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Sample records for hybrid ash tree

  1. Emerald ash borer biocontrol in ash saplings: The potential for early stage recovery of North American ash trees

    Science.gov (United States)

    Jian J. Duan; Leah S. Bauer; Roy G. Van Driesche

    2017-01-01

    In many parts of North America, ash (Fraxinus) stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees, saplings, basal sprouts, and seedlings. Without a soil seed bank for Fraxinus spp., tree recovery will require survival and maturation of these...

  2. Genome sequence and genetic diversity of European ash trees

    DEFF Research Database (Denmark)

    Sollars, Elizabeth S A; Harper, Andrea L; Kelly, Laura J;

    2016-01-01

    Ash trees (genus Fraxinus, family Oleaceae) are widespread throughout the Northern Hemisphere, but are being devastated in Europe by the fungus Hymenoscyphus fraxineus, causing ash dieback, and in North America by the herbivorous beetle Agrilus planipennis. Here we sequence the genome of a low...... to an emerging health threat in a non-model organism opens the way for mitigation of the epidemic....

  3. Genome sequence and genetic diversity of European ash trees

    DEFF Research Database (Denmark)

    Sollars, Elizabeth S A; Harper, Andrea L; Kelly, Laura J;

    2016-01-01

    Ash trees (genus Fraxinus, family Oleaceae) are widespread throughout the Northern Hemisphere, but are being devastated in Europe by the fungus Hymenoscyphus fraxineus, causing ash dieback, and in North America by the herbivorous beetle Agrilus planipennis. Here we sequence the genome of a low......-heterozygosity Fraxinus excelsior tree from Gloucestershire, UK, annotating 38,852 protein-coding genes of which 25% appear ash specific when compared with the genomes of ten other plant species. Analyses of paralogous genes suggest a whole-genome duplication shared with olive (Olea europaea, Oleaceae). We also re......-sequence 37 F. excelsior trees from Europe, finding evidence for apparent long-term decline in effective population size. Using our reference sequence, we re-analyse association transcriptomic data, yielding improved markers for reduced susceptibility to ash dieback. Surveys of these markers in British...

  4. Optimizing Use of Girdled Ash Trees for Management of Low-Density Emerald Ash Borer (Coleoptera: Buprestidae) Populations.

    Science.gov (United States)

    Siegert, Nathan W; McCullough, Deborah G; Poland, Therese M; Heyd, Robert L

    2017-06-01

    Effective survey methods to detect and monitor recently established, low-density infestations of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), remain a high priority because they provide land managers and property owners with time to implement tactics to slow emerald ash borer population growth and the progression of ash mortality. We evaluated options for using girdled ash (Fraxinus spp.) trees for emerald ash borer detection and management in a low-density infestation in a forested area with abundant green ash (F. pennsylvanica). Across replicated 4-ha plots, we compared detection efficiency of 4 versus 16 evenly distributed girdled ash trees and between clusters of 3 versus 12 girdled trees. We also examined within-tree larval distribution in 208 girdled and nongirdled trees and assessed adult emerald ash borer emergence from detection trees felled 11 mo after girdling and left on site. Overall, current-year larvae were present in 85-97% of girdled trees and 57-72% of nongirdled trees, and larval density was 2-5 times greater on girdled than nongirdled trees. Low-density emerald ash borer infestations were readily detected with four girdled trees per 4-ha, and 3-tree clusters were as effective as 12-tree clusters. Larval densities were greatest 0.5 ± 0.4 m below the base of the canopy in girdled trees and 1.3 ± 0.7 m above the canopy base in nongirdled trees. Relatively few adult emerald ash borer emerged from trees felled 11 mo after girdling and left on site through the following summer, suggesting removal or destruction of girdled ash trees may be unnecessary. This could potentially reduce survey costs, particularly in forested areas with poor accessibility. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  5. Genome sequence and genetic diversity of European ash trees.

    Science.gov (United States)

    Sollars, Elizabeth S A; Harper, Andrea L; Kelly, Laura J; Sambles, Christine M; Ramirez-Gonzalez, Ricardo H; Swarbreck, David; Kaithakottil, Gemy; Cooper, Endymion D; Uauy, Cristobal; Havlickova, Lenka; Worswick, Gemma; Studholme, David J; Zohren, Jasmin; Salmon, Deborah L; Clavijo, Bernardo J; Li, Yi; He, Zhesi; Fellgett, Alison; McKinney, Lea Vig; Nielsen, Lene Rostgaard; Douglas, Gerry C; Kjær, Erik Dahl; Downie, J Allan; Boshier, David; Lee, Steve; Clark, Jo; Grant, Murray; Bancroft, Ian; Caccamo, Mario; Buggs, Richard J A

    2017-01-12

    Ash trees (genus Fraxinus, family Oleaceae) are widespread throughout the Northern Hemisphere, but are being devastated in Europe by the fungus Hymenoscyphus fraxineus, causing ash dieback, and in North America by the herbivorous beetle Agrilus planipennis. Here we sequence the genome of a low-heterozygosity Fraxinus excelsior tree from Gloucestershire, UK, annotating 38,852 protein-coding genes of which 25% appear ash specific when compared with the genomes of ten other plant species. Analyses of paralogous genes suggest a whole-genome duplication shared with olive (Olea europaea, Oleaceae). We also re-sequence 37 F. excelsior trees from Europe, finding evidence for apparent long-term decline in effective population size. Using our reference sequence, we re-analyse association transcriptomic data, yielding improved markers for reduced susceptibility to ash dieback. Surveys of these markers in British populations suggest that reduced susceptibility to ash dieback may be more widespread in Great Britain than in Denmark. We also present evidence that susceptibility of trees to H. fraxineus is associated with their iridoid glycoside levels. This rapid, integrated, multidisciplinary research response to an emerging health threat in a non-model organism opens the way for mitigation of the epidemic.

  6. Cluster Tree Based Hybrid Document Similarity Measure

    Directory of Open Access Journals (Sweden)

    M. Varshana Devi

    2015-10-01

    Full Text Available tree based hybrid similarity measure is established to measure the hybrid similarity. In cluster tree, the hybrid similarity measure can be calculated for the random data even it may not be the co-occurred and generate different views. Different views of tree can be combined and choose the one which is significant in cost. A method is proposed to combine the multiple views. Multiple views are represented by different distance measures into a single cluster. Comparing the cluster tree based hybrid similarity with the traditional statistical methods it gives the better feasibility for intelligent based search. It helps in improving the dimensionality reduction and semantic analysis.

  7. Protection of individual ash trees from emerald ash borer (Coleoptera: Buprestidae) with basal soil applications of imidacloprid.

    Science.gov (United States)

    Smitley, D R; Rebek, E J; Royalty, R N; Davis, T W; Newhouse, K F

    2010-02-01

    We conducted field trials at five different locations over a period of 6 yr to investigate the efficacy of imidacloprid applied each spring as a basal soil drench for protection against emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Canopy thinning and emerald ash borer larval density were used to evaluate efficacy for 3-4 yr at each location while treatments continued. Test sites included small urban trees (5-15 cm diameter at breast height [dbh]), medium to large (15-65 cm dbh) trees at golf courses, and medium to large street trees. Annual basal drenches with imidacloprid gave complete protection of small ash trees for three years. At three sites where the size of trees ranged from 23 to 37 cm dbh, we successfully protected all ash trees beginning the test with tree size explains 46% of the variation in efficacy of imidacloprid drenches. The smallest trees (dbh) remained in excellent condition for 3 yr, whereas most of the largest trees (>38 cm dbh) declined to a weakened state and undesirable appearance. The five-fold increase in trunk and branch surface area of ash trees as the tree dbh doubles may account for reduced efficacy on larger trees, and suggests a need to increase treatment rates for larger trees.

  8. Effects of the emerald ash borer invasion on the community composition of arthropods associated with ash tree boles

    Science.gov (United States)

    Emerald ash borer (EAB), Agrilus planipennis Fairmaire is an invasive non-native wood-boring beetle that has killed hundreds of millions of ash trees (Fraxinus spp.) in North America, and threatens to extirpate the ecological services provided by the genus. Identifying the arthropod community assoc...

  9. How fast will trees die? A transition matrix model of ash decline in forest stands infested by emerald ash borer

    Science.gov (United States)

    Kathleen S. Knight; Robert P. Long; Joanne Rebbeck; Annemarie Smith; Kamal Gandhi; Daniel A. Herms

    2008-01-01

    We recorded Fraxinus spp. tree health and other forest stand characteristics for 68 plots in 21 EAB-infested forest stands in Michigan and Ohio in 2005 and 2007. Fraxinus spp. were a dominant component of these stands, with more than 900 ash trees (including Fraxinus americana, Fraxinus pennsylvanica, Fraxinus profunda...

  10. Distribution of trunk-injected 14C-imidacloprid in ash trees and effects on emerald ash borer (Coleoptera: Buprestidae) adults

    Science.gov (United States)

    David Mota-Sánchez; Bert M. Cregg; Deborah G. McCullough; Therese M. Poland; Robert M. Hollingworth

    2009-01-01

    The emerald ash borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae) is a destructive exotic pest of North American ash (Fraxinus sp.) trees. Trunk injection of imidacloprid is commonly used to protect landscape ash trees from A. planipennis damage. Efficacy can vary and little is known about the...

  11. Overcoming obstacles to interspecies hybridization of ash

    Science.gov (United States)

    Jennifer L. Koch; David W. Carey; Mary E. Mason; M. Nurul. Islam-Faridi

    2010-01-01

    Tree species that share a long co-evolutionary history with insects and pathogens are likely to have developed mechanisms of resistance that allow them to coexist. When insects and pathogens are introduced to different parts of the world, high levels of susceptibility can be observed, presumably in part due to the lack of co-evolutionary history between the insect (or...

  12. Effects of coal fly ash on tree swallow reproduction in Watts Bar Reservoir, Tennessee.

    Science.gov (United States)

    Walls, Suzanne J; Meyer, Carolyn B; Iannuzzi, Jacqueline; Schlekat, Tamar H

    2015-01-01

    Coal-fly ash was released in unprecedented amounts (4.1 × 10(6) m(3) ) into the Emory River from the Tennessee Valley Authority Kingston Fossil Plant on Watts Bar Reservoir in Tennessee. Tree swallows were exposed to ash-related constituents at the ash release via their diet of emergent aquatic insects, whose larval forms can accumulate constituents from submerged river sediments. Reproduction of tree swallow colonies was assessed over a 2-year period by evaluating whether 1) ash constituent concentrations were elevated in egg, eggshell, and nestling tissues at colonies near ash-impacted river reaches compared to reference colonies, 2) production of fledglings per nesting female was significantly lower in ash-impacted colonies versus reference colonies, and 3) ash constituent concentrations or diet concentrations were correlated with nest productivity measures (clutch size, hatching success, and nestling survival, and fledglings produced per nest). Of the 26 ash constituents evaluated, 4 (Se, Sr, Cu, and Hg) were significantly elevated in tissues potentially from the ash, and 3 (Se, Sr, and Cu) in tissues or in swallow diet items were weakly correlated to at least one nest-productivity measure or egg weight. Tree swallow hatching success was significantly reduced by 12%, but fledgling production per nest was unaffected due to larger clutch sizes in the impacted than reference colonies. Bioconcentration from the ash to insects in the diet to tree swallow eggs appears to be low. Overall, adverse impacts of the ash on tree swallow reproduction were not observed, but monitoring is continuing to further ensure Se from the residual ash does not adversely affect tree swallow reproduction over time. Integr Environ Assess Manag 2015;11:56-66. © 2014 SETAC.

  13. Assortative mating and differential male mating success in an ash hybrid zone population

    Directory of Open Access Journals (Sweden)

    Frascaria-Lacoste Nathalie

    2006-11-01

    Full Text Available Abstract Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash and F. angustifolia Vahl (narrow-leaved ash, which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears

  14. Strategic removal of host trees in isolated, satellite infestations of emerald ash borer can reduce population growth

    Science.gov (United States)

    Samuel J. Fahrner; Mark Abrahamson; Robert C. Venette; Brian H. Aukema

    2017-01-01

    Emerald ash borer is an invasive beetle causing significant mortality of ash trees (Fraxinus spp.) in North America and western Russia. The invasive range has expanded to more than half of the states in the United States since the initial detection in Michigan, USA in 2002. Emerald ash borer is typically managed with a combination of techniques...

  15. Interspecific variation in resistance to emerald ash borer (Coleoptera: Buprestidae) among North American and Asian ash (Fraxinus spp.).

    Science.gov (United States)

    Rebek, Eric J; Herms, Daniel A; Smitley, David R

    2008-02-01

    We conducted a 3-yr study to compare the susceptibility of selected North American ash and an Asian ash species to emerald ash borer, Agrilus planipennis Fairmaire, an invasive wood-boring beetle introduced to North America from Asia. Because of a coevolutionary relationship between Asian ashes and emerald ash borer, we hypothesized an Asian ash species, Manchurian ash, is more resistant to the beetle than its North American congeners. Consistent with our hypothesis, Manchurian ash experienced far less mortality and yielded far fewer adult beetles than several cultivars of North American green and white ash. Surprisingly, a black ash (North American) x Manchurian ash hybrid was highly susceptible to emerald ash borer, indicating this cultivar did not inherit emerald ash borer resistance from its Asian parent. A corollary study investigated the efficacy of soil-applied imidacloprid, a systemic, neonicotinoid insecticide, for controlling emerald ash borer in each of the five cultivars. Imidacloprid had no effect on emerald ash borer colonization of Manchurian ash, which was low in untreated and treated trees. In contrast, imidacloprid did enhance survival of the North American and hybrid cultivars and significantly reduced the number of emerald ash borer adults emerging from green and white ash cultivars. We identify a possible mechanism of resistance of Manchurian ash to emerald ash borer, which may prove useful for screening, selecting, and breeding emerald ash borer-resistant ash trees.

