bioavailability and nutrient content of pine trees (Pinus thunbergii) in areas impacted by acid deposition in Korea.

PubMed

Yang, Jae E; Lee, Wi-Young; Ok, Yong Sik; Skousen, Jeffrey

2009-10-01

Acid deposition has caused detrimental effects on tree growth near industrial areas of the world. Preliminary work has indicated that concentrations of NO(3-), SO(4)(2-), F( - ) and Al in soil solutions were 2 to 33 times higher in industrial areas compared to non-industrial areas in Korea. This study evaluated soil nutrient bioavailability and nutrient contents of red pine (Pinus thunbergii) needles in forest soils of industrial and non-industrial areas of Korea. Results confirm that forest soils of industrial areas have been acidified mainly by deposition of sulfate, resulting in increases of Al, Fe and Mn and decreases of Ca, Mg and K concentrations in soils and soil solutions. In soils of industrial areas, the molar ratios of Ca/Al and Mg/Al in forest soils were <2, which can lead to lower levels and availability of nutrients for tree growth. The Ca/Al molar ratio of Pinus thunbergii needles on non-industrial sites was 15, while that of industrial areas was 10. Magnesium concentrations in needles of Pinus thunbergii were lower in soils of industrial areas and the high levels of acid cations such as Al and Mn in these soils may have antagonized the uptake of base cations like Mg. Continued acidification can further reduce uptake of base cations by trees. Results show that Mg deficiency and high concentrations of Al and Mn in soil solution can be limiting factors for Pinus thunbergii growth in industrial areas of Korea.

The Acute Effect of Humic Acid on Iron Accumulation in Rats.

PubMed

Cagin, Yasir Furkan; Sahin, N; Polat, A; Erdogan, M A; Atayan, Y; Eyol, E; Bilgic, Y; Seckin, Y; Colak, C

2016-05-01

Free iron leads to the formation of pro-oxidant reactive oxygen species (ROS). Humic acids (HAs) enhance permeability of cellular wall and act as a chelator through electron transferring. This study was designed to test chelator effect of HA on iron as well as its anti-oxidant effect against the iron-induced hepatotoxicity and cardiotoxicity. The rats used were randomly divided into four groups (n = 8/group): group I (the control group); group II (the HA group), humic acid (562 mg/kg) was given over 10 days by oral gavage; group III (the iron group), iron III hydroxide polymaltose (250 mg/kg) was given over 10 days by intraperitoneal route; and group IV (the HA plus iron group), received the iron (similar to group II) plus humic acid (similar to those in groups II and III) group. Blood and two tissue samples both from liver and heart were obtained for biochemical and histopathological evaluations. Iron deposition, the iron-induced hepatotoxicity, and cardiotoxicity were demonstrated by histopathological and biochemical manner. However, no significant differences were observed in the serum biochemical values and the histopathological results among the iron and the HA plus iron groups in the liver tissue but not in the heart tissue. The protective effects of humic acid against iron-induced cardiotoxicity were shown but not against hepatotoxicity in our study.

Effect of surface deposits on electromagnetic propagation in uniform ducts

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.

1991-01-01

A finite-element Galerkin formulation has been used to study the effect of material surface deposits on the reflective characteristics of straight uniform ducts with PEC (perfectly electric conducting) walls. Over a wide frequency range, the effect of both single and multiple dielectric surface deposits on the duct reflection coefficient were examined. The power reflection coefficient was found to be significantly increased by the addition of deposits on the wall.

An Experimental Model to Study the Impact of Lipid Oxidation on Contact Lens Deposition In Vitro.

PubMed

Schuett, Burkhardt S; Millar, Thomas J

2017-09-01

This study was to establish a controlled in vitro test system to study the effect of lipid oxidation on lipid deposition on contact lenses. Fatty acids with varying degree of unsaturation were oxidized using the Fenton reaction. The degree of lipid oxidation and the lipid moieties formed during the oxidation were identified and estimated by various lipid staining techniques following separation with thin-layer chromatography, and by measuring thiobarbituric acid reactive substances or peroxides in solution. Two different silicone hydrogel-based contact lenses (Balafilcon A and Senofilcon A) were incubated with fatty acids laced with radioactive tracer oxidized to varying degrees, and the amount of lipid deposition was measured using unoxidized lipid samples as controls. The Fenton reaction together with the analytical methods to analyze the lipid oxidation can be used to control oxidation of lipids to a desired amount. In general, saturated fatty acids are not oxidized, the monounsaturated oleic acid produced peroxides while poly-unsaturated lipids initially produced peroxides and then fragmented into reactive aldehydes. Incubation with mildly oxidized lipids (most likely lipid peroxides) resulted in increased lipid deposition on Balafilcon A lenses compared to unoxidized lipids, but this was not observed for Senofilcon A lenses. Further oxidation of the lipids (carbon chain breakup) on the other hand resulted in diminished lipid deposition for both contact lens types. This study provides a method for inducing and controlling lipid oxidation so that the effect of lipid oxidation on contact lens binding can be compared. It could be shown that the degree of lipid oxidation has different effects on the lipid deposition on different contact lens types.

Do the paleolimnological reconstructions reflect the influence of acid deposition?

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

Smirnov, D.Y.

1996-12-31

The using possibility of paleolimnological analyses was considered with the documentation aim of acid-forming substances distant transfer on territory of Northern Fennoscandia. The Holocene and ancient interglacial lakes pH-and alkalinity trends, reconstructed by means of bottom sediments diatomic analyses, were studied. It has been made evident that the tendency to sharp changes of these data is revealed on final stages of interglacial periods. At that time the high amplitude of climatic changes with low periodicity is resulting in catastrophic changes of landscapes in the frames of water-catchments bodies. During the last millennium the climatic situation in the Northern Fennoscandia wasmore » changing repeatedly (Medieval Warm Epoch, Little Ice Age, the rise in temperature in 20-40`s of XXth century). In the Little Ice Age (XVI-XIX centuries) the decrease of average annual temperature and intensification of winds velocity have caused a rapid retreat of latitudinal and high-altitude forest boundaries, accompanied by sharp reconstruction of tundra-,forest-tundra-and northern taiga landscapes. These processes have accelerated due to the enforcement of economic activity which caused the destruction of vegetation cover (salt-working, and ship-building since the XIXth century, pasture of reindeer herds since the end of XIXth century). Acidifying of ground and surface waters in the current century could be caused by the increased entry of organic acids, as a result of plant residues decomposition. The decomposition process was activated in the end of XIXth - beginning of XXth century in connection with the rise of temperature and increase of precipitation. Thus, the trends in pH and alkalinity changes in this region can not be used as indicators of acid-forming substances atmospheric deposition increase.« less

Properties influencing fat, oil, and grease deposit formation.

PubMed

Keener, Kevin M; Ducoste, Joel J; Holt, Leon M

2008-12-01

Fat, oil, and grease (FOG) deposits are the reported cause of 50 to 75% of sanitary sewer overflows in the United States, resulting in 1.8 X 10(6) m3 (500 mil. gal) of raw wastewater released into the environment annually. The objective of this research was to characterize the chemical and physical properties of FOG deposits. Twenty-three cities from around the United States contributed FOG samples for the study. The FOG deposits showed a wide range in yield strength (4 to 34 kPa), porosity (10 to 24%), and moisture content (10 to 60%), suggesting uncontrolled formation processes. A majority of these deposits display hard, sandstonelike texture, with distinct layering effects, suggesting a discontinuous formation process. The results found that 84% of FOG deposits contained high concentrations of saturated fatty acids and calcium, suggesting preferential accumulation.

Bulk deposition of base cationic nutrients in China's forests: Annual rates and spatial characteristics

Treesearch

Enzai Du; Wim de Vries; Steven McNulty; Mark E. Fenn

2018-01-01

Base cations, such as potassium (K+), calcium (Ca2+) and magnesium (Mg2+), are essential nutrients for plant growth and their atmospheric inputs can buffer the effect of acid deposition by nitrogen (N) and sulphur (S) compounds. However, the spatial variation in atmospheric deposition of these base...

Transcriptomic Analysis Identifies Candidate Genes Related to Intramuscular Fat Deposition and Fatty Acid Composition in the Breast Muscle of Squabs (Columba)

PubMed Central

Ye, Manhong; Zhou, Bin; Wei, Shanshan; Ding, MengMeng; Lu, Xinghui; Shi, Xuehao; Ding, Jiatong; Yang, Shengmei; Wei, Wanhong

2016-01-01

Despite the fact that squab is consumed throughout the world because of its high nutritional value and appreciated sensory attributes, aspects related to its characterization, and in particular genetic issues, have rarely been studied. In this study, meat traits in terms of pH, water-holding capacity, intramuscular fat content, and fatty acid profile of the breast muscle of squabs from two meat pigeon breeds were determined. Breed-specific differences were detected in fat-related traits of intramuscular fat content and fatty acid composition. RNA-Sequencing was applied to compare the transcriptomes of muscle and liver tissues between squabs of two breeds to identify candidate genes associated with the differences in the capacity of fat deposition. A total of 27 differentially expressed genes assigned to pathways of lipid metabolism were identified, of which, six genes belonged to the peroxisome proliferator-activated receptor signaling pathway along with four other genes. Our results confirmed in part previous reports in livestock and provided also a number of genes which had not been related to fat deposition so far. These genes can serve as a basis for further investigations to screen markers closely associated with intramuscular fat content and fatty acid composition in squabs. The data from this study were deposited in the National Center for Biotechnology Information (NCBI)’s Sequence Read Archive under the accession numbers SRX1680021 and SRX1680022. This is the first transcriptome analysis of the muscle and liver tissue in Columba using next generation sequencing technology. Data provided here are of potential value to dissect functional genes influencing fat deposition in squabs. PMID:27175015

Effective removal of calcified deposits on microstructured titanium fixture surfaces of dental implants with erbium lasers.

PubMed

Takagi, Toru; Aoki, Akira; Ichinose, Shizuko; Taniguchi, Yoichi; Tachikawa, Noriko; Shinoki, Takeshi; Meinzer, Walter; Sculean, Anton; Izumi, Yuichi

2018-03-13

Recently, the occurrence of peri-implantitis has been increasing. However, a suitable method to debride the contaminated surface of titanium implants has not been established. The aim of this study was to investigate the morphological changes of the microstructured fixture surface after erbium laser irradiation, and to clarify the effects of the erbium lasers when used to remove calcified deposits from implant fixture surfaces. In experiment 1, sandblasted, large grit, acid etched surface implants were treated with Er:YAG laser or Er,Cr:YSGG laser at 30-60 mJ/pulse and 20 Hz with water spray. In experiments 2 and 3, the effects of erbium lasers used to remove calcified deposits (artificially prepared deposits on virgin implants and natural calculus on failed implants) were investigated and compared with mechanical debridement using either a titanium curette or cotton pellets. After the various debridement methods, all specimens were analyzed by stereomicroscopy (SM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Stereomicroscopy and SEM showed that erbium lasers with optimal irradiation parameters did not have an effect on titanium microstructures. Compared to mechanical debridement, erbium lasers were more capable of removing calcified deposits on the microstructured surface without surface alteration using a non-contact sweeping irradiation at 40 mJ/pulse (ED 14.2 J/cm 2 /pulse) and 20 Hz with water spray. These results indicate that Er:YAG and Er,Cr:YSGG lasers are more advantageous in removing calcified deposits on the microstructured surface of titanium implants without inducing damage, compared to mechanical therapy by cotton pellet or titanium curette. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The effect of activated carbon support surface modification on characteristics of carbon nanospheres prepared by deposition precipitation of Fe-catalyst

NASA Astrophysics Data System (ADS)

Kristianto, H.; Arie, A. A.; Susanti, R. F.; Halim, M.; Lee, J. K.

2016-11-01

In this study the effect of activated carbon support modification to synthesis of CNSs was observed. Modification of activated carbon was done by using nitric acid. The effect of modification was analyzed from its FTIR spectra. The Fe catalysts were deposited on to the support by using urea deposition precipitation method at various initial catalysts concentration. CNSs was synthesized by utilizing cooking palm oil as renewable carbon source, and pyrolized at 700°C for 1 hour under nitrogen atmosphere. The products obtained then analyzed using SEM-EDS, TEM, XRD, and Raman spectroscopy. The modification of activated carbon support had increased the oxygen functional group. This increase resulted on increase of metal catalysts deposited on activated carbon surface. Peak of C (100) was observed, while ID/IG of samples were obtained around 0.9, which is commonly obtained for CNSs. High catalysts loading on modified activated carbon support caused decomposition of CNSs and formation carbon onion.

Effects of Additives on Electrochemical Growth of Cu Film on Co/SiO2/Si Substrate by Alternating Underpotential Deposition of Pb and Surface-Limited Redox Replacement by Cu

NASA Astrophysics Data System (ADS)

Fang, J. S.; Lin, L. Y.; Wu, C. L.; Cheng, Y. L.; Chen, G. S.

2017-11-01

The effects of additives to an acidic electrolyte for electrochemical deposition of copper film to prevent corrosion of the Co/SiO2/Si substrate have been investigated. A sacrificial Pb layer was formed by underpotential deposition (UPD), then a Cu layer was prepared using surface-limited redox replacement (SLRR) to exchange the UPD-Pb layer in an acidic copper electrolyte with trisodium citrate, sodium perchlorate, and ethylenediamine as additives. The additives significantly affected the replacement of UPD-Pb by Cu and prevented galvanic corrosion of the Co/SiO2/Si substrate in the acidic Cu electrolyte. The results showed that both sodium perchlorate and ethylenediamine reduced the corrosion of the Co substrate and resulted in Cu film with low electrical resistivity. However, residual Pb was present in the Cu film when using trisodium citrate, as the citrate ions slowed copper displacement. The proposed sequential UPD-Pb and SLRR-Cu growth method may enable electrochemical deposition for fabrication of Cu interconnects on Co substrate from acidic Cu electrolyte.

[Effects of simulated nitrogen deposition on soil acid phosphomonoesterase activity and soil available phosphorus content in subtropical forests in Dinghushan Mountain].

PubMed

Li, Yin; Zeng, Shu-cai; Huang, Wen-juan

2011-03-01

An in situ field experiment was conducted to study the effects of simulated nitrogen (N) deposition on soil acid phosphomonoesterase activity (APA) and soil available phosphorous (AP) content in Pinus massoniana forest (PF), coniferous and broad-leaved mixed forest (MF), and monsoon evergreen broad-leaved forest (MEBF) in Dinghushan Mountain. In PF and MF, three treatments were installed, i.e., CK (0 kg N x hm(-2) x a(-1)), low N (50 kg N x hm(-2) x a(-1)), and medium N (100 kg N x hm(-2) x a(-1)); in MEBF, four treatments were installed, i.e., CK, low N, medium N, and high N (150 kg N x hm(-2) x a(-1)). The soil APA and soil AP content decreased with soil depth. The soil APA was the highest in MEBF, while the AP content had no significant difference in the three forests. The effects of N addition on soil APA differed with forest types. In MEBF, the APA was the highest (19.52 micromol x g(-1) x h(-1)) in low N treatment; while in PF and MF, the APA was the highest (12.74 and 11.02 micromol x g(-1) x h(-1), respectively) in medium N treatment. In the three forests, soil AP content was the highest in low N treatment, but had no significant differences among the N treatments. There was a significant positive correlation between soil APA and soil AP content.

Vapor-deposited water and nitric acid ices

NASA Astrophysics Data System (ADS)

Leu, Ming-Taun; Keyser, Leon F.

Ices formed by vapor deposition have been the subject of numerous laboratory investigations in connection with snow and glaciers on the ground, ice clouds in the terrestrial atmosphere, surfaces of other planets and their satellites, and the interstellar medium. In this review we will focus on these specific subjects: (1) heterogeneous chemistry on the surfaces of polar stratospheric clouds (PSCs) and (2) surfaces of satellites of the outer planets in our solar system. Stratospheric ozone provides a protective shield for mankind and the global biosphere from harmful ultraviolet solar radiation. In past decades, theoretical atmospheric models for the calculation of ozone balance frequently used only homogeneous gas-phase reactions in their studies. Since the discovery of the Antarctic ozone hole in 1985, however, it has been demonstrated that knowledge of heterogeneous reactions on the surface of PSCs is definitely needed to understand this significant natural event due to the anthropogenic emission of chlorofluorocarbons (CFCs). We will briefly discuss the experimental techniques for the investigation of heterogeneous chemistry on ice surfaces carried out in our laboratories. The experimental apparatus used include: several flow-tube reactors, an electron-impact ionization mass spectrometer, a Fourier transform infrared spectrometer, a BET adsorption apparatus, and a scanning environmental electron microscope. The adsorption experiments and electron microscopic work have demonstrated that the vapor-deposited ices are highly porous. Therefore, it is necessary to develop theoretical models for the elucidation of the uptake and reactivity of trace gases in porous ice substrates. Several measurements of uptake and reaction probabilities of these trace gases on water ices and nitric acid ices have been performed under ambient conditions in the upper troposphere and lower stratosphere, mainly in the temperature range 180-220 K. The trace gases of atmospheric importance

Contractile function recovery in severely injured gastrocnemius muscle of rats treated with either oleic or linoleic acid.

PubMed

Abreu, Phablo; Pinheiro, Carlos H J; Vitzel, Kaio F; Vasconcelos, Diogo A A; Torres, Rosângela P; Fortes, Marco S; Marzuca-Nassr, Gabriel N; Mancini-Filho, Jorge; Hirabara, Sandro M; Curi, Rui

2016-11-01

What is the central question of this study? Oleic and linoleic acids modulate fibroblast proliferation and myogenic differentiation in vitro. However, their in vivo effects on muscle regeneration have not yet been examined. We investigated the effects of either oleic or linoleic acid on a well-established model of muscle regeneration after severe laceration. What is the main finding and its importance? We found that linoleic acid increases fibrous tissue deposition and impairs muscle regeneration and recovery of contractile function, whereas oleic acid has the opposite effects in severely injured gastrocnemius muscle, suggesting that linoleic acid has a harmful effect and oleic acid a potential therapeutic effect on muscle regeneration. Oleic and linoleic acids control fibroblast proliferation and myogenic differentiation in vitro; however, there was no study in skeletal muscle in vivo. The aim of this study was to evaluate the effects of either oleic or linoleic acid on the fibrous tissue content (collagen deposition) of muscle and recovery of contractile function in rat gastrocnemius muscle after being severely injured by laceration. Rats were supplemented with either oleic or linoleic acid for 4 weeks after laceration [0.44 g (kg body weight) -1 day -1 ]. Muscle injury led to an increase in oleic-to-stearic acid and palmitoleic-to-palmitic acid ratios, suggesting an increase in Δ 9 desaturase activity. Increased fibrous tissue deposition and reduced isotonic and tetanic specific forces and resistance to fatigue were observed in the injured muscle. Supplementation with linoleic acid increased the content of eicosadienoic (20:2, n-6) and arachidonic (20:4, n-6) acids, reduced muscle mass and fibre cross-sectional areas, increased fibrous tissue deposition and further reduced the isotonic and tetanic specific forces and resistance to fatigue induced by laceration. Supplementation with oleic acid increased the content of docosahexaenoic acid (22:6, n-3) and

Fatty acid utilization by young Wistar rats fed a cafeteria diet.

PubMed

Esteve, M; Rafecas, I; Fernández-López, J A; Remesar, X; Alemany, M

1992-12-02

The content and accretion of fatty acids in 30, 45 and 60-day old Wistar rats fed either reference chow or a cafeteria diet has been studied, together with their actual fatty acid intake during that period. Diet had a small overall effect on the pattern of deposition of fatty acids, but the deposition of fat was much higher in cafeteria rats. The fat-rich cafeteria diet allowed the direct incorporation of most fatty acids into lipid storage, whilst chow-feeding activated lipogenesis and the deposition of a shorter chain and more saturated type of fatty acids. During the second month of the rat's life, the elongation pathway as well as delta 9-desaturase became functional, thus helping to shape the pattern of fatty acids actually accrued. The 60-day rats showed a relative impairment in the operation of delta 5-desaturase, since their lipids had a higher C20:4/C20:3 ratio than those of the diet ingested. Cafeteria-diet feeding minimized this effect since the large supply of dietary polyunsaturated fatty acids made the operation of the elongation-desaturase pathways practically unnecessary.

Effect of heat treatment on the characteristics of tool steel deposited by the directed energy deposition process

NASA Astrophysics Data System (ADS)

Park, Jun Seok; Lee, Min-Gyu; Cho, Yong-Jae; Sung, Ji Hyun; Jeong, Myeong-Sik; Lee, Sang-Kon; Choi, Yong-Jin; Kim, Da Hye

2016-01-01

The directed energy deposition process has been mainly applied to re-work and the restoration of damaged steel. Differences in material properties between the base and the newly deposited materials are unavoidable, which may affect the mechanical properties and durability of the part. We investigated the effect of heat treatment on the characteristics of tool steel deposited by the DED process. We prepared general tool steel materials of H13 and D2 that were deposited onto heat-treated substrates of H13 and D2, respectively, using a direct metal tooling process. The hardness and microstructure of the deposited steel before and after heat treatment were investigated. The hardness of the deposited H13 steel was higher than that of wrought H13 steel substrate, while that of the deposited D2 was lower than that of wrought D2. The evolution of the microstructures by deposition and heat treatment varied depending on the materials. In particular, the microstructure of the deposited D2 steel after heat treatment consisted of fine carbides in tempered martensite and it is expected that the deposited D2 steel will have isotropic properties and high hardness after heat treatment.

Deposition and maturation of eggs of Schistosoma mansoni in vitro: importance of fatty acids in serum-free media.

PubMed

Newport, G R; Weller, T H

1982-03-01

A serum-free medium which supports miracidial development in some eggs deposited by adult Schistosoma mansoni in vitro is described. Derivation of the medium involved examination of the supportiveness of nine chemically defined media, selection of one promoting the highest degree of worm oviposition, and supplementation of the latter with various serum fractions. The serum fraction supporting egg maturation was nondialyzable, and precipitated at 50-60% ammonium sulfate saturation. This fraction could be replaced by bovine serum albumin; however, the supportive activity disappeared if this material was delipidated. Addition of soybean lecithin, or stearic acid, to fatty-acid-free, albumin-supplemented media yielded intermediate results, while similar addition of other nonesterified fatty acids proved non stimulatory. A fatty acid mixture, rich in stearic acid, was then developed which, when added to delipidated-albumin supplemented media, supported a degree of egg development comparable to that obtained with media supplemented with 8% newborn calf serum.

Relationships between acid deposition, watershed characteristics, and stream chemistry in Maryland's coastal plain. Final report. Volume 1. Text. Report for May 1984-June 1985

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

Campbell, S.; Bartoshesky, J.; Heimbuch, D.

1987-06-01

Precipitation and stream-water chemistry data were collected from three watersheds in the Coastal Plain region of Maryland during the period May 1984 through June 1985 in an attempt to determine the potential effects of acidic deposition on the chemistry of these streams. The study streams included Lyons Creek, Morgan Creek, and Granny Finley Branch; these streams were chosen based on their differential responses to storm events observed in a survey of Coastal Plain streams in the spring of 1983. Lyons Creek typically exhibited lower pH, acid-neutralizing capacity, and concentrations of base cations than observed in the other streams. Sulfate massmore » balances suggest that the soils in the Lyons Creek watershed also have less affinity for sulfur retention than do soils of the other watersheds. Acidic pulses were observed in all three streams during the spring months; however, the magnitude of these pulses was less than that observed in 1983. Modeling of the relationships between precipitation chemistry, watershed interactions, and stream chemistry suggests that precipitation acidity can influence stream-water acidity, depending upon hydrological conditions and availabiility of acid-neutralizing materials in the watersheds.« less

Response of fish assemblages to declining acidic deposition in Adirondack Mountain lakes, 1984-2012

NASA Astrophysics Data System (ADS)

Baldigo, B. P.; Roy, K. M.; Driscoll, C. T.

2016-12-01

Adverse effects of acidic deposition on the chemistry and fish communities were evident in Adirondack Mountain lakes during the 1980s and 1990s. Fish assemblages and water chemistry in 43 Adirondack Long-Term Monitoring (ALTM) lakes were sampled by the Adirondack Lakes Survey Corporation and the New York State Department of Environmental Conservation during three periods (1984-87, 1994-2005, and 2008-12) to document regional impacts and potential biological recovery associated with the 1990 amendments to the 1963 Clean Air Act (CAA). We assessed standardized data from 43 lakes sampled during the three periods to quantify the response of fish-community richness, total fish abundance, and brook trout (Salvelinus fontinalis) abundance to declining acidity that resulted from changes in U.S. air-quality management between 1984 and 2012. During the 28-year period, mean acid neutralizing capacity (ANC) increased significantly from 3 to 30 μeq/L and mean inorganic monomeric Al concentrations decreased significantly from 2.22 to 0.66 μmol/L, yet mean species richness, all species or total catch per net night (CPNN), and brook trout CPNN did not change significantly in the 43 lakes. Regression analyses indicate that fishery metrics were not directly related to the degree of chemical recovery and that brook trout CPNN may actually have declined with increasing ANC. While the richness of fish communities increased with increasing ANC as anticipated in several Adirondack lakes, observed improvements in water quality associated with the CAA have generally failed to produce detectable shifts in fish assemblages within a large number of ALTM lakes. Additional time may simply be needed for biological recovery to progress, or else more proactive efforts may be necessary to restore natural fish assemblages in Adirondack lakes in which water chemistry is steadily recovering from acidification.

The response of gene expression associated with lipid metabolism, fat deposition and fatty acid profile in the longissimus dorsi muscle of Gannan yaks to different energy levels of diets

PubMed Central

Liu, Jianbin; Wu, Xiaoyun; Bao, Pengjia; Long, Ruijun; Guo, Xian; Ding, Xuezhi; Yan, Ping

2017-01-01

The energy available from the diet, which affects fat deposition in vivo, is a major factor in the expression of genes regulating fat deposition in the longissimus dorsi muscle. Providing high-energy diets to yaks might increase intramuscular fat deposition and fatty acid concentrations under a traditional grazing system in cold seasons. A total of fifteen adult castrated male yaks with an initial body weight 274.3 ± 3.14 kg were analyzed for intramuscular adipose deposition and fatty acid composition. The animals were divided into three groups and fed low-energy (LE: 5.5 MJ/kg), medium-energy (ME: 6.2 MJ/kg) and high-energy (HE: 6.9 MJ/kg) diets, respectively. All animals were fed ad libitum twice daily at 08:00–09:00 am and 17:00–18:00 pm and with free access to water for 74 days, including a 14-d period to adapt to the diets and the environment. Intramuscular fat (IMF) content, fatty acid profile and mRNA levels of genes involved in fatty acid synthesis were determined. The energy levels of the diets significantly (P<0.05) affected the content of IMF, total SFA, total MUFA and total PUFA. C16:0, C18:0 and C18:1n9c account for a large proportion of total fatty acids. Relative expression of acetyl-CoA carboxylase (ACACA), fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ) and fatty acid-binding protein 4 (FABP4) was greater in HE than in LE yaks (P<0.05). Moreover, ME yaks had higher (P<0.05) mRNA expression levels of PPARγ, ACACA, FASN, SCD and FABP4 than did the LE yaks. The results demonstrate that the higher energy level of the diets increased IMF deposition and fatty acid content as well as increased intramuscular lipogenic gene expression during the experimental period. PMID:29121115

UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

PubMed Central

Saita, Makiko; Ikeda, Takayuki; Yamada, Masahiro; Kimoto, Katsuhiko; Lee, Masaichi Chang-Il; Ogawa, Takahiro

2016-01-01

Background Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV) light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability. Methods and results Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light) were immersed in simulated body fluid (SBF) for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition in the valleys and at the inclines of micro-roughened structures without affecting the existing micro-configuration. Micro-roughened titanium and apatite-deposited titanium surfaces had similar roughness values. The attachment, spreading, settling, proliferation, and alkaline phosphate activity of bone marrow-derived osteoblasts were promoted on apatite-coated titanium with photofunctionalization. Conclusion UV-photofunctionalization of titanium enabled faster deposition of nanoscale biomimetic apatite, resulting in the improved biological capability compared to the similarly prepared apatite-deposited titanium without photofunctionalization. Photofunctionalization-assisted biomimetic apatite

Different sources of omega-3 polyunsaturated fatty acids affects apparent digestibility, tissue deposition, and tissue oxidative stability in growing female rats

PubMed Central

2011-01-01

Background Numerous health benefits associated with increased omega-3 polyunsaturated fatty acid (n-3 PUFA) consumption has lead to an increasing variety of available n-3 PUFA sources. However, sources differ in the type, amount, and structural form of the n-3 PUFAs. Therefore, the objective of this study was to determine the effect of different sources of ω-3 PUFAs on digestibility, tissue deposition, eicosanoid metabolism, and oxidative stability. Methods Female Sprague-Dawley rats (age 28 d) were randomly assigned (n = 10/group) to be fed a high fat 12% (wt) diet consisting of either corn oil (CO) or n-3 PUFA rich flaxseed (FO), krill (KO), menhaden (MO), salmon (SO) or tuna (TO) oil for 8 weeks. Rats were individually housed in metabolic cages to determine fatty acid digestibility. Diet and tissue fatty acid composition was analyzed by gas chromatography and lipid classes using thin layer chromatography. Eicosanoid metabolism was determined by measuring urinary metabolites of 2-series prostaglandins (PGs) and thromoboxanes (TXBs) using enzyme immunoassays. Oxidative stability was assessed by measuring thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) using colorimetric assays. Gene expression of antioxidant defense enzymes was determined by real time quantitative polymerase chain reaction (RT-qPCR). Results Rats fed KO had significantly lower DHA digestibility and brain DHA incorporation than SO and TO-fed rats. Of the n-3 PUFA sources, rats fed SO and TO had the highest n-3 PUFAs digestibility and in turn, tissue accretion. Higher tissue n-3 LC-PUFAs had no significant effect on 2-series PG and TXB metabolites. Despite higher tissue n-3 LC-PUFA deposition, there was no increase in oxidation susceptibility indicated by no significant increase in TBARS or decrease in TAC and gene expression of antioxidant defense enzymes, in SO or TO-fed rats. Conclusions On the basis that the optimal n-3 PUFA sources should provide high

Cotransport of bacteria with hematite in porous media: Effects of ion valence and humic acid.

PubMed

Yang, Haiyan; Ge, Zhi; Wu, Dan; Tong, Meiping; Ni, Jinren

2016-01-01

This study investigated the influence of multiple colloids (hematite and humic acid) on the transport and deposition of bacteria (Escherichia coli) in packed porous media in both NaCl (5 mM) and CaCl2 (1 mM) solutions at pH 6. Due to the alteration of cell physicochemical properties, the presence of hematite and humic acid in cell suspensions significantly affected bacterial transport and deposition in quartz sand. Specifically, the presence of hematite (5 mg/L) decreased cell transport (increased cell deposition) in quartz sand in both NaCl and CaCl2 solutions, which could be attributed to the less negative overall zeta potentials of bacteria induced by the adsorption of positively charged hematite onto cell surfaces. The presence of a low concentration (0.1 mg/L) of humic acid in bacteria and hematite mixed suspensions reduced the adsorption of hematite onto cell surfaces, leading to increased cell transport in quartz sand in NaCl solutions, whereas, in CaCl2 solutions, the presence of 0.1 mg/L humic acid increased the formation of hematite-cell aggregates and thus decreased cell transport in quartz sand. When the concentration of humic acid was increased to 1 mg/L, enhanced cell transport was observed in both NaCl and CaCl2 solutions. The decreased adsorption of hematite onto cell surfaces as well as the competition of deposition sites on quartz sand with bacteria by the suspended humic acid contributed to the increased cell transport. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stemflow Acid Neutralization Capacity in a Broadleaved Deciduous Forest: The Role of Edge Effects

NASA Astrophysics Data System (ADS)

Levia, D. F., Jr.; Shiklomanov, A.

2014-12-01

The fragmentation of forests is occurring at an accelerated rate in parts of the United States. Forest fragmentation creates edge habitat that affects the biogeochemistry of forests. Atmospheric deposition is known to increase at the forest edge in comparison to the forest interior. Past research has demonstrated the critical role of edge effects on throughfall chemistry but no known work has examined the relationship between stemflow chemistry and edge effects. To fill this data gap, we quantified the stemflow acid neutralization capacity (ANC) of nineteen Liriodendron tulipifera L. (yellow poplar) trees between forest edge and interior locations in the Piedmont of the mid-Atlantic USA. ANC was measured directly by potentiometric titration. Both stemflow pH and ANC were higher for L. tulipifera trees on the forest edge as opposed to those in interior locations (p < 0.01), although marked variability was observed among individual trees. It is critical to note that the ANC of stemflow of edge trees is almost certainly contextual, depending on geographic locality. This is to say that stemflow from edge trees may neutralize acid inputs in some locations (as in our case) but lead to enhanced acidification of aqueous inputs to forest soils in other locales where the dry deposition of acid anions is high. The experimental results have ramifications for forest management schema seeking to increase or decrease the extent of edge habitat in forest fragments.

Forest canopy uptake of atmospheric nitrogen deposition at eastern U.S. conifer sites: Carbon storage implications?

Treesearch

Herman Sievering; Ivan Fernandez; John Lee; John Hom; Lindsey Rustad

2000-01-01

Dry deposition determinations, along with wet deposition and throughfall (TF) measurements, at a spruce fir forest in central Maine were used to estimate the effect of atmospherically deposited nitrogen (N) uptake on forest carbon storage. Using nitric acid and particulate N as well as TF ammonium and nitrate data, the growing season (May-October) net canopy uptake of...

Effects of digestion, chemical separation, and deposition on Po-210 quantitative analysis

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

Seiner, Brienne N.; Morley, Shannon M.; Beacham, Tere A.

Polonium-210 is a radioactive isotope often used to study sedimentation processes, food chains, aerosol behavior, and atmospheric circulations related to environmental sciences. Materials for the analysis of Po-210 range from tobacco leaves or cotton fibers, to soils and sediments. The purpose of this work was to determine polonium losses from a variety of sample types (soil, cotton fiber, and air filter) due to digestion technique, chemical separation, and deposition method for alpha energy analysis. Results demonstrated that yields from a perchloric acid wet-ash were similar to that from a microwave digestion. Both were greater than the dry-ash procedure. The poloniummore » yield from the perchloric acid wet ash was 87 ± 5%, the microwave digestion had a yield of 100 ± 7%, and the dry ash had a yield of 38 ± 5%. The chemical separation of polonium by an anion exchange resin was used only on the soil samples due to the complex nature of this sample. The yield of Po-209 tracer after chemical separation and deposition for alpha analysis was 83 ± 7% for the soil samples. Spontaneous deposition yields for the cotton and air filters were 87 ± 4% and 92 ± 6%, respectively. Based on the overall process yields for each sample type the amount of Po-210 was quantified using alpha energy analysis. The soil contained 0.18 ± 0.08 Bq/g, the cotton swipe contained 0.7 mBq/g, and the air filter contained 0.04 ± 0.02 mBq/g. High and robust yields of polonium are possible using a suitable digestion, separation, and deposition method.« less

Electrogeochemical sampling with NEOCHIM - results of tests over buried gold deposits

USGS Publications Warehouse

Leinz, R.W.; Hoover, D.B.; Fey, D.L.; Smith, D.B.; Patterson, T.

1998-01-01

Electrogeochemical extraction methods are based on the migration of ions in an electric field. Ions present in soil moisture are transported by an applied current into fluids contained in special electrodes placed on the soil. The fluids are then collected and analyzed. Extractions are governed by Faraday's and Ohm's laws and are modeled by the operation of a simple Hittord transference apparatus. Calculations show that the volume of soil sampled in an ideal electrogeochemical extraction can be orders of magnitude greater than the volumes used in more popular geochemical extraction methods, although this has not been verified experimentally. CHIM is a method of in-situ electrogeochemical extraction that was developed in the former Soviet Union and has been tested and applied internationally to exploration for buried mineral deposits. Tests carried out at the US Geological Survey (USGS) indicated that there were problems inherent in the use of CHIM technology. The cause of the problems was determined to be the diffusion of acid from the conventional electrode into the soil. The NEOCHIM electrode incorporates two compartments and a salt bridge in a design that inhibits diffusion of acid and enables the collection of anions or cations. Tests over a gold-enriched vein in Colorado and over buried, Carlin-type, disseminated gold deposits in northern Nevada show that there are similarities and differences between NEOCHIM results and those by partial extractions of soils which include simple extractions with water, dilute acids and solutions of salts used as collector fluids in the electrodes. Results of both differ from the results obtained by total chemical digestion. The results indicate that NEOCHIM responds to mineralized faults associated with disseminated gold deposits whereas partial and total chemical extraction methods do not. This suggests that faults are favored channels for the upward migration of metals and that NEOCHIM may be more effective in exploration

Response of fish assemblages to decreasing acid deposition in Adirondack Mountain lakes

USGS Publications Warehouse

Baldigo, Barry P.; Roy, Karen; Driscoll, Charles T.

2016-01-01

The CAA and other federal regulations have clearly reduced emissions of NOx and SOx, acidic deposition, and the acidity and toxicity of waters in the ALTM lakes, but these changes have not triggered widespread recovery of brook trout populations or fish communities. The lack of detectable biological recovery appears to result from relatively recent chemical recovery and an insufficient period for species populations to take advantage of improved water quality. Recovery of extirpated species’ populations may simply require more time for individuals to migrate to and repopulate formerly occupied lakes. Supplemental stocking of selected species may be required in some lakes with no remnant (or nearby) populations or with physical barriers between the recovered lake and source populations. The lack of detectable biological recovery could also be related to our inability to calculate measures of uncertainty or error and, thus, examine temporal changes or differences in populations and community metrics in more depth (e.g., within individual lakes) using existing datasets. Indeed, recovery of brook trout populations and partial recovery of fish communities are documented in several lakes of the region, both with and without human intervention. Multiple fish surveys (annually or within the same year) or the use of mark and recapture methods within individual lakes would help alleviate the issue (provide measures of error for key fishery metrics) within the context of a more focused sampling strategy. Efforts to evaluate and detect recovery in fish assemblages from streams may be more effective than in lakes because various life stages, species’ populations, and entire assemblages are easier to quantify, with known levels of error, in streams than in lakes. Such long-term monitoring efforts could increase our ability to detect and quantify biological recovery in recovering (neutralizing) surface waters throughout the Adirondack Region.

Acid Rain

USGS Publications Warehouse

Bricker, Owen P.; Rice, Karen C.

1995-01-01

Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

Modeling potential interactions of acid deposition and climate change at four watersheds in Shenandoah National Park, VA using the dynamic biogeochemical model PnET-BGC

NASA Astrophysics Data System (ADS)

Robison, A.; Scanlon, T. M.; Cosby, B. J.; Webb, J. R.; Hayhoe, K.; Galloway, J. N.

2013-12-01

The ecological threat imposed by acid deposition on watersheds in the eastern U.S. has, to a certain extent, been alleviated by the passage of the Clean Air Act and subsequent amendments. At the same time, as climate change continues to emerge as a global issue affecting temperature regimes and hydrological cycling among many other variables, new concerns are developing for these watershed ecosystems. Considering that climate change and acid deposition do not influence watersheds independently, there is an opportunity and need to examine both the potential interactions and the impacts of these two biogeochemical drivers. Long-term monitoring of four streams in Shenandoah National Park, VA has provided a favorable setting for analyzing this interaction. Deposition of both sulfur and nitrogen has significantly decreased over the past 30 years in the region. Meanwhile, all four streams have warmed significantly over the past 20-33 years at an average rate of 0.07 oC yr-1, a trend that is closely tied to atmospheric warming rather than changes in hydrology. We applied a dynamic biogeochemical model (PnET-BGC) to these four watersheds to a) investigate how climate change will affect watershed response to reduced acid deposition; b) identify the key processes through which this interaction will be manifested; and c) examine how differences in watershed characteristics (e.g. bedrock and soil properties) affect the response to these two biogeochemical drivers. Included in model application are statistically downscaled climate projections of temperature maximums and minimums, precipitation, and solar radiation. Results will be used to assess the relative impact of these climate variables in regulating stream acid-base status. This study will also provide insight into the future ecological health of these ecosystems, primarily through examination of aquatic habitat suitability based on temperature and acidity.

Imbalance in Fatty-Acid-Chain Length of Gangliosides Triggers Alzheimer Amyloid Deposition in the Precuneus

PubMed Central

Oikawa, Naoto; Matsubara, Teruhiko; Fukuda, Ryoto; Yasumori, Hanaki; Hatsuta, Hiroyuki; Murayama, Shigeo; Sato, Toshinori; Suzuki, Akemi; Yanagisawa, Katsuhiko

2015-01-01

Amyloid deposition, a crucial event of Alzheimer’s disease (AD), emerges in distinct brain regions. A key question is what triggers the assembly of the monomeric amyloid ß-protein (Aß) into fibrils in the regions. On the basis of our previous findings that gangliosides facilitate the initiation of Aß assembly at presynaptic neuritic terminals, we investigated how lipids, including gangliosides, cholesterol and sphingomyelin, extracted from synaptic plasma membranes (SPMs) isolated from autopsy brains were involved in the Aß assembly. We focused on two regions of the cerebral cortex; precuneus and calcarine cortex, one of the most vulnerable and one of the most resistant regions to amyloid deposition, respectively. Here, we show that lipids extracted from SPMs isolated from the amyloid-bearing precuneus, but neither the amyloid-free precuneus nor the calcarine cortex, markedly accelerate the Aß assembly in vitro. Through liquid chromatography-mass spectrometry of the lipids, we identified an increase in the ratio of the level of GD1b-ganglioside containing C20:0 fatty acid to that containing C18:0 as a cause of the enhanced Aß assembly in the precuneus. Our results suggest that the local glycolipid environment play a critical role in the initiation of Alzheimer amyloid deposition. PMID:25798597

A Martian analog in Kansas: Comparing Martian strata with Permian acid saline lake deposits

NASA Astrophysics Data System (ADS)

Benison, Kathleen C.

2006-05-01

An important result of the Mars Exploration Rover's (MER) mission has been the images of sedimentary structures and diagenetic features in the Burns Formation at Meridiani Planum. Bedding, cross-bedding, ripple marks, mud cracks, displacive evaporite crystal molds, and hematite concretions are contained in these Martian strata. Together, these features are evidence of past saline groundwater and ephemeral shallow surface waters on Mars. Geochemical analyses of these Martian outcrops have established the presence of sulfates, iron oxides, and jarosite, which strongly suggests that these waters were also acidic. The same assemblage of sedimentary structures and diagenetic features is found in the salt-bearing terrestrial red sandstones and shales of the middle Permian (ca. 270 Ma) Nippewalla Group of Kansas, which were deposited in and around acid saline ephemeral lakes. These striking sedimentological and mineralogical similarities make these Permian red beds and evaporites the best-known terrestrial analog for the Martian sedimentary rocks at Meridiani Planum.

Effect of surface deposits on electromagnetic waves propagating in uniform ducts

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.

1990-01-01

A finite-element Galerkin formulation was used to study the effect of material surface deposits on the reflective characteristics of straight uniform ducts with PEC (perfectly electric conducting) walls. Over a wide frequency range, the effect of both single and multiple surface deposits on the duct reflection coefficient were examined. The power reflection coefficient was found to be significantly increased by the addition of deposits on the wall.

An evaluation of the regional acid deposition model surface module for ozone uptake at three sites in the San Joaquin Valley of California

NASA Technical Reports Server (NTRS)

Massman, W. J.; Pederson, J.; Delany, A.; Grantz, D.; Hertog, G. Den; Neumann, H. H.; Oncley, S. P.; Pearson, R., Jr.; Shaw, R. H.

1994-01-01

Plants and soils act as major sinks for the destruction of tropospheric ozone, especially during daylight hours when plant stomata open and are thought to provide the dominant pathway for the uptake of ozone. The present study, part of the California Ozone Deposition Experiment, compares predictions of the regional acid deposition model ozone surface conductance module with surface conductance data derived from eddy covariance measurements of ozone flux taken at a grape, a cotton, and a grassland site in the San Joaquin Valley of California during the summer of 1991. Results indicate that the model (which was developed to provide long-term large-area estimates for the eastern United States) significantly overpredicts the surface conductance at all times of the day for at least two important types of plant cover of the San Joaquin Valley and that it incorrectly partitions the ozone flux between transpiring and nontranspiring components of the surface at the third site. Consequently, the model either overpredicts or inaccurately represents the observed deposition velocities. Other results indicate that the presence of dew does not reduce the rate of ozone deposition, contradicting to model assumptions, and that model assumptions involving the dependency of stomata upon environmental temperature are unnecessary. The effects of measurement errors and biases, arising from the presence of the roughness sublayer and possible photochemical reactions, are also discussed. A simpler model for ozone surface deposition (at least for the San Joaquin Valley) is proposed and evaluated.

The effect of nutrient deposition on bacterial communities in Arctic tundra soil

Treesearch

Barbara J. Campbell; Shawn W. Polson; Thomas E. Hanson; Michelle C. Mack; Edward A.G. Schuur

2010-01-01

The microbial communities of high-latitude ecosystems are expected to experience rapid changes over the next century due to climate warming and increased deposition of reactive nitrogen, changes that will likely affect microbial community structure and function. In moist acidic tundra (MAT) soils on the North Slope of the Brooks Range, Alaska, substantial losses of C...

Climax-Type Porphyry Molybdenum Deposits

USGS Publications Warehouse

Ludington, Steve; Plumlee, Geoffrey S.

2009-01-01

Climax-type porphyry molybdenum deposits, as defined here, are extremely rare; thirteen deposits are known, all in western North America and ranging in age from Late Cretaceous to mainly Tertiary. They are consistently found in a postsubduction, extensional tectonic setting and are invariably associated with A-type granites that formed after peak activity of a magmatic cycle. The deposits consist of ore shells of quartz-molybdenite stockwork veins that lie above and surrounding the apices of cupola-like, highly evolved, calc-alkaline granite and subvolcanic rhyolite-porphyry bodies. These plutons are invariably enriched in fluorine (commonly >1 percent), rubidium (commonly >500 parts per million), and niobium-tantalum (Nb commonly >50 parts per million). The deposits are relatively high grade (typically 0.1-0.3 percent Mo) and may be very large (typically 100-1,000 million tons). Molybdenum, as MoS2, is the primary commodity in all known deposits. The effect on surface-water quality owing to natural influx of water or sediment from a Climax-type mineralized area can extend many kilometers downstream from the mineralized area. Waste piles composed of quartz-silica-pyrite altered rocks will likely produce acidic drainage waters. The potential exists for concentrations of fluorine or rare metals in surface water and groundwater to exceed recommended limits for human consumption near both mined and unmined Climax-type deposits.

Effects of debris flow composition on runout, depositional mechanisms, and deposit morphology in laboratory experiments

NASA Astrophysics Data System (ADS)

Haas, Tjalling; Braat, Lisanne; Leuven, Jasper R. F. W.; Lokhorst, Ivar R.; Kleinhans, Maarten G.

2015-09-01

Predicting debris flow runout is of major importance for hazard mitigation. Apart from topography and volume, runout distance and area depends on debris flow composition and rheology, but how is poorly understood. We experimentally investigated effects of composition on debris flow runout, depositional mechanisms, and deposit geometry. The small-scale experimental debris flows were largely similar to natural debris flows in terms of flow behavior, deposit morphology, grain size sorting, channel width-depth ratio, and runout. Deposit geometry (lobe thickness and width) in our experimental debris flows is largely determined by composition, while the effects of initial conditions of topography (i.e., outflow plain slope and channel slope and width) and volume are negligible. We find a clear optimum in the relations of runout with coarse-material fraction and clay fraction. Increasing coarse-material concentration leads to larger runout. However, excess coarse material results in a large accumulation of coarse debris at the flow front and enhances diffusivity, increasing frontal friction and decreasing runout. Increasing clay content initially enhances runout, but too much clay leads to very viscous flows, reducing runout. Runout increases with channel slope and width, outflow plain slope, debris flow volume, and water fraction. These results imply that debris flow runout depends at least as much on composition as on topography. This study improves understanding of the effects of debris flow composition on runout and may aid future debris flow hazard assessments.

Ecological effects of nitrogen deposition in the western United States

USGS Publications Warehouse

Fenn, M.E.; Baron, Jill S.; Allen, E.B.; Rueth, H.M.; Nydick, K.R.; Geiser, L.; Bowman, W.D.; Sickman, J.O.; Meixner, T.; Johnson, D.W.; Neitlich, P.

2003-01-01

In the western United States vast acreages of land are exposed to low levels of atmospheric nitrogen (N) deposition, with interspersed hotspots of elevated N deposition downwind of large, expanding metropolitan centers or large agricultural operations. Biological response studies in western North America demonstrate that some aquatic and terrestrial plant and microbial communities are significantly altered by N deposition. Greater plant productivity is counterbalanced by biotic community changes and deleterious effects on sensitive organisms (lichens and phytoplankton) that respond to low inputs of N (3 to 8 kilograms N per hectare per year). Streamwater nitrate concentrations are elevated in high-elevation catchments in Colorado and are unusually high in southern California and in some chaparral catchments in the southwestern Sierra Nevada. Chronic N deposition in the West is implicated in increased fire frequency in some areas and habitat alteration for threatened species. Between hotspots, N deposition is too low to cause noticeable effects or has not been studied.

The smog-fog-smog cycle and acid deposition

NASA Astrophysics Data System (ADS)

Pandis, Spyros N.; Seinfeld, John H.; Pilinis, Christodoulos

1990-10-01

A model including descriptions of aerosol and droplet microphysics, gas and aqueous-phase chemistry, and deposition is used to study the transformation of aerosol to fog droplets and back to aerosol in an urban environment. Fogs in polluted environments have the potential to increase aerosol sulfate concentrations but at the same time to cause reductions in the aerosol concentration of nitrate, chloride, ammonium and sodium and well as in the total aerosol mass concentration. The sulfate produced during fog episodes favors the aerosol particles that have access to most of the fog liquid water which are usually the large particles. Aerosol scavenging efficiencies of around 80 percent are calculated for urban fogs. Sampling and subsequent mixing of fog droplets of different sizes may result in measured concentrations that are not fully representative of the fogwater chemical composition and can introduce errors in the reported values of the ionic species deposition velocities. Differences in the major ionic species deposition velocities can be explained by their distribution over the droplet size spectrum and can be correlated with the species average diameter. Two different expressions are derived for use in fog models for the calculation of the liquid water deposition velocity during fog growth and dissipation stages.

Missing effects of anthropogenic nutrient deposition on sentinel alpine ecosystems.

PubMed

Vinebrooke, Rolf D; Maclennan, Megan M; Bartrons, Mireia; Zettel, James P

2014-07-01

Anthropogenic nitrogen (N) deposition affects unproductive remote alpine and circumpolar ecosystems, which are often considered sentinels of global change. Human activities and forest fires can also elevate phosphorus (P) deposition, possibly compounding the ecological effects of increased N deposition given the ubiquity of nutrient co-limitation of primary producers. Low N : P ratios coupled with evidence of NP-limitation from bioassays led us to hypothesize that P indirectly stimulates phytoplankton by amplifying the direct positive effect of N (i.e. serial N-limitation) in alpine ponds. We tested the hypothesis using the first replicated N × P enrichment experiment conducted at the whole-ecosystem level, which involved 12 alpine ponds located in the low N deposition backcountry of the eastern Front Range of the Canadian Rockies. Although applications of N and P elevated ambient N and P concentrations by 2-5×, seston and plankton remained relatively unaffected in the amended ponds. However, additions of ammonium nitrate elevated the δ(15) N signals of both primary producers and herbivores (fairy shrimp; Anostraca), attesting to trophic transfer of N deposition to consumers. Further, in situ bioassays revealed that grazing by high ambient densities of fairy shrimp together with potential competition from algae lining the pond bottoms suppressed the otherwise serially N-limited response by phytoplankton. Our findings highlight how indirect effects of biotic interactions rather the often implicit direct effects of chemical changes can regulate the sensitivities of extreme ecosystems to nutrient deposition. © 2014 John Wiley & Sons Ltd.

Groundtruthing and potential for predicting acid deposition impacts in headwater streams using bedrock geology, GIS, angling, and stream chemistry.

PubMed

Kirby, C S; McInerney, B; Turner, M D

2008-04-15

Atmospheric acid deposition is of environmental concern worldwide, and the determination of impacts in remote areas can be problematic. Rainwater in central Pennsylvania, USA, has a mean pH of approximately 4.4. Bedrock varies dramatically in its ability to neutralize acidity. A GIS database simplified reconnaissance of non-carbonate bedrock streams in the Valley and Ridge Province and identified potentially chronically impacted headwater streams, which were sampled for chemistry and brook trout. Stream sites (n=26) that originate in and flow through the Tuscarora had a median pH of 5.0 that was significantly different from other formations. Shawangunk streams (n=6) and non-Tuscarora streams (n=20) had a median pH of 6.0 and 6.3, respectively. Mean alkalinity for non-Tuscarora streams (2.6 mg/L CaCO(3)) was higher than the mean for Tuscarora streams (0.5 mg/L). Lower pH and alkalinity suggest that the buffering capability of the Tuscarora is inferior to that of adjacent sandstones. Dissolved aluminum concentrations were much higher for Tuscarora streams (0.2 mg/L; approximately the lethal limit for brook trout) than for non-Tuscarora streams (0.03 mg/L) or Shawangunk streams (0.02 mg/L). Hook-and-line methods determined the presence/absence of brook trout in 47 stream reaches with suitable habitat. Brook trout were observed in 21 of 22 non-Tuscarora streams, all 6 Shawangunk streams, and only 9 of 28 Tuscarora stream sites. Carefully-designed hook-and-line sampling can determine the presence or absence of brook trout and help confirm biological impacts of acid deposition. 15% of 334 km of Tuscarora stream lengths are listed as "impaired" due to atmospheric deposition by the Pennsylvania Department of Environmental Protection. 65% of the 101 km of Tuscarora stream lengths examined in this study were impaired.