  16. STUDY ON CORROSION RESISTANCE OF REBAR IN HYBRID GRINDING FLY ASH-LIME SILICATE CONCRETE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The corrosion resistance of rebar in fly ash-lime sili cate concrete as well as its marco properties and pore distribution is investiga ted.The results show that the fly ash is activated, the compressive strength of the silicate concrete is strengthened and its pore structure is modified after f ly ash and lime being hybrid ground.Also the corrosion resistance of rebar in the silicate concrete is improved.

  17. Bud Necrosis of Green Ash Nursery Trees is Influenced by Nitrogen Availability and Fertilizer Type

    Science.gov (United States)

    A study was conducted to determine whether nitrogen (N) status of nursery-grown green ash (Fraxinus pennsylvanica ‘Summit’) trees in the autumn is related to tip die back during the following spring. In 2005, different rates of N from either urea formaldehyde (UF) or a controlled release fertilizer ...

  18. Detectability of the emerald ash borer (Coleoptera: Buprestidae) in asymptomatic urban trees by using branch samples.

    Science.gov (United States)

    Ryall, Krista L; Fidgen, Jeffrey G; Turgeon, Jean J

    2011-06-01

    The emerald ash borer, Agrilus planipennis Fairmaire, is an exotic invasive insect causing extensive mortality to ash trees, Fraxinus spp., in Canada and the United States. Detection of incipient populations of this pest is difficult because of its cryptic life stages and a multiyear time lag between initial attack and the appearance of signs or symptoms of infestation. We sampled branches from open-grown urban ash trees to develop a sample unit suitable for detecting low density A. planipennis infestation before any signs or symptoms are evident. The sample unit that maximized detection rates consisted of one 50-cm-long piece from the base of a branch ≥6 cm diameter in the midcrown. The optimal sample size was two such branches per tree. This sampling method detected ≈75% of asymptomatic trees known to be infested by using more intensive sampling and ≈3 times more trees than sampling one-fourth of the circumference of the trunk at breast height. The method is less conspicuous and esthetically damaging to a tree than the removal of bark from the main stem or the use of trap trees, and could be incorporated into routine sanitation or maintenance of city-owned trees to identify and delineate infested areas. This research indicates that branch sampling greatly reduces false negatives associated with visual surveys and window sampling at breast height. Detection of A. planipennis-infested asymptomatic trees through branch sampling in urban centers would provide landowners and urban foresters with more time to develop and implement management tactics.

  19. Evidence of cross-reactivity between olive, ash, privet, and Russian olive tree pollen allergens.

    Science.gov (United States)

    Kernerman, S M; McCullough, J; Green, J; Ownby, D R

    1992-12-01

    In a clinical investigation, 103 Michigan residents with symptoms suggestive of allergic rhinitis or asthma were skin tested with olive (Olea europaea) pollen extract. Nineteen had positive reactions. Since the olive tree is not native to nor grown in Michigan, this study was undertaken to determine whether the skin test reactivity was the result of cross-reactivity among tree pollen allergens. ELISAs were developed to measure olive, ash (Fraxinus americana), privet (Ligustrum vulgare), and Russian olive (Elaeagnus angustifolia) specific IgE antibodies. Inhibition studies were performed to determine whether pollen extracts from each of these tree species could inhibit IgE antibody binding to olive extracts. Eleven of the 19 skin test-positive patients were olive-ELISA positive, eight either were ELISA-positive to ash, seven to privet and ten to Russian olive. There were significant correlations between the ELISA results to olive and each of the other three pollens. The inhibition studies demonstrated that all three of the tree pollens were capable of inhibiting the binding of IgE to olive extract in a dose-response fashion. IgE-immunoblot studies demonstrated several proteins common to olive, ash, and privet. Twelve of the olive skin test-positive patients were contacted and 75% were exposed to one or more of the studied trees in their yards. Five patients had traveled to areas where olive trees are grown. We conclude that there is a high degree of cross-reactivity among allergens from native Michigan trees and from olive trees. This cross-reactivity is the most likely reason for skin test reactivity to olive pollen extract in Michigan.

  20. Fabrication and adsorption properties of hybrid fly ash composites

    Science.gov (United States)

    Gao, Mengfan; Ma, Qingliang; Lin, Qingwen; Chang, Jiali; Ma, Hongzhu

    2017-02-01

    In order to realize the utilization of fly ash (FA) as industrial solid waste better, high-efficient inorganic/organic hybrid composite adsorbents derived from (Ca(OH)2/Na2FeO4) modified FA (MF) was fabricated. The hydrophilic cationic polymer (P(DMDAAC-co-AAM) or hydrophobic modifier (KH-570) were used. The prepared composites were characterized by X-ray fluorescence spectroscopy, energy dispersive spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller, Fourier transform infrared spectroscopy, thermogravimetry, and contact angle test. The adsorption of cationic composites MF/P(DMDAAC-co-AAM) towards Orange II in wastewater was investigated. The results show that: adsorption amount of 24.8 mg/g with 2000 mg/L of composites, 50 mg/L Orange II, original pH (6-8), at 40 min and room temperature, was obtained. Meanwhile, oil adsorption ratio Q(g/g) of hydrophobic composites MF/KH-570 was also evaluated. The maximum Q of 17.2 g/g to kerosene was obtained at 40 min. The isotherm and kinetics of these two adsorption processes were also studied. The results showed that the fabricated MF composites modified with hydrophilic or hydrophobic group can be used to adsorb dye in wastewater or oil effectively.

  1. Hydration of Hybrid Alkaline Cement Containing a Very Large Proportion of Fly Ash: A Descriptive Model

    Directory of Open Access Journals (Sweden)

    Inés Garcia-Lodeiro

    2016-07-01

    Full Text Available In hybrid alkaline fly ash cements, a new generation of binders, hydration, is characterized by features found in both ordinary portland cement (OPC hydration and the alkali activation of fly ash (AAFA. Hybrid alkaline fly ash cements typically have a high fly ash (70 wt % to 80 wt % and low clinker (20 wt % to 30 wt % content. The clinker component favors curing at ambient temperature. A hydration mechanism is proposed based on the authors’ research on these hybrid binders over the last five years. The mechanisms for OPC hydration and FA alkaline activation are summarized by way of reference. In hybrid systems, fly ash activity is visible at very early ages, when two types of gel are formed: C–S–H from the OPC and N–A–S–H from the fly ash. In their mutual presence, these gels tend to evolve, respectively, into C–A–S–H and (N,C–A–S–H. The use of activators with different degrees of alkalinity has a direct impact on reaction kinetics but does not modify the main final products, a mixture of C–A–S–H and (N,C–A–S–H gels. The proportion of each gel in the mix does, however, depend on the alkalinity generated in the medium.

  2. The relationship between trees and human health: evidence from the spread of the emerald ash borer.

    Science.gov (United States)

    Donovan, Geoffrey H; Butry, David T; Michael, Yvonne L; Prestemon, Jeffrey P; Liebhold, Andrew M; Gatziolis, Demetrios; Mao, Megan Y

    2013-02-01

    Several recent studies have identified a relationship between the natural environment and improved health outcomes. However, for practical reasons, most have been observational, cross-sectional studies. A natural experiment, which provides stronger evidence of causality, was used to test whether a major change to the natural environment-the loss of 100 million trees to the emerald ash borer, an invasive forest pest-has influenced mortality related to cardiovascular and lower-respiratory diseases. Two fixed-effects regression models were used to estimate the relationship between emerald ash borer presence and county-level mortality from 1990 to 2007 in 15 U.S. states, while controlling for a wide range of demographic covariates. Data were collected from 1990 to 2007, and the analyses were conducted in 2011 and 2012. There was an increase in mortality related to cardiovascular and lower-respiratory-tract illness in counties infested with the emerald ash borer. The magnitude of this effect was greater as infestation progressed and in counties with above-average median household income. Across the 15 states in the study area, the borer was associated with an additional 6113 deaths related to illness of the lower respiratory system, and 15,080 cardiovascular-related deaths. Results suggest that loss of trees to the emerald ash borer increased mortality related to cardiovascular and lower-respiratory-tract illness. This finding adds to the growing evidence that the natural environment provides major public health benefits. Published by Elsevier Inc.

  3. Environmental safety to decomposer invertebrates of azadirachtin (neem) as a systemic insecticide in trees to control emerald ash borer.

    Science.gov (United States)

    Kreutzweiser, David; Thompson, Dean; Grimalt, Susana; Chartrand, Derek; Good, Kevin; Scarr, Taylor

    2011-09-01

    The non-target effects of an azadirachtin-based systemic insecticide used for control of wood-boring insect pests in trees were assessed on litter-dwelling earthworms, leaf-shredding aquatic insects, and microbial communities in terrestrial and aquatic microcosms. The insecticide was injected into the trunks of ash trees at a rate of 0.2 gazadirachtin cm(-1) tree diameter in early summer. At the time of senescence, foliar concentrations in most (65%) leaves where at or below detection (emerald ash borer, resultant foliar concentrations in senescent leaf material are likely to pose little risk of harm to decomposer invertebrates.

  4. The effect of wood ash fertilization on soil respiration and tree stand growth in boreal peatland forests

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    Liimatainen, Maarit; Maljanen, Marja; Hytönen, Jyrki

    2017-04-01

    Out of Finland's original 10 million hectares of peatlands over half has been drained for forestry. Natural peatlands act as a sink for carbon but when peatland is drained, increased oxygen concentration in the peat accelerates the aerobic decomposition of the old organic matter of the peat leading to carbon dioxide (CO2) emissions to atmosphere. Increasing use of bioenergy increases also the amount of ash produced as a byproduct in power plants. Wood ash contains all essential nutrients for trees to grow except nitrogen. Therefore, wood ash is ideal fertilizer for nitrogen rich peatland forests where lack of phosphorus or potassium may restrict tree growth. At the moment, wood ash is the only available PK-fertilizer for peatland forests in Finland and areas of peatland forests fertilized with ash are increasing annually. The effects of wood ash on vegetation, soil properties and tree growth are rather well known although most of the studies have been made using fine ash whereas nowadays mostly stabilized ash (e.g. granulated) is used. Transporting and spreading of stabilized ash is easier than that of dusty fine ash. Also, slower leaching rate of nutrients is environmentally beneficial and prolongs the fertilizer effect. The knowledge on the impact of granulated wood ash on greenhouse gas emissions is still very limited. The aim of this study was to examine the effects of granulated wood ash on CO2 emissions from peat and tree stand growth. Field measurements were done in two boreal peatland forests in 2011 and 2012. One of the sites is more nutrient rich with soil carbon to nitrogen ratio (C/N) of 18 whereas the other site is nutrient poor with C/N ratio of 82. Both sites were fertilized with granulated wood ash in 2003 (5000 kg ha-1). The effect of fertilization was followed with tree stand measurements conducted 0, 5 and 10 years after the fertilization. The CO2 emissions of the decomposing peat (heterotrophic respiration) were measured from study plots where

  5. Weighted Hybrid Decision Tree Model for Random Forest Classifier

    Science.gov (United States)

    Kulkarni, Vrushali Y.; Sinha, Pradeep K.; Petare, Manisha C.

    2016-06-01

    Random Forest is an ensemble, supervised machine learning algorithm. An ensemble generates many classifiers and combines their results by majority voting. Random forest uses decision tree as base classifier. In decision tree induction, an attribute split/evaluation measure is used to decide the best split at each node of the decision tree. The generalization error of a forest of tree classifiers depends on the strength of the individual trees in the forest and the correlation among them. The work presented in this paper is related to attribute split measures and is a two step process: first theoretical study of the five selected split measures is done and a comparison matrix is generated to understand pros and cons of each measure. These theoretical results are verified by performing empirical analysis. For empirical analysis, random forest is generated using each of the five selected split measures, chosen one at a time. i.e. random forest using information gain, random forest using gain ratio, etc. The next step is, based on this theoretical and empirical analysis, a new approach of hybrid decision tree model for random forest classifier is proposed. In this model, individual decision tree in Random Forest is generated using different split measures. This model is augmented by weighted voting based on the strength of individual tree. The new approach has shown notable increase in the accuracy of random forest.