Effects of different ratios of monounsaturated and polyunsaturated fatty acids to saturated fatty acids on regulating body fat deposition in hamsters.

PubMed

Liao, Fang-Hsuean; Liou, Tsan-Hon; Shieh, Ming-Jer; Chien, Yi-Wen

2010-01-01

Effects of monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid consumption on regulating body fat accumulation and body weight gain are controversial between animal and human studies. We designed a 2 x 2 factorial study, with two levels of MUFAs (60% and 30%) and two levels of polyunsaturated-to-saturated fatty acid (P/S) ratio (5 and 3) to prepare four kinds of experimental oils consisting of 60% MUFAs with a high or low P/S ratio (HMHR or HMLR, respectively) or 30% MUFAs with a high or low P/S ratio (LMHR or LMLR, respectively). Thirty-two male golden Syrian hamsters were randomly divided into four groups and fed the experimental diets containing 15% (w/w) fat for 12 wk. No difference was observed in the mean daily food intake. Hamsters fed the LMLR diet had increased weight gain, epididymal and retroperitoneal white adipose tissues, plasma non-esterified fatty acids, insulin, hepatic acetyl coenzyme A carboxylase and malic enzyme activities, and mRNA expressions of peroxisome proliferator-activated receptor-alpha and sterol regulatory element-binding protein-1c among all groups (P < 0.05). Hamsters fed the HMHR diet had lower plasma insulin levels and hepatic acetyl coenzyme A carboxylase activities among groups (P < 0.05) and elevated hepatic acyl coenzyme A oxidase and carnitine palmitoyltransferase-I activities compared with those fed the LMLR diet (P < 0.05). Hamsters fed the LMLR diet had increased weight gain and body fat accumulation, whereas the HMHR diet appeared to be beneficial in preventing white adipose tissue accumulation by decreasing plasma insulin levels and increasing hepatic lipolytic enzyme activities involved in beta-oxidation. 2010 Elsevier Inc. All rights reserved.

Incidence of twolined chestnut borer and Hypoxylon atropunctatum on dead oaks along an acidic deposition gradient from Arkansas to Ohio

Treesearch

R.A. Haack; R.W. Blank

1991-01-01

The incidence of twolined chestnut borer (TLCB), Agrilus bilineatus (Weber), and the canker fungus Hypoxylon atropunctatum (Schw. ex Fr.) Cke. was recoreded on dead oak (Quercus) trees !Y7 cm diameter at breast height (DBH) along an acidic deposition gradient from Arkansas to Ohio in 1989 and 1990. Approximately...

MEAD Marine Effects of Atmospheric Deposition

NASA Astrophysics Data System (ADS)

Jickells, T.; Spokes, L.

2003-04-01

The coastal seas are one of the most valuable resources on the planet but they are threatened by human activity. We rely on the coastal area for mineral resources, waste disposal, fisheries and recreation. In Europe, high population densities and high levels of industrial activity mean that the pressures arising from these activities are particularly acute. One of the main problems concerning coastal seas is the rapid increase in the amounts of nitrogen-based pollutants entering the water. They come from many sources, the most important ones being traffic, industry and agriculture. These pollutants can be used by algae as nutrients. The increasing concentrations of these nutrients have led to excessive growth of algae, some of which are harmful. When algae die and decay, oxygen in the water is used up and the resulting lower levels of oxygen may lead to fish kills. Human activity has probably doubled the amount of chemically and biologically reactive nitrogen present globally. In Europe the increases have been greater than this, leading to real concern over the health of coastal waters. Rivers have, until recently, been thought to be the most important source of reactive nitrogen to the coastal seas but we now know that inputs from the atmosphere are large and can equal, or exceed, those from the rivers. Our initial hypothesis was that atmospheric inputs are important and potentially different in their effect on coastal ecosystems to riverine inputs and hence require different management strategies. However, we had almost no information on the direct effects of atmospheric deposition on marine ecosystems, though clearly such a large external nitrogen input should lead to enhanced phytoplankton growth The aim of this European Union funded MEAD project has been to determine how inputs of nitrogen from the atmosphere affect the chemistry and biology of coastal waters. To try to answer this, we have conducted field experiments in the Kattegat, an area where we know

Acidic fog and temperature effects on stigmatic receptivity in two birch species

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

Hughes, R.N.; Cox, R.M.

Factorial assays were performed to determine the effects of simulated acid fog (SAF) and temperature on stigmatic receptivity in two birch species. Excised reproductive branches were sampled from representative individuals of mountain paper birch (Betula cordifolia Regel.) and paper birch (Betula papyrifera Marsh.) in populations adjacent to the Bay of Fundy, New Brunswick, Canada. Since 1979 these trees have exhibited branch dieback in association with abnormal foliar browning symptoms. This browning has been linked with acidity and nitrate deposited by fog, which is frequent in the area. In general, experimental results indicated that pollen germination increased with temperature, but pHmore » effects were less obvious. Similarly, pollen tube growth responded positively to temperature and was little affected by fog acidity. ANOVA tests indicated a significant difference (P < 0.05) between species in their pollen germination response only at 12{degrees}C, and not at the other three temperatures tested. For pollen tube growth, significant differences between species (P < 0.05) were demonstrated at 12 and 22{degrees}C. A significant pH effect was demonstrated at 27{degrees}C for germination, while pH effects on tube growth were significant at 27 and 12{degrees}C (P < 0.01). A response surface regression analysis indicated that acidity significantly affected pollen germination in mountain paper birch (P < 0.001) but not in paper birch. Temperature was not a significant factor for in vivo pollen germination in either species. For pollen tube growth, however, temperature was more important than pH and produced highly significant effects in both species (P < 0.001). Acidity was also a significant factor in pollen tube growth for paper birch. 39 refs., 4 figs., 3 tabs.« less

Response of fish assemblages to declining acidic deposition in Adirondack Mountain lakes, 1984–2012

USGS Publications Warehouse

Baldigo, Barry P.; Roy, Karen; Driscoll, Charles T.

2016-01-01

Adverse effects of acidic deposition on the chemistry and fish communities were evident in Adirondack Mountain lakes during the 1980s and 1990s. Fish assemblages and water chemistry in 43 Adirondack Long-Term Monitoring (ALTM) lakes were sampled by the Adirondack Lakes Survey Corporation and the New York State Department of Environmental Conservation during three periods (1984–87, 1994–2005, and 2008–12) to document regional impacts and potential biological recovery associated with the 1990 amendments to the 1963 Clean Air Act (CAA). We assessed standardized data from 43 lakes sampled during the three periods to quantify the response of fish-community richness, total fish abundance, and brook trout (Salvelinus fontinalis) abundance to declining acidity that resulted from changes in U.S. air-quality management between 1984 and 2012. During the 28-year period, mean acid neutralizing capacity (ANC) increased significantly from 3 to 30 μeq/L and mean inorganic monomeric Al concentrations decreased significantly from 2.22 to 0.66 μmol/L, yet mean species richness, all species or total catch per net night (CPNN), and brook trout CPNN did not change significantly in the 43 lakes. Regression analyses indicate that fishery metrics were not directly related to the degree of chemical recovery and that brook trout CPNN may actually have declined with increasing ANC. While the richness of fish communities increased with increasing ANC as anticipated in several Adirondack lakes, observed improvements in water quality associated with the CAA have generally failed to produce detectable shifts in fish assemblages within a large number of ALTM lakes. Additional time may simply be needed for biological recovery to progress, or else more proactive efforts may be necessary to restore natural fish assemblages in Adirondack lakes in which water chemistry is steadily recovering from acidification.

In vivo quantitation of platelet deposition on human peripheral arterial bypass grafts using indium-111-labeled platelets. Effect of dipyridamole and aspirin

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

Pumphrey, C.W.; Chesebro, J.H.; Dewanjee, M.K.

Indium-111-labeled autologous platelets, injected 48 hours after operation, were used to evaluate the thrombogenicity of prosthetic material and the effect of platelet inhibitor therapy in vivo. Dacron double-velour (Microvel) aortofemoral artery bifurcation grafts were placed in 16 patients and unilateral polytetrafluoroethylene femoropopliteal grafts were placed in 10 patients. Half the patients in each group received platelet inhibitors before operation (dipyridamole, 100 mg 4 times a day) and after operation (dipyridamole, 75 mg, and acetylsalicylic acid, 325 mg 3 times a day); the rest of the patients served as control subjects. Five-minute scintigrams of the graft region were taken with amore » gamma camera interfaced with a computer 48, 72, and 96 hours after injection of the labeled platelets. Platelet deposition was estimated from the radioactivities of the grafts and expressed as counts per 100 pixels per microcurie injected. Dipyridamole and aspirin therapy significantly reduced the number of platelets deposited on Dacron grafts and prevented platelet accumulation over 3 days. With the small amount of platelet deposition on polytetrafluoroethylene femoropopliteal artery grafts even in control patients, platelet inhibitor therapy had no demonstrable effect on platelet deposition on these grafts. It is concluded that (1) platelet deposition on vascular grafts in vivo can be quantitated by noninvasive methods, and (2) dipyridamole and aspirin therapy reduced platelet deposition on Dacron aortofemoral artery grafts.« less

The Effect of Deposit Temperature on the Catalytic SO2-to-SO3 Conversion in a Copper Flash Smelting Heat Recovery Boiler

NASA Astrophysics Data System (ADS)

Lehmusto, Juho; Vainio, Emil; Laurén, Tor; Lindgren, Mari

2018-02-01

The aim of the work was to study the catalytic role of copper flash smelter deposit in the SO2-to-SO3 conversion. In addition, the effect of process gas temperature at 548 K to 1173 K (275 °C to 900 °C) on the amount of SO3 formed was addressed both in the absence and presence of genuine copper flash smelter deposit. The SO3 conversion rate changed as a function of process gas temperature, peaking at 1023 K (750 °C). A dramatic increase in the SO2-to-SO3 conversion was observed when process dust was present, clearly indicating that process dust catalyzes the SO2-to-SO3 conversion. Based on these results, the catalytic ability of the deposit may lead to sulfuric acid dew point corrosion.

Atmospheric wet deposition of sulfur and nitrogen in Jiuzhaigou National Nature Reserve, Sichuan Province, China.

PubMed

Qiao, Xue; Xiao, Weiyang; Jaffe, Daniel; Kota, Sri Harsha; Ying, Qi; Tang, Ya

2015-04-01

In the last two decades, remarkable ecological changes have been observed in Jiuzhaigou National Nature Reserve (JNNR). Some of these changes might be related to excessive deposition of sulfur (S) and nitrogen (N), but the relationship has not been quantified due to lack of monitoring data, particularly S and N deposition data. In this study, we investigated the concentrations, fluxes, and sources of S and N wet deposition in JNNR from April 2010 to May 2011. The results show that SO4(2-), NO3-, and NH4+ concentrations in the wet deposition were 39.4-170.5, 6.2-34.8, and 0.2-61.2 μeq L(-1), with annual Volume-Weighted Mean (VWM) concentrations of 70.5, 12.7, and 13.4 μeq L(-1), respectively. Annual wet deposition fluxes of SO4(2-), NO3-, and NH4+ were 8.06, 1.29, and 1.39 kg S(N)ha(-1), respectively, accounting for about 90% of annual atmospheric inputs of these species at the monitoring site. The results of Positive Matrix Factorization (PMF) analysis show that fossil fuel combustion, agriculture, and aged sea salt contributed to 99% and 83% of annual wet deposition fluxes of SO4(2-) and NO3-, respectively. Agriculture alone contributed to 89% of annual wet deposition flux of NH4+. Although wet deposition in JNNR was polluted by anthropogenic acids, the acidity was largely neutralized by the Ca2+ from crust and 81% of wet deposition samples had a pH higher than 6.00. However, acid rain mainly caused by SO4(2-) continued to occur in the wet season, when ambient alkaline dust concentration was lower. Since anthropogenic emissions have elevated S and N deposition and caused acid rain in JNNR, further studies are needed to better quantify the regional sources and ecological effects of S and N deposition for JNNR. Copyright © 2014 Elsevier B.V. All rights reserved.

Long-Term Simulated Atmospheric Nitrogen Deposition Alters ...

EPA Pesticide Factsheets

Atmospheric nitrogen deposition has been suggested to increase forest carbon sequestration across much of the Northern Hemisphere; slower organic matter decomposition could contribute to this increase. At four sugar maple (Acer saccharum)-dominated northern hardwood forests, we previously observed that 10 years of chronic simulated nitrogen deposition (30 kg N ha-1 yr-1) increased soil organic carbon. Over three years at these sites, we investigated the effects of nitrogen additions on decomposition of two substrates with documented differences in biochemistry: leaf litter (more labile) and fine roots (more recalcitrant). Further, we combined decomposition rates with annual leaf and fine root litter production to estimate how nitrogen additions altered the accumulation of soil organic matter. Nitrogen additions marginally stimulated early-stage decomposition of leaf litter, a substrate with little acid-insoluble material (e.g., lignin). In contrast, nitrogen additions inhibited the late stage decomposition of fine roots, a substrate with high amount of acid insoluble material and a change consistent with observed decreases in lignin-degrading enzyme activities with nitrogen additions at these sites. At the ecosystem scale, the slower fine root decomposition led to additional root mass retention (g m-2), which explained 5, 48, and 52 % of previously-documented soil carbon accumulation due to nitrogen additions. Our results demonstrated that nitrogen deposition ha

Changing trends in sulfur emissions in Asia: implications for acid deposition, air pollution, and climate.

PubMed

Carmichael, Gregory R; Streets, David G; Calori, Giuseppe; Amann, Markus; Jacobson, Mark Z; Hansen, James; Ueda, Hiromasa

2002-11-15

In the early 1990s, it was projected that annual SO2 emissions in Asia might grow to 80-110 Tg yr(-1) by 2020. Based on new high-resolution estimates from 1975 to 2000, we calculate that SO2 emissions in Asia might grow only to 40-45 Tg yr(-1) by 2020. The main reason for this lower estimate is a decline of SO2 emissions from 1995 to 2000 in China, which emits about two-thirds of Asian SO2. The decline was due to a reduction in industrial coal use, a slowdown of the Chinese economy, and the closure of small and inefficient plants, among other reasons. One effect of the reduction in SO2 emissions in China has been a reduction in acid deposition not only in China but also in Japan. Reductions should also improve visibility and reduce health problems. SO2 emission reductions may increase global warming, but this warming effect could be partially offset by reductions in the emissions of black carbon. How SO2 emissions in the region change in the coming decades will depend on many competing factors (economic growth, pollution control laws, etc.). However a continuation of current trends would result in sulfur emissions lower than any IPCC forecasts.

Mechanisms of nitrogen deposition effects on temperate forest lichens and trees

USGS Publications Warehouse

Carter, Therese S.; Clark, Christopher M.; Fenn, Mark E.; Jovan, Sarah E.; Perakis, Steven; Riddell, Jennifer; Schaberg, Paul G.; Greaver, Tara; Hastings, Meredith

2017-01-01

We review the mechanisms of deleterious nitrogen (N) deposition impacts on temperate forests, with a particular focus on trees and lichens. Elevated anthropogenic N deposition to forests has varied effects on individual organisms depending on characteristics both of the N inputs (form, timing, amount) and of the organisms (ecology, physiology) involved. Improved mechanistic knowledge of these effects can aid in developing robust predictions of how organisms respond to either increases or decreases in N deposition. Rising N levels affect forests in micro- and macroscopic ways from physiological responses at the cellular, tissue, and organism levels to influencing individual species and entire communities and ecosystems. A synthesis of these processes forms the basis for the overarching themes of this paper, which focuses on N effects at different levels of biological organization in temperate forests. For lichens, the mechanisms of direct effects of N are relatively well known at cellular, organismal, and community levels, though interactions of N with other stressors merit further research. For trees, effects of N deposition are better understood for N as an acidifying agent than as a nutrient; in both cases, the impacts can reflect direct effects on short time scales and indirect effects mediated through long-term soil and belowground changes. There are many gaps on fundamental N use and cycling in ecosystems, and we highlight the most critical gaps for understanding potential deleterious effects of N deposition. For lichens, these gaps include both how N affects specific metabolic pathways and how N is metabolized. For trees, these gaps include understanding the direct effects of N deposition onto forest canopies, the sensitivity of different tree species and mycorrhizal symbionts to N, the influence of soil properties, and the reversibility of N and acidification effects on plants and soils. Continued study of how these N response mechanisms interact with one

Dendritic Zinc Growth in Acid Electrolyte: Effect of the pH

NASA Astrophysics Data System (ADS)

Bengoa, Leandro N.; Pary, Paola; Seré, Pablo R.; Conconi, M. Susana; Egli, Walter A.

2018-03-01

In this paper, dendritic growth at the edges of electrogalvanized steel strip has been studied using a specially designed rotating washer electrode which simulates the fluid dynamic conditions and the current density distribution at the steel strip edge found in a production line. The effect of electrolyte pH and current density on dendritic growth in an acidic zinc plating bath (ZnSO4 and H2SO4) was addressed. The temperature was kept constant at 60 °C. Solution pH was adjusted to 1, 2 or 3 using different amounts of H2SO4. In addition, the influence of temperature on the pH of the solution was determined. The current density was set at 40 or 60 A/dm2, similar to that used in the industry. Deposits were characterized using SEM and XRD. The results showed that pH strongly affects dendrites shape, length and texture. Furthermore, the morphology of dendrites at the washer edge and of deposits on the flat portion of the washer changed considerably as solution pH was increased from 1 to 3. It was found that the morphology of dendrites at the washer edge stems from the morphology of the deposit on its flat portion, which in turn determines their shape.

National Acid Precipitation Assessment Program Report to Congress: An Integrated Assessment

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

Uhart, M.; et al,

2005-08-01

Under Title IX of the 1990 Clean Air Act Amendments, Congress reauthorized the National Acid Precipitation Assessment Program (NAPAP) to continue coordinating acid rain research and monitoring, as it had done during the previous decade, and to provide Congress with periodic reports. In particular, Congress asked NAPAP to assess all available data and information to answer two questions: (1) What are the costs, benefits, and effectiveness of Title IV? This question addresses the costs and economic impacts of complying with the Acid Rain Program as well as benefit analyses associated with the various human health and welfare effects, including reducedmore » visibility, damages to materials and cultural resources, and effects on ecosystems. (2) What reductions in deposition rates are needed to prevent adverse ecological effects? This complex questions addresses ecological systems and the deposition levels at which they experience harmful effects. The results of the assessment of the effects of Title IV and of the relationship between acid deposition rates and ecological effects were to be reported to Congress quadrennially, beginning with the 1996 report to Congress. The objective of this Report is to address the two main questions posed by Congress and fully communicate the results of the assessment to decision-makers. Given the primary audience, most of this report is not written as a technical document, although information supporting the conclusions is provided along with references.« less

Estimating Chemical Exchange between Atmospheric Deposition and Forest Canopy in Guizhou, China.

PubMed

Li, Wei; Gao, Fang; Liao, Xueqin

2013-01-01

To evaluate the effects of atmospheric deposition on forest ecosystems, wet-only precipitation and throughfall samples were collected in two forest types (Masson pine [ Lamb.] forests and mixed conifer and broadleaf forests) in the Longli forest in the Guizhou province of southwestern China for a period of 21 successive months from April 2007 to December 2008. The pH and chemical components of precipitation and throughfall were analyzed. In addition, the canopy budget model was applied to distinguish between in-canopy and atmospheric sources of chemical compounds. Canopy leaching and total potentially acidifying deposition fluxes were calculated. The results showed that the average pH and the concentration of ions in throughfall were higher than those in precipitation, with the exception of the NH concentration. Dry deposition of S and N accumulated more in Masson pine forests than in mixed conifer and broadleaf forests. Canopy leaching was the most significant source of base cations in forest throughfall, which was higher in the mixed forests than in the coniferous forests. Anions in throughfall deposition in Masson pine forests exceeded those in the mixed forests. Higher total potentially acidifying deposition fluxes reflected the more effective amounts of acid delivered to Masson pine forests compared with mixed conifer and broadleaf forests. In addition, acid deposition induced the leaching and loss of nutrient ions such as Mg, K, and Ca. Although the trees of the studied areas have not shown any symptoms of cation loss, a potentially harmful influence was engendered by atmospheric deposition in the two forest types in the Longli area. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Atomic Layer Deposition of L-Alanine Polypeptide

DOE PAGES

Fu, Yaqin; Li, Binsong; Jiang, Ying-Bing; ...

2014-10-30

L-Alanine polypeptide thin films were synthesized via atomic layer deposition (ALD). Rather, instead of using an amino acid monomer as the precursor, an L-alanine amino acid derivatized with a protecting group was used to prevent self-polymerization, increase the vapor pressure, and allow linear cycle-by-cycle growth emblematic of ALD. Moreover, the successful deposition of a conformal polypeptide film has been confirmed by FTIR, TEM, and Mass Spectrometry, and the ALD process has been extended to polyvaline.

Nitrogen and Sulfur Deposition Effects on Forest Biogeochemical Processes.

NASA Astrophysics Data System (ADS)

Goodale, C. L.

2014-12-01

Chronic atmospheric deposition of nitrogen and sulfur have widely ranging biogeochemical consequences in terrestrial ecosystems. Both N and S deposition can affect plant growth, decomposition, and nitrous oxide production, with sometimes synergistic and sometimes contradictory responses; yet their separate effects are rarely isolated and their interactive biogeochemical impacts are often overlooked. For example, S deposition and consequent acidification and mortality may negate stimulation of plant growth induced by N deposition; decomposition can be slowed by both N and S deposition, though through different mechanisms; and N2O production may be stimulated directly by N and indirectly by S amendments. Recent advances in conceptual models and whole-ecosystem experiments provide novel means for disentangling the impacts of N and S in terrestrial ecosystems. Results from a new whole-ecosystem N x S- addition experiment will be presented in detail, examining differential response of tree and soil carbon storage to N and S additions. These results combine with observations from a broad array of long-term N addition studies, atmospheric deposition gradients, stable isotope tracer studies, and model analyses to inform the magnitude, controls, and stability of ecosystem C storage in response to N and S addition.

Effects of complexing agents on electrochemical deposition of FeS x O y in ZnO/FeS x O y heterostructures

NASA Astrophysics Data System (ADS)

Supee, A.; Ichimura, M.

2017-12-01

Heterostructures which consist of ZnO and FeS x O y were deposited via electrochemical deposition (ECD) for application to solar cells. Galvanostatic ECD was used in FeS x O y deposition with a solution containing 100 mM Na2S2O3 and 30 mM FeSO4. To alter the film properties, L(+)-tartaric acid (C4H6O6) and lactic acid [CH3CH(OH)COOH] were introduced as the complexing agents into the FeS x O y deposition solution. Larger film thickness and smaller oxygen content were obtained for the films deposited with the complexing agents. ZnO was deposited on FeS x O y by two-step pulse ECD from a solution containing Zn(NO3)2. For the ZnO/FeS x O y heterostructures fabricated with/without complexing agents, rectifying properties were confirmed in the current density-voltage ( J- V) characteristics. However, photovoltaic properties were not improved with addition of both complexing agents.

The effects of atmospheric nitrogen deposition on terrestrial and freshwater biodiversity

USGS Publications Warehouse

Baron, Jill S.; Barber, Mary C.; Adams, Mark; Agboola, Julius I.; Allen, Edith B.; Bealey, William J.; Bobbink, Roland; Bobrovsky, Maxim V.; Bowman, William D.; Branquinho, Cristina; Bustamente, Mercedes M. C.; Clark, Christopher M.; Cocking, Edward C.; Cruz, Cristina; Davidson, Eric A.; Denmead, O. Tom; Dias, Teresa; Dise, Nancy B.; Feest, Alan; Galloway, James N.; Geiser, Linda H.; Gilliam, Frank S.; Harrison, Ian J.; Khanina, Larisa G.; Lu, Xiankai; Manrique, Esteban; Ochoa-Hueso, Raul; Ometto, Jean P. H. B.; Payne, Richard; Scheuschner, Thomas; Sheppard, Lucy J.; Simpson, Gavin L.; Singh, Y. V.; Stevens, Carly J.; Strachan, Ian; Sverdrup, Harald; Tokuchi, Naoko; van Dobben, Hans; Woodin, Sarah

2014-01-01

This chapter reports the findings of a Working Group on how atmospheric nitrogen (N) deposition affects both terrestrial and freshwater biodiversity. Regional and global scale impacts on biodiversity are addressed, together with potential indicators. Key conclusions are that: the rates of loss in biodiversity are greatest at the lowest and initial stages of N deposition increase; changes in species compositions are related to the relative amounts of N, carbon (C) and phosphorus (P) in the plant soil system; enhanced N inputs have implications for C cycling; N deposition is known to be having adverse effects on European and North American vegetation composition; very little is known about tropical ecosystem responses, while tropical ecosystems are major biodiversity hotspots and are increasingly recipients of very high N deposition rates; N deposition alters forest fungi and mycorrhyzal relations with plants; the rapid response of forest fungi and arthropods makes them good indicators of change; predictive tools (models) that address ecosystem scale processes are necessary to address complex drivers and responses, including the integration of N deposition, climate change and land use effects; criteria can be identified for projecting sensitivity of terrestrial and aquatic ecosystems to N deposition. Future research and policy-relevant recommendations are identified.

Map scale effects on estimating the number of undiscovered mineral deposits

USGS Publications Warehouse

Singer, D.A.; Menzie, W.D.