  6. Transport of soluble carbohydrates in temperate deciduous trees: beech (Fagus sylvatica) and ash (Fraxinus excelsior) in comparison

    Science.gov (United States)

    Thoms, Ronny; Köhler, Michael; Gessler, Arthur; Gleixner, Gerd

    2015-04-01

    The structure of phloem cells and the physiology of the transport of soluble carbohydrates in plants are well studied. However, the influence of different phloem un- and uploading strategies on the translocation of carbohydrates in different tree species is largely unknown. Therefore, we conducted a pulse labeling on 20 young trees of European beech (Fagus sylvatica) and European ash (Fraxinus excelsior) respectively, using the stable isotope 13C in a temperate deciduous forest in Central Germany. In one growing season each tree species was labeled in a closed transparent plastic chamber with 99% 13CO2 for 5 h. The compound specific δ 13C from carbohydrates in the different compartments leaf, branch, stem and root was measured by high-performance liquid chromatography linked with an isotope ratio mass spectrometer (HPLC-IRMS). We found that both tree species used sucrose as a transport sugar, but carbohydrates of the raffinose group (RFO) served as main transport sugar in ash trees. This indicate that beech used only the apoplastic loading strategy into the phloem cells while ash trees relied on both, apoplastic and symplastic loading, preferring the latter at the end of the growing season. Furthermore, we observed different transport velocities of labeled sugars in the two species. Here, sucrose in beech and carbohydrates of the RFO in ash were transported fastest, whereas sucrose was constantly slowest in ash trees. The label of carbohydrates was found over 60 day in the roots of both tree species, with the highest δ 13C enrichment in carbohydrates of RFO than in the other sugars. Accordingly, the mean residence time (MRT) and half life time (HLT) of 13C in different compartments were longest for carbohydrates of RFO in roots (25.6 days) and sucrose in stems (14.9 days), while the shortest MRT and HLT for sucrose appeared in beech in all compartments. Our results give evidence that RFO are preferentially transported to the root tissue as an agent against frost

  7. Biotic mortality factors affecting emerald ash borer (Agrilus planipennis) are highly dependent on life stage and host tree crown condition.

    Science.gov (United States)

    Jennings, D E; Duan, J J; Shrewsbury, P M

    2015-10-01

    Emerald ash borer (EAB), Agrilus planipennis, is a serious invasive forest pest in North America responsible for killing tens to hundreds of millions of ash trees since it was accidentally introduced in the 1990 s. Although host-plant resistance and natural enemies are known to be important sources of mortality for EAB in Asia, less is known about the importance of different sources of mortality at recently colonized sites in the invaded range of EAB, and how these relate to host tree crown condition. To further our understanding of EAB population dynamics, we used a large-scale field experiment and life-table analyses to quantify the fates of EAB larvae and the relative importance of different biotic mortality factors at 12 recently colonized sites in Maryland. We found that the fates of larvae were highly dependent on EAB life stage and host tree crown condition. In relatively healthy trees (i.e., with a low EAB infestation) and for early instars, host tree resistance was the most important mortality factor. Conversely, in more unhealthy trees (i.e., with a moderate to high EAB infestation) and for later instars, parasitism and predation were the major sources of mortality. Life-table analyses also indicated how the lack of sufficient levels of host tree resistance and natural enemies contribute to rapid population growth of EAB at recently colonized sites. Our findings provide further evidence of the mechanisms by which EAB has been able to successfully establish and spread in North America.

  8. Ethylenediurea (EDU) affects the growth of ozone-sensitive and tolerant ash (Fraxinus excelsior) trees under ambient O3 conditions.

    Science.gov (United States)

    Paoletti, Elena; Contran, Nicla; Manning, William J; Tagliaferro, Francesco

    2007-03-21

    Adult ash trees (Fraxinus excelsior L.), known to be sensitive or tolerant to ozone, determined by presence or absence of foliar symptoms in previous years, were treated with ethylenediurea (EDU) at 450 ppm by gravitational trunk infusion over the 2005 growing season (32.5 ppm h AOT40). Tree and shoot growth were recorded in May and September. Leaf area, ectomycorrhizal infection, and leaf and fine root biomass were determined in September. EDU enhanced shoot length and diameter, and the number and area of leaves, in both O3-sensitive and tolerant trees. However, no EDU effects were recorded at the fine root and tree level. Therefore, a potential for EDU protection against O3-caused growth losses of forest trees should be evaluated during longer-term experiments.

  9. Hybrid Parallel Contour Trees, Version 1.0

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-03

    A common operation in scientific visualization is to compute and render a contour of a data set. Given a function of the form f : R^d -> R, a level set is defined as an inverse image f^-1(h) for an isovalue h, and a contour is a single connected component of a level set. The Reeb graph can then be defined to be the result of contracting each contour to a single point, and is well defined for Euclidean spaces or for general manifolds. For simple domains, the graph is guaranteed to be a tree, and is called the contour tree. Analysis can then be performed on the contour tree in order to identify isovalues of particular interest, based on various metrics, and render the corresponding contours, without having to know such isovalues a priori. This code is intended to be the first data-parallel algorithm for computing contour trees. Our implementation will use the portable data-parallel primitives provided by Nvidia’s Thrust library, allowing us to compile our same code for both GPUs and multi-core CPUs. Native OpenMP and purely serial versions of the code will likely also be included. It will also be extended to provide a hybrid data-parallel / distributed algorithm, allowing scaling beyond a single GPU or CPU.

  10. Designing Strategies for Epidemic Control in a Tree Nursery: the Case of Ash Dieback in the UK

    Directory of Open Access Journals (Sweden)

    Vasthi Alonso Chavez

    2015-11-01

    Full Text Available Ash dieback is a fungal disease (causal agent Hymenoscyphus fraxineus infecting Common ash (Fraxinus excelsior throughout temperate Europe. The disease was first discovered in the UK in 2012 in a nursery in Southern England, in plants which had been imported from the Netherlands. After sampling other recently planted sites across England, more infected trees were found. Tree trade from outside and across the UK may have facilitated the spread of invasive diseases which threaten the sustainability of forestry business, ecological niches and amenity landscapes. Detecting a disease in a nursery at an early stage and knowing how likely it is for the disease to have spread further in the plant trade network, can help control an epidemic. Here, we test two simple sampling rules that 1 inform monitoring strategies to detect a disease at an early stage, and 2 inform the decision of tracking forward the disease after its detection. We apply these expressions to the case of ash dieback in the UK and test them in different scenarios after disease introduction. Our results are useful to inform policy makers’ decisions on monitoring for the control and spread of tree diseases through the nursery trade.

  11. Study on Drive System of Hybrid Tree Harvester

    Directory of Open Access Journals (Sweden)

    Shen Rong-feng

    2017-01-01

    Full Text Available Hybrid tree harvester with a 60 kW diesel engine combined with a battery pile could be a “green” forest harvesting and transportation system. With the new design, the diesel engine maintains a constant engine speed, keeping fuel consumption low while charging the batteries that drive the forwarder. As an additional energy saving method, the electric motors work as generators to charge the battery pile when the vehicle moves downhill. The vehicle is equipped with six large wheels providing high clearance over uneven terrain while reducing ground pressure. Each wheel is driven via a hub gear by its own alternating current motor, and each of the three wheel pairs can be steered independently. The combination of the diesel engine and six electric motors provides plenty of power for heavy lifting and pulling. The main component parameters of the drive system are calculated and optimized with a set of dynamics and simulated with AVL Cruise software. The results provide practical insights for the fuel tree harvester and are helpful to reduce the structure and size of the tree harvester. Advantage Environment provides information about existing and future products designed to reduce environmental impacts.

  12. THE HIGH VOLUME REUSE OF HYBRID BIOMASS ASH AS A PRIMARY BINDER IN CEMENTLESS MORTAR BLOCK

    Directory of Open Access Journals (Sweden)

    Cheah Chee Ban

    2014-01-01

    Full Text Available High Calcium Wood Ash (HCWA and Pulverised Fuel Ash (PFA are by-products from the wood biomass and coal energy production which are produced in large quantity with combined annual production of 500 million tonnes. This poses a serious problem for disposal of the waste material especially at places where land is scarce. The prescribed study was aimed to examine the mineralogical phases and their respective amount present in the industrial wastes which governs the hydration mechanism towards self-sustained solidification of the ashes when used in combination. Besides, the influence of various forming pressure and hydrothermal treatment temperature on mechanical strength performance of HCWA-PFA cementless mortar blocks was also examined. In the study, the mechanical strength of the HCWA-PFA cementless mortar block produced using various forming pressure and hydrothermal treatment temperature was assessed in terms of compressive strength and dynamic modulus. The results of the study are indicative that HCWA is rich in calcium oxide and potassium oxide content. This enables the hybridization of HCWA with the amorphous silica and alumina rich PFA to form a solid geopolymer binder matrix for fabrication of cementless mortar block. Throughout the study, dimensionally and mechanically stable HCWA-PFA geopolymer mortar blocks were successfully produced by press forming and hydrothermal treatment method. Based on statistical analysis, the hydrothermal treatment temperature has a statistically insignificant effect on the mechanical strength of the HCWA-PFA cementless mortar blocks. The dominant factor which governs the mechanical strength of the HCWA-PFA cementless mortar blocks was found to be the hydraulic forming pressure. Moreover, it was found that hybridized HCWA-PFA can be recycled as the sole binder for fabrication of cementless concrete block which is a useful construction material.

  13. The Legacy of Past Tree Planting Decisions for a City Confronting Emerald Ash Borer (Agrilus planipennis Invasion

    Directory of Open Access Journals (Sweden)

    Christopher Sean Greene

    2016-03-01

    Full Text Available Management decisions grounded in ecological understanding are essential to the maintenance of a healthy urban forest. Decisions about where and what tree species to plant have both short and long-term consequences for the future function and resilience of city trees. Through the construction of a theoretical damage index, this study examines the legacy effects of a street tree planting program in a densely populated North American city confronting an invasion of emerald ash borer (Agrilus planipennis. An investigation of spatial autocorrelation for locations of high damage potential across the City of Toronto, Canada was then conducted using Getis-Ord Gi*. Significant spatial clustering of high damage index values affirmed that past urban tree planting practices placing little emphasis on species diversity have created time-lagged consequences of enhanced vulnerability of trees to insect pests. Such consequences are observed at the geographically local scale, but can easily cascade to become multi-scalar in their spatial extent. The theoretical damage potential index developed in this study provides a framework for contextualizing historical urban tree planting decisions where analysis of damage index values for Toronto reinforces the importance of urban forest management that prioritizes proactive tree planting strategies that consider species diversity in the context of planting location.

  14. Study on Strength of Hybrid Mortar Synthesis with Epoxy Resin, Fly Ash and Quarry Dust Under Extreme Conditions

    Science.gov (United States)

    Sudheer, P.; Muni Reddy, M. G., Dr.; Adiseshu, S., Dr.

    2017-08-01

    Blend and characterization of Bisphenol-A diglycidyl ether based thermosetting polymer mortar comprising an epoxy resin, Fly ash and Quarry dust are presented here for the strength study. The specimens have been prepared by means of an innovative process in Extreme conditions of commercial epoxy resin, Fly ash and Quarry dust based paste. In this way, thermosetting based hybrid mortars characterized by a different contents of normalized Fly ash and Quarry dust by a homogeneous distribution of the resin have been attained. Once hardened, these new composite materials show improved compressive strength and toughness in respect to both the Fly ash and Rock sand pastes since the Resin provides a more cohesive microstructure, with a reduced number of micro cracks. The micro structural characterization allows pointing out the presence of an Interfacial Transition Zone similar to that observed in cement based mortars. A correlation between micro-structural features and mechanical properties of the mortar has also been studied in Extreme conditions.

  15. The probability of a gene tree topology within a phylogenetic network with applications to hybridization detection.

    Directory of Open Access Journals (Sweden)

    Yun Yu

    Full Text Available Gene tree topologies have proven a powerful data source for various tasks, including species tree inference and species delimitation. Consequently, methods for computing probabilities of gene trees within species trees have been developed and widely used in probabilistic inference frameworks. All these methods assume an underlying multispecies coalescent model. However, when reticulate evolutionary events such as hybridization occur, these methods are inadequate, as they do not account for such events. Methods that account for both hybridization and deep coalescence in computing the probability of a gene tree topology currently exist for very limited cases. However, no such methods exist for general cases, owing primarily to the fact that it is currently unknown how to compute the probability of a gene tree topology within the branches of a phylogenetic network. Here we present a novel method for computing the probability of gene tree topologies on phylogenetic networks and demonstrate its application to the inference of hybridization in the presence of incomplete lineage sorting. We reanalyze a Saccharomyces species data set for which multiple analyses had converged on a species tree candidate. Using our method, though, we show that an evolutionary hypothesis involving hybridization in this group has better support than one of strict divergence. A similar reanalysis on a group of three Drosophila species shows that the data is consistent with hybridization. Further, using extensive simulation studies, we demonstrate the power of gene tree topologies at obtaining accurate estimates of branch lengths and hybridization probabilities of a given phylogenetic network. Finally, we discuss identifiability issues with detecting hybridization, particularly in cases that involve extinction or incomplete sampling of taxa.

  16. Realization of R-tree for GIS on hybrid clustering algorithm

    Institute of Scientific and Technical Information of China (English)

    HUANG Ji-xian; BAO Guang-shu; LI Qing-song

    2005-01-01

    The characteristic of geographic information system(GIS) spatial data operation is that query is much more frequent than insertion and deletion, and a new hybrid spatial clustering method used to build R-tree for GIS spatial data was proposed in this paper. According to the aggregation of clustering method, R-tree was used to construct rules and specialty of spatial data. HCR-tree was the R-tree built with HCR algorithm. To test the efficiency of HCR algorithm, it was applied not only to the data organization of static R-tree but also to the nodes splitting of dynamic R-tree. The results show that R-tree with HCR has some advantages such as higher searching efficiency, less disk accesses and so on.