2008-01-01

Estimates of numbers of undiscovered mineral deposits, fundamental to assessing mineral resources, are affected by map scale. Where consistently defined deposits of a particular type are estimated, spatial and frequency distributions of deposits are linked in that some frequency distributions can be generated by processes randomly in space whereas others are generated by processes suggesting clustering in space. Possible spatial distributions of mineral deposits and their related frequency distributions are affected by map scale and associated inclusions of non-permissive or covered geological settings. More generalized map scales are more likely to cause inclusion of geologic settings that are not really permissive for the deposit type, or that include unreported cover over permissive areas, resulting in the appearance of deposit clustering. Thus, overly generalized map scales can cause deposits to appear clustered. We propose a model that captures the effects of map scale and the related inclusion of non-permissive geologic settings on numbers of deposits estimates, the zero-inflated Poisson distribution. Effects of map scale as represented by the zero-inflated Poisson distribution suggest that the appearance of deposit clustering should diminish as mapping becomes more detailed because the number of inflated zeros would decrease with more detailed maps. Based on observed worldwide relationships between map scale and areas permissive for deposit types, mapping at a scale with twice the detail should cut permissive area size of a porphyry copper tract to 29% and a volcanic-hosted massive sulfide tract to 50% of their original sizes. Thus some direct benefits of mapping an area at a more detailed scale are indicated by significant reductions in areas permissive for deposit types, increased deposit density and, as a consequence, reduced uncertainty in the estimate of number of undiscovered deposits. Exploration enterprises benefit from reduced areas requiring

Effectiveness of Natural Field Induced Polarization for Detecting Polymetallic Deposits

NASA Astrophysics Data System (ADS)

YANG, Jin; LIU, Zhaoping; WANG, Long

To validate the effect of Natural Field Induced Polarization (NFIP), a certain polymetallic deposit was chosen as the test site, where Induced Polarization (IP) using gradient array and the Magnetotelluric (MT) sounding were conducted simultaneously. Analysis and comparison of the data indicated that the anomaly of the Relative Percent Frequency Effect (RPFE) from the MT data and the anomaly of IP coincided well with each other in the extents of the anomalous site and anomaly magnitudes. The results showed that NFIP was effective in the exploration of polymetallic deposits, under certain conditions.

Transient inhibition of connective tissue infiltration and collagen deposition into porous poly(lactic-co-glycolic acid) discs.

PubMed

Love, Ryan J; Jones, Kim S

2013-12-01

Connective tissue rapidly proliferates on and around biomaterials implanted in vivo, which impairs the function of the engineered tissues, biosensors, and devices. Glucocorticoids can be utilized to suppress tissue ingrowth, but can only be used for a limited time because they nonselectively arrest cell proliferation in the local environment. The present study examined use of a prolyl-4-hydroxylase inhibitor, 1,4-dihydrophenonthrolin-4-one-3-carboxylic acid (1,4-DPCA), to suppress connective tissue ingrowth in porous PLGA discs implanted in the peritoneal cavity for 28 days. The prolyl-4-hydroxylase inhibitor was found to be effective at inhibiting collagen deposition within and on the outer surface of the disc, and also limited connective tissue ingrowth, but not to the extent of glucocorticoid inhibition. Finally, it was discovered that 1,4-DPCA suppressed Scavenger Receptor A expression on a macrophage-like cell culture, which may account for the drug's ability to limit connective tissue ingrowth in vivo. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

Arc-related porphyry molybdenum deposit model: Chapter D in Mineral deposit models for resource assessment

USGS Publications Warehouse

Taylor, Ryan D.; Hammarstrom, Jane M.; Piatak, Nadine M.; Seal, Robert R.

2012-01-01

Geoenvironmental concerns are generally low because of low volumes of sulfide minerals. Most deposits are marginally acid-generating to non-acid-generating with drainage waters being near-neutral pH because of the acid generating potential of pyrite being partially buffered by late-stage calcite-bearing veins. The low ore content results in a waste:ore ratio of nearly 1:1 and large tailings piles from the open-pit method of mining.

Dissolution of synthetic uranium dibutyl phosphate deposits in oxidizing and reducing chemical formulations.

PubMed

Rufus, A L; Sathyaseelan, V S; Narasimhan, S V; Velmurugan, S

2013-06-15

Permanganate and nitrilotriacetic acid (NTA) based dilute chemical formulations were evaluated for the dissolution of uranium dibutyl phosphate (U-DBP), a compound that deposits over the surfaces of nuclear reprocessing plants and waste storage tanks. A combination of an acidic, oxidizing treatment (nitric acid with permanganate) followed by reducing treatment (NTA based formulation) efficiently dissolved the U-DBP deposits. The dissolution isotherm of U-DBP in its as precipitated form followed a logarithmic fit. The same chemical treatment was also effective in dissolving U-DBP coated on the surface of 304-stainless steel, while resulting in minimal corrosion of the stainless steel substrate material. Investigation of uranium recovery from the resulting decontamination solutions by ion exchange with a bed of mixed anion and cation resins showed quantitative removal of uranium. Copyright © 2013 Elsevier B.V. All rights reserved.

Iron deposition as acidic groundwater encounters carbonates in the alluvium of Pinal Creek, Arizona, U.S.A.

USGS Publications Warehouse

Lind, Carol J.; Oscarson, R.L.

1997-01-01

In a column experiment, acidic groundwater from Pinal Creek Arizona, a Cu mining area, was eluted through a composited alluvial sample obtained from a core that had been removed from a well downgradient of the acidic groundwater. The minerals present in typical grains and flakes in the alluvium before and after the elution were determined by X-ray diffraction (XRD), scanning electron microscopy, and energy dispersive multichannel analyses (EDX). The concentrations of Fe, Ti, Mn, Si, Al, Na, Ca, K, Mg and S in these grains and flakes and in their microcrystalline surface coatings were measured by EDX. In addition to magnetite, hematite, and Fe-Ti oxides, Fe was most concentrated in micas (especially biotite-like flakes) and in the microcrystalline coatings. The measured elements in these microcrystalline coatings were primarily K, Fe, Al, and Si. The microcrystalline coatings on the mica flakes also contained Mg. The approximate 1:3 Mg:Si atomic ratios (ARs) of the biotite-like flakes both before and after the elution would suggest that the Fe deposited during the elution had not substituted for Mg in these flakes. As a result of the elution, assuming no loss of Si, the averaged recorded Fe:Si AR of the microcrystalline coatings increased from (0,46 to 0.58):3.00. Iron deposition on the typical grains and flakes may relate to the presence of Fe in the particle on which it is deposited or to the presence of Fe in the microcrystalline surface coatings before elution. The data here are not sufficient for a statistical evaluation, but elution caused the following trends: (1) The Fe:Si A R increased in the (K,Fe,Al,Si)-microcrystalline surface coatings; (2) For the mica flakes, there was more than a 2-fold increase in the Fe:Si AR for the microcrystalline surface coatings of the Fe-rich biotite-like flakes but no measurable increase of the Fe:Si AR for the microcrystalline surface coatings of the muscovite-like flakes that contained 3-5 times less Fe; (3) Also for the

Rapid Deposition of Oxidized Biogenic Compounds to a Temperate Forest

NASA Technical Reports Server (NTRS)

Nguyen, Tran B.; Crounse, John D.; Teng, Alex P.; St. Clair, Jason M.; Paulot, Fabien; Wolfe, Glenn M.; Wennberg, Paul O.

2015-01-01

We report fluxes and dry deposition velocities for 16 atmospheric compounds above a southeastern United States forest, including: hydrogen peroxide (H2O2), nitric acid (HNO3), hydrogen cyanide (HCN), hydroxymethyl hydroperoxide, peroxyacetic acid, organic hydroxy nitrates, and other multifunctional species derived from the oxidation of isoprene and monoterpenes. The data suggest that dry deposition is the dominant daytime sink for small, saturated oxygenates. Greater than 6 wt %C emitted as isoprene by the forest was returned by dry deposition of its oxidized products. Peroxides account for a large fraction of the oxidant flux, possibly eclipsing ozone in more pristine regions. The measured organic nitrates comprise a sizable portion (15%) of the oxidized nitrogen input into the canopy, with HNO3 making up the balance. We observe that water-soluble compounds (e.g., strong acids and hydroperoxides) deposit with low surface resistance whereas compounds with moderate solubility (e.g., organic nitrates and hydroxycarbonyls) or poor solubility (e.g., HCN) exhibited reduced uptake at the surface of plants. To first order, the relative deposition velocities of water-soluble compounds are constrained by their molecular diffusivity. From resistance modeling, we infer a substantial emission flux of formic acid at the canopy level (approx. 1 nmol m(exp.-2)·s(exp.-1)). GEOS-Chem, awidely used atmospheric chemical transport model, currently underestimates dry deposition for most molecules studied in this work. Reconciling GEOS-Chem deposition velocities with observations resulted in up to a 45% decrease in the simulated surface concentration of trace gases.

Rapid deposition of oxidized biogenic compounds to a temperate forest

PubMed Central

Nguyen, Tran B.; Crounse, John D.; Teng, Alex P.; St. Clair, Jason M.; Paulot, Fabien; Wolfe, Glenn M.; Wennberg, Paul O.

2015-01-01

We report fluxes and dry deposition velocities for 16 atmospheric compounds above a southeastern United States forest, including: hydrogen peroxide (H2O2), nitric acid (HNO3), hydrogen cyanide (HCN), hydroxymethyl hydroperoxide, peroxyacetic acid, organic hydroxy nitrates, and other multifunctional species derived from the oxidation of isoprene and monoterpenes. The data suggest that dry deposition is the dominant daytime sink for small, saturated oxygenates. Greater than 6 wt %C emitted as isoprene by the forest was returned by dry deposition of its oxidized products. Peroxides account for a large fraction of the oxidant flux, possibly eclipsing ozone in more pristine regions. The measured organic nitrates comprise a sizable portion (15%) of the oxidized nitrogen input into the canopy, with HNO3 making up the balance. We observe that water-soluble compounds (e.g., strong acids and hydroperoxides) deposit with low surface resistance whereas compounds with moderate solubility (e.g., organic nitrates and hydroxycarbonyls) or poor solubility (e.g., HCN) exhibited reduced uptake at the surface of plants. To first order, the relative deposition velocities of water-soluble compounds are constrained by their molecular diffusivity. From resistance modeling, we infer a substantial emission flux of formic acid at the canopy level (∼1 nmol m−2⋅s−1). GEOS−Chem, a widely used atmospheric chemical transport model, currently underestimates dry deposition for most molecules studied in this work. Reconciling GEOS−Chem deposition velocities with observations resulted in up to a 45% decrease in the simulated surface concentration of trace gases. PMID:25605913

Understanding processes affecting mineral deposits in humid environments

USGS Publications Warehouse

Seal, Robert R.; Ayuso, Robert A.

2011-01-01

Recent interdisciplinary studies by the U.S. Geological Survey have resulted in substantial progress toward understanding the influence that climate and hydrology have on the geochemical signatures of mineral deposits and the resulting mine wastes in the eastern United States. Specific areas of focus include the release, transport, and fate of acid, metals, and associated elements from inactive mines in temperate coastal areas and of metals from unmined mineral deposits in tropical to subtropical areas; the influence of climate, geology, and hydrology on remediation options for abandoned mines; and the application of radiogenic isotopes to uniquely apportion source contributions that distinguish natural from mining sources and extent of metal transport. The environmental effects of abandoned mines and unmined mineral deposits result from a complex interaction of a variety of chemical and physical factors. These include the geology of the mineral deposit, the hydrologic setting of the mineral deposit and associated mine wastes, the chemistry of waters interacting with the deposit and associated waste material, the engineering of a mine as it relates to the reactivity of mine wastes, and climate, which affects such factors as temperature and the amounts of precipitation and evapotranspiration; these factors, in turn, influence the environmental behavior of mineral deposits. The role of climate is becoming increasingly important in environmental investigations of mineral deposits because of the growing concerns about climate change.

Elimination of a pollution associated with chromic acid during the electro-deposition of Cr(III) using appropriate anodic and membrane materials in a double film bath.

PubMed

Jiang, Xiaojun; Chen, Wenchao; Xu, Hongbo

2009-01-01

A method using trivalent chromium has been used to replace hexavalent chromium for the electro-deposition of chromium. Using a tri-chamber bath system various anodic materials and membranes were evaluated to minimize the production of environmentally and health damaging chromic acid. By measuring the absorbance of Cr(VI) at 640 nm, the results indicate that the use of a titanium plated ruthenium (Ti-Ru) anode produces the least amount of chromic acid byproduct compared to lead-gold alloy and graphite anodes. The concentration of Cr(VI) in the immediate vicinity of the Ti-Ru anode decreased from 0.389 mg/L to 0 during a 40-min deposition period. The use of a Nafion(TM) quaternary cation exchange membrane portioning the buffer and anode selectively prevented Cr(III) from entering the anode compartment whilst allowing the migration of H(+) to maintain overall voltaic continuity. It has been demonstrated that the use of a Ti-Ru anode with a Nafion(TM) membrane can eliminate the production of chromic acid associated with the electro-deposition of chromium plate thereby preventing its health damaging exposure to plant operators and preventing discharge of Cr(VI) into the environment. Addition of a surfactant improved current efficiency by 34.7%.

Effect of deposition pressure on the morphology and structural properties of carbon nanotubes synthesized by hot-filament chemical vapor deposition.

PubMed

Arendse, C J; Malgas, G F; Scriba, M R; Cummings, F R; Knoesen, D

2007-10-01

Hot-filament chemical vapor deposition has developed into an attractive method for the synthesis of various carbon nanostructures, including carbon nanotubes. This is primarily due to its versatility, low cost, repeatability, up-scalability, and ease of production. The resulting nano-material synthesized by this technique is dependent on the deposition conditions which can be easily controlled. In this paper we report on the effect of the deposition pressure on the structural properties and morphology of carbon nanotubes synthesized by hot-filament chemical vapor deposition, using Raman spectroscopy and high-resolution scanning electron microscopy, respectively. A 10 nm-thick Ni layer, deposited on a SiO2/Si substrate, was used as catalyst for carbon nanotube growth. Multi-walled carbon nanotubes with diameters ranging from 20-100 nm were synthesized at 500 degrees C with high structural perfection at deposition pressures between 150 and 200 Torr. Raman spectroscopy measurements confirm that the carbon nanotube deposit is homogeneous across the entire substrate area.

Air pollution: Tropospheric ozone, and wet deposition of sulfate and inorganic nitrogen

Treesearch

John W. Coulston

2009-01-01

The influence of air pollutants on ecosystems in the United States is an important environmental issue. The term “air pollution” encompasses a wide range of topics, but acid deposition and ozone are primary concerns in the context of forest health. Acid deposition partially results from emissions of sulfur dioxide, nitrogen oxides, and ammonia that are deposited in wet...

Studies on morphology of Langmuir-Blodgett films of stearic acid deposited with different orientation of substrates with respect to compression

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

Choudhary, Keerti; Manjuladevi, V.; Gupta, R. K., E-mail: raj@pilani.bits-pilani.ac.in

2016-05-06

The Langmuir monolayer at an air-water interface shows remarkably different surface pressure – area isotherm, when measured with the surface normal of a Wilhemly plate parallel or perpendicular to the direction of compression of the monolayer. Such difference arises due to difference in stress exerted by the monolayer on the plate in different direction. In this article, we report the effect of changing the direction of substrate normal with respect to the compression of the monolayer during Langmuir-Blodgett (LB) film deposition on the morphology of the films. The morphology of the LB film of stearic acid was studied using anmore » atomic force microscope (AFM). The morphology of the LB films was found to be different due to difference in the stress in different directions.« less

Advanced zirconia-coated carbonyl-iron particles for acidic magnetorheological finishing of chemical-vapor-deposited ZnS and other IR materials

NASA Astrophysics Data System (ADS)

Salzman, S.; Giannechini, L. J.; Romanofsky, H. J.; Golini, N.; Taylor, B.; Jacobs, S. D.; Lambropoulos, J. C.

2015-10-01

We present a modified version of zirconia-coated carbonyl-iron (CI) particles that were invented at the University of Rochester in 2008. The amount of zirconia on the coating is increased to further protect the iron particles from corrosion when introduced to an acidic environment. Five low-pH, magnetorheological (MR) fluids were made with five acids: acetic, hydrochloric, nitric, phosphoric, and hydrofluoric. All fluids were based on the modified zirconia-coated CI particles. Off-line viscosity and pH stability were measured for all acidic MR fluids to determine the ideal fluid composition for acidic MR finishing of chemical-vapor-deposited (CVD) zinc sulfide (ZnS) and other infrared (IR) optical materials, such as hot-isostatic-pressed (HIP) ZnS, CVD zinc selenide (ZnSe), and magnesium fluoride (MgF2). Results show significant reduction in surface artifacts (millimeter-size, pebble-like structures on the finished surface) for several standard-grade CVD ZnS substrates and good surface roughness for the non-CVD MgF2 substrate when MR finished with our advanced acidic MR fluid.

Zn-Mn alloy coatings from acidic chloride bath: Effect of deposition conditions on the Zn-Mn electrodeposition-morphological and structural characterization

NASA Astrophysics Data System (ADS)

Loukil, N.; Feki, M.

2017-07-01

Zn-Mn alloy electrodeposition on steel electrode in chloride bath was investigated using cyclic voltammetric, chronopotentiometric and chronoamperometric techniques. Cyclic voltammetries (CV) reveal a deep understanding of electrochemical behaviors of each metal Zn, Mn, proton discharge and Zn-Mn co-deposition. The electrochemical results show that with increasing Mn2+ ions concentration in the electrolytic bath, Mn2+ reduction occurs at lower over-potential leading to an enhancement of Mn content into the Zn-Mn deposits. A dimensionless graph model was used to analyze the effect of Mn2+ ions concentration on Zn-Mn nucleation process. It was found that the nucleation process is not extremely affected by Mn2+ concentration. Nevertheless, it significantly depends on the applied potential. Several parameters such as Mn2+ ions concentration, current density and stirring were investigated with regard to the Mn content into the final Zn-Mn coatings. It was found that the Mn content increases with increasing the applied current density jimp and Mn2+ ions concentration in the electrolytic bath. However, stirring of the solution decreases the Mn content in the Zn-Mn coatings. The phase structure and surface morphology of Zn-Mn deposits are characterized by means of X-ray diffraction analysis and Scanning Electron Microscopy (SEM), respectively. The Zn-Mn deposited at low current density is tri-phasic and consisting of η-Zn, ζ-MnZn13 and hexagonal close packed ε-Zn-Mn. An increase in current density leads to a transition from crystalline to amorphous structure, arising from the hydroxide inclusions in the Zn-Mn coating at high current density.

Effect of catalyst on deposition of vanadium oxide in plasma ambient

NASA Astrophysics Data System (ADS)

Singh, Megha; Kumar, Prabhat; Saini, Sujit K.; Reddy, G. B.

2018-05-01

In this paper, we have studied effect of catalyst (buffer layer) on structure, morphology, crystallinity, uniformity of nanostructured thin films deposited in nitrogen plasma ambient keeping all other process parameters constant. The process used for deposition is novel known as Plasma Assisted Sublimation Process (PASP). Samples were then studied using SEM, TEM, HRTEM, Raman spectroscopy. By structural analysis it was found out that samples deposited on Ni layer composed chiefly of α-V2O5 but minor amount of other phases were present in the sample. Samples deposited on Al catalyst layer revealed different phase of V2O5, where sample deposited on Ag was composed chiefly of VO2±x phase. Further analysis revealed that morphology of samples is also affected by catalyst. While samples deposited in Al and Ag layer tend to have reasonably defined geometry, sample deposited on Ni layer were irregular in shape and size. All the results well corroborate with each other.

Effects of Deposition Parameters on Thin Film Properties of Silicon-Based Electronic Materials Deposited by Remote Plasma-Enhanced Chemical-Vapor Deposition

NASA Astrophysics Data System (ADS)

Theil, Jeremy Alfred

The motivation of this thesis is to discuss the major issues of remote plasma enhanced chemical vapor deposition (remote PECVD) that affect the properties Si-based thin films. In order to define the issues required for process optimization, the behavior of remote PECVD process must be understood. The remote PECVD process is defined as having four segments: (1) plasma generation, (2) excited species extraction, (3) excited species/downstream gas mixing, and (4) surface reaction. The double Langmuir probe technique is employed to examine plasma parameters under 13.56 MHz and 2.54 GHz excitation. Optical emission spectroscopy is used to determine changes in the excited states of radiating species in the plasma afterglow. Mass spectrometry is used to determine the excitation and consumption of process gases within the reactor during film growth. Various analytical techniques such as infrared absorption spectroscopy, (ir), high resolution transmission electron microscopy, (HRTEM), and reflected high energy electron diffraction, (RHEED), are used to ascertain film properties. The results of the Langmuir probe show that plasma coupling is frequency dependent and that the capacitive coupling mode is characterized by orders of magnitude higher electron densities in the reactor than inductive coupling. These differences can be manifested in the degree to which a hydrogenated amorphous silicon, a-Si:H, component co-deposition reaction affects film stoichiometry. Mass spectrometry shows that there is an additional excitation source in the downstream glow. In addition the growth of microcrystalline silicon, muc-Si, is correlated with the decrease in the production of disilane and heavier Si-containing species. Chloronium, H_2 Cl^{+}, a super acid ion is identified for the first time in a CVD reactor. It forms from plasma fragmentation of SiH_2 Cl_2, and H_2 . Addition of impurity gases was shown not to affect the electron temperature of the plasma. By products of deposition

Forest fire effects on mercury deposition in the boreal forest

Treesearch

Emma L. Witt; Randall K. Kolka; Edward A. Nater; Trent R. Wickman

2009-01-01

The objective of this study was to determine how forest fire effects Hg deposition to nearby landscapes impacted by smoke plumes. Hg concentrations and deposition were hypothesized to increase in throughfall and open precipitation after fire, and canopy type was hypothesized to influence the magnitude of the increase. Conifer canopies, which are better able to scavenge...

Distillation Separation of Hydrofluoric Acid and Nitric Acid from Acid Waste Using the Salt Effect on Vapor-Liquid Equilibrium

NASA Astrophysics Data System (ADS)

Yamamoto, Hideki; Sumoge, Iwao

2011-03-01

This study presents the distillation separation of hydrofluoric acid with use of the salt effect on the vapor-liquid equilibrium for acid aqueous solutions and acid mixtures. The vapor-liquid equilibrium of hydrofluoric acid + salt systems (fluorite, potassium nitrate, cesium nitrate) was measured using an apparatus made of perfluoro alkylvinylether. Cesium nitrate showed a salting-out effect on the vapor-liquid equilibrium of the hydrofluoric acid-water system. Fluorite and potassium nitrate showed a salting-in effect on the hydrofluoric acid-water system. Separation of hydrofluoric acid from an acid mixture containing nitric acid and hydrofluoric acid was tested by the simple distillation treatment using the salt effect of cesium nitrate (45 mass%). An acid mixture of nitric acid (5.0 mol · dm-3) and hydrofluoric acid (5.0 mol · dm-3) was prepared as a sample solution for distillation tests. The concentration of nitric acid in the first distillate decreased from 5.0 mol · dm-3 to 1.13 mol · dm-3, and the concentration of hydrofluoric acid increased to 5.41 mol · dm-3. This first distillate was further distilled without the addition of salt. The concentrations of hydrofluoric acid and nitric acid in the second distillate were 7.21 mol · dm-3 and 0.46 mol · dm-3, respectively. It was thus found that the salt effect on vapor-liquid equilibrium of acid mixtures was effective for the recycling of acids from acid mixture wastes.

Chemical and mineralogical changes of waste and tailings from the Murgul Cu deposit (Artvin, NE Turkey): implications for occurrence of acid mine drainage.

PubMed

Sağlam, Emine Selva; Akçay, Miğraç

2016-04-01

Being one of the largest copper-producing resources in Turkey, the Murgul deposit has been a source of environmental pollution for very long time. Operated through four open pits with an annual production of about 3 million tons of ore at an average grade of about 0.5% Cu, the deposit to date has produced an enormous pile of waste (exceeding 100 million tons) with tailings composed of 36 % SiO2, 39% Fe2O3 and 32% S, mainly in the form of pyrite and quartz. Waters in the vicinity of the deposit vary from high acid-acid (2.71-3.85) and high-extremely metal rich (34.48-348.12 mg/l in total) in the open pits to near neutral (6.51-7.83) and low metal (14.39-973.52 μg/l in total) in downstream environments. Despite low metal contents and near neutral pH levels of the latter, their suspended particle loads are extremely high and composed mainly of quartz and clay minerals with highly elevated levels of Fe (3.5 to 24.5% Fe2O3; 11% on average) and S (0.5 to 20.6% S; 7% on average), showing that Fe is mainly in the form of pyrite and lesser hematite. They also contain high concentrations of As, Au, Ba, Cu, Pb, and Zn. Waters collected along the course of polluted drainages are supersaturated with respect to Fe phases such as goethite, hematite, maghemite, magnetite, schwertmannite and ferrihydrite. Secondary phases such as Fe-sulphates are only found near the pits, but not along the streams due to neutral pH conditions, where pebbles are covered and cemented by Fe-oxides and hydroxides indicating that oxidation of pyrite has taken place especially at times of low water load. It follows, then, that the pyrite-rich sediment load of streams fed by the waste of the Murgul deposit is currently a big threat to the aquatic life and environment and will continue to be so even after the closure of the deposit. In fact, the oxidation will be enhanced and acidity increased due to natural conditions, which necessitates strong remedial actions to be taken.

Is There Scientific Consensus on Acid Rain? -- Excerpts from Six Governmental Reports.

ERIC Educational Resources Information Center

Environmental Education Report and Newsletter, 1986

1986-01-01

Compiles a series of direct quotations from six governmental reports that reflect a scientific consensus on major aspects of acid deposition. Presents the statements in a question and answer format. Also reviews the sources, extent, and effects of acid rain. (ML)

Multi-material poly(lactic acid) scaffold fabricated via fused deposition modeling and direct hydroxyapatite injection as spacers in laminoplasty

NASA Astrophysics Data System (ADS)

Syuhada, Ghifari; Ramahdita, Ghiska; Rahyussalim, A. J.; Whulanza, Yudan

2018-02-01

Nowadays, additive manufacturing method has been used extensively to realize any product with specific attributes rather than the conventional subtractive manufacturing method. For instance, the additive manufacturing has enable us to construct a product layer-by-layer by successively depositing several materials in one session and one platform. This paper studied the properties of a 3D printed scaffold fabricated through Poly(Lactic-acid) (PLA) deposition modelling in combination with injectable hydroxyapatite (HA)/alginate as cell carrier. The scaffold was designed to serve as a spacer in cervical laminoplasty. Therefore, a series of test were conducted to elaborate the mechanical property, porosity and in-vitro toxicity testing. The results showed that the method is reliable to fabricate the scaffold as desired although the toxicity test needs more confirmation.