  17. Synthesis, characterization, and mercury adsorption properties of hybrid mesoporous aluminosilicate sieve prepared with fly ash.

    Science.gov (United States)

    Liu, Minmin; Hou, Li-An; Xi, Beidou; Zhao, Ying; Xia, Xunfeng

    2013-05-15

    A novel hybrid mesoporous aluminosilicate sieve (HMAS) was prepared with fly ash and impregnated with zeolite A precursors. This improved the mercury adsorption of HMAS compared to original MCM-41. The HMAS was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM) images and (29)Si and (27)Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra. These showed that the HMAS structure was still retained after impregnated with zeolite A. But the surface area and pore diameter of HMAS decreased due to pore blockage. Adsorption of mercury from aqueous solution was studied on untreated MCM-41and HMAS. The mercury adsorption rate of HMAS was higher than that of origin MCM-41. The adsorption of mercury was investigated on HMAS regarding the pH of mercury solution, initial mercury concentration, and the reaction temperature. The experimental data fit well to Langmuir and Freundlich isotherm models. The Dublin-Radushkevich isotherm and the characterization show that the mercury adsorption on HMAS involved the ion-exchange mechanisms. In addition, the thermodynamic parameters suggest that the adsorption process was endothermic in nature. The adsorption of mercury on HMAS followed the first order kinetics.

  18. Synthesis, characterization, and mercury adsorption properties of hybrid mesoporous aluminosilicate sieve prepared with fly ash

    Science.gov (United States)

    Liu, Minmin; Hou, Li-an; Xi, Beidou; Zhao, Ying; Xia, Xunfeng

    2013-05-01

    A novel hybrid mesoporous aluminosilicate sieve (HMAS) was prepared with fly ash and impregnated with zeolite A precursors. This improved the mercury adsorption of HMAS compared to original MCM-41. The HMAS was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM) images and 29Si and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra. These showed that the HMAS structure was still retained after impregnated with zeolite A. But the surface area and pore diameter of HMAS decreased due to pore blockage. Adsorption of mercury from aqueous solution was studied on untreated MCM-41and HMAS. The mercury adsorption rate of HMAS was higher than that of origin MCM-41. The adsorption of mercury was investigated on HMAS regarding the pH of mercury solution, initial mercury concentration, and the reaction temperature. The experimental data fit well to Langmuir and Freundlich isotherm models. The Dublin-Radushkevich isotherm and the characterization show that the mercury adsorption on HMAS involved the ion-exchange mechanisms. In addition, the thermodynamic parameters suggest that the adsorption process was endothermic in nature. The adsorption of mercury on HMAS followed the first order kinetics.

  19. Synthesis, characterization, and mercury adsorption properties of hybrid mesoporous aluminosilicate sieve prepared with fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Minmin [School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Hou, Li-an, E-mail: 11liuminmin@tongji.edu.cn [School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Xi, Beidou; Zhao, Ying; Xia, Xunfeng [China Research Academy of Environmental Science, Beijing 200012 (China)

    2013-05-15

    A novel hybrid mesoporous aluminosilicate sieve (HMAS) was prepared with fly ash and impregnated with zeolite A precursors. This improved the mercury adsorption of HMAS compared to original MCM-41. The HMAS was characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption, Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM) images and {sup 29}Si and {sup 27}Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra. These showed that the HMAS structure was still retained after impregnated with zeolite A. But the surface area and pore diameter of HMAS decreased due to pore blockage. Adsorption of mercury from aqueous solution was studied on untreated MCM-41and HMAS. The mercury adsorption rate of HMAS was higher than that of origin MCM-41. The adsorption of mercury was investigated on HMAS regarding the pH of mercury solution, initial mercury concentration, and the reaction temperature. The experimental data fit well to Langmuir and Freundlich isotherm models. The Dublin–Radushkevich isotherm and the characterization show that the mercury adsorption on HMAS involved the ion-exchange mechanisms. In addition, the thermodynamic parameters suggest that the adsorption process was endothermic in nature. The adsorption of mercury on HMAS followed the first order kinetics.

  20. Biosurfactant from red ash trees enhances the bioremediation of PAH contaminated soil at a former gasworks site.

    Science.gov (United States)

    Blyth, Warren; Shahsavari, Esmaeil; Morrison, Paul D; Ball, Andrew S

    2015-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are persistent contaminants that accumulate in soil, sludge and on vegetation and are produced through activities such as coal burning, wood combustion and in the use of transport vehicles. Naturally occurring surfactants have been known to enhance PAH-removal from soil by improving PAH solubilization thereby increasing PAH-microbe interactions. The aim of this research was to determine if a biosurfactant derived from the leaves of the Australian red ash (Alphitonia excelsa) would enhance bioremediation of a heavily PAH-contaminated soil and to determine how the microbial community was affected. Results of GC-MS analysis show that the extracted biosurfactant was significantly more efficient than the control in regards to the degradation of total 16 US EPA priority PAHs (78.7% degradation compared to 62.0%) and total petroleum hydrocarbons (TPH) (92.9% degradation compared to 44.3%). Furthermore the quantification of bacterial genes by qPCR analysis showed that there was an increase in the number of gene copies associated with Gram positive PAH-degrading bacteria. The results suggest a commercial potential for the use of the Australian red ash tree as a source of biosurfactant for use in the accelerated degradation of hydrocarbons.

  1. Dissolution of granulated wood ash examined by in situ incubation: Effects of tree species and soil type

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Ingerslev, M.; Raulund-Rasmussen, K.

    2007-01-01

    Wood ash recycling to forests may counteract nutrient losses caused by biomass harvest, since most nutrients except nitrogen are largely retained in the ash. Raw wood ash has an alkaline reaction with water and contains easily soluble as well as resistant compounds. Ash can be treated to ease...

  2. One and two-entry tree volume tables for the new-established ash-sycamore forest types at a pre-alpine territory.

    Directory of Open Access Journals (Sweden)

    Fabrizio Ferretti

    2010-12-01

    Full Text Available Ash-sycamore stands have been assuming a considerable territorial importance in Northern Italy over the last decades. According to the National Forest and Carbon Sinks Inventory (INFC, these stands form the type of “sycamore-lime mountain & ash forests” and “Apennine maple forests”. These forests amount to 153904 hectares (88% in the Northern regions and 23600 hectares, respectively. In the Veneto Region, ash-sycamore are mainly secondary forests and occupy 9258 hectares. These stands spread easily throughout the agriculture set-aside lands thanks to their colonizing ability and to the favourable soil conditions in the pre-alpine region. Experimental thinnings framed into a wider project aimed at producing management guidelines according to a single-tree oriented approach, provided a sample of 385 trees. On the basis of this dataset, the first tree volume tables for these ash-sycamore stands have been elaborated. Data collection and data processing are being described in the paper. A two-entry tree volume table was set up by the stepwise analysis procedure and a one tree volume table was derived from the two-entry tree volume table. st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabella normale"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  3. Hybrid tree-rule firewall for high speed data transmission

    NARCIS (Netherlands)

    Chomsiri, Thawatchai; He, Xiangjian; Nanda, Priyadarsi; Tan, Zhiyuan

    2016-01-01

    Traditional firewalls employ listed rules in both configuration and process phases to regulate network traffic. However, configuring a firewall with listed rules may create rule conflicts, and slows down the firewall. To overcome this problem, we have proposed a Tree-rule firewall in our previous st

  4. Progress and gaps in understanding mechanisms of ash tree resistance to emerald ash borer, a model for wood-boring insects that kill angiosperms.

    Science.gov (United States)

    Villari, Caterina; Herms, Daniel A; Whitehill, Justin G A; Cipollini, Don; Bonello, Pierluigi

    2016-01-01

    We review the literature on host resistance of ash to emerald ash borer (EAB, Agrilus planipennis), an invasive species that causes widespread mortality of ash. Manchurian ash (Fraxinus mandshurica), which coevolved with EAB, is more resistant than evolutionarily naïve North American and European congeners. Manchurian ash was less preferred for adult feeding and oviposition than susceptible hosts, more resistant to larval feeding, had higher constitutive concentrations of bark lignans, coumarins, proline, tyramine and defensive proteins, and was characterized by faster oxidation of phenolics. Consistent with EAB being a secondary colonizer of coevolved hosts, drought stress decreased the resistance of Manchurian ash, but had no effect on constitutive bark phenolics, suggesting that they do not contribute to increased susceptibility in response to drought stress. The induced resistance of North American species to EAB in response to the exogenous application of methyl jasmonate was associated with increased bark concentrations of verbascoside, lignin and/or trypsin inhibitors, which decreased larval survival and/or growth in bioassays. This finding suggests that these inherently susceptible species possess latent defenses that are not induced naturally by larval colonization, perhaps because they fail to recognize larval cues or respond quickly enough. Finally, we propose future research directions that would address some critical knowledge gaps.

  5. ON MULTICAST TREE CONSTRUCTION IN IPV4-IPV6 HYBRID NETWORK

    Institute of Scientific and Technical Information of China (English)

    Zhang Chao; Zhang Yuan; Huang Yongfeng; Li Xing

    2010-01-01

    With the IPv4 addresses exhausting and IPv6 emerging,the Peer-to-Peer (P2P) overlay is becoming increasingly heterogeneous and complex: pure IPv4,dual stack and pure IPv6 hosts coexist,and the connectivity limitation between IPv4 and IPv6 hosts requires the overlay protocols to be fit for this hybrid situation. This paper sets out to answer the question of how to construct multicast tree on top of IPv4-IPv6 hybrid network. Our solution is a New Greedy Algorithm (NGA) which eliminates the problem of joining failure in the hybrid network and keeps the efficiency of greedy algorithm in tree construction. Simulation results show that our algorithm has excellent performance,which is very close to the optimal in many cases.

  6. Induction of hybrid decision tree based on post-discretization strategy

    Institute of Scientific and Technical Information of China (English)

    WANG Limin; YUAN Senmiao

    2004-01-01

    By redefining test selection measure, we propose in this paper a new algorithm, Flexible NBTree, which induces a hybrid of decision tree and Naive Bayes. Flexible NBTree mitigates the negative effect of information loss on test selection by applying postdiscretization strategy: at each internal node in the tree, we first select the test which is the most useful for improving classification accuracy, then apply discretization of continuous tests. The finial decision tree nodes contain univariate splits as regular decision trees, but the leaves contain Naive Bayesian classifiers. To evaluate the performance of Flexible NBTree, we compare it with NBTree and C4.5, both applying pre-discretization of continuous attributes. Experimental results on a variety of natural domains indicate that the classification accuracy of Flexible NBTree is substantially improved.

  7. Sperm competition and offspring viability at hybridization in Australian tree frogs, Litoria peronii and L. tyleri.

    Science.gov (United States)

    Sherman, C D H; Wapstra, E; Olsson, M

    2010-02-01

    Hybridization between closely related species often leads to reduced viability or fertility of offspring. Complete failure of hybrid offspring (post-zygotic hybrid incompatibilities) may have an important role in maintaining the integrity of reproductive barriers between closely related species. We show elsewhere that in Peron's tree frog, Litoria peronii, males more closely related to a female sire more offspring in sperm competition with a less related rival male. Observations of rare 'phenotypic intermediate' males between L. peronii and the closely related L. tyleri made us suggest that these relatedness effects on siring success may be because of selection arising from risks of costly hybridization between the two species. Here, we test this hypothesis in an extensive sperm competition experiment, which shows that there is no effect of species identity on probability of fertilization in sperm competition trials controlling for sperm concentration and sperm viability. Instead, there was a close agreement between a male's siring success in isolation with a female and his siring success with the same female in competition with a rival male regardless of species identity. Offspring viability and survival, however, were strongly influenced by species identity. Over a 14-day period, hybrid offspring suffered increasing mortality and developed more malformations and an obvious inability to swim and right themselves, leading to compromised probability of survival. Thus, hybridization in these sympatric tree frogs does not compromise fertilization but has a strong impact on offspring viability and opportunity for reinforcement selection on mate choice for conspecific partners.

  8. Effects of ash recycling on spruce stands with whole tree harvesting; Effekter av askaaterfoering till granplanteringar med ristaekt

    Energy Technology Data Exchange (ETDEWEB)

    Westling, Olle; Andersson, Ingvar [Swedish Environmental Research Institute, Goeteborg (Sweden); Oerlander, Goeran [Vaexjoe Univ. (Sweden)

    2004-01-01

    Ash-treated areas were compared to non-treated areas where logging waste (branches, twigs and needles) was/was not harvested. The study shows that: Harvesting of logging waste tends to reduce the leaching of nitrogen the first years after the harvest. Ash fertilization of 3-7 years old harvesting areas had no effects on the leaching, but recycling to a new area increased the leaching for a short period. Six years after recycling, the plant volumes were significantly greater on ash-recycled areas than on the control areas. The growth was smallest on areas with waste harvesting and no ash recycling.

  9. Investigation of Tribological Behavior of a Novel Hybrid Composite Prepared with Al-Coconut Shell Ash Mixed with Graphite

    Science.gov (United States)

    Siva Sankara Raju, R.; Panigrahi, M. K.; Ganguly, R. I.; Srinivasa Rao, G.