Growth of SiO 2 on InP substrate by liquid phase deposition

NASA Astrophysics Data System (ADS)

Lei, Po Hsun; Yang, Chyi Da

2010-04-01

We have grown silicon dioxide (SiO 2) on indium phosphorous (InP) substrate by liquid phase deposition (LPD) method. With inserting InP wafer in the treatment solution composed of SiO 2 saturated hydrofluorosilicic acid (H 2SiF 6), 0.1 M boric acid (H 3BO 3) and 1.74 M diluted hydrochloric acid (HCl), the maximum deposition rate and refractive index for the as-grown LPD-SiO 2 film were about 187.5 Å/h and 1.495 under the constant growth temperature of 40 °C. The secondary ion mass spectroscope (SIMS) and energy dispersive X-ray (EDX) confirmed that the elements of silicon, oxygen, and chloride were found in the as-grown LPD-SiO 2 film. On the other hand, the effects of treatment solution incorporated with the hydrogen peroxide (H 2O 2) that can regulate the concentration of OH - ion were also shown in this article. The experimental results represented that the deposition rate decreases with increasing the concentration of hydrogen peroxide due to the reduced concentration of SiO 2 saturated H 2SiF 6 in treatment solution.

Effects of ammonium on elemental nutrition of red spruce and indicator plants grown in acid soil

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

Hoelldampf, B.; Barker, A.V.

Decline of high elevation red spruce forests in the northeastern United States has been related to acid rain, particularly with respect to the deposition of nitrogenous materials. Ca and Mg deficiencies may be induced by input of air-borne nitrogenous nutrients into the forest ecosystem. This research investigated the effects of N nutrition on mineral nutrition of red spruce and radish, as an indicator plant, grown in acid forest soil. Red spruce and radishes in the greenhouse were treated with complete nutrient solutions with 15 mM N supplied as 0, 3.75, 7.5, 11.25, or 15 mM NH[sub 4][sup +] with themore » remainder being supplied as NO[sub 3][sup [minus

Clean air act and acid precipitation receiving increased attention

NASA Astrophysics Data System (ADS)

Burns, Douglas A.; Lawrence, Gregory B.; Murdoch, Peter S.

In 1990 the U.S. Congress passed Title IV of the Clean Air Act Amendments, which was intended to reduce the adverse effects of acid deposition by reducing emissions of the acid precursors,sulfur dioxide (SO2) and nitrogen oxides (Nox). Passage of Title IV was a response to the findings of a decade of research performed in large part through the National Acid Precipitation Assessment Program (NAPAP), which concluded that acid deposition posed a current and future threat to vulnerable forest and aquatic ecosystems [NAPAP, 1991].Now,with reauthorization of the 1990 Clean Air Act Amendments scheduled for 2000, Congress is considering several bills that would further reduce emissions to ensure the restoration of damaged ecosystems. Title IV requires a 10 million ton per year reduction in SO2 emissions below 1980 levels by 2010 and establishes a national cap of 8.95 million tons per year on utility emissions by 2010. Atmospheric sulfur deposition began to decline in the late 1970s as a result of energy conservation and provisions of the Clean Air Act of 1980. Since implementation of Phase I of Title IV in 1995, SO2 emissions have dropped from more than 20 million tons per year in the early 1990s to 18.3 million tons in 1995 [NAPAP, 1998].Consequently, reductions in atmospheric sulfur deposition have accelerated throughout the United States since 1995.

Runoff of acidic substances that originated from atmospheric deposition on Yakushima Island, a world natural heritage site.

PubMed

Nagafuchi, O; Kakimoto, H; Ebise, S; Inoue, T; Koga, M

2001-01-01

In this paper we present monitoring data of stream waters that may reflect acidic impacts on the island as well as the rainwater qualities. The pH ranges of the river water in the Kawara streams in the western part of the island and the Yodogo stream in the central part of the island were 5.71-6.35 and 5.85-6.12 during 1992-1999, respectively. The concentrations of SO4(2-) and NO3- in the river water were lower than those in the rainwater. Many differences were observed among the sampling sites. Higher concentrations of acid substances are found in the stream waters of the western area compared to the other areas. On the other hand, sulfuric acid is the major acid in the rainwater, snow and rime ice. No differences were observed in the ion constituents of the rainwater collected in the areas. These results suggested that the densely growing canopy may play a role in holding air pollutants, and acidic substances deposited on the canopy would be discharged as a through-fall and a stem flow. Furthermore, the water mass containing high ionic substances in the western area has been held in the groundwater layer, continuously supplying the stream waters during dry weather days. On the other hand, part of the basic runoff will be diluted with a surface runoff during the rainy days. As a result, the concentrations of the ionic substances in the stream waters during rainy days decreased.

Comparison of forest edge effects on throughfall deposition in different forest types.

PubMed

Wuyts, Karen; De Schrijver, An; Staelens, Jeroen; Gielis, Leen; Vandenbruwane, Jeroen; Verheyen, Kris

2008-12-01

This study examined the influence of distance to the forest edge, forest type, and time on Cl-, SO4(2-), NO3(-), and NH4+ throughfall deposition in forest edges. The forests were dominated by pedunculate oak, silver birch, or Corsican/Austrian pine, and were situated in two regions of Flanders (Belgium). Along transects, throughfall deposition was monitored at distances of 0-128 m from the forest edge. A repeated-measures analysis demonstrated that time, forest type, and distance to the forest edge significantly influenced throughfall deposition of the ions studied. The effect of distance to the forest edge depended significantly on forest type in the deposition of Cl-, SO4(2-), and NO3(-): the edge effect was significantly greater in pine stands than in deciduous birch and oak stands. This finding supports the possibility of converting pine plantations into oak or birch forests in order to mitigate the input of nitrogen and potentially acidifying deposition.

THE EFFECT OF ORALLY ADMINISTERED EPSILON AMINOCAPROIC ACID ON THE DEPOSITION AND/OR RETENTION OF RADIOIODINATED FIBRINOGEN AND ANTIBODIES TO FIBRINOGEN IN SUBCUTANEOUS RAT PLASMA CLOTS AND TURPENTINE-INDUCED ABSCESSES OF THE RAT

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

Mutschler, L.E.

1963-01-25

Treatment of metastatic cancer through the use of highly radioactive labeled tumor-localizing antibodies would have the advantage over conventional radiation therapy techniques of delivering large doses of radiation to areas of malignancy while at the same time sparing vital normal tissue from excessive radiation. Intravenously administered I/sup 131/-labeled rat fibrinogen and antibodies to rat fibrin or fibrinogen were found to localize with considerable specificity in the rat-carried Murphy-Sturm lymphosarcoma. lt was suggested that fibrin deposition in tumors is a phenomenon associated with the growth of these tumors and may be of significance in rapidly growing tumors. An apparent lack ofmore » I/sup 131/-fibrinogen localization was observed in some transplantable rat tumors, such as the Walker carcinoma 256. The hypothesis that fibrin deposition is masked by its subsequent rapid removal by fibrinolytic processes was investigated. Data are presented from an investigation of the in vivo antifibrinolytic properties of epsilon aminocapronic acid (EACA), a potent in vitro fibrinolytic inhibitor. Two basic test systems, both using the rat as an experimental animal, were employed. The first involved measuring the effect of orally administered EACA on the retention of subcutaneous clots labeled with either I/sup 131/-fibrinogen or I/sup 131/-antibody against rat fibrinogen. The second system involved measuring the effect of EACA treatment on the deposition and retention of intravenously injected I/sup 131/-fibrinogen and I/sup 131/- antibody in subcutaneous turpentine-induced abscesses. Data indicate that EACA is a potent in vivo anti-fibrinolytic agent and that the mechanism by which EACA treatment brings about increased tumor localization of I/sup 131/-fibrinogen and I/sup 131/antibody is the inhibition of their subsequent removal by fibrinolytic processes. (C.H.)« less

Effects of Micronic Filtration on Turbine Engine Lubricant Deposition.

DTIC Science & Technology

1983-10-01

lubricant 0-82-3. Coupon Wear. Table 3 presents average wear as determined by weighing the coupons both pretest and posttest . The average coupons wear that...T AD-A141 802 EFFECTS Or MICRNI CFILTRATION ON TURBINE ENGINE 1/ LUBRICANT DEPOSITION(U) SOUTHWEST RESEARCH INST SAN ANTONIO TX J C TYLER ET AL. OCT...DEPOSITION SOUTHWEST RESEARCH INSTITUTE 6220 CULEBRA ROAD SAN ANTONIO, TEXAS 78284 c 4 0o OCTOBER 1983 co VT w FINAL REPORT FOR PERIOD 15 AUGUST 1980

Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: potential use in environmental risk assessment.

PubMed

Neves, Natália Rust; Oliva, Marco Antonio; da Cruz Centeno, Danilo; Costa, Alan Carlos; Ribas, Rogério Ferreira; Pereira, Eduardo Gusmão

2009-06-01

The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM(Fe)) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM(Fe) application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

Low historical nitrogen deposition effect on carbon sequestration in the boreal zone

NASA Astrophysics Data System (ADS)

Fleischer, K.; Wârlind, D.; van der Molen, M. K.; Rebel, K. T.; Arneth, A.; Erisman, J. W.; Wassen, M. J.; Smith, B.; Gough, C. M.; Margolis, H. A.; Cescatti, A.; Montagnani, L.; Arain, A.; Dolman, A. J.

2015-12-01

Nitrogen (N) cycle dynamics and N deposition play an important role in determining the terrestrial biosphere's carbon (C) balance. We assess global and biome-specific N deposition effects on C sequestration rates with the dynamic global vegetation model LPJ-GUESS. Modeled CN interactions are evaluated by comparing predictions of the C and CN version of the model with direct observations of C fluxes from 68 forest FLUXNET sites. N limitation on C uptake reduced overestimation of gross primary productivity for boreal evergreen needleleaf forests from 56% to 18%, presenting the greatest improvement among forest types. Relative N deposition effects on C sequestration (dC/dN) in boreal, temperate, and tropical sites ranged from 17 to 26 kg C kg N-1 when modeled at site scale and were reduced to 12-22 kg C kg N-1 at global scale. We find that 19% of the recent (1990-2007) and 24% of the historical global C sink (1900-2006) was driven by N deposition effects. While boreal forests exhibit highest dC/dN, their N deposition-induced C sink was relatively low and is suspected to stay low in the future as no major changes in N deposition rates are expected in the boreal zone. N deposition induced a greater C sink in temperate and tropical forests, while predicted C fluxes and N-induced C sink response in tropical forests were associated with greatest uncertainties. Future work should be directed at improving the ability of LPJ-GUESS and other process-based ecosystem models to reproduce C cycle dynamics in the tropics, facilitated by more benchmarking data sets. Furthermore, efforts should aim to improve understanding and model representations of N availability (e.g., N fixation and organic N uptake), N limitation, P cycle dynamics, and effects of anthropogenic land use and land cover changes.

Effects of phosphoric acid on the lead-acid battery reactions

NASA Astrophysics Data System (ADS)

Ikeda, Osamu; Iwakura, Chiaki; Yoneyama, Hiroshi; Tamura, Hideo

1986-10-01

The addition of a small amount of phosphoric acid to 5 M H2SO4 (commercial electrolyte of lead-acid batteries) results in various positive effects on the lead-acid battery reactions: (1) depression of the corrosion rate of the lead substrate through a preferential formation of alpha-PbO2 on the substrate surface; (2) retardation of hard sulfate formation or of deactivation of active materials; and (3) change in the crystal morphology of PbSO2 formed on the discharge of PbO2. Most of these effects results from chemisorption of phosphoric acid on PbSO4 crystals produced in the discharge process of PbO2.

Acid precipitation; an annotated bibliography

USGS Publications Warehouse

Wiltshire, Denise A.; Evans, Margaret L.

1984-01-01

This collection of 1660 bibliographies references on the causes and environmental effects of acidic atmospheric deposition was compiled from computerized literature searches of earth-science and chemistry data bases. Categories of information are (1) atmospheric chemistry (gases and aerosols), (2) precipitation chemistry, (3) transport and deposition (wet and dry), (4) aquatic environments (biological and hydrological), (5) terrestrial environments, (6) effects on materials and structures, (7) air and precipitation monitoring and data collection, and (8) modeling studies. References date from the late 1800 's through December 1981. The bibliography includes short summaries of most documents. Omitted are unpublished manuscripts, publications in press, master 's theses and doctoral dissertations, newspaper articles, and book reviews. Coauthors and subject indexes are included. (USGS)

Early indications of soil recovery from acidic deposition in U.S. red spruce forests

USGS Publications Warehouse

Lawrence, Gregory B.; Shortle, Walter C.; David, Mark B.; Smith, Kevin T.; Warby, Richard A.F.; Lapenis, Andrei G.

2012-01-01

Forty to fifty percent decreases in acidic deposition through the 1980s and 1990s led to partial recovery of acidified surface waters in the northeastern United States; however, the limited number of studies that have assessed soil change found increased soil acidification during this period. From existing data, it's not clear whether soils continued to worsen in the 1990s or if recovery had begun. To evaluate possible changes in soils through the 1990s, soils in six red spruce (Picea rubens Sarg.) stands in New York, Vermont, New Hampshire, and Maine, first sampled in 1992 to 1993, were resampled in 2003 to 2004. The Oa-horizon pH increased (P 42−, which decreased the mobility of Al throughout the upper soil profile. Results indicate a nascent recovery driven largely by vegetation processes.

ACID AIR AND AEROBIOLOGY RELATED TO THE MATURING HUMAN LUNG

EPA Science Inventory

The effect of 'acid air' on human health was studied by considering the effects of hygroscopicity upon aerosol deposition in the lung as a function of human subject age. Children are a critical sub-population to be incorporated into health effects analyses following ambient expos...

Effect of multiple deposition of NiO layer on the performance of inverted type organic solar cell based on ZnO/P3HT:PCBM

NASA Astrophysics Data System (ADS)

Sabri, Nasehah Syamin; Lim, Eng Liang; Yap, Chi Chin; Yahaya, Muhammad; Salleh, Muhamad Mat; Jumali, Mohammad Hafizuddin Haji

2017-05-01

In this work, the effect of multiple deposition of nickel oxide (NiO) hole transport layer (HTL) on the performance of inverted type organic solar cell with a configuration of fluorine tin oxide (FTO)/zinc oxide (ZnO) nanorods/ poly(3-hexylthiopene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM)/NiO/silver (Ag) was investigated. The NiO nanoparticles solution was spin-coated on top of the photoactive layer (P3HT:PCBM) prior to deposition of Ag electrode. Different numbers of NiO layers (1, 2, and 4) were deposited on the photoactive layer to obtain the optimum surface morphology of HTL. The device with 2 layers of NiO exhibited the optimum power conversion efficiency of 1.10%. It is believed that the optimum NiO deposition layer gives the complete coverage at photoactive layer and forms ohmic contact between the photoactive layer and Ag electrode.

Effects of simulated acid rain on soil fauna community composition and their ecological niches.

PubMed

Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

2017-01-01

Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO 2 ], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electrochemical Deposition of Niobium onto the Surface of Copper Using a Novel Choline Chloride-Based Ionic Liquid

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

Wixtroma, Alex I.; Buhlera, Jessica E.; Reece, Charles E.

2013-06-01

Recent research has shown that choline chloride-based solutions can be used to replace acid-based electrochemical polishing solutions. In this study niobium metal was successfully deposited on the surface of copper substrate via electrochemical deposition using a novel choline chloride-based ionic liquid. The niobium metal used for deposition on the Cu had been dissolved in the solution from electrochemical polishing of a solid niobium piece prior to the deposition. The visible coating on the surface of the Cu was analyzed using scanning electron microscopy (SEM) and electron dispersive x-ray spectroscopy (EDX). This deposition method effectively recycles previously dissolved niobium from electrochemicalmore » polishing.« less

Effects of sulfuric, nitric, and mixed acid rain on Chinese fir sapling growth in Southern China.

PubMed

Liu, Xin; Fu, Zhiyuan; Zhang, Bo; Zhai, Lu; Meng, Miaojing; Lin, Jie; Zhuang, Jiayao; Wang, G Geoff; Zhang, Jinchi

2018-09-30

The influence of acid rain on plant growth includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in root growth. In addition, the concentration of NO 3 - in acid rain increases along with the rapid growth of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 1:0, 5:1, 1:1, 1:5 and 0:1, on Chinese fir sapling growth from March 2015 to April 2016. Results showed that Chinese fir sapling height growth rate (HGR) and basal diameter growth rate (DGR) decreased as acid rain pH decreased, and also decreased as the percentage of NO 3 - increased in acid rain. Acid rain pH significantly decreased the Chlorophyll a (Chla) and Chlorophyll b (Chlb) content, and Chla and Chlb contents with acid rain S/N 1:5 were significantly lower than those with S/N 1:0 at pH 2.5. The chlorophyll fluorescence parameters, maximal efficiency of Photosystem II photochemistry (Fv/Fm) and non-photochemical quenching coefficient (NPQ), with most acid rain treatments were significantly lower than those with CK treatments. Root activities first increased and then decreased as acid rain pH decreased, when acid rain S/N ratios were 1:1, 1:5 and 0:1. Redundancy discriminant analysis (RDA) showed that the Chinese fir DGR and HGR had positive correlations with Chla, Chlb, Fv/Fm ratio, root activity, catalase and superoxide dismutase activities in roots under the stress of acid rain with different pH and S/N ratios. The structural equation modelling (SEM) results showed that acid rain NO 3 - concentration and pH had stronger direct effects on Chinese fir sapling HGR and DGR, and the direct effects of acid rain NO 3 - concentration and pH on HGR were lower than those on DGR. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect the sustainable development of monoculture Chinese fir plantations in southern China

Effects of dietary betaine on growth performance, fat deposition and serum lipids in broilers subjected to chronic heat stress.

PubMed

He, Shaojun; Zhao, Shujing; Dai, Sifa; Liu, Deyi; Bokhari, Shehla Gul

2015-10-01

We evaluated the effects of supplementing betaine on growth performance, fat deposition and lipid metabolism status in broilers kept under chronic heat stress. Five hundred and forty chicks were randomly divided into six groups and the two normal temperature groups were held at normal ambient temperature and fed the basal diet (CONT) and basal diet plus 0.1% betaine, respectively. Heat stressed (HS) broilers were held at 32 ± 1°C from days 22 to 42 and fed the basal diet containing variable levels of betaine. Broilers were examined at days 28, 35 and 42 for body weight, feed consumption, fat deposition and serum lipids. The CONT and betaine-supplemented groups showed higher (P < 0.01 or P < 0.05) feed consumption, body weight gain, and lower feed : gain ratio compared with the HS-CONT group. Meanwhile, heat stress increased abdominal, intermuscular and subcutaneous fat deposition, whereas the supplemental betaine significantly decreased those compared with the HS-CONT group. Additionally, betaine supplementation significantly decreased triglyceride, free fatty acids, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol compared with HS-CONT. Chronic HS reduces broiler production performance. However, betaine can reverse these negative effects partially and thus improve carcass composition by changing lipid metabolism. © 2015 Japanese Society of Animal Science.

Thermal Stability of Jet Fuels: Kinetics of Forming Deposit Precursors

NASA Technical Reports Server (NTRS)

Naegeli, David W.

1997-01-01

The focus of this study was on the autoxidation kinetics of deposit precursor formation in jet fuels. The objectives were: (1) to demonstrate that laser-induced fluorescence is a viable kinetic tool for measuring rates of deposit precursor formation in jet fuels; (2) to determine global rate expressions for the formation of thermal deposit precursors in jet fuels; and (3) to better understand the chemical mechanism of thermal stability. The fuels were isothermally stressed in small glass ampules in the 120 to 180 C range. Concentrations of deposit precursor, hydroperoxide and oxygen consumption were measured over time in the thermally stressed fuels. Deposit precursors were measured using laser-induced fluorescence (LIF), hydroperoxides using a spectrophotometric technique, and oxygen consumption by the pressure loss in the ampule. The expressions, I.P. = 1.278 x 10(exp -11)exp(28,517.9/RT) and R(sub dp) = 2.382 x 10(exp 17)exp(-34,369.2/RT) for the induction period, I.P. and rate of deposit precursor formation R(sub dp), were determined for Jet A fuel. The results of the study support a new theory of deposit formation in jet fuels, which suggest that acid catalyzed ionic reactions compete with free radical reactions to form deposit precursors. The results indicate that deposit precursors form only when aromatics are present in the fuel. Traces of sulfur reduce the rate of autoxidation but increase the yield of deposit precursor. Free radical chemistry is responsible for hydroperoxide formation and the oxidation of sulfur compounds to sulfonic acids. Phenols are then formed by the acid catalyzed decomposition of benzylic hydroperoxides, and deposit precursors are produced by the reaction of phenols with aldehydes, which forms a polymer similar to Bakelite. Deposit precursors appear to have a phenolic resin-like structure because the LIF spectra of the deposit precursors were similar to that of phenolic resin dissolved in TAM.

The effects of Bacillus coagulans-fermented and non-fermented Ginkgo biloba on abdominal fat deposition and meat quality of Peking duck.

PubMed

Liu, Xiaoyan; Cao, Guanjun; Zhou, Jinglong; Yao, Xuan; Fang, Binghu

2017-07-01

In order to evaluate the effects of Bacillus coagulans-fermented Ginkgo biloba (FG) and non-fermented G. biloba (NFG) on abdominal fat deposition and meat quality, 270 female Peking ducks were randomly assigned to the following experimental groups: a control group (fed a basal diet), an NFG group (fed a basal diet + 0.3% NFG), and an FG group (fed a basal diet + 0.3% FG). Body weight and feed intake were recorded weekly, and feed conversion ratio was calculated to assess growth performance. After 6 wk, 18 ducks from each group were killed. Abdominal fat ratio and pH (at 45 min and 24 h postmortem), color parameters (lightness, redness, and yellowness), water-holding capacity, cooking loss, shear force, and intramuscular fat and fatty acid contents were measured. Six more ducks were killed to isolate RNA from their abdominal fat tissue for measurements of peroxisome proliferator-activated receptor-γ (PPARγ), obese (leptin), and adiponectin (ADP) expression using real-time polymerase chain reaction. The results revealed that body weight gain was higher in the FG group than in the control and NFG groups, whereas feed conversion ratio was lower (P < 0.05). The abdominal fat contents were lower in the NFG and FG groups than in the control group (P < 0.05). The NFG and FG groups had lower levels of saturated fatty acids (mainly palmitic acid) and higher levels of polyunsaturated fatty acids (mainly linoleic acid and arachidonic acid) than the control group. The mRNA expressions of PPARγ, leptin, and ADP in abdominal fat tissue were significantly increased in the NFG and FG groups, and the mRNA expression of PPARγ was higher in the FG group than in the NFG group (P < 0.05). These results suggest that fermenting G. biloba reduces the deposition of abdominal fat and improves the fatty acid profile of Peking duck meat. © 2017 Poultry Science Association Inc.

Water geochemistry of the Qiantangjiang River, East China: Chemical weathering and CO2 consumption in a basin affected by severe acid deposition

NASA Astrophysics Data System (ADS)

Liu, Wenjing; Shi, Chao; Xu, Zhifang; Zhao, Tong; Jiang, Hao; Liang, Chongshan; Zhang, Xuan; Zhou, Li; Yu, Chong

2016-09-01

The chemical composition of the Qiantangjiang River, the largest river in Zhejiang province in eastern China, was measured to understand the chemical weathering of rocks and the associated CO2 consumption and anthropogenic influences within a silicate-dominated river basin. The average total dissolved solids (TDS, 113 mg l-1) and total cation concentration (TZ+, 1357 μeq l-1) of the river waters are comparable with those of global major rivers. Ca2+ and HCO3- followed by Na2+ and SO42-, dominate the ionic composition of the river water. There are four major reservoirs (carbonates, silicates, atmospheric and anthropogenic inputs) contributing to the total dissolved load of the investigated rivers. The dissolved loads of the rivers are dominated by both carbonate and silicate weathering, which together account for about 76.3% of the total cationic load origin. The cationic chemical weathering rates of silicate and carbonate for the Qiantangjiang basin are estimated to be approximately 4.9 ton km-2 a-1 and 13.9 ton km-2 a-1, respectively. The calculated CO2 consumption rates with the assumption that all the protons involved in the weathering reaction are provided by carbonic acid are 369 × 103 mol km-2 a-1 and 273 × 103 mol km-2 a-1 by carbonate and silicate weathering, respectively. As one of the most severe impacted area by acid rain in China, H2SO4 from acid precipitation is also an important proton donor in weathering reactions. When H2SO4 is considered, the CO2 consumption rates for the river basin are estimated at 286 × 103 mol km-2 a-1 for carbonate weathering and 211 × 103 mol km-2 a-1 for silicate weathering, respectively. The results highlight that the drawdown effect of CO2 consumption by carbonate and silicate weathering can be largely overestimated if the role of sulfuric acid is ignored, especially in the area heavily impacted by acid deposition like Qiantangjiang basin. The actual CO2 consumption rates (after sulfuric acid weathering effect

Dry deposition of reduced and reactive nitrogen: A surrogate surfaces approach

NASA Astrophysics Data System (ADS)

Shahin, Usama Mohammed

Nitrogen deposition constitutes an important component of acidic deposition to terrestrial surfaces. However, deposition flux and ambient concentration measurement methods and are still under development. A new sampler using water as a surrogate surface was developed in the Department of Environmental Engineering at Illinois Institute of Technology. This study investigated nitrate and ammonia dry deposition to the water surface sampler, a Nylasorb filter, a citric acid impregnated filter, and a greased strip on the dry deposition plate. The nitrogen containing species that may be responsible for nitrate dry deposition to the WSS include nitrogen monoxide (NO), nitrogen dioxide (NO2), peroxyacetyl nitrate (PAN), nitrous acid (HNO2), nitric acid (HNO3), and particulate nitrate. The experimental measurements showed that HNO3 and particulate nitrate are the major nitrate contributors to the WSS. Ammonia sources to the water surface are ammonia gas (NH3) and ammonium (NH4+). The experimental results showed that these two species are the sole sources to ammonium deposition. Comparison between the measured deposition velocity of SO2, and HNO3, shows that their dry deposition velocities are statistically the same at the 95% confidence level and NH3 deposition velocity and the water evaporation rate are also the same. It was also shown that the air side MTC of two different compounds were correlated to the square root of the inverse of the molecular weight for compounds. The measured MTC was tested by the application of two models, the resistance model and the water evaporation model. The resistance model prediction of the MTC was very close to the measured value but the evaporation model prediction was not. This result is compatible with the finding of Yi, (1997) who used the same WSS for measurements of SO2. The experimental data collected in this research project was used to develop an empirical model to measure the MTC that is [kl/over D] = 0.0426 ([lv/rho/over /mu])0

Mechanisms of nitrogen deposition effects on temperate forest lichens and trees

Treesearch

Therese S. Carter; Christopher M. Clark; Mark E. Fenn; Sarah Jovan; Steven S. Perakis; Jennifer Riddell; Paul G. Schaberg; Tara L. Greaver; Meredith G. Hastings

2017-01-01

We review the mechanisms of deleterious nitrogen (N) deposition impacts on temperate forests, with a particular focus on trees and lichens. Elevated anthropogenic N deposition to forests has varied effects on individual organisms depending on characteristics both of the N inputs (form, timing, amount) and of the organisms (ecology, physiology) involved. Improved...

Low-fluorine Stockwork Molybdenite Deposits

USGS Publications Warehouse

Ludington, Steve; Hammarstrom, Jane; Piatak, Nadine M.

2009-01-01

Low-fluorine stockwork molybdenite deposits are closely related to porphyry copper deposits, being similar in their tectonic setting (continental volcanic arc) and the petrology (calc-alkaline) of associated igneous rock types. They are mainly restricted to the Cordillera of western Canada and the northwest United States, and their distribution elsewhere in the world may be limited. The deposits consist of stockwork bodies of molybdenite-bearing quartz veinlets that are present in and around the upper parts of intermediate to felsic intrusions. The deposits are relatively low grade (0.05 to 0.2 percent Mo), but relatively large, commonly >50 million tons. The source plutons for these deposits range from granodiorite to granite in composition; the deposits primarily form in continental margin subduction-related magmatic arcs, often concurrent with formation of nearby porphyry copper deposits. Oxidation of pyrite in unmined deposits or in tailings and waste rock during weathering can lead to development of acid-rock drainage and limonite-rich gossans. Waters associated with low-fluorine stockwork molybdenite deposits tend to be nearly neutral in pH; variable in concentrations of molybdenum (10,000 ug/L); below regulatory guidelines for copper, iron, lead, zinc, and mercury; and locally may exceed guidelines for arsenic, cadmium, and selenium.

Differential effects of high-fat diets varying in fatty acid composition on the efficiency of lean and fat tissue deposition during weight recovery after low food intake.

PubMed

Dulloo, A G; Mensi, N; Seydoux, J; Girardier, L

1995-02-01

The energetics of body weight recovery after low food intake was examined in the rat during refeeding for 2 weeks with isocaloric amounts of high-fat (HF) diets providing 50% of energy as either lard, coconut oil, olive oil, safflower oil, menhaden fish oil, or a mixture of all these fat types. The results indicate that for both body fat and protein, the efficiency of deposition was dependent on the dietary fat type. The most striking differences were found (1) between diets rich in n-3 and n-6 polyunsaturated fatty acids (PUFA), with the diet high in fish oil resulting in a greater body fat deposition and lower protein gain than the diet high in safflower oil; and (2) between diets rich in long-chain (LCT) and medium-chain triglycerides (MCT), with the diet high in lard resulting in a greater gain in both body fat and protein than the diet high in coconut oil. Furthermore, the diet high in olive oil (a monounsaturated fat) and the mixed-fat diet (containing all fat types) were found to be similar to the fish oil diet in that the efficiency of fat deposition was greater (and that of protein gain lower) than with the diet high in safflower oil. Neither the efficiency of fat gain nor that of protein gain were found to correlate with fasting plasma insulin, the insulin to glucose ratio, or plasma lipids.(ABSTRACT TRUNCATED AT 250 WORDS)

Spatial variation in the flux of atmospheric deposition and its ecological effects in arid Asia

NASA Astrophysics Data System (ADS)

Jiao, Linlin; Wang, Xunming; Li, Danfeng

2018-06-01

Atmospheric deposition is one of the key land surface processes, and plays important roles in regional ecosystems and global climate change. Previous studies have focused on the magnitude of and the temporal and spatial variations in the flux of atmospheric deposition, and the composition of atmospheric deposition on a local scale. However, there have been no comprehensive studies of atmospheric deposition on a regional scale and its ecological effects in arid Asia. The temporal and spatial patterns, composition of atmospheric deposition, and its potential effects on regional ecosystems in arid Asia are investigated in this study. The results show that the annual deposition flux is high on the Turan Plain, Aral Sea Desert, and Tarim Basin. The seasonal deposition flux also varies remarkably among different regions. The Tarim Basin shows higher deposition flux in both spring and summer, southern Mongolian Plateau has a higher deposition flux in spring, and the deposition flux of Iran Plateau is higher in summer. Multiple sources of elements in deposited particles are identified. Calcium, iron, aluminum, and magnesium are mainly derived from remote regions, while zinc, copper and lead have predominantly anthropogenic sources. Atmospheric deposition can provide abundant nutrients to vegetation and consequently play a role in the succession of regional ecosystems by affecting the structure, function, diversity, and primary production of the vegetation, especially the exotic or short-lived opportunistic species in arid Asia. Nevertheless, there is not much evidence of the ecological effects of atmospheric deposition on the regional and local scale. The present results may help in further understanding the mechanism of atmospheric deposition as well as providing a motivation for the protection of the ecological environment in arid Asia.

Effect of acetic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

PubMed

Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

2014-09-01

An integrated citric acid-methane fermentation process was proposed to solve the problem of extraction wastewater in citric acid fermentation process. Extraction wastewater was treated by anaerobic digestion and then recycled for the next batch of citric acid fermentation to eliminate wastewater discharge and reduce water resource consumption. Acetic acid as an intermediate product of methane fermentation was present in anaerobic digestion effluent. In this study, the effect of acetic acid on citric acid fermentation was investigated and results showed that lower concentration of acetic acid could promote Aspergillus niger growth and citric acid production. 5-Cyano-2,3-ditolyl tetrazolium chloride (CTC) staining was used to quantify the activity of A. niger cells, and the results suggested that when acetic acid concentration was above 8 mM at initial pH 4.5, the morphology of A. niger became uneven and the part of the cells' activity was significantly reduced, thereby resulting in deceasing of citric acid production. Effects of acetic acid on citric acid fermentation, as influenced by initial pH and cell number in inocula, were also examined. The result indicated that inhibition by acetic acid increased as initial pH declined and was rarely influenced by cell number in inocula.

Phyllosilicate and Hydrated Sulfate Deposits in Meridiani

NASA Technical Reports Server (NTRS)

Wiseman, S. M.; Avidson, R. E.; Murchie, S.; Poulet, F.; Andrews-Hanna, J. C.; Morris, R. V.; Seelos, F. P.

2008-01-01

Several phyllosilicate and hydrated sulfate deposits in Meridiani have been mapped in detail with high resolution MRO CRISM [1] data. Previous studies have documented extensive exposures of outcrop in Meridiani (fig 1), or etched terrain (ET), that has been interpreted to be sedimentary in origin [e.g., 2,3]. These deposits have been mapped at a regional scale with OMEGA data and show enhanced hydration (1.9 m absorption) in several areas [4]. However, hydrated sulfate detections were restricted to valley exposures in northern Meridiani ET [5]. New high resolution CRISM images show that hydrated sulfates are present in several spatially isolated exposures throughout the ET (fig 1). The hydrated sulfate deposits in the valley are vertically heterogeneous with layers of mono and polyhydrated sulfates and are morphologically distinct from other areas of the ET. We are currently mapping the detailed spatial distribution of sulfates and searching for distinct geochemical horizons that may be traced back to differential ground water recharge and/or evaporative loss rates. The high resolution CRISM data has allowed us to map out several phyllosilicate deposits within the fluvially dissected Noachian cratered terrain (DCT) to the south and west of the hematite-bearing plains (Ph) and ET (fig 1). In Miyamoto crater, phyllosilicates are located within 30km of the edge of Ph, which is presumably underlain by acid sulfate deposits similar to those explored by Opportunity. The deposits within this crater may record the transition from fluvial conditions which produced and/or preserved phyllosilicates deposits to a progressively acid sulfate dominated groundwater system in which large accumulations of sulfate-rich evaporites were deposited .

Long term response of acid-sensitive Vermont Lakes to sulfate deposition

EPA Science Inventory

Atmospheric deposition of sulfur can negatively affect the health of lakes and streams, particularly in poorly buffered catchments. In response to the Clean Air Act Amendments, wet deposition of sulfate decreased more than 35% in Vermont between 1990 and 2008. However, most of ...

Particle characteristics and lung deposition patterns in a human airway replica of a dry powder formulation of polylactic acid produced using supercritical fluid technology.

PubMed

Cheng, Y S; Yazzie, D; Gao, J; Muggli, D; Etter, J; Rosenthal, G J

2003-01-01

Polylactic acid (PLA) powders have been used as vector particles to carry pharmaceutical material. Drugs incorporated in the PLA powder can be retained in the lung for a longer period and may be more effective than free-form drugs. A new formulation of L-PLA dry powder, which was easy to disperse in the air, was produced by using a supercritical technology. The L-PLA powder was characterized in terms of physical particle size and aerodynamic size as generated with a Turbuhaler dry powder inhaler (DPI). Electron microscopy analysis of the particles indicated that they were individual particles in bulk form and became aggregate particles after generation by the Turbuhaler. Aerodynamic particle size analysis using both an Aerodynamic Particle Sizer (APS) aerosol spectrometer and Andersen impactor showed that the aerodynamic size decreased as the flow rate in the Turbuhaler increased from 28.3 to 90 L min(-1). Deposition patterns in the human respiratory tract were estimated using a realistic physical replica of human airways. Deposition of the L-PLA was high (80.8%) in the oral airway at 28.3 L min(-1) and an average of 73.4% at flow rates of 60 and 90 L min(-1). In the lung region, the deposition totaled 7.2% at 28.3 L min(-1), 18.3% at 60 L min(-1), and 17.6% at 90 L min(-1). These deposition patterns were consistent with aerodynamic size measurement, which showed 76 to 86% deposition in the USP/EP (US Pharmacopoeia/European Pharmacopoeia) induction port. As the flow rate increased, fewer aggregates were formed resulting in the smaller aerodynamic particles. As a result, more particles penetrated the oral airways and were available for deposition in the lung. Our results showed that L-PLA particles as manufactured by the supercritical technology could be used in a DPI that does not require the use of carrier particles to facilitate aerosol delivery.

Modelling impacts of temperature, and acidifying and eutrophying deposition on DOC trends

NASA Astrophysics Data System (ADS)

Sawicka, Kasia; Rowe, Ed; Evans, Chris; Monteith, Don; Vanguelova, Elena; Wade, Andrew; Clark, Joanna

2017-04-01

Surface water dissolved organic carbon (DOC) concentrations in large parts of the northern hemisphere have risen over the past three decades, raising concern about enhanced contributions of carbon to the atmosphere and seas and oceans. The effect of declining acid deposition has been identified as a key control on DOC trends in soil and surface waters, since pH and ionic strength affect sorption and desorption of DOC. However, since DOC is derived mainly from recently-fixed carbon, and organic matter decomposition rates are considered sensitive to temperature, uncertainty persists regarding the extent to the relative importance of different drivers that affect these upward trends. We ran the dynamic model MADOC (Model of Acidity and Soil Organic Carbon) for a range of UK soils (podzols, gleysols and peatland), for which the time-series were available, to consider the likely relative importance of decreased deposition of sulphate and chloride, accumulation of reactive N, and higher temperatures, on DOC production in different soils. Modelled patterns of DOC change generally agreed favourably with measurements collated over 10-20 years, but differed markedly between sites. While the acidifying effect of sulphur deposition appeared to be the predominant control on the observed soil water DOC trends in all the soils considered other than a blanket peat, the model suggested that over the long term, the effects of nitrogen deposition on N-limited soils may have been sufficient to elevate the DOC recovery trajectory significantly. The second most influential cause of rising DOC in the model simulations was N deposition in ecosystems that are N-limited and respond with stimulated plant growth. Although non-marine chloride deposition made some contribution to acidification and recovery, it was not amongst the main drivers of DOC change. Warming had almost no effect on modelled historic DOC trends, but may prove to be a significant driver of DOC in future via its influence

Effects of experimental canopy manipulation on amphibian egg deposition

Treesearch

Zachary I. Felix; Yong Wang; Callie J. Schweitzer

2010-01-01

Although effects of forest management on amphibians are relatively well studied, few studies have examined how these practices affect egg deposition by adults, which can impact population recruitment. We quantified the effects of 4 canopy tree-retention treatments on amphibian oviposition patterns in clusters of 60-L aquatic mesocosms located in each treatment. We also...

Geochemical characterization of acid mine lakes in northwest Turkey and their effect on the environment.

PubMed

Yucel, Deniz Sanliyuksel; Baba, Alper

2013-04-01

Mining activity generates a large quantity of mine waste. The potential hazard of mine waste depends on the host mineral. The tendency of mine waste to produce acid mine drainage (AMD) containing potentially toxic metals depends on the amounts of sulfide, carbonate minerals, and trace-element concentrations found in ore deposits. The acid mine process is one of the most significant environmental challenges and a major source of water pollution worldwide. AMD and its effects were studied in northwest Turkey where there are several sedimentary and hydrothermal mineral deposits that have been economically extracted. The study area is located in Can county of Canakkale province. Canakkale contains marine, lagoon, and lake sediments precipitated with volcanoclastics that occurred as a result of volcanism, which was active during various periods from the Upper Eocene to Plio-Quaternary. Can county is rich in coal with a total lignite reserve >100 million tons and contains numerous mines that were operated by private companies and later abandoned without any remediation. As a result, human intervention in the natural structure and topography has resulted in large open pits and deterioration in these areas. Abandoned open pit mines typically fill with water from runoff and groundwater discharge, producing artificial lakes. Acid drainage waters from these mines have resulted in the degradation of surface-water quality around Can County. The average pH and electrical conductivity of acid mine lakes (AMLs) in this study were found to be 3.03 and 3831.33 μS cm(-1), respectively. Total iron (Fe) and aluminum (Al) levels were also found to be high (329.77 and 360.67 mg L(-1), respectively). The results show that the concentration of most elements, such as Fe and Al in particular, exceed national and international water-quality standards.

Anthropogenically driven changes in chloride complicate interpretation of base cation trends in lakes recovering from acidic deposition.

PubMed

Rosfjord, Catherine H; Webster, Katherine E; Kahl, Jeffrey S; Norton, Stephen A; Fernandez, Ivan J; Herlihy, Alan T

2007-11-15

Declines in Ca and Mg in low ANC lakes recovering from acidic deposition are widespread across the northern hemisphere. We report overall increases between 1984 and 2004 in the concentrations of Ca + Mg and Cl in lakes representing the statistical population of nearly 4000 low ANC lakes in the northeast U.S. Increases in Cl occurred in nearly all lakes in urbanized southern New England, but only 18% of lakes in more remote Maine had Cl increases. This spatial pattern implicates road salt application as the major source of the increased Cl salts. Among the 48% of the lake population classified as salt-affected, the median changes in Cl (+133 microeq/L) and Ca + Mg (+47 microeq/ L) were large and positive in direction over the 20 years. However, in the unaffected lakes, Cl remained stable and Ca + Mg decreased (-3 microeq/L), consistent with reported long-term trends in base cations of acid-sensitive lakes. This discrepancy between the Cl groups suggests that changes in ion exchange processes in salt-affected watersheds have altered the geochemical cycling of Ca and Mg. One policy-relevant implication is that waters influenced by Cl salts complicate regional assessments of surface water recovery from "acid rain" related to the passage of the Clean Air Act.

Effects of climate, land management, and sulfur deposition on soil base cation supply in national forests of the southern Appalachian mountains

Treesearch

T.C. McDonnell; T.J. Sullivan; B.J. Cosby; W.A. Jackson; K.J. Elliott

2013-01-01

Forest soils having low exchangeable calcium (Ca) and other nutrient base cation (BC) reserves may induce nutrient deficiencies in acid-sensitive plants and impact commercially important tree species. Past and future depletion of soil BC in response to acidic sulfur (S) deposition, forest management, and climate change alter the health and productivity of forest trees...

Atomic and molecular layer deposition for surface modification

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

Vähä-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.fi; Sievänen, Jenni; Salo, Erkki

2014-06-01

Atomic and molecular layer deposition (ALD and MLD, respectively) techniques are based on repeated cycles of gas–solid surface reactions. A partial monolayer of atoms or molecules is deposited to the surface during a single deposition cycle, enabling tailored film composition in principle down to molecular resolution on ideal surfaces. Typically ALD/MLD has been used for applications where uniform and pinhole free thin film is a necessity even on 3D surfaces. However, thin – even non-uniform – atomic and molecular deposited layers can also be used to tailor the surface characteristics of different non-ideal substrates. For example, print quality of inkjetmore » printing on polymer films and penetration of water into porous nonwovens can be adjusted with low-temperature deposited metal oxide. In addition, adhesion of extrusion coated biopolymer to inorganic oxides can be improved with a hybrid layer based on lactic acid. - Graphical abstract: Print quality of a polylactide film surface modified with atomic layer deposition prior to inkjet printing (360 dpi) with an aqueous ink. Number of printed dots illustrated as a function of 0, 5, 15 and 25 deposition cycles of trimethylaluminum and water. - Highlights: • ALD/MLD can be used to adjust surface characteristics of films and fiber materials. • Hydrophobicity after few deposition cycles of Al{sub 2}O{sub 3} due to e.g. complex formation. • Same effect on cellulosic fabrics observed with low temperature deposited TiO{sub 2}. • Different film growth and oxidation potential with different precursors. • Hybrid layer on inorganic layer can be used to improve adhesion of polymer melt.« less

Chronic nitrogen deposition influences the chemical dynamics ...

EPA Pesticide Factsheets

Atmospheric nitrogen deposition induces a forest carbon sink across broad parts of the Northern Hemisphere; this carbon sink may partly result from slower litter decomposition. Although microbial responses to experimental nitrogen deposition have been well-studied, evidence linking these microbial responses to changes in the degradation of specific compounds in decaying litter is sparse. We used wet chemistry and Fourier transform infrared spectroscopy (FTIR) methodologies to study the effects of chronic simulated nitrogen deposition on leaf litter and fine root chemistry during a three-year decomposition experiment at four northern hardwood forests in the north-central USA. Leaf litter and fine roots were highly different in initial chemistry such as concentrations of acid-insoluble fraction (AIF, or Klason lignin) and condensed tannins (CTs). These initial differences persisted over the course of decomposition. Results from gravimetrically-defined AIF and lignin/carbohydrate reference IR peak ratios both provide evidence that lignin in fine roots was selectively preserved under simulated nitrogen deposition. Lignin/carbohydrate peak ratios were strongly correlated with AIF, suggesting that AIF is a good predictor of lignin. Because AIF is abundant in fine roots, slower AIF degradation was the major driver of the slower fine root decomposition under nitrogen enrichment, explaining 73.9 % of the additional root mass retention. Nitrogen enrichment also slowed the

The erosion of carbonate stone by acid rain: Laboratory and field investigations

USGS Publications Warehouse

Baedecker, P.A.; Reddy, M.M.

1993-01-01

One of the goals of research on the effects of acidic deposition on carbonate stone surfaces is to define the incremental impact of acidic deposition relative to natural weathering processes on the rate of carbonate stone erosion. If rain that impacts carbonate stone surfaces is resident on the surface long enough to approach chemical equilibrium, the incremental effect of hydrogen ion is expected to be small (i.e., 6% for a rain of pH 4.0). Under nonequilibrium (i.e., high flow rate) conditions, kinetic considerations suggest that the incremental effect of hydrogen ion deposition could be quite significant. Field run-off experiments involving the chemical analysis of rain collected from inclined stone slabs have been used to evaluate stone dissolution processes under ambient conditions of wet and dry deposition of acidic species. The stoichiometry of the reaction of stone with hydrogen ion is difficult to define from the field data due to scatter in the data attributed to hydrodynamic effects. Laboratory run-off experiments show that the stoichiometry is best defined by a reaction with H+ in which CO2 is released from the system. The baseline effect caused by water in equilibrium with atmospheric CO2 is identical in the field and in laboratory simulation. The experiments show that the solutions are close enough to equilibrium for the incremental effect of hydrogen ion to be minor (i.e., 24% for marble for a rain of pH 4.0) relative to dissolution due to water and carbonic acid reactions. Stone erosion rates based on physical measurement are approximately double the recession rates that are due to dissolution (estimated from the observed calcium content of the run-off solutions). The difference may reflect the loss of granular material not included in recession estimates based on the run-off data. Neither the field nor the laboratory run-off experiments indicate a pH dependence for the grain-removal process.

Synergy of combined Doxycycline/TUDCA treatment in lowering Transthyretin deposition and associated biomarkers: studies in FAP mouse models

PubMed Central

2010-01-01

Familial Amyloidotic Polyneuropathy (FAP) is a disorder characterized by the extracellular deposition of fibrillar Transthyretin (TTR) amyloid, with a special involvement of the peripheral nerve. We had previously shown that doxycycline administered for 3 months at 40 mg/Kg/ml in the drinking water, was capable of removing TTR amyloid deposits present in stomachs of old TTR-V30M transgenic mice; the removal was accompanied by a decrease in extracellular matrix remodeling proteins that accompany fibrillar deposition, but not of non-fibrillar TTR deposition and/or markers associated with pre-fibrillar deposits. On the other hand, Tauroursodeoxycholic acid (TUDCA), a biliary acid, administrated to the same mouse model was shown to be effective at lowering deposited non-fibrillar TTR, as well as the levels of markers associated with pre-fibrillar TTR, but only at young ages. In the present work we evaluated different doxycycline administration schemes, including different periods of treatment, different dosages and different FAP TTR V30M animal models. Evaluation included CR staining, immunohistochemistry for TTR, metalloproteinase 9 (MMP-9) and serum amyloid P component (SAP). We determined that a minimum period of 15 days of treatment with a 8 mg/Kg/day dosage resulted in fibril removal. The possibility of intermittent treatments was also assessed and a maximum period of 15 days of suspension was determined to maintain tissues amyloid-free. Combined cycled doxycycline and TUDCA administration to mice with amyloid deposition, using two different concentrations of both drugs, was more effective than either individual doxycycline or TUDCA, in significantly lowering TTR deposition and associated tissue markers. The observed synergistic effect of doxycycline/TUDCA in the range of human tolerable quantities, in the transgenic TTR mice models prompts their application in FAP, particularly in the early stages of disease. PMID:20673327

[Effects of simulated nitrogen deposition on organic matter leaching in forest soil].

PubMed

Duan, Lei; ma, Xiao-Xiao; Yu, De-Xiang; Tan, Bing-Quan

2013-06-01

The impact of nitrogen deposition on the dynamics of carbon pool in forest soil was studied through a field experiment at Tieshanping, Chongqing in Southwest China. The changes of dissolved organic matter (DOM) concentration in soil water in different soil layers were monitored for five years after addition of ammonium nitrate (NH4NO3) or sodium nitrate (NaNO3) at the same dose as the current nitrogen deposition to the forest floor. The results indicated that the concentration and flux of dissolved organic carbon (DOC) were increased in the first two years and then decreased by fertilizing. Fertilizing also reduced the DOC/DON (dissolved organic nitrogen) ratio of soil water in the litter layer and the DOC concentration of soil water in the upper mineral layer, but had no significant effect on DOC flux in the lower soil layer. Although there was generally no effect of increasing nitrogen deposition on the forest carbon pool during the experimental period, the shift from C-rich to N-rich DOM might occur. In addition, the species of nitrogen deposition, i. e., NH4(+) and NO3(-), did not show difference in their effect on soil DOM with the same equivalence.

Electroless deposition of Ni Cu P alloy and study of the influences of some parameters on the properties of deposits

NASA Astrophysics Data System (ADS)

Ashassi-Sorkhabi, H.; Dolati, H.; Parvini-Ahmadi, N.; Manzoori, J.

2002-01-01

Cupronickel alloys are known for their excellent corrosion resistance, especially in marine atmosphere. The development of an appropriate electroless bath involves the use of a reducing agent, complexing and stabilizing compounds and metallic salts. In this work, autocatalytic deposition of Ni-Cu-P alloys (28-95 wt.% Ni, 66-0 wt.% Cu, 7.5-3 wt.% P) has been carried out on 302 b steel sheets from bath containing: NiCl 2·6H 2O, CuCl 2·2H 2O, NaH 2PO 2, Na citrate, sulphosalicilic acid and triethanolamine. The effects of pH, temperature, and bath composition on the hardness and the composition of deposits have been studied. In addition, the deposition rates of alloy, nickel, copper and phosphorus were investigated and optimum conditions were obtained. The average rate of alloy deposition was 9 mg cm -2 h -1 and the optimum pH and temperature were 8.5 and 80 °C, respectively. The chemical stability of bath was desirable, and no spontaneous decomposition occurred. The changes in the structure of deposit by heat treatment were studied by the X-ray diffraction (XRD) method. The XRD patterns indicate that the copper content affects the structure changes. With increasing copper content, the phosphorus content decreased and the crystallinity of the deposits grew. After heat treatment of alloys with lower copper content at 400 °C for 1 h, the crystallization to Ni 3P was observed.

Nitrogen (N) Deposition Impacts Seedling Growth of Pinus massoniana via N:P Ratio Effects and the Modulation of Adaptive Responses to Low P (Phosphorus)

PubMed Central

Zhang, Yi; Zhou, Zhichun; Yang, Qing

2013-01-01

Background In forest ecosystems with phosphorus (P) deficiency, the impact of atmospheric nitrogen (N) deposition on nutritional traits related to P uptake and P use potentially determines plant growth and vegetation productivity. Methodology/Principal Findings Two N deposition simulations were combined with three soil P conditions (homogeneous P deficiency with evenly low P; heterogeneous P deficiency with low subsoil P and high topsoil P; high P) using four full-sib families of Masson pine (Pinus massoniana). Under homogeneous P deficiency, N had a low effect on growth due to higher N:P ratios, whereas N-sensitive genotypes had lower N:P ratios and greater N sensitivity. The N effect increased under higher P conditions due to increased P concentration and balanced N:P ratios. An N:P threshold of 12.0–15.0 was detected, and growth was increased by N with an N:P ratio ≤ 12.0 and increased by P with an N:P ratio ≥ 15.0. Under homogeneous P deficiency, increased P use efficiency by N deposition improved growth. Under heterogeneous P deficiency, a greater P deficiency under N deposition due to increased N:P ratios induced greater adaptive responses to low P (root acid phosphatase secretion and topsoil root proliferation) and improved P acquisition and growth. Conclusions/Significance N deposition diversely affected seedling growth across different P conditions and genotypes via N:P ratio effects and the modulation of adaptive responses to low P. The positive impact of N on growth was genotype-specific and increased by soil P addition due to balanced N:P ratios. These results indicate the significance of breeding N-sensitive tree genotypes and improving forest soil P status to compensate for increasing N deposition. PMID:24205376

Electrocatalytic performance of Pt nanoparticles sputter-deposited on indium tin oxide toward methanol oxidation reaction: The particle size effect

NASA Astrophysics Data System (ADS)

Ting, Chao-Cheng; Chao, Chih-Hsuan; Tsai, Cheng Yu; Cheng, I.-Kai; Pan, Fu-Ming

2017-09-01

We sputter-deposited Pt nanoparticles with an average size ranging from 2.0 nm to 8.5 nm on the indium-tin oxide (ITO) glass substrate, and studied the effect of the size of Pt nanoparticles on electrocatalytic activity of the Pt/ITO electrode toward methanol oxidation reaction (MOR) in acidic solution. X-ray photoelectron spectroscopy (XPS) reveals an interfacial oxidized Pt layer present between Pt nanoparticles and the ITO substrate, which may modify the surface electronic structure of Pt nanoparticles and thus influences the electrocatalytic properties of the Pt catalyst toward MOR. According to electrochemical analyses, smaller Pt nanoparticles exhibit slower kinetics for CO electrooxidation and MOR. However, a smaller particle size enables better CO tolerance because the bifunctional mechanism is more effective on smaller Pt nanoparticles. The electrocatalytic activity decays rapidly for Pt nanoparticles with a size smaller than 3 nm and larger than 8 nm. The rapid activity decay is attributed to Pt dissolution for smaller nanoparticles and to CO poisoning for larger ones. Pt nanoparticles of 5-6 nm in size loaded on ITO demonstrate a greatly improved electrocatalytic activity and stability compared with those deposited on different substrates in our previous studies.