    2017-08-01

    The present investigation develops a next-generation hybrid Al metal matrix composite using coconut shell ash (CSA) and graphite (Gr) reinforcement. Stir-casting is adapted to prepare an Al-1100-based composite. Three other composites of Al-Al2O3, Al-Al2O3-Gr, and Al-CSA are prepared that contain equivalent volume fractions of Al2O3, CSA, and Gr. These assist in comparisons among the three composites and the developed hybrid Al-CSA-Gr composite. The study reveals that the addition of 3 pct Gr improves the specific strength, toughness, and tribological properties. The Al-CSA composite shows better mechanical properties, such as tensile strength and hardness, than the other three composites. Gr addition helps the hybrid Al-CSA-Gr composite to attain better tribological properties with a slightly lower specific strength. Scanning electron microscopy studies of the worn material surfaces corroborate the findings of the abrasion testing. Elemental analyses by energy-dispersive X-ray spectroscopy of the debris from the counter-face of the tribo surface confirm the presence of Al, O, Si, Fe, Mn, and C.

  10. Do Hybrid Trees Inherit Invasive Characteristics? Fruits of Corymbia torelliana X C. citriodora Hybrids and Potential for Seed Dispersal by Bees.

    Science.gov (United States)

    Wallace, Helen Margaret; Leonhardt, Sara Diana

    2015-01-01

    Tree invasions have substantial impacts on biodiversity and ecosystem functioning, and trees that are dispersed by animals are more likely to become invasive. In addition, hybridisation between plants is well documented as a source of new weeds, as hybrids gain new characteristics that allow them to become invasive. Corymbia torelliana is an invasive tree with an unusual animal dispersal mechanism: seed dispersal by stingless bees, that hybridizes readily with other species. We examined hybrids between C. torelliana and C. citriodora subsp. citriodora to determine whether hybrids have inherited the seed dispersal characteristics of C. torelliana that allow bee dispersal. Some hybrid fruits displayed the characteristic hollowness, resin production and resin chemistry associated with seed dispersal by bees. However, we did not observe bees foraging on any hybrid fruits until they had been damaged. We conclude that C. torelliana and C. citriodora subsp. citriodora hybrids can inherit some fruit characters that are associated with dispersal by bees, but we did not find a hybrid with the complete set of characters that would enable bee dispersal. However, around 20,000 hybrids have been planted in Australia, and ongoing monitoring is necessary to identify any hybrids that may become invasive.

  11. Research on the adaptive hybrid search tree anti-collision algorithm in RFID system

    Institute of Scientific and Technical Information of China (English)

    靳晓芳

    2016-01-01

    Due to more tag-collisions result in failed transmissions, tag anti-collision is a very vital issue in the radio frequency identification ( RFID) system.However, so far decreases in communication time and increases in throughput are very limited.In order to solve these problems, this paper presents a novel tag anti-collision scheme, namely adaptive hybrid search tree ( AHST) , by combining two al-gorithms of the adaptive binary-tree disassembly ( ABD) and the combination query tree ( CQT) , in which ABD has superior tag identification velocity and CQT has optimum performance in system throughput and search timeslots.From the theoretical analysis and numerical simulations, the pro-posed algorithm can colligate the advantages of above algorithms, improve the system throughput and reduce the searching timeslots dramatically.

  12. QoS Supported IPTV Service Architecture over Hybrid-Tree-Based Explicit Routed Multicast Network

    Directory of Open Access Journals (Sweden)

    Chih-Chao Wen

    2012-01-01

    Full Text Available With the rapid advance in multimedia streaming and multicast transport technology, current IP multicast protocols, especially PIM-SM, become the major channel delivery mechanism for IPTV system over Internet. The goals for IPTV service are to provide two-way interactive services for viewers to select popular program channel with high quality for watching during fast channel surfing period. However, existing IP multicast protocol cannot meet above QoS requirements for IPTV applications between media server and subscribers. Therefore, we propose a cooperative scheme of hybrid-tree based on explicit routed multicast, called as HT-ERM to combine the advantages of shared tree and source tree for QoS-supported IPTV service. To increase network utilization, the constrained shortest path first (CSPF routing algorithm is designed for construction of hybrid tree to deliver the high-quality video stream over watching channel and standard quality over surfing channel. Furthermore, the Resource Reservation Protocol- Traffic Engineering (RSVP-TE is used as signaling mechanism to set up QoS path for multicast channel admission control. Our simulation results demonstrated that the proposed HT-ERM scheme outperforms other multicast QoS-based delivery scheme in terms of channel switching delay, resource utilization, and blocking ratio for IPTV service.

  13. GPU accelerated Hybrid Tree Algorithm for Collision-less N-body Simulations

    CERN Document Server

    Watanabe, Tsuyoshi

    2014-01-01

    We propose a hybrid tree algorithm for reducing calculation and communication cost of collision-less N-body simulations. The concept of our algorithm is that we split interaction force into two parts: hard-force from neighbor particles and soft-force from distant particles, and applying different time integration for the forces. For hard-force calculation, we can efficiently reduce the calculation and communication cost of the parallel tree code because we only need data of neighbor particles for this part. We implement the algorithm on GPU clusters to accelerate force calculation for both hard and soft force. As the result of implementing the algorithm on GPU clusters, we were able to reduce the communication cost and the total execution time to 40% and 80% of that of a normal tree algorithm, respectively. In addition, the reduction factor relative the normal tree algorithm is smaller for large number of processes, and we expect that the execution time can be ultimately reduced down to about 70% of the norma...

  14. Advanced hybrid query tree algorithm based on slotted backoff mechanism in RFID

    Directory of Open Access Journals (Sweden)

    XIE Xiaohui

    2013-12-01

    Full Text Available The merits of performance quality for a RFID system are determined by the effectiveness of tag anti-collision algorithm.Many algorithms for RFID system of tag identification have been proposed,but they all have obvious weaknesses,such as slow speed of identification,unstable and so on.The existing algorithms can be divided into two groups,one is based on ALOHA and another is based on query tree.This article is based on the hybrid query tree algorithm,combined with a slotted backoff mechanism and a specific encoding (Manchester encoding.The number of value“1” in every three consecutive bits of tags is used to determine the tag response time slots,which will greatly reduce the time slot of the collision and improve the recognition efficiency.

  15. Microstructure and Mechanical Behaviour of Stir-Cast Al-Mg-Sl Alloy Matrix Hybrid Composite Reinforced with Corn Cob Ash and Silicon Carbide

    Directory of Open Access Journals (Sweden)

    Oluwagbenga Babajide Fatile

    2014-10-01

    Full Text Available In this present study, the microstructural and mechanical behaviour of Al-Mg-Si alloy matrix composites reinforced with silicon carbide (SiC and Corn cob ash (An agro‑waste was investigated. This research work was aimed at assessing the suitability of developing low cost- high performance Al-Mg-Si hybrid composite. Silicon carbide (SiC particulates added with 0,1,2,3 and 4 wt% Corn cob ash (CCA were utilized to prepare 10 wt% of the reinforcing phase with Al-Mg-Si alloy as matrix using two-step stir casting method. Microstructural characterization, density measurement, estimated percent porosity, tensile testing, and micro‑hardness measurement were used to characterize the composites produced. From the results obtained, CCA has great potential to serve as a complementing reinforcement for the development of low cost‑high performance aluminum hybrid composites.

  16. Emerald ash borer biocontrol in ash saplings: the potential for early stage recovery of North American ash

    Science.gov (United States)

    In many parts of North America, ash stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees and young basal sprouts, saplings, and seedlings. Without a seed bank, ash tree recovery will require survival and maturation of these younger cohorts...

  17. EVALUATION & COMPARISION OF MECHANICAL PROPERTIES OF ALUMINIUM ALLOY 5052 REINFORCED WITH SILICONCARBIDE, GRAPHITE AND FLY ASH HYBRID METAL MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    ANKUSH SACHDEVA

    2013-10-01

    Full Text Available The engineering fraternity has always been looking forward to develop an outstanding and wonder-materials which would fit the ever-changing demands of the world. In order to fullfill the demands various newdiscoveries have been made by scientists, engineers and resrearchers. In todays competitive world many, materials have been tried for various unexplored conditions , but the never ending demand of the world encourages the researchers to develop the new material. Now the researchers are preparing the material by the combination of different materials called hybrid composite material.. Metal Matrix Composites (MMCs have emerged as a class of materials suitable for structural, aerospace, automotive, electronic, thermal and wearapplications owing to their advantages over the conventional materials. The present study was taken up to explore the possibility of using different reinforcements (silicon carbide, fly ash and graphite to enhance the properties of aluminium alloy (Al5052 composites. Different samples were prepared from the aluminium withvarying reinforcement composition. The mechanical properties studied after the experiment were strength, hardness and elongation.Further, these composites were characterized with the help of, mechanical testing and scanning electron microscopy.

  18. Hybrid threshold adaptable quantum secret sharing scheme with reverse Huffman-Fibonacci-tree coding

    Science.gov (United States)

    Lai, Hong; Zhang, Jun; Luo, Ming-Xing; Pan, Lei; Pieprzyk, Josef; Xiao, Fuyuan; Orgun, Mehmet A.

    2016-08-01

    With prevalent attacks in communication, sharing a secret between communicating parties is an ongoing challenge. Moreover, it is important to integrate quantum solutions with classical secret sharing schemes with low computational cost for the real world use. This paper proposes a novel hybrid threshold adaptable quantum secret sharing scheme, using an m-bonacci orbital angular momentum (OAM) pump, Lagrange interpolation polynomials, and reverse Huffman-Fibonacci-tree coding. To be exact, we employ entangled states prepared by m-bonacci sequences to detect eavesdropping. Meanwhile, we encode m-bonacci sequences in Lagrange interpolation polynomials to generate the shares of a secret with reverse Huffman-Fibonacci-tree coding. The advantages of the proposed scheme is that it can detect eavesdropping without joint quantum operations, and permits secret sharing for an arbitrary but no less than threshold-value number of classical participants with much lower bandwidth. Also, in comparison with existing quantum secret sharing schemes, it still works when there are dynamic changes, such as the unavailability of some quantum channel, the arrival of new participants and the departure of participants. Finally, we provide security analysis of the new hybrid quantum secret sharing scheme and discuss its useful features for modern applications.

  19. A Hybrid Optimized Weighted Minimum Spanning Tree for the Shortest Intrapath Selection in Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Matheswaran Saravanan

    2014-01-01

    Full Text Available Wireless sensor network (WSN consists of sensor nodes that need energy efficient routing techniques as they have limited battery power, computing, and storage resources. WSN routing protocols should enable reliable multihop communication with energy constraints. Clustering is an effective way to reduce overheads and when this is aided by effective resource allocation, it results in reduced energy consumption. In this work, a novel hybrid evolutionary algorithm called Bee Algorithm-Simulated Annealing Weighted Minimal Spanning Tree (BASA-WMST routing is proposed in which randomly deployed sensor nodes are split into the best possible number of independent clusters with cluster head and optimal route. The former gathers data from sensors belonging to the cluster, forwarding them to the sink. The shortest intrapath selection for the cluster is selected using Weighted Minimum Spanning Tree (WMST. The proposed algorithm computes the distance-based Minimum Spanning Tree (MST of the weighted graph for the multihop network. The weights are dynamically changed based on the energy level of each sensor during route selection and optimized using the proposed bee algorithm simulated annealing algorithm.

  20. The Hybrid of Classification Tree and Extreme Learning Machine for Permeability Prediction in Oil Reservoir

    KAUST Repository

    Prasetyo Utomo, Chandra

    2011-06-01

    Permeability is an important parameter connected with oil reservoir. Predicting the permeability could save millions of dollars. Unfortunately, petroleum engineers have faced numerous challenges arriving at cost-efficient predictions. Much work has been carried out to solve this problem. The main challenge is to handle the high range of permeability in each reservoir. For about a hundred year, mathematicians and engineers have tried to deliver best prediction models. However, none of them have produced satisfying results. In the last two decades, artificial intelligence models have been used. The current best prediction model in permeability prediction is extreme learning machine (ELM). It produces fairly good results but a clear explanation of the model is hard to come by because it is so complex. The aim of this research is to propose a way out of this complexity through the design of a hybrid intelligent model. In this proposal, the system combines classification and regression models to predict the permeability value. These are based on the well logs data. In order to handle the high range of the permeability value, a classification tree is utilized. A benefit of this innovation is that the tree represents knowledge in a clear and succinct fashion and thereby avoids the complexity of all previous models. Finally, it is important to note that the ELM is used as a final predictor. Results demonstrate that this proposed hybrid model performs better when compared with support vector machines (SVM) and ELM in term of correlation coefficient. Moreover, the classification tree model potentially leads to better communication among petroleum engineers concerning this important process and has wider implications for oil reservoir management efficiency.

  1. Subcellular nutrient element localization and enrichment in ecto- and arbuscular mycorrhizas of field-grown beech and ash trees indicate functional differences.