Atmospheric deposition effects on the chemistry of a stream in Northeastern Georgia

USGS Publications Warehouse

Buell, G.R.; Peters, N.E.

1988-01-01

The quantity and quality of precipitation and streamwater were measured from August 1985 through September 1986 in the Brier Creek watershed, a 440-ha drainage in the Southern Blue Ridge Province of northeastern Georgia, to determine stream sensitivity to acidic deposition. Precipitation samples collected at 2 sites had a volume-weighted average pH of 4.40 whereas stream samples collected near the mouth of Brier Creek had a discharge-weighted average pH of 6.70. Computed solute fluxes through the watershed and observed changes in streamwater chemistry during stormflow suggest that cation exchange, mineral weathering, SO42- adsorption by the soil, and groundwater discharge to the stream are probable factors affecting neutralization of precipitation acidity. Net solute fluxes for the watershed indicate that, of the precipitation input, > 99% of the H+, 93% of the NH4+ and NO3-, and 77% of the SO42- were retained. Sources within the watershed yielded base cations, Cl-, and HCO3- and accounted for 84, 47, and 100% of the net transport, respectively. Although streamwater SO42- and NO3- concentrations increased during stormflow, peak concentrations of these anions were much less than average concentrations in the precipitation. This suggests retention of these solutes occurs even when water residence time is short.The quantity and quality of precipitation and streamwater were measured from August 1985 through September 1986 in the Brier Creek watershed, a 440-ha drainage in the Southern Blue Ridge Province of northeastern Georgia, to determine stream sensitivity to acidic deposition. Precipitation samples collected at 2 sites had a volume-weighted average pH of 4.40 whereas stream samples collected near the mouth of Brier Creek had a discharge-weighted average pYH of 6.70. Computed solute fluxes through the watershed and observed changes in streamwater chemistry drying stormflow suggest that cation exchange, mineral weathering, SO42- adsorption by the soil, and

Protoporphyrin hepatopathy. Effects of cholic acid ingestion in murine griseofulvin-induced protoporphyria.

PubMed Central

Poh-Fitzpatrick, M B; Sklar, J A; Goldsman, C; Lefkowitch, J H

1983-01-01

Short-term effects of cholic acid ingestion on hepatic accumulation, fecal excretion, and blood levels of protoporphyrin were studied in vivo in griseofulvin-induced protoporphyric mice. Experimental mice that received feed with 2% griseofulvin and 0.5% cholic acid were compared with control mice that received feed with 2% griseofulvin for 4 wk. Five mice from each group were assessed each week for liver and blood porphyrin levels. Fecal protoporphyrin was compared weekly in the total pooled output of each population. Mean protoporphyrin levels were significantly lower for liver (P less than 0.0001), erythrocytes (P less than 0.05), and plasma (P less than 0.05), and higher for feces (P less than 0.001) for the mice that were fed cholic acid. Microscopic protoporphyrin deposits, inflammation, necrosis, and dysplasia were more severe in livers of control mice. A second experimental design compared four regimens in the feed given to all mice after 1-wk induction with 2% griseofulvin: (a) 0.5% cholic acid, (b) no adulterant, (c) 2% griseofulvin and 0.5% cholic acid, and (d) 2% griseofulvin. No difference in protoporphyrin removal from livers of mice in groups 1 and 2 was observed after 1 and 2 wk of these regimens. The apparent reduction in hepatic protoporphyrin content in mice of group 3 as compared with group 4 at weeks 2 and 3 was not significant at P less than 0.05. These data suggest that in selected circumstances, hepatic protoporphyrin secretion may be enhanced in protoporphyric disease states by bile salt supplementation. Images PMID:6630515

Health risks from acid rain: a Canadian perspective.

PubMed

Franklin, C A; Burnett, R T; Paolini, R J; Raizenne, M E

1985-11-01

Acidic deposition, commonly referred to as acid rain, is causing serious environmental damage in eastern Canada. The revenues from forest products, tourism and sport fishing are estimated to account for about 8% of the gross national product. The impact on human health is not as clearcut and a multi-department program on the Long-Range Transport of Airborne Pollutants (LRTAP) was approved by the federal government in June 1980. The objectives of the LRTAP program are to reduce wet sulfate deposition to less than 20 kg/ha per year in order to protect moderately sensitive areas. This will require a 50% reduction in Canadian SO2 emissions east of the Saskatchewan/Manitoba border and concomitant reductions in the eastern U.S.A. The objectives of the health sector of the program are to assess the risk to health posed by airborne pollutants which are subjected to long-range transport and to monitor the influence of abatement programs. Two major epidemiology studies were undertaken in 1983, one in which the health effects related to acute exposure to transported air pollutants were studied in asthmatic and nonasthmatic children, and another in which the effects of chronic exposure to these pollutants were studied in school children living in towns with high and low levels of pollutants. Preliminary analysis of the data do not indicate major health effects, but definitive conclusions must await final analysis. Studies on the indirect effects of acid deposition on water quality have shown that acidified lake water left standing in the plumbing system can adversely affect water quality and that federally set guidelines for copper and lead are exceeded. Flushing of the system before using the water rectifies the situation. Additional studies are planned to further delineate the magnitude of the health effects of acidified lake water.

Health risks from acid rain: a Canadian perspective.

PubMed Central

Franklin, C A; Burnett, R T; Paolini, R J; Raizenne, M E

1985-01-01

Acidic deposition, commonly referred to as acid rain, is causing serious environmental damage in eastern Canada. The revenues from forest products, tourism and sport fishing are estimated to account for about 8% of the gross national product. The impact on human health is not as clearcut and a multi-department program on the Long-Range Transport of Airborne Pollutants (LRTAP) was approved by the federal government in June 1980. The objectives of the LRTAP program are to reduce wet sulfate deposition to less than 20 kg/ha per year in order to protect moderately sensitive areas. This will require a 50% reduction in Canadian SO2 emissions east of the Saskatchewan/Manitoba border and concomitant reductions in the eastern U.S.A. The objectives of the health sector of the program are to assess the risk to health posed by airborne pollutants which are subjected to long-range transport and to monitor the influence of abatement programs. Two major epidemiology studies were undertaken in 1983, one in which the health effects related to acute exposure to transported air pollutants were studied in asthmatic and nonasthmatic children, and another in which the effects of chronic exposure to these pollutants were studied in school children living in towns with high and low levels of pollutants. Preliminary analysis of the data do not indicate major health effects, but definitive conclusions must await final analysis. Studies on the indirect effects of acid deposition on water quality have shown that acidified lake water left standing in the plumbing system can adversely affect water quality and that federally set guidelines for copper and lead are exceeded. Flushing of the system before using the water rectifies the situation. Additional studies are planned to further delineate the magnitude of the health effects of acidified lake water. Images FIGURE 1. FIGURE 2. PMID:4076081

Chemical and biological characteristics of Emerald Lake and the streams in its watershed and the responses of the lake and streams to acidic deposition. Final report

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

Melack, J.M.; Cooper, S.D.; Jenkins, T.M.

1989-03-14

This report describes the results of field work conducted at Emerald Lake in Sequoia National Park during the period of 1983-88, with an emphasis on the effects of acid deposition on a high-elevation lake in the Sierra Nevada. Time-series data were collected for major ions, nutrients, trace metals, chlorophyll, zooplankton and zoobenthos. Mass balances were calculated for major solutes in the lake, including analysis of the inflows and major solutes in the lake, including analysis of the inflows and outflow from the lake. The ecology and population dynamics of the resident population of brook trout were studied in detail. Biologicalmore » surveys indicated the presence of the Pacific tree frog in small ponds in the vicinity of Emerald Lake. Experimental acidification of large bags in the lake was used to develop dose-response relationships for the major zooplankton species, especially Daphnia. The conclusion of the research to date is that Emerald Lake is not currently showing serious chemical or biological effects of acidification. Acid-sensitive animals are found in the lake and associated streams. The surface waters of the Emerald Basin are extremely dilute and ANC-generating processes in the lake are small compared to that of the watershed. Acidic episodes have been recorded. If these episodes were to increase, the surface waters and the biological populations could be readily affected.« less

[Effects of simulated nitrogen deposition on weeds growth and nitrogen uptake].

PubMed

Jiang, Qiqing; Tang, Jianjun; Chen, Xin; Chen, Jing; Yang, Ruyi; Hu, S

2005-05-01

In this paper, a greenhouse experiment was conducted to study the responses of different functional groups weeds to simulated nitrogen deposition (4.0 g N.m(-2).yr(-1)). Native weed species Poa annua, Lolium perenne, Avena fatua, Medicago lupulina, Trifolium repens, Plantago virginica, Veronica didyma, Echinochloa crusgalli var. mitis, Eleusine indica and Amaranthus spinosus in orchard ecosystem were used test materials, and their above-and underground biomass and nitrogen uptake were measured. The results showed that under simulated N deposition, the total biomass, shoot biomass and root biomass of all weed species tended increase, while the total biomass was differed for different functional groups of weeds. The biomass of C4 grass, legumes and C3 grass was significantly increased under N deposition, while that of C3 and C4 forbs was not significantly impacted. The root/shoot biomass ratio of Avena fatua and Plantago virginica was enhanced by N deposition, but that of Poa annu, Lolium perenne, Medicago lupulina, Trifolium repens and Amarathus spinosus was not impacted significantly. N deposition had no significant effect on plant N concentration, but significantly enhanced the N uptake of all test weed species except Amarathus spinosus, Poa annua and Veronica didyma. was suggested that the further increase of N deposition might speed up the changes of the community structure weed species due to their different responses to N deposition.

A Geochemical and Mineralogical Model for Formation of Layered Sulfate Deposits at Meridiani Planum by Hydrothermal Acid-sulfate Alteration of Pyroclastic Basalt

NASA Astrophysics Data System (ADS)

McCollom, T. M.; Hynek, B. M.

2012-12-01

The Mars Exploration Rover (MER) Opportunity has extensively characterized sulfate-rich, hematite-bearing bedrock exposed at Meridiani Planum, Mars. Based on various measurements, the mineral composition of the bedrocks has been interpreted to include: amorphous silica/glass/phyllosilicates, Mg-, Ca-, and Fe-bearing sulfates including jarosite, minor amounts of igneous phases including plagioclase, pyroxene, olivine, and magnetite, and hematite [1,2]. Chemically, the bedrocks closely resemble the composition of pristine martian basalt with addition of S and O, and minor variations of Mg and Cl with depth [3,4]. Based on these and other observations, the MER team has proposed that the bedrocks represent chemically altered siliciclastic sediments combined with sulfate salts formed by evaporation of sulfate-bearing fluids, modified by transport and multiple stages of infiltrating groundwater [3,5]. Several alternative scenarios have been proposed for the origin of the rocks including large impacts [6], evaporating glacial deposits [7], acid-fog alteration [8], and hydrothermal acid-sulfate alteration of basalt [4]. In order to further evaluate the potential contribution of hydrothermal proceeses to the deposits, we performed numerical geochemical models of acid-sulfate alteration of martian basalt based on constraints provided by recent laboratory experiments. Experimental studies of alteration of basalt conducted in our lab [9] indicate that the initial stages of acid-sulfate alteration of pyroclastic basalt are characterized by rapid decomposition of igneous crystalline phases including plagioclase, pyroxene, and olivine, while the glass (and igneous phases protected within the glass) remain unreactive. Elements released by dissolving minerals are precipitated primarily as amorphous silica and Ca-, Al-, Fe- and Mg-bearing sulfates, while precipitation of phyllosilicates and Fe-oxides/oxyhydroxides (FeOx) is kinetically inhibited. Based on these constraints, models

[Effect of Gram-negative bacteria on fatty acids].

PubMed

Vuillemin, N; Dupeyron, C; Leluan, G; Bory, J

1981-01-01

The gram-negative bacteria investigated exert various effects on fatty acids. P. aeruginosa and A. calcoaceticus catabolize any of the fatty acids tested. S. marcescens is effective upon all fatty acids excepting butyric acid. The long chain fatty acids only are degraded by E. coli, meanwhile the other fatty acids present a bacteriostatic or bactericidal activity on it. The authors propose a simple and original method for testing the capability of degradation of fatty acids by some bacterial species.

Acid Precipitation: A current awareness bulletin

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

Blackburn, P.S.

1988-01-01

Acid Precipition (APC) announces on a monthly basis the current worldwide information on acid precipation and closely related subjects, including wet and dry deposition, long-range transport, environmental effects, modeling, and socioeconomic factors. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Data Base (EDB) during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or goverment-to-government agreements.

Protective effects of ursodeoxycholic acid in experimental corrosive esophagitis injury in rats.

PubMed

Ku Çu K, Adem; Topaloglu, Naci; Yildirim, Sule; Tekin, Mustafa; Erbas, Mesut; Kiraz, Hasan Ali; Erdem, Havva; Özkan, Aybars

2017-01-01

Accidental caustic ingestions are serious medical problems especially in childhood. Various treatment modalities are being used for the complications of caustic injuries such as stricture formation. The aim of this study is to establish whether ursodeoxycholic acid (UDCA) has protective effects on experimental corrosive esophagitis in rats. Twenty four Wistar-albino rats, weighing 220-240 g, were used in the study. Experimental animals were divided in three groups randomly: UDCA treatment group (Group T, n:8), control group (Group K, n: 8) and sham group (Group S, n: 8). In group T and S corrosive esophagitis was induced. UDCA (5 mg/kg) was performed to the group T for 10 days orally. All animals were sacrificed at the end of procedures and histopathological changes in esophageal tissue were scored by a single investigator who was blind to the groups. In group T inflammation was present in two rats, muscularis mucosa injury in two rats, grade 1 collagen deposition in six rats and grade 2 in two rats. In comparison with group S these were statistically significant (p value was 0.003, 0.003 and 0.015, respectively). UDCA has protective effect in experimental corrosive esophagitis. Corrosive esophagitis, Rat, Stricture, Ursodeoxycholic acid.

Photodegradation of perfluorooctanoic acid by graphene oxide-deposited TiO2 nanotube arrays in aqueous phase.

PubMed

Park, Kyungmin; Ali, Imran; Kim, Jong-Oh

2018-07-15

Perfluorooctanoic acid (PFOA) is a persistent organic pollutant in the environment with serious health risks including endocrine-disrupting characteristics, immunotoxicity, and causing developmental defects. The photocatalytic deposition has proven to be an inexpensive, effective, and sustainable technology for the removal of PFOA in the aqueous phase. Most investigations are conducted in ultrapure water at concentrations higher than those detected in actual water systems. A few studies deal with the toxicity of treated water. In this research, the photocatalytic degradation of PFOA, including photo-oxidative and photo-reductive degradation, is reviewed comprehensively. Compared to photo-oxidation, photo-reduction is more suitable for PFOA removal since it favors defluorination of PFOA and complete mineralization. We used graphene oxide/TiO 2 nanotubes array for photocatalytic degradation of PFOA. The effects of key parameters on the photocatalytic degradation and defluorination processes of PFOA, such as initial PFOA concentration, initial pH of the solution, an initial temperature of the solution, and external bias constant potential, are addressed. We observed that at pH 3 the PFOA degradation was around 83% in 4 h, and at 75 °C almost complete PFOA degradation was observed in 2.5 h. In photoelectrocatalytic process at 2.0 V external bias 97% of PFOA was degraded in 4 h. The mechanisms of the PFOA photodegradation process are also discussed in detail. Copyright © 2018 Elsevier Ltd. All rights reserved.

Studying the loading effect of acidic type antioxidant on amorphous silica nanoparticle carriers

NASA Astrophysics Data System (ADS)

Ravinayagam, Vijaya; Rabindran Jermy, B.

2017-06-01

The study investigates the suitable nanosilica carriers to transport acidic type cargo molecules for potential targeted drug delivery application. Using phenolic acidic type antioxidant gallic acid (GA) as model compound, the present study investigates the loading effect of GA (0.3-15.9 mmol GA g-1 support) on textural characteristics of amorphous silica nanoparticles such as Q10 silica (1D), structured two-dimensional Si-MCM-41 (2D), and three-dimensional Si-SBA-16 (3D). The variation in the nature of textures after GA loading was analyzed using X-ray diffraction, N2 adsorption, FT-IR, scanning electron microscopy with energy dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. Among the nanocarriers, high adsorption of GA was found in the following order: Si-SBA-16 (3D)˜Si-KIT-6 (3D) > Si-MCM-41 (2D) > ultralarge pore FDU-12 (ULPFDU-12; 3D) > Q10 (1D)˜mesostructured cellular silica foam (MSU-F). 3D-type silicas Si-SBA-16 and KIT-6 were shown to maintain structural integrity at acidic condition (pH ˜3) and accommodate GA in non-crystalline form. In the case of ULPFDU-12 and MSU-F cellular foam, only crystalline deposition of GA occurs with a significant variation in the surface area and pore volume. [Figure not available: see fulltext.

National Acid Precipitation Assessment Program Report to Congress: An integrated assessment

USGS Publications Warehouse

Burns, Douglas A.; Fenn, Mark E.; Baron, Jill S.; Lynch, Jason A.; Cosby, Bernard J.

2011-01-01

Acid deposition, more commonly known as acid rain, occurs when emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) react in the atmosphere with water, oxygen, and oxidants to form various acidic compounds. Prevailing winds transport the acidic compounds hundreds of miles, often across state and national borders. These acidic compounds then fall to earth in either a wet form (rain, snow, and fog) or a dry form (gases, aerosols, and particles). At certain levels, the acidic compounds, including small particles such as sulfates and nitrates, can cause many negative human health and environmental effects.

Differential effects of eicosapentaenoic acid and docosahexaenoic acid on human skin fibroblasts.

PubMed

Brown, E R; Subbaiah, P V

1994-12-01

To better understand the mode of action of omega 3 fatty acids in cell membranes, human foreskin fibroblasts were grown in serum-free medium supplemented with 50 microM oleic acid linoleic acid, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), and the effects on membrane composition, fluorescence polarization and enzyme activities were followed. The cells were enriched with EPA and DHA up to 7 and 13% of total lipids, respectively, of which > 95% was associated with phospholipids. In addition, the concentration of 22:5n-3 increased with both EPA and DHA to 7.5, and 2.1% of the total fatty acids, respectively. When compared to controls (oleic acid), cells treated with DHA showed a decrease in cholesterol, phospholipids, arachidonic acid (AA) and free cholesterol/phospholipid ratio (P < 0.05). In the presence of EPA, only decreases in AA and cholesterol were significant (P < 0.05). Membrane fluidity, assessed by fluorescence anisotropy, was increased 16% in cells enriched with DHA (P < 0.05), but showed no change with EPA or linoleic acid. There was an increase in membrane-associated 5'-nucleotidase (+27%) and adenylate cyclase (+19%) activities (P < 0.05), in DHA-enriched, but not in EPA-enriched cells, when compared with oleate controls. The studies show that incorporation of DHA, but not EPA, into cell membranes of fibroblasts alters membrane biophysical characteristics and function. We suggest that these two major n-3 fatty acids of fish oils have differential effects on cell membranes, and this may be related to the known differences in their physiological effects.

Combining Long-Term Watershed Monitoring at Buck Creek with Spatially Extensive Ecosystem Data to Understand the Processes of Acid Rain Effects and Recovery

NASA Astrophysics Data System (ADS)

Lawrence, G. B.; Ross, D. S.; Sullivan, T. J.; McDonnell, T. C.; Bailey, S. W.; Dukett, J. E.

2014-12-01

The Buck Creek Monitoring Watershed, in the western Adirondack Region of New York, has provided long-term data back to 1982 for tracking acid rain effects and recovery, and for supporting fundamental research on environmental change. At Buck Creek, monitoring acidic deposition effects as they worsened, then diminished, has advanced our understanding of key biogeochemical processes such as Al mobilization. Although Al mobilization has been one of the primary adverse effects of acidic deposition, in the recovery phase it is now affecting terrestrial and aquatic ecosystems in new ways that could be both positive and negative, as soils and surface waters respond to further declines in acidic deposition. Using stream Al measurements from Buck Creek over varying seasons and flows, a new index, the base cation surplus (BCS), was developed to account for dissolved organic carbon (DOC) effects on the relationship between ANC and inorganic Al. Mobilization of inorganic Al, the form toxic to biota, occurs below a BCS of zero, regardless of DOC concentrations. Soil and stream data from Adirondack surveys showed that a BCS value of zero corresponds to a soil base saturation value in the B horizon of approximately 12%. Additional Adirondack survey work indicated that, where sugar maple stands grew in soils with base saturation values below 12%, seedling regeneration was nearly zero, suggesting a link between Al mobilization and impairment of tree regeneration. In recovering Adirondack lakes, the BCS was also used to show that increasing trends in DOC were accelerating decreases of inorganic Al beyond what would be expected from the increasing trends of ANC. Similar decreases of inorganic Al in Buck Creek, were coupled with increases in organic Al concentrations, which resulted in no trend in total Al concentrations despite a strong increase in pH. Sampling of Buck Creek soils in 1997, and again in 2009-2010, indicated a substantial decrease in forest floor exchangeable Al, of

A robust upscaling of the effective particle deposition rate in porous media

NASA Astrophysics Data System (ADS)

Boccardo, Gianluca; Crevacore, Eleonora; Sethi, Rajandrea; Icardi, Matteo

2018-05-01

In the upscaling from pore to continuum (Darcy) scale, reaction and deposition phenomena at the solid-liquid interface of a porous medium have to be represented by macroscopic reaction source terms. The effective rates can be computed, in the case of periodic media, from three-dimensional microscopic simulations of the periodic cell. Several computational and semi-analytical models have been studied in the field of colloid filtration to describe this problem. They typically rely on effective deposition rates defined by complex fitting procedures, neglecting the advection-diffusion interplay, the pore-scale flow complexity, and assuming slow reactions (or large Péclet numbers). Therefore, when these rates are inserted into general macroscopic transport equations, they can lead to several conceptual inconsistencies and significant errors. To study more accurately the dependence of deposition on the flow parameters, in this work we advocate a clear distinction between the surface processes (that altogether defines the so-called attachment efficiency), and the pore-scale processes. With this approach, valid when colloidal particles are small enough, we study Brownian and gravity-driven deposition on a face-centred cubic (FCC) arrangement of spherical grains, and define a robust upscaling based on a linear effective reaction rate. The case of partial deposition, defined by an attachment probability, is studied and the limit of perfect sink is retrieved as a particular case. We introduce a novel upscaling approach and a particularly convenient computational setup that allows the direct computation of the asymptotic stationary value of effective rates. This allows to drastically reduce the computational domain down to the scale of the single repeating periodic unit. The savings are ever more noticeable in the case of higher Péclet numbers, when larger physical times are needed to reach the asymptotic regime and thus, equivalently, much larger computational domain and

Precipitation-mediated responses of soil acid buffering capacity to long-term nitrogen addition in a semi-arid grassland

NASA Astrophysics Data System (ADS)

Cai, Jiangping; Luo, Wentao; Liu, Heyong; Feng, Xue; Zhang, Yongyong; Wang, Ruzhen; Xu, Zhuwen; Zhang, Yuge; Jiang, Yong

2017-12-01

Atmospheric nitrogen (N) deposition can result in soil acidification and reduce soil acid buffering capacity. However, it remains poorly understood how changes in precipitation regimes with elevated atmospheric N deposition affect soil acidification processes in a water-limited grassland. Here, we conducted a 9-year split-plot experiment with water addition as the main factor and N addition as the second factor. Results showed that soil acid buffering capacity significantly decreased with increased N inputs, mainly due to the decline of soil effective cation exchange capacity (ECEC) and exchangeable basic cations (especially Ca2+), indicating an acceleration of soil acidification status in this steppes. Significant interactive N and water effects were detected on the soil acid buffering capacity. Water addition enhanced the soil ECEC and exchangeable base cations and thus alleviated the decrease of soil acid buffering capacity under N addition. Our findings suggested that precipitation can mitigate the impact of increased N deposition on soil acidification in semi-arid grasslands. This knowledge should be used to improve models predicting soil acidification processes in terrestrial ecosystems under changing environmental conditions.

42 CFR 35.48 - Deposit of unclaimed money; sale of unclaimed effects and deposit of proceeds.

Code of Federal Regulations, 2011 CFR

2011-10-01

... effects and deposit of proceeds. 35.48 Section 35.48 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Disposal of Money... Deceased Patients, Public Health Service.” If, within six months after the death of a patient, no claim has...

42 CFR 35.48 - Deposit of unclaimed money; sale of unclaimed effects and deposit of proceeds.

Code of Federal Regulations, 2010 CFR

2010-10-01

... effects and deposit of proceeds. 35.48 Section 35.48 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Disposal of Money... Deceased Patients, Public Health Service.” If, within six months after the death of a patient, no claim has...

42 CFR 35.48 - Deposit of unclaimed money; sale of unclaimed effects and deposit of proceeds.

Code of Federal Regulations, 2012 CFR

2012-10-01

... effects and deposit of proceeds. 35.48 Section 35.48 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Disposal of Money... Deceased Patients, Public Health Service.” If, within six months after the death of a patient, no claim has...

Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis

Treesearch

R. Bobbink; K. Hicks; J. Galloway; T. Spranger; R. Alkemade; M. Ashmore; M. Bustamante; S. Cinderby; E. Davidson; F. Dentener; B. Emmett; J.-W. Erisman; M. Fenn; F. Gilliam; A. Nordin; L. Pardo; W. De Vries

2010-01-01

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to...