    Directory of Open Access Journals (Sweden)

    Jasmin Seven

    Full Text Available Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior are colonized by arbuscular mycorrhizal fungi (AM and beech roots (Fagus sylvatica by ectomycorrhizal fungi (EcM. Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations

  2. Subcellular nutrient element localization and enrichment in ecto- and arbuscular mycorrhizas of field-grown beech and ash trees indicate functional differences.

    Science.gov (United States)

    Seven, Jasmin; Polle, Andrea

    2014-01-01

    Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of

  3. Trees

    Science.gov (United States)

    Al-Khaja, Nawal

    2007-01-01

    This is a thematic lesson plan for young learners about palm trees and the importance of taking care of them. The two part lesson teaches listening, reading and speaking skills. The lesson includes parts of a tree; the modal auxiliary, can; dialogues and a role play activity.

  4. Types of tree growth and fruit setting in F1 apple hybrids

    Directory of Open Access Journals (Sweden)

    Radu E. SESTRAS

    1998-08-01

    Full Text Available 1656 F1 hybrid apple seedlings, belonging to 127 combinations, have been screened according to their growing and fruit setting types, as it was phenotypically expressed. LESPINASSE (1977; 1992 amalgamated these two traits into a single one which was named ";ideotype";. The screened F1 individuals have been considered as resembling one of the following four architectural ideotypes of the trees indicated by Lespinasse: columnar, spur, standard and weeping. Different ratios of spur, standard and columnar F1 individuals were obtained depending on genitors and on the fact that a certain genitor had been used as a maternal or paternal partner in direct/reciprocal crosses. The monogenic inheritance of the columnar ideotype, proposed by Kelsey and Brown (1992; Lane (1992, does not seem to be the only genetic mechanism involved in the inheritance of this trait. Our experimental results suggest the polygenic determination of this ideotype as more probable than the monogenic one.

  5. Protection of ash (Fraxinus excelsior) trees from ozone injury by ethylenediurea (EDU): roles of biochemical changes and decreased stomatal conductance in enhancement of growth.

    Science.gov (United States)

    Paoletti, Elena; Contran, Nicla; Manning, William J; Castagna, Antonella; Ranieri, Annamaria; Tagliaferro, Francesco

    2008-10-01

    Treatments with ethylenediurea (EDU) protect plants from ozone foliar injury, but the processes underlying this protection are poorly understood. Adult ash trees (Fraxinus excelsior), with or without foliar ozone symptoms in previous years, were treated with EDU at 450 ppm by gravitational trunk infusion in May-September 2005 (32.5 ppm h AOT40). At 30-day intervals, shoot growth, gas exchange, chlorophyll a fluorescence, and water potential were determined. In September, several biochemical parameters were measured. The protective influence of EDU was supported by enhancement in the number of leaflets. EDU did not contribute its nitrogen to leaf tissue as a fertiliser, as determined from lack of difference in foliar N between treatments. Both biochemical (increase in ascorbate-peroxidase and ascorbic acid, and decrease in apoplastic hydrogen peroxide) and biophysical (decrease in stomatal conductance) processes regulated EDU action. As total ascorbic acid increased only in the asymptomatic trees, its role in alleviating O(3) effects on leaf growth and visible injury is controversial.

  6. A Hybrid Vector Quantization Combining a Tree Structure and a Voronoi Diagram

    Directory of Open Access Journals (Sweden)

    Yeou-Jiunn Chen

    2014-01-01

    Full Text Available Multimedia data is a popular communication medium, but requires substantial storage space and network bandwidth. Vector quantization (VQ is suitable for multimedia data applications because of its simple architecture, fast decoding ability, and high compression rate. Full-search VQ can typically be used to determine optimal codewords, but requires considerable computational time and resources. In this study, a hybrid VQ combining a tree structure and a Voronoi diagram is proposed to improve VQ efficiency. To efficiently reduce the search space, a tree structure integrated with principal component analysis is proposed, to rapidly determine an initial codeword in low-dimensional space. To increase accuracy, a Voronoi diagram is applied to precisely enlarge the search space by modeling relations between each codeword. This enables an optimal codeword to be efficiently identified by rippling an optimal neighbor from parts of neighboring Voronoi regions. The experimental results demonstrated that the proposed approach improved VQ performance, outperforming other approaches. The proposed approach also satisfies the requirements of handheld device application, namely, the use of limited memory and network bandwidth, when a suitable number of dimensions in principal component analysis is selected.

  7. Corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites reinforced with rice husk ash and silicon carbide

    OpenAIRE

    Kenneth Kanayo Alaneme; Tolulope Moyosore Adewale; Peter Apata Olubambi

    2014-01-01

    The corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites developed with the use of rice husk ash (RHA) and silicon carbide (SiC) particulates as reinforcements were investigated. RHA and SiC mixed in weight ratios 0:1, 1:3, 1:1, 3:1, and 1:0 were utilized to prepare 5, 7.5 and 10 wt% of the reinforcing phase with Al Mg Si alloy as matrix using double stir casting process. Open circuit corrosion potential (OCP) and potentiodynamic polarization measurements were used to study...

  8. Economic analysis of emerald ash borer (Coleoptera: Buprestidae) management options.

    Science.gov (United States)

    Vannatta, A R; Hauer, R H; Schuettpelz, N M

    2012-02-01

    Emerald ash borer, Agrilus planipennis (Fairmaire) (Coleoptera: Buprestidae), plays a significant role in the health and extent of management of native North American ash species in urban forests. An economic analysis of management options was performed to aid decision makers in preparing for likely future infestations. Separate ash tree population valuations were derived from the i-Tree Streets program and the Council of Tree and Landscape Appraisers (CTLA) methodology. A relative economic analysis was used to compare a control option (do-nothing approach, only removing ash trees as they die) to three distinct management options: 1) preemptive removal of all ash trees over a 5 yr period, 2) preemptive removal of all ash trees and replacement with comparable nonash trees, or 3) treating the entire population of ash trees with insecticides to minimize mortality. For each valuation and management option, an annual analysis was performed for both the remaining ash tree population and those lost to emerald ash borer. Retention of ash trees using insecticide treatments typically retained greater urban forest value, followed by doing nothing (control), which was better than preemptive removal and replacement. Preemptive removal without tree replacement, which was the least expensive management option, also provided the lowest net urban forest value over the 20-yr simulation. A "no emerald ash borer" scenario was modeled to further serve as a benchmark for each management option and provide a level of economic justification for regulatory programs aimed at slowing the movement of emerald ash borer.

  9. Different tree ages and change of ash content in Cinnamomi Cortex%肉桂树龄与其灰分含量变化的关系研究

    Institute of Scientific and Technical Information of China (English)

    李玲; 杨炯珍; 姜平川

    2012-01-01

    objective To describe the relation between different tree ages and quality of Cinnamomi Cortex. Methods The ash of cinnamon of different ages in 16 Guangxi geographic mark protection was determined. Results When the age of cinnamon was less than 10 years, the ash content was in line with the Pharmacopoeia; when the tree age of cinnamon more than 15 years, the ash content of most did not meet the Pharmacopoeia. Conclusion We suggest that Chinese Pharmacopoeia for the total ash part of cinnamon should be modified.%目的 对肉桂树龄与其灰分含量变化的关系进行研究.方法 对广西肉桂地理标志保护范围内的16个地区、市、县的不同树龄的肉桂进行灰分测定.结果 当肉桂树龄<10年,其总灰分含量符合药典规定;而当肉桂树龄≥15年时,其灰分含量大多数不符合药典规定.结论 建议对中国药典2010版一部中对于肉桂检查项下的总灰分部分的相关规定进行修改.

  10. Ash addition after whole-tree harvesting on fertile sites in southern Sweden Establishment of two field trials; Askaaterfoering efter skogsbraensleuttag paa boerdig skogsmark i soedra Sverige Anlaeggning av tvaa faeltfoersoek

    Energy Technology Data Exchange (ETDEWEB)

    Sikstroem, Ulf; Hoegbom, Lars; Jacobson, Staffan; Lundstroem, Hagos; Ring, Eva

    2012-02-15

    In Sweden, the Swedish Forest Agency recommend ash recycling after whole-tree harvest (WTH), i.e. the whole tree above the stump is harvested. If this recommendation is complied, ash recycling will become a quite extensive forestry practice. To gain more knowledge regarding effects of ash on tree growth, storage of carbon (C) and nitrogen (N) in the upper soil, and soil-water chemistry, two field experiments were established. The experimental design was a randomized block design. Both experiments were installed on quite fertile sites in southern Sweden. On fertile sites (C/N less than 30), ash addition is hypothesized to increase tree growth, reduce the storage of C and N in the upper soil, and increase the concentrations of nitrate in soil water. One experiment (291 Guvarp) was established on a recently harvested clear cut. The sample plots were soil scarified by disc trenching and planted with Norway spruce (Picea abies L. Karst.) seedlings. Seedling height was measured at planting, and, two months later, seedling survival and height growth in 2011 was recorded. The other experiment (290 Bala) was located to a Norway spruce stand that was thinned by WTH. The initial registration and sampling comprised stand data and sampling of the upper soil (FH-layer). In addition, suction cups were installed at 50 cm depth for sampling of soil water. The experiments were designed for long-term monitoring, comprising several decades. For most of the variables registered, data did not show any significant differences among means for the plots representing different treatments. Pre-treatment data for individual plots showed acceptable comparability among plots within the blocks, which is a good starting point for detecting future changes caused by the treatments

  11. Trees

    OpenAIRE

    Henri Epstein

    2016-01-01

    An algebraic formalism, developed with V. Glaser and R. Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large cate...

  12. Trees

    OpenAIRE

    Epstein, Henri

    2016-01-01

    An algebraic formalism, developped with V. Glaser and R. Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large cat...

  13. Trees

    CERN Document Server

    Epstein, Henri

    2016-01-01

    An algebraic formalism, developped with V.~Glaser and R.~Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large category of space-times.

  14. Perturbed lignification impacts tree growth in hybrid poplar--a function of sink strength, vascular integrity, and photosynthetic assimilation.

    Science.gov (United States)

    Coleman, Heather D; Samuels, A Lacey; Guy, Robert D; Mansfield, Shawn D

    2008-11-01

    The effects of reductions in cell wall lignin content, manifested by RNA interference suppression of coumaroyl 3'-hydroxylase, on plant growth, water transport, gas exchange, and photosynthesis were evaluated in hybrid poplar trees (Populus alba x grandidentata). The growth characteristics of the reduced lignin trees were significantly impaired, resulting in smaller stems and reduced root biomass when compared to wild-type trees, as well as altered leaf morphology and architecture. The severe inhibition of cell wall lignification produced trees with a collapsed xylem phenotype, resulting in compromised vascular integrity, and displayed reduced hydraulic conductivity and a greater susceptibility to wall failure and cavitation. In the reduced lignin trees, photosynthetic carbon assimilation and stomatal conductance were also greatly reduced, however, shoot xylem pressure potential and carbon isotope discrimination were higher and water-use efficiency was lower, inconsistent with water stress. Reductions in assimilation rate could not be ascribed to increased stomatal limitation. Starch and soluble sugars analysis of leaves revealed that photosynthate was accumulating to high levels, suggesting that the trees with substantially reduced cell wall lignin were not carbon limited and that reductions in sink strength were, instead, limiting photosynthesis.

  15. Exposure to residual concentrations of elements from a remediated coal fly ash spill does not adversely influence stress and immune responses of nestling tree swallows.

    Science.gov (United States)

    Beck, Michelle L; Hopkins, William A; Hallagan, John J; Jackson, Brian P; Hawley, Dana M

    2014-01-01

    Anthropogenic activities often produce pollutants that can affect the physiology, growth and reproductive success of wildlife. Many metals and trace elements play important roles in physiological processes, and exposure to even moderately elevated concentrations of essential and non-essential elements could have subtle effects on physiology, particularly during development. We examined the effects of exposure to a number of elements from a coal fly ash spill that occurred in December 2008 and has since been remediated on the stress and immune responses of nestling tree swallows. We found that nestlings at the site of the spill had significantly greater blood concentrations of Cu, Hg, Se and Zn in 2011, but greater concentrations only of Se in 2012, in comparison to reference colonies. The concentrations of elements were below levels of significant toxicological concern in both years. In 2011, we found no relationship between exposure to elements associated with the spill and basal or stress-induced corticosterone concentrations in nestlings. In 2012, we found that Se exposure was not associated with cell-mediated immunity based on the response to phytohaemagglutinin injection. However, the bactericidal capacity of nestling plasma had a positive but weak association with blood Se concentrations, and this association was stronger at the spill site. Our results indicate that exposure to these low concentrations of elements had few effects on nestling endocrine and immune physiology. The long-term health consequences of low-level exposure to elements and of exposure to greater element concentrations in avian species require additional study.

  16. A Hybrid Windkessel Model of Blood Flow in Arterial Tree Using Velocity Profile Method

    Science.gov (United States)

    Aboelkassem, Yasser; Virag, Zdravko

    2016-11-01

    For the study of pulsatile blood flow in the arterial system, we derived a coupled Windkessel-Womersley mathematical model. Initially, a 6-elements Windkessel model is proposed to describe the hemodynamics transport in terms of constant resistance, inductance and capacitance. This model can be seen as a two compartment model, in which the compartments are connected by a rigid pipe, modeled by one inductor and resistor. The first viscoelastic compartment models proximal part of the aorta, the second elastic compartment represents the rest of the arterial tree and aorta can be seen as the connection pipe. Although the proposed 6-elements lumped model was able to accurately reconstruct the aortic pressure, it can't be used to predict the axial velocity distribution in the aorta and the wall shear stress and consequently, proper time varying pressure drop. We then modified this lumped model by replacing the connection pipe circuit elements with a vessel having a radius R and a length L. The pulsatile flow motions in the vessel are resolved instantaneously along with the Windkessel like model enable not only accurate prediction of the aortic pressure but also wall shear stress and frictional pressure drop. The proposed hybrid model has been validated using several in-vivo aortic pressure and flow rate data acquired from different species such as, humans, dogs and pigs. The method accurately predicts the time variation of wall shear stress and frictional pressure drop. Institute for Computational Medicine, Dept. Biomedical Engineering.

  17. Using Hybrid Decision Tree -Houph Transform Approach For Automatic Bank Check Processing

    Directory of Open Access Journals (Sweden)

    Heba A. Elnemr

    2012-05-01

    Full Text Available One of the first steps in the realization of an automatic system of bank check processing is the automatic classification of checks and extraction of handwritten area. This paper presents a new hybrid method which couple together the statistical color histogram features, the entropy, the energy and the Houph transform to achieve the automatic classification of checks as well as the segmentation and recognition of the various information on the check. The proposed method relies on two stages. First, a two-step classification algorithm is implemented. In the first step, a decision classification tree is built using the entropy, the energy, the logo location and histogram features of colored bank checks. These features are used to classify checks into several groups. Each group may contain one or more type of checks. Therefore, in the second step the bank logo or bank name are matched against its stored template to identify the correct prototype. Second, Hough transform is utilized to detect lines in the classified checks. These lines are used as indicator to the bank check fields. A group of experiments is performed showing that the proposed technique is promising as regards classifying the bank checks and extracting the important fields in that check.

  18. Green revolution trees: semidwarfism transgenes modify gibberellins, promote root growth, enhance morphological diversity, and reduce competitiveness in hybrid poplar.

    Science.gov (United States)

    Elias, Ani A; Busov, Victor B; Kosola, Kevin R; Ma, Cathleen; Etherington, Elizabeth; Shevchenko, Olga; Gandhi, Harish; Pearce, David W; Rood, Stewart B; Strauss, Steven H

    2012-10-01

    Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI) and Repressor of GAI-Like, which affect gibberellin (GA) action, and the GA catabolic gene, GA 2-oxidase, in nursery beds and in 2-year-old high-density stands of hybrid poplar (Populus tremula × Populus alba). Twenty-nine traits were analyzed, including measures of growth, morphology, and physiology. Endogenous GA levels were modified in most transgenic events; GA(20) and GA(8), in particular, had strong inverse associations with tree height. Nearly all measured traits varied significantly among genotypes, and several traits interacted with planting density, including aboveground biomass, root-shoot ratio, root fraction, branch angle, and crown depth. Semidwarfism promoted biomass allocation to roots over shoots and substantially increased rooting efficiency with most genes tested. The increased root proportion and increased leaf chlorophyll levels were associated with changes in leaf carbon isotope discrimination, indicating altered water use efficiency. Semidwarf trees had dramatically reduced growth when in direct competition with wild-type trees, supporting the hypothesis that semidwarfism genes could be effective tools to mitigate the spread of exotic, hybrid, and transgenic plants in wild and feral populations.

  19. Evaluation of relationships between growth rate, tree size, lignocellulose composition and enzymatic saccharification in interspecific Corymbia hybrids and parental taxa.

    Directory of Open Access Journals (Sweden)

    Adam L Healey

    2016-11-01

    Full Text Available In order for a lignocellulosic bioenergy feedstock to be considered sustainable, it must possess a high rate of growth to supply biomass for conversion. Despite the desirability of a fast growth rate for industrial application, it is unclear what effect growth rate has on biomass composition or saccharification. We characterized Klason lignin, glucan, and xylan content with response to growth in Corymbia interspecific F1 hybrid families (HF and parental species C. torelliana (CT and C. citriodora subspecies variegata (CCV and measured the effects on enzymatic hydrolysis from hydrothermally pretreated biomass. Analysis of biomass composition within Corymbia populations found similar amounts of Klason lignin content (19.7-21.3% among parental and hybrid populations, whereas glucan content was clearly distinguished within CCV (52% and HF148 (60% as compared to other populations (28-38%. Multiple linear regression indicates that biomass composition is significantly impacted by tree size measured at the same age, with Klason lignin content increasing with diameter breast height (DBH (+0.12% per cm DBH increase, and glucan and xylan typically decreasing per DBH cm increase (-0.7% and -0.3%, respectively. Polysaccharide content within CCV and HF-148 were not significantly affected by tree size. High-throughput enzymatic saccharification of hydrothermally pretreated biomass found significant differences among Corymbia populations for total glucose production from biomass, with parental CT and hybrids HF-148 and HF-51 generating the highest amounts of glucose (~180 mg/g biomass, respectively, with HF-51 undergoing the most efficient glucan-to-glucose conversion (74%. Based on growth rate, biomass composition, and further optimization of enzymatic saccharification yield, high production Corymbia hybrid trees are potentially suitable for fast-rotation bioenergy or biomaterial production.

  20. Genetic analysis of an ephemeral intraspecific hybrid zone in the hypervariable tree, Metrosideros polymorpha, on Hawai'i Island.

    Science.gov (United States)

    Stacy, E A; Johansen, J B; Sakishima, T; Price, D K

    2016-09-01

    Intraspecific hybrid zones involving long-lived woody species are rare and can provide insights into the genetic basis of early-diverging traits in speciation. Within the landscape-dominant Hawaiian tree, Metrosideros polymorpha, are morphologically distinct successional varieties, incana and glaberrima, that dominate new and old lava flows, respectively, below 1200 me on volcanically active Hawai'i Island, with var. glaberrima also extending to higher elevations and bogs. Here, we use morphological measurements on 86 adult trees to document the presence of an incana-glaberrima hybrid zone on the 1855 Mauna Loa lava flow on east Hawai'i Island and parent-offspring analysis of 1311 greenhouse seedlings from 71 crosses involving 72 adults to estimate heritabilities and genetic correlations among vegetative traits. Both the variation in adult leaf pubescence at the site and the consistency between adult and offspring phenotypes suggest the presence of two hybrid classes, F1s and var. incana backcrosses, as would be expected on a relatively young lava flow. Nine nuclear microsatellite loci failed to distinguish parental and hybrid genotypes. All four leaf traits examined showed an additive genetic basis with moderate to strong heritabilities, and genetic correlations were stronger for the more range-restricted var. incana. The differences between varieties in trait values, heritabilities and genetic correlations, coupled with high genetic variation within but low genetic variation between varieties, are consistent with a multi-million-year history of alternating periods of disruptive selection in contrasting environments and admixture in ephemeral hybrid zones. Finally, the contrasting genetic architectures suggest different evolutionary trajectories of leaf traits in these forms.

  1. Growth of Larval Agrilus planipennis (Coleoptera: Buprestidae) and Fitness of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Blue Ash (Fraxinus quadrangulata) and Green Ash (F. pennsylvanica).

    Science.gov (United States)

    Peterson, Donnie L; Duan, Jian J; Yaninek, J S; Ginzel, Matthew D; Sadof, Clifford S

    2015-12-01

    Emerald ash borer (Agrilus planipennis Fairmaire) is an invasive primary pest of North American ash (Fraxinus spp.) trees. Blue ash (F. quadrangulata) is less susceptible to emerald ash borer infestations in the forest than other species of North American ash. Whereas other studies have examined adult host preferences, we compared the capacity of emerald ash borer larvae reared from emerald ash borer eggs in the field and in the laboratory to survive and grow in blue ash and the more susceptible green ash (F. pennsylvanica). Emerald ash borer larval survivorship was the same on both ash species. Mortality due to wound periderm formation was only observed in living field grown trees, but was low (<4%) in both green and blue ash. No difference in larval mortality in the absence of natural enemies suggests that both green and blue ash can support the development of emerald ash borer. Larvae reared from eggs on blue ash were smaller than on green ash growing in the field and also in bolts that were infested under laboratory conditions. In a laboratory study, parasitism rates of confined Tetrastichus planipennisi were similar on emerald ash borer larvae reared in blue and green ash bolts, as were fitness measures of the parasitoid including brood size, sex ratio, and adult female size. Thus, we postulate that emerald ash borer larvae infesting blue ash could support populations of T. planipennisi and serve as a potential reservoir for this introduced natural enemy after most of the other native ash trees have been killed.

  2. Partial results regarding the selection of some nut tree hybrids in order to obtain generative mother plants

    Directory of Open Access Journals (Sweden)

    Eliane Teodora STANCIOIU

    2008-05-01

    Full Text Available In Romania, the establishment of nut tree plantations is continuously expanding, yet the seeding material production has never raised up to the level of cultivators requirements.In our country, although the mother plants are confirmed as Targu Jiu 1, Secular and recently Portval, because of lack of seed tree materials, at present, most of the varieties are being grafted on saplings proceeded from a mixture of genotypes belonging to the species of Juglans regia.By studying the rich stock of germoplasma, present in the district of Gorj, 20 hybrids, that have appropriate features to their formation as mother plants have been collected, so that they might improve the existing variety.

  3. Transcriptomic signatures of ash (Fraxinus spp. phloem.

    Directory of Open Access Journals (Sweden)

    Xiaodong Bai

    Full Text Available BACKGROUND: Ash (Fraxinus spp. is a dominant tree species throughout urban and forested landscapes of North America (NA. The rapid invasion of NA by emerald ash borer (Agrilus planipennis, a wood-boring beetle endemic to Eastern Asia, has resulted in the death of millions of ash trees and threatens billions more. Larvae feed primarily on phloem tissue, which girdles and kills the tree. While NA ash species including black (F. nigra, green (F. pennsylvannica and white (F. americana are highly susceptible, the Asian species Manchurian ash (F. mandshurica is resistant to A. planipennis perhaps due to their co-evolutionary history. Little is known about the molecular genetics of ash. Hence, we undertook a functional genomics approach to identify the repertoire of genes expressed in ash phloem. METHODOLOGY AND PRINCIPAL FINDINGS: Using 454 pyrosequencing we obtained 58,673 high quality ash sequences from pooled phloem samples of green, white, black, blue and Manchurian ash. Intriguingly, 45% of the deduced proteins were not significantly similar to any sequences in the GenBank non-redundant database. KEGG analysis of the ash sequences revealed a high occurrence of defense related genes. Expression analysis of early regulators potentially involved in plant defense (i.e. transcription factors, calcium dependent protein kinases and a lipoxygenase 3 revealed higher mRNA levels in resistant ash compared to susceptible ash species. Lastly, we predicted a total of 1,272 single nucleotide polymorphisms and 980 microsatellite loci, among which seven microsatellite loci showed polymorphism between different ash species. CONCLUSIONS AND SIGNIFICANCE: The current transcriptomic data provide an invaluable resource for understanding the genetic make-up of ash phloem, the target tissue of A. planipennis. These data along with future functional studies could lead to the identification/characterization of defense genes involved in resistance of ash to A. planipennis

  4. Microstructural characteristics, mechanical and wear behaviour of aluminium matrix hybrid composites reinforced with alumina, rice husk ash and graphite

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2015-09-01

    Full Text Available The microstructural characteristics, mechanical and wear behaviour of Aluminium matrix hybrid composites reinforced with alumina, rice husk ash (RHA and graphite were investigated. Alumina, RHA and graphite mixed in varied weight ratios were utilized to prepare 10 wt% hybrid reinforced Al-Mg-Si alloy based composites using two-step stir casting. Hardness, tensile properties, scanning electron microscopy, and wear tests were used to characterize the composites produced. The results show that Hardness decreases with increase in the weight ratio of RHA and graphite in the composites; and with RHA content greater than 50%, the effect of graphite on the hardness becomes less significant. The tensile strength for the composites containing o.5wt% graphite and up to 50% RHA was observed to be higher than that of the composites without graphite. The toughness values for the composites containing 0.5wt% graphite were in all cases higher than that of the composites without graphite. The % Elongation for all composites produced was within the range of 10–13% and the values were invariant to the RHA and graphite content. The tensile fracture surface morphology in all the composites produced was identical characterized with the presence of reinforcing particles housed in ductile dimples. The composites without graphite exhibited greater wear susceptibility in comparison to the composite grades containing graphite. However the wear resistance decreased with increase in the graphite content from 0.5 to 1.5 wt%.

  5. Outlook for ash in your forest: results of emerald ash borer research and implications for management

    Science.gov (United States)

    Kathleen S. Knight

    2014-01-01

    Since its accidental introduction near Detroit, Michigan, in the mid-1990s, emerald ash borer (EAB) has rapidly spread through much of the U.S. and adjacent Canada, leaving millions of dead ash trees in Midwestern states (4,11). Unfortunately, EAB attacks trees as small as an inch in stem diameter and it attacks all five ash species native to the region - white, green...

  6. Corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites reinforced with rice husk ash and silicon carbide

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2014-01-01

    Full Text Available The corrosion and wear behaviour of Al–Mg–Si alloy matrix hybrid composites developed with the use of rice husk ash (RHA and silicon carbide (SiC particulates as reinforcements were investigated. RHA and SiC mixed in weight ratios 0:1, 1:3, 1:1, 3:1, and 1:0 were utilized to prepare 5, 7.5 and 10 wt% of the reinforcing phase with Al Mg Si alloy as matrix using double stir casting process. Open circuit corrosion potential (OCP and potentiodynamic polarization measurements were used to study the corrosion behaviour while coefficient of friction was used to assess the wear behaviour of the composites. The corrosion and wear mechanisms were established with the aid of scanning electron microscopy. The results show that the effect of RHA/SiC weight ratio on the corrosion behaviour of the composites in 3.5% NaCl solution was not consistent for the different weight percent of reinforcement (5, 7.5, and 10 wt% used in developing the Al–Mg–Si based composites. It was evident that for most cases the use of hybrid reinforcement of RHA and SiC resulted in improved corrosion resistance of the composites in 3.5% NaCl solution. Preferential dissolution of the more anodic Al–Mg–Si alloy matrix around the Al–Mg–Si matrix/RHA/SiC particle interfaces was identified as the primary corrosion mechanism. The coefficient of friction and consequently the wear resistance of the hybrid composites were comparable to that of the Al–Mg–Si alloy matrix reinforced with only SiC.

  7. Cloning and Overproduction of Gibberellin 3-Oxidase in Hybrid Aspen Trees. Effects on Gibberellin Homeostasis and Development1

    Science.gov (United States)

    Israelsson, Maria; Mellerowicz, Ewa; Chono, Makiko; Gullberg, Jonas; Moritz, Thomas

    2004-01-01

    To broaden our understanding of gibberellin (GA) biosynthesis and the mechanism whereby GA homeostasis is maintained in plants, we have investigated the degree to which the enzyme GA 3-oxidase (GA3ox) limits the formation of bioactive GAs in elongating shoots of hybrid aspen (Populus tremula × Populus tremuloides). We describe the cloning of a hybrid aspen GA3ox and its functional characterization, which confirmed that it has 3β-hydroxylation activity and more efficiently converts GA9 to GA4 than GA20 to GA1. To complement previous studies, in which transgenic GA 20-oxidase (GA20ox) overexpressers were found to produce 20-fold higher bioactive GA levels and subsequently grew faster than wild-type plants, we overexpressed an Arabidopsis GA3ox in hybrid aspen. The generated GA3ox overexpresser lines had increased 3β-hydroxylation activity but exhibited no major changes in morphology. The nearly unaltered growth pattern was associated with relatively small changes in GA1 and GA4 levels, although tissue-dependent differences were observed. The absence of increases in bioactive GA levels did not appear to be due to feedback or feed-forward regulation of dioxygenase transcripts, according to semiquantitative reverse transcription polymerase chain reaction analysis of PttGA20ox1, PttGA3ox1, and two putative PttGA2ox genes. We conclude that 20-oxidation is the limiting step, rather than 3β-hydroxylation, in the formation of GA1 and GA4 in elongating shoots of hybrid aspen, and that ectopic GA3ox expression alone cannot increase the flux toward bioactive GAs. Finally, several lines of evidence now suggest that GA4 has a more pivotal role in the tree hybrid aspen than previously believed. PMID:15122019

  8. Cloning and overproduction of gibberellin 3-oxidase in hybrid aspen trees. Effects on gibberellin homeostasis and development.

    Science.gov (United States)

    Israelsson, Maria; Mellerowicz, Ewa; Chono, Makiko; Gullberg, Jonas; Moritz, Thomas

    2004-05-01

    To broaden our understanding of gibberellin (GA) biosynthesis and the mechanism whereby GA homeostasis is maintained in plants, we have investigated the degree to which the enzyme GA 3-oxidase (GA3ox) limits the formation of bioactive GAs in elongating shoots of hybrid aspen (Populus tremula x Populus tremuloides). We describe the cloning of a hybrid aspen GA3ox and its functional characterization, which confirmed that it has 3beta-hydroxylation activity and more efficiently converts GA9 to GA4 than GA20 to GA1. To complement previous studies, in which transgenic GA 20-oxidase (GA20ox) overexpressers were found to produce 20-fold higher bioactive GA levels and subsequently grew faster than wild-type plants, we overexpressed an Arabidopsis GA3ox in hybrid aspen. The generated GA3ox overexpresser lines had increased 3beta-hydroxylation activity but exhibited no major changes in morphology. The nearly unaltered growth pattern was associated with relatively small changes in GA1 and GA4 levels, although tissue-dependent differences were observed. The absence of increases in bioactive GA levels did not appear to be due to feedback or feed-forward regulation of dioxygenase transcripts, according to semiquantitative reverse transcription polymerase chain reaction analysis of PttGA20ox1, PttGA3ox1, and two putative PttGA2ox genes. We conclude that 20-oxidation is the limiting step, rather than 3beta-hydroxylation, in the formation of GA1 and GA4 in elongating shoots of hybrid aspen, and that ectopic GA3ox expression alone cannot increase the flux toward bioactive GAs. Finally, several lines of evidence now suggest that GA4 has a more pivotal role in the tree hybrid aspen than previously believed.

  9. New Hybrid Algorithms for Estimating Tree Stem Diameters at Breast Height Using a Two Dimensional Terrestrial Laser Scanner.

    Science.gov (United States)

    Kong, Jianlei; Ding, Xiaokang; Liu, Jinhao; Yan, Lei; Wang, Jianli

    2015-07-02

    In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH) for tree trunks in forest areas is proposed. First, the information is collected by a two-dimensional terrestrial laser scanner (2DTLS), which emits laser pulses to generate a point cloud. After extraction and filtration, the laser point clusters of the trunks are obtained, which are optimized by an arithmetic means method. Then, an algebraic circle fitting algorithm in polar form is non-linearly optimized by the Levenberg-Marquardt method to form a new hybrid algorithm, which is used to acquire the diameters and positions of the trees. Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time. Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.

  10. New Hybrid Algorithms for Estimating Tree Stem Diameters at Breast Height Using a Two Dimensional Terrestrial Laser Scanner

    Science.gov (United States)

    Kong, Jianlei; Ding, Xiaokang; Liu, Jinhao; Yan, Lei; Wang, Jianli

    2015-01-01

    In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH) for tree trunks in forest areas is proposed. First, the information is collected by a two-dimensional terrestrial laser scanner (2DTLS), which emits laser pulses to generate a point cloud. After extraction and filtration, the laser point clusters of the trunks are obtained, which are optimized by an arithmetic means method. Then, an algebraic circle fitting algorithm in polar form is non-linearly optimized by the Levenberg-Marquardt method to form a new hybrid algorithm, which is used to acquire the diameters and positions of the trees. Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time. Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents. PMID:26147726

  11. New Hybrid Algorithms for Estimating Tree Stem Diameters at Breast Height Using a Two Dimensional Terrestrial Laser Scanner

    Directory of Open Access Journals (Sweden)

    Jianlei Kong

    2015-07-01

    Full Text Available In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH for tree trunks in forest areas is proposed. First, the information is collected by a two-dimensional terrestrial laser scanner (2DTLS, which emits laser pulses to generate a point cloud. After extraction and filtration, the laser point clusters of the trunks are obtained, which are optimized by an arithmetic means method. Then, an algebraic circle fitting algorithm in polar form is non-linearly optimized by the Levenberg-Marquardt method to form a new hybrid algorithm, which is used to acquire the diameters and positions of the trees. Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time. Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.

  12. Hybrid Medical Image Classification Using Association Rule Mining with Decision Tree Algorithm

    OpenAIRE

    Rajendran, P.; M.Madheswaran

    2010-01-01

    The main focus of image mining in the proposed method is concerned with the classification of brain tumor in the CT scan brain images. The major steps involved in the system are: pre-processing, feature extraction, association rule mining and hybrid classifier. The pre-processing step has been done using the median filtering process and edge features have been extracted using canny edge detection technique. The two image mining approaches with a hybrid manner have been proposed in this paper....

  13. Nature of fly ash amendments differently influences oxidative stress alleviation in four forest tree species and metal trace element phytostabilization in aged contaminated soil: A long-term field experiment.

    Science.gov (United States)

    Labidi, Sonia; Firmin, Stéphane; Verdin, Anthony; Bidar, Géraldine; Laruelle, Frédéric; Douay, Francis; Shirali, Pirouz; Fontaine, Joël; Lounès-Hadj Sahraoui, Anissa

    2017-04-01

    Aided phytostabilization using coal fly ashes (CFAs) is an interesting technique to clean-up polluted soils and valorizing industrial wastes. In this context, our work aims to study the effect of two CFAs: silico-aluminous (CFA1) and sulfo-calcic (CFA2) ones, 10 years after their addition, on the phytostabilization of a highly Cd (cadmium), Pb (lead) and Zn (zinc) contaminated agricultural soil, with four forest tree species: Robinia pseudoacacia, Alnus glutinosa, Acer pseudoplatanus and Salix alba. To assess the effect of CFAs on trees, leaf fatty acid composition, malondialdehyde (MDA), oxidized and reduced glutathione contents ratio (GSSG: GSH), 8-hydroxy-2'-deoxyguanosine (8-OHdG), Peroxidase (PO) and Superoxide dismutase (SOD) activities were examined. Our results showed that CFA amendments decreased the CaCl2-extractable fraction of Cd and Zn from the soil. However, no significant effect was observed on metal trace element (MTE) concentrations in leaves. Fatty acid percentages were only affected by the addition of sulfo-calcic CFA. The most affected species were A. glutinosa and R. pseudoacacia in which C16:0, C18:0 and C18:2 percentages increased significantly whereas the C18:3 decreased. The addition of sulfo-calcic CFA induced the antioxidant systems response in tree leaves. An increase of SOD and POD activities in leaves of trees planted on the CFA2-amended plot was recorded. Conversely, silico-aluminous CFA generated a reduction of lipid and DNA oxidation associated with the absence or low induction of anti-oxidative processes. Our study evidenced oxidative stress alleviation in tree leaves due to CFA amendments. MTE mobility in contaminated soil and their accumulation in leaves differed with the nature of CFA amendments and the selected tree species.

  14. Tree-based intercropping systems increase growth and nutrient status of hybrid poplar: a case study from two Northeastern American experiments.

    Science.gov (United States)

    Rivest, David; Cogliastro, Alain; Olivier, Alain

    2009-01-01

    Tree-based intercropping is considered to be a potentially useful land use system for mitigating negative environmental impacts from intensive agriculture such as nutrient leaching and greenhouse gas emissions. Rapid early growth of trees is critical for rapidly accruing environmental benefits provided by the trees. We tested the hypothesis that intercropping increases the growth and nutrient status of young hybrid poplars (Populus spp.), compared to a harrowing alley treatment (i.e., no intercrop), in two experimental sites (St-Rémi and St-Edouard) in southern Québec, Canada. Three hybrid poplar clones (TD3230, Populus trichocarpa x deltoides; DN3308, P. deltoides x nigra; and NM3729, P. nigra x maximowiczii) were planted at St-Rémi. Clones DN3333 and DN3570 were planted at St-Edouard. At St-Rémi, intercropping comprised a 4-year succession of three crops of soybean (Glycine max (L.) Merr.) and barley (Hordeum vulgare L.). At St-Edouard, intercropping comprised a 3-year succession of buckwheat (Fagopyrum esculentum Moench), winter rye (Secale cereale L.), and winter wheat (Triticum aestivum L.). At St-Rémi, four years after treatment began, leafless aboveground biomass of hybrid poplars in the intercropping treatment was 37% higher compared to that in the harrowing treatment. At St-Edouard, after the third growing season, leafless aboveground biomass of hybrid poplars in the intercropping treatment was significantly higher by 40%. Vector analysis of foliar nutrient concentrations and comparison with critical concentration values showed that N (both sites) and K (St-Edouard) were the most limiting nutrients. Hybrid poplar clones responded similarly to treatments, with no consistent differences in tree growth observed between clones. We conclude that tree-based intercropping systems may offer an effective means of improving the early growth of hybrid poplars planted to provide both environmental services and high-value timber.

  15. 10 Risk to Ash from Emerald Ash Borer: Can Biological Control Prevent the Loss of Ash Stands

    Science.gov (United States)

    Ash trees were once relatively free of serious, major diseases and insect pests in North America until the arrival of EAB, which was first detected in North America in Michigan in 2002. As of February 2014, EAB had been detected in 22 U.S. states and two Canadian provinces, killing millions of ash ...

  16. Microsatellites for the mangrove tree Avicennia germinans (Acanthaceae): Tools for hybridization and mating system studies.

    Science.gov (United States)

    Mori, Gustavo M; Zucchi, Maria I; Sampaio, Iracilda; Souza, Anete P

    2010-09-01

    We developed a new set of microsatellite markers for the black mangrove Avicennia germinans, to provide new informative tools for further studies of the mating system, interspecific hybridization, and population genetics. • We used the microsatellite-enriched library approach to isolate and characterize 25 new primer pairs. Sixteen of them are polymorphic, showing a variable degree of variation in A. germinans, while nine were monomorphic in the samples examined. Eight exhibited private alleles in A. schaueriana. • These results indicate that these new microsatellite markers will be useful molecular tools for further studies of A. germinans and A. schaueriana