Effect of Energy Input on the Characteristic of AISI H13 and D2 Tool Steels Deposited by a Directed Energy Deposition Process

NASA Astrophysics Data System (ADS)

Park, Jun Seok; Park, Joo Hyun; Lee, Min-Gyu; Sung, Ji Hyun; Cha, Kyoung Je; Kim, Da Hye

2016-05-01

Among the many additive manufacturing technologies, the directed energy deposition (DED) process has attracted significant attention because of the application of metal products. Metal deposited by the DED process has different properties than wrought metal because of the rapid solidification rate, the high thermal gradient between the deposited metal and substrate, etc. Additionally, many operating parameters, such as laser power, beam diameter, traverse speed, and powder mass flow rate, must be considered since the characteristics of the deposited metal are affected by the operating parameters. In the present study, the effect of energy input on the characteristics of H13 and D2 steels deposited by a direct metal tooling process based on the DED process was investigated. In particular, we report that the hardness of the deposited H13 and D2 steels decreased with increasing energy input, which we discuss by considering microstructural observations and thermodynamics.

Replacing dietary nonessential amino acids with ammonia nitrogen does not alter amino acid profile of deposited protein in the carcass of growing pigs fed a diet deficient in nonessential amino acid nitrogen.

PubMed

Mansilla, W D; Htoo, J K; de Lange, C F M

2017-10-01

Amino acid usage for protein retention, and, consequently, the AA profile of retained protein, is the main factor for determining AA requirements in growing animals. The objective of the present study was to determine the effect of supplementing ammonia N on whole-body N retention and the AA profile of retained protein in growing pigs fed a diet deficient in nonessential AA (NEAA) N. In total, 48 barrows with a mean initial BW of 13.6 kg (SD 0.7) were used. At the beginning of the study, 8 pigs were euthanized for determination of initial protein mass. The remaining animals were individually housed and fed 1 of 5 dietary treatments. A common basal diet (95% of experimental diets) was formulated to meet the requirements for all essential AA (EAA) but to be deficient in NEAA N (CP = 8.01%). The basal diet was supplemented (5%) with cornstarch (negative control) or 2 N sources (ammonia or NEAA) at 2 levels each to supply 1.35 or 2.70% extra CP. The final standardized ileal digestible (SID) NEAA content in the high-NEAA-supplemented diet (positive control) was based on the NEAA profile of whole-body protein of 20-kg pigs, and it was expected to reduce the endogenous synthesis of NEAA. Pigs were fed at 3.0 times maintenance energy requirements for ME in 3 equal meals daily. At the end of a 3-wk period, pigs were euthanized and the carcass and visceral organs were weighed, frozen, and ground for determination of protein mass. From pigs in the initial, negative control, high-ammonia, and high-NEAA groups, AA contents in the carcass and pooled visceral organs were analyzed to determine the total and deposited protein AA profile, dietary EAA efficiencies, and minimal de novo synthesis of NEAA. Carcass weight and whole-body N retention linearly increased ( < 0.05) with N supplementation. The AA profile of protein and deposited protein in the carcass was not different ( > 0.10) between N sources, but Cys content increased ( < 0.05) with NEAA compared with ammonia in visceral

Kinetics and toxic effects of repeated intravenous dosage of formic acid in rabbits.

PubMed Central

Liesivuori, J.; Kosma, V. M.; Naukkarinen, A.; Savolainen, H.

1987-01-01

Adult male rabbits were injected i.v. with 100 mg buffered formic acid per kg body weight daily for 5 days with 24 h between the doses. The fifth dose was labelled with 14C-formic acid. Rabbits were killed 1, 2 and 20 h after the last injection. The highest formic acid concentrations were found one hour after the fifth dose. Total formic acid concentrations were always higher than radiometrically measured. The maximum concentrations of formic acid in brain, heart, kidney and liver were roughly similar to the concentration which inhibits half of the cytochrome oxidase activity in vitro. Histological studies clearly demonstrated the histotoxic changes at cellular level. Calcium deposits were detected in all organs of the injected rabbits. They were absent in control animals. It seems that the formic acid metabolism is slow and that it may cause sufficient hypoxic acidosis to allow the calcium influx and cellular damage. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:3426949

The Cardioprotective Effects of Citric Acid and L-Malic Acid on Myocardial Ischemia/Reperfusion Injury

PubMed Central

Tang, Xilan; Liu, Jianxun; Dong, Wei; Li, Peng; Li, Lei; Lin, Chengren; Zheng, Yongqiu; Hou, Jincai; Li, Dan

2013-01-01

Organic acids in Chinese herbs, the long-neglected components, have been reported to possess antioxidant, anti-inflammatory, and antiplatelet aggregation activities; thus they may have potentially protective effect on ischemic heart disease. Therefore, this study aims to investigate the protective effects of two organic acids, that is, citric acid and L-malic acid, which are the main components of Fructus Choerospondiatis, on myocardial ischemia/reperfusion injury and the underlying mechanisms. In in vivo rat model of myocardial ischemia/reperfusion injury, we found that treatments with citric acid and L-malic acid significantly reduced myocardial infarct size, serum levels of TNF-α, and platelet aggregation. In vitro experiments revealed that both citric acid and L-malic acid significantly reduced LDH release, decreased apoptotic rate, downregulated the expression of cleaved caspase-3, and upregulated the expression of phosphorylated Akt in primary neonatal rat cardiomyocytes subjected to hypoxia/reoxygenation injury. These results suggest that both citric acid and L-malic acid have protective effects on myocardial ischemia/reperfusion injury; the underlying mechanism may be related to their anti-inflammatory, antiplatelet aggregation and direct cardiomyocyte protective effects. These results also demonstrate that organic acids, besides flavonoids, may also be the major active ingredient of Fructus Choerospondiatis responsible for its cardioprotective effects and should be attached great importance in the therapy of ischemic heart disease. PMID:23737849

Comparative effects of simulated acid rain of different ratios of SO42- to NO3- on fine root in subtropical plantation of China.

PubMed

Liu, Xin; Zhao, Wenrui; Meng, Miaojing; Fu, Zhiyuan; Xu, Linhao; Zha, Yan; Yue, Jianmin; Zhang, Shuifeng; Zhang, Jinchi

2018-03-15

The influence of acid rain on forest trees includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in fine-root growth. In addition, the concentration of NO 3 - in acid rain increases with the rapidly growing of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 5:1 (S), 1:1 (SN) and 1:5 (N), on fine-root growth from March 2015 to February 2016. Results showed that fine roots were more sensitive to the effects of acid rain than soils in the short-term. Both soil pH and fine root biomass (FRB) significantly decreased as acid rain pH decreased, and also decreased with the percentage of NO 3 - increased in acid rain. Acid rain pH significantly influenced soil total carbon and available potassium in summer. Higher acidity level (pH=2.5), especially of the N treatments, had the strongest inhibitory impact on soil microbial activity after summer. The structural equation modelling results showed that acid rain S/N ratio and pH had stronger direct effects on FRB than indirect effects via changed soil and fine root properties. Fine-root element contents and antioxidant enzymes activities were significantly affected by acid rain S/N ratio and pH during most seasons. Fine-root Al ion content, Ca/Al, Mg/Al ratios and catalase activity were used as better indicators than soil parameters for evaluating the effects of different acid rain S/N ratios and pH on forests. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect fine-root growth in subtropical forests of China. Copyright © 2017. Published by Elsevier B.V.

Effect of baseline plasma fatty acids on eicosapentaenoic acid levels in individuals supplemented with alpha-linolenic acid.

PubMed

DeFilippis, Andrew P; Harper, Charles R; Cotsonis, George A; Jacobson, Terry A

2009-01-01

We previously reported a >50% increase in mean plasma eicosapentaenoic acid levels in a general medicine clinic population after supplementation with alpha-linolenic acid. In the current analysis, we evaluate the variability of changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid and evaluated the impact of baseline plasma fatty acids levels on changes in eicosapentaenoic acid levels in these individuals. Changes in eicosapentaenoic acid levels among individuals supplemented with alpha-linolenic acid ranged from a 55% decrease to a 967% increase. Baseline plasma fatty acids had no statistically significant effect on changes in eicosapentaenoic levels acid after alpha-linolenic acid supplementation. Changes in eicosapentaenoic acid levels varied considerably in a general internal medicine clinic population supplemented with alpha-linolenic acid. Factors that may impact changes in plasma eicosapentaenoic acid levels after alpha-linolenic acid supplementation warrant further study.

Effect of the ratio of dietary n-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid on broiler breeder performance, egg quality, and yolk fatty acid composition at different breeder ages.

PubMed

Koppenol, A; Delezie, E; Aerts, J; Willems, E; Wang, Y; Franssens, L; Everaert, N; Buyse, J

2014-03-01

When added to the feed of broiler breeder hens, dietary polyunsaturated fatty acids (FA) can be incorporated into the yolk and therefore become available to the progeny during their early development. The mechanism involved in lipid metabolism and deposition in the egg may be influenced by breeder age. Before the effect of an elevated concentration of certain polyunsaturated FA on the embryo can be investigated, the effect at breeder level and egg quality must be further assessed. The aim of the present experiment was to evaluate the effects of dietary n-6/n-3 ratios and dietary eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) ratios, provided to broiler breeder hens, in terms of their zoo technical performance, egg quality, and yolk FA composition. Starting at 6 wk of age, 640 Ross-308 broiler breeder hens were fed 1 of 4 different diets. The control diet was a basal diet, rich in n-6 FA. The 3 other diets were enriched in n-3 FA, formulated to obtain a different EPA/DHA ratio of 1/1 (EPA = DHA), 1/2 (DHA), or 2/1 (EPA). In fact, after analysis the EPA/DHA ratio was 0.8, 0.4, or 2.1, respectively. Dietary EPA and DHA addition did not affect the performance of the breeder hens, except for egg weight. Egg weight was lower (P < 0.001) for all n-3 treatments. Dietary EPA improved number of eggs laid in the first 2 wk of the production cycle (P = 0.029). The absolute and relative yolk weight of eggs laid by EPA = DHA fed hens was lowest (P = 0.004 and P = 0.025, respectively). The EPA and DHA concentrations in the yolk were highly dependent on dietary EPA and DHA concentrations with a regression coefficient equal to 0.89. It can be concluded that dietary EPA and DHA can be incorporated in the breeder egg yolk to become available for the developing embryo, without compromising the performance and egg quality of the flock.

Early diagenesis of recently deposited organic matter: A 9-yr time-series study of a flood deposit

NASA Astrophysics Data System (ADS)

Tesi, T.; Langone, L.; Goñi, M. A.; Wheatcroft, R. A.; Miserocchi, S.; Bertotti, L.

2012-04-01

In Fall 2000, the Po River (Italy) experienced a 100-yr return period flood that resulted in a 1-25 cm-thick deposit in the adjacent prodelta (10-25 m water depth). In the following years, numerous post-depositional perturbations occurred including bioturbation, reworking by waves with heights exceeding 5 m, as well as periods of extremely high and low sediment supply. Cores collected in the central prodelta after the Fall 2000 flood and over the following 9 yr, allowed characterization of the event-strata in their initial state and documentation of their subsequent evolution. Sedimentological characteristics were investigated using X-radiographs and sediment texture analyses, whereas the composition of sedimentary organic matter (OM) was studied via bulk and biomarker analyses, including organic carbon (OC), total nitrogen (TN), carbon stable isotope composition (δ13C), lignin phenols, cutin-products, p-hydroxy benzenes, benzoic acids, dicarboxylic acids, and fatty acids. The 9-yr time-series analysis indicated that roughly the lower half of the original event bed was preserved in the sediment record. Conversely, the upper half of the deposit experienced significant alterations including bioturbation, addition of new material, as well as coarsening. Comparison of the recently deposited material with 9-yr old preserved strata represented a unique natural laboratory to investigate the diagenesis of sedimentary OM in a non-steady system. Bulk data indicated that OC and TN were degraded at similar rates (loss ∼17%) whereas biomarkers exhibited a broad spectrum of reactivities (loss from ∼6% to ∼60%) indicating selective preservation during early diagenesis. Given the relevance of episodic sedimentation in several margins, this study has demonstrated the utility of event-response and time-series sampling of the seabed for understanding the early diagenesis in non-steady conditions.

Effects of argon addition on a-CNx film deposition by hot carbon filament chemical vapor deposition

NASA Astrophysics Data System (ADS)

Watanabe, Yoshihisa; Aono, Masami; Yamazaki, Ayumi; Kitazawa, Nobuaki; Nakamura, Yoshikazu

2002-07-01

Using a carbon filament which supplies carbon and heat, amorphous carbon nitride (a-CNx) films were prepared on Si (100) substrates by hot filament chemical vapor deposition. Deposition was performed in a low-pressure atmosphere of pure nitrogen and a gas mixture of nitrogen and argon. Effects of argon additions to the nitrogen atmosphere on the film microstructure and interface composition between the film and substrate were studied by field-emission scanning electron microscopy (FESEM) and x-ray photoelectron spectroscopy (XPS). FESEM observations reveal that the film prepared in a pure nitrogen atmosphere has uniform nucleation and a densely packed columnar pieces structure. The film prepared in the nitrogen and argon gas mixture exhibits preferential nucleation and a tapered structure with macroscopic voids. Depth analyses using XPS reveal that the film prepared in pure nitrogen possesses a broad interface, which includes silicon carbide as well as a-CNx, whereas a sharp interface is discerned in the film prepared in the mixed nitrogen and argon gas. We observed that silicon carbide formation is suppressed by an argon addition to the nitrogen atmosphere during deposition. copyright 2002 American Vacuum Society.

Interactive Effects of Jasmonic Acid, Salicylic Acid, and Gibberellin on Induction of Trichomes in Arabidopsis1

PubMed Central

Traw, M. Brian; Bergelson, Joy

2003-01-01

Leaf trichomes protect plants from attack by insect herbivores and are often induced following damage. Hormonal regulation of this plant induction response has not been previously studied. In a series of experiments, we addressed the effects of artificial damage, jasmonic acid, salicylic acid, and gibberellin on induction of trichomes in Arabidopsis. Artificial damage and jasmonic acid caused significant increases in trichome production of leaves. The jar1-1 mutant exhibited normal trichome induction following treatment with jasmonic acid, suggesting that adenylation of jasmonic acid is not necessary. Salicylic acid had a negative effect on trichome production and consistently reduced the effect of jasmonic acid, suggesting negative cross-talk between the jasmonate and salicylate-dependent defense pathways. Interestingly, the effect of salicylic acid persisted in the nim1-1 mutant, suggesting that the Npr1/Nim1 gene is not downstream of salicylic acid in the negative regulation of trichome production. Last, we found that gibberellin and jasmonic acid had a synergistic effect on the induction of trichomes, suggesting important interactions between these two compounds. PMID:14551332

Amino acid analysis

NASA Technical Reports Server (NTRS)

Winitz, M.; Graff, J. (Inventor)

1974-01-01

The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: Implications for winter dry deposition

USGS Publications Warehouse

Clow, David W.; Ingersoll, George P.; Mast, M. Alisa; Turk, John T.; Campbell, Donald H.

2002-01-01

Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data were compared to snowpack concentrations using the paired t-test and the Wilcoxon signed-rank test. No statistically significant differences were indicated in concentrations of SO42- or NO3- (p>0.1). Small, but statistically significant differences (p???0.03) were indicated for all other solutes analyzed. Differences were largest for Ca2+ concentrations, which on average were 2.3??eql-1 (43%) higher in the snowpack than in winter NADP/NTN samples. Eolian carbonate dust appeared to influence snowpack chemistry through both wet and dry deposition, and the effect increased from north to south. Dry deposition of eolian carbonates was estimated to have neutralized an average of 6.9??eql-1 and a maximum of 12??eql-1 of snowpack acidity at the southernmost sites. The good agreement between snowpack and winter NADP/NTN SO42- and NO3- concentrations indicates that for those solutes the two data sets can be combined to increase data density in high-elevation areas, where few NADP/NTN sites exist. This combination of data sets will allow for better estimates of atmospheric deposition of SO42- and NO3- across the Rocky Mountain region.

Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: implications for winter dry deposition

NASA Astrophysics Data System (ADS)

Clow, David W.; Ingersoll, George P.; Mast, M. Alisa; Turk, John T.; Campbell, Donald H.

Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data were compared to snowpack concentrations using the paired t-test and the Wilcoxon signed-rank test. No statistically significant differences were indicated in concentrations of SO 42- or NO 3- ( p>0.1). Small, but statistically significant differences ( p⩽0.03) were indicated for all other solutes analyzed. Differences were largest for Ca 2+ concentrations, which on average were 2.3 μeq l -1 (43%) higher in the snowpack than in winter NADP/NTN samples. Eolian carbonate dust appeared to influence snowpack chemistry through both wet and dry deposition, and the effect increased from north to south. Dry deposition of eolian carbonates was estimated to have neutralized an average of 6.9 μeq l -1 and a maximum of 12 μeq l -1 of snowpack acidity at the southernmost sites. The good agreement between snowpack and winter NADP/NTN SO 42- and NO 3- concentrations indicates that for those solutes the two data sets can be combined to increase data density in high-elevation areas, where few NADP/NTN sites exist. This combination of data sets will allow for better estimates of atmospheric deposition of SO 42- and NO 3- across the Rocky Mountain region.

The Consistency of Isotopologues of Ambient Atmospheric Nitric Acid in Passively Collected Samples

NASA Astrophysics Data System (ADS)

Bell, M. D.; Sickman, J. O.; Bytnerowicz, A.; Padgett, P.; Allen, E. B.

2012-12-01

sources of atmospheric nitric acid accounted for 58% of the atmospheric nitric acid at the high deposition sites and 36.5% of the atmospheric nitric acid at the low deposition sites. The nylon filters proved to be an effective means of collecting isotopologues of HNO3 consistent with atmospheric concentrations. A length of the exposure of two weeks stabilizes isotopologue composition and minimizes the chance of variable weather events altering atmospheric values.

Effect of deposition rate and NNN interactions on adatoms mobility in epitaxial growth

NASA Astrophysics Data System (ADS)

Hamouda, Ajmi B. H.; Mahjoub, B.; Blel, S.

2017-07-01

This paper provides a detailed analysis of the surface diffusion problem during epitaxial step-flow growth using a simple theoretical model for the diffusion equation of adatoms concentration. Within this framework, an analytical expression for the adatom mobility as a function of the deposition rate and the Next-Nearest-Neighbor (NNN) interactions is derived and compared with the effective mobility computed from kinetic Monte Carlo (kMC) simulations. As far as the 'small' step velocity or relatively weak deposition rate commonly used for copper growth is concerned, an excellent quantitative agreement with the theoretical prediction is found. The effective adatoms mobility is shown to exhibit an exponential decrease with NNN interactions strength and increases in roughly linear behavior versus deposition rate F. The effective step stiffness and the adatoms mobility are also shown to be closely related to the concentration of kinks.

Effects of five years of frequent N additions, with or without acidity, on the growth and below-ground dynamics of a young Sitka spruce stand growing on an acid peat: implications for sustainability

NASA Astrophysics Data System (ADS)

Stutter, M. I.; Alam, M. S.; Langan, S. J.; Woodin, S. J.; Smart, R. P.; Cresser, M. S.

2004-06-01

An experiment comparing effects of sulphuric acid and reduced N deposition on soil water quality and on chemical and physical growth indicators for forest ecosystems is described. Six H2SO4 and (NH4)2SO4 treatment loads, from 0 - 44 and 0 - 25 kmolc ha-1 yr-1, respectively, were applied to outdoor microcosms of Pinus sylvestris seedlings in 3 acid to intermediate upland soils (calc-silicate, quartzite and granite) for 2 years. Different soil types responded similarly to H2SO4 loads, resulting in decreased leachate pH, but differently to reduced N inputs. In microcosms of calc-silicate soil, nitrification of NH4 resulted in lower pH and higher cation leaching than in acid treatments. By contrast, in quartzite and granite soils, (NH4)2SO4 promoted direct cation leaching, although leachate pH increased. The results highlighted the importance of soil composition on the nature of the cations leached, the SO4 adsorption capacities and microbial N transformations. Greater seedling growth on calc-silicate soils under both treatment types was related to sustained nutrient availability. Reductions in foliar P and Mg with higher N treatments were observed for seedlings in the calc-silicate soil. There were few treatment effects on quartzite and granite microcosm tree seedlings since P limitation precluded seedling growth responses to treatments. Hence, any benefits of N deposition to seedlings on quartzite and granite soils appeared limited by availability of co-nutrients, exacerbated by rapid depletion of soil exchangeable base cations.

Correlation of film density and wet etch rate in hydrofluoric acid of plasma enhanced atomic layer deposited silicon nitride

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

Provine, J., E-mail: jprovine@stanford.edu; Schindler, Peter; Kim, Yongmin

2016-06-15

The continued scaling in transistors and memory elements has necessitated the development of atomic layer deposition (ALD) of silicon nitride (SiN{sub x}), particularly for use a low k dielectric spacer. One of the key material properties needed for SiN{sub x} films is a low wet etch rate (WER) in hydrofluoric (HF) acid. In this work, we report on the evaluation of multiple precursors for plasma enhanced atomic layer deposition (PEALD) of SiN{sub x} and evaluate the film’s WER in 100:1 dilutions of HF in H{sub 2}O. The remote plasma capability available in PEALD, enabled controlling the density of the SiN{submore » x} film. Namely, prolonged plasma exposure made films denser which corresponded to lower WER in a systematic fashion. We determined that there is a strong correlation between WER and the density of the film that extends across multiple precursors, PEALD reactors, and a variety of process conditions. Limiting all steps in the deposition to a maximum temperature of 350 °C, it was shown to be possible to achieve a WER in PEALD SiN{sub x} of 6.1 Å/min, which is similar to WER of SiN{sub x} from LPCVD reactions at 850 °C.« less

Sulfur accumulation and atmospherically deposited sulfate in the Lake States.

Treesearch

Mark B. David; George Z. Gernter; David F. Grigal; Lewis F. Ohmann

1989-01-01

Characterizes the mass of soil sulfur (adjusted for nitrogen), and atmospherically deposited sulfate along an acid precipitation gradient from Minnesota to Michigan. The relationship of these variables, presented graphically through contour mapping, suggests that patterns of atmospheric wet sulfate deposition are reflected in soil sulfur pools.

Developing Critical Loads of acidity for streams in the Great Smoky Mountains National Park, using PnET-BGC model

NASA Astrophysics Data System (ADS)

Fakhraei, H.

2015-12-01

Acid deposition has impaired acid-sensitive streams and reduced aquatic biotic integrity in Great Smoky Mountains National Park (GRSM) by decreasing pH and acid neutralizing capacity (ANC). Twelve streams in GRSM are listed by the state of Tennessee as impaired due to low stream pH (pH<6.0) under Section 303(d) of the Clean Water Act. A dynamic biogeochemical model, PnET-BGC, was used to evaluate past, current and potential future changes in soil and water chemistry of watersheds of GRSM in response to changes in acid deposition. Calibrating 30 stream-watersheds in GRSM (including 12 listed impaired streams) to the long-term stream chemistry observations, the model was parameterized for the Park. The calibrated model was used to evaluate the level of atmospheric deposition above which harmful effects occur, known as "critical loads", for individual study watersheds. Estimated critical loads and exceedances (levels of deposition above the critical load) of atmospheric sulfur and nitrogen deposition were depicted through geographic information system maps. Accuracy of model simulations in the presence of uncertainties in the estimated model parameters and inputs was assessed using three uncertainty and sensitivity techniques.

Effects of alkali or acid treatment on the isomerization of amino acids.

PubMed

Ohmori, Taketo; Mutaguchi, Yuta; Doi, Katsumi; Ohshima, Toshihisa

2012-10-01

The effect of alkali treatment on the isomerization of amino acids was investigated. The 100×D/(D+L) values of amino acids from peptide increased with increase in the number of constituent amino acid residues. Furthermore, the N-terminal amino acid of a dipeptide was isomerized to a greater extent than the C-terminal residue. Copyright © 2012. Published by Elsevier B.V.

The radiolysis and radioracemization of amino acids on silica surfaces

NASA Technical Reports Server (NTRS)

Bonner, W. A.; Lemmon, R. M.

1981-01-01

Results are presented of experiments on the radioracemization of amino acids in the presence of silica surfaces such as may have been found on the prebiotic earth. L-leucine and a DL-leucine mixture deposited on samples of 1-quartz and an amorphous silica preparation (Syloid 63) was subjected to Co-60 gamma-ray irradiation, then analyzed by gas chromatography to determine the radiolysis and racemization rates. The quartz surface is found to have a marginal efficacy in enhancing radiolysis when compared with a crystalline L-leucine control, although enhancing radioracemization symmetrically by a factor of two. Both the radiolysis and radioracemization of L-leucine and DL-leucine on a Syloid-63 silica surface are observed to increase with increasing radiation dose, and to be substantially greater than in the crystalline controls. Additional experiments with the nonprotein amino acid isovaline deposited on Syloid 63 confirm the greater radiolysis susceptibility of amino acids deposited on silica with respect to the crystalline state, although racemization is not observed. The observations suggest that the presence of a silica surface would have a deleterious effect on any mechanism for the origin of molecular chirality relying on stereoselective beta-radiolysis.

Forward osmosis filtration for removal of organic foulants: Effects of combined tannic and alginic acids.

PubMed

Wang, Lin; Zhang, Wanzhu; Chu, Huaqiang; Dong, Bingzhi

2016-03-15

The filtration performance of combined organic foulants by forward osmosis (FO) in active-layer-facing-the-draw-solution (AL-facing-DS) orientation was investigated systematically. Tannic acid and alginate were used as model organic foulants for polysaccharides and humic dissolved organic matters, respectively. The FO could reject combined and single tannic acid and alginate foulants effectively. The more severe fouling flux decline, accompanied with lower combined foulants' retention, was observed with increasing proportions of tannic acid in the combined foulants-containing feed, which was ascribed mainly to the more severe fouling resulting from tannic acid adsorption within the porous support layer of the FO membrane compared to minor alginate deposition on the membrane surface. It was found that the higher the initial flux level and cross flow velocity, the faster the flux decline with lower mixed foulants retention. It was also revealed that the calcium ions in a basic solution enhanced the combined fouling flux reduction and combined foulants retention. As the major constituent of the combined fouling layer, the adsorption of tannic acid might play a more significant role in the mixed fouling of the FO membrane, which was probably influenced by permeation drag caused by water flux and chemical interactions induced by feed solution pH and calcium ion concentration. Copyright © 2016 Elsevier Ltd. All rights reserved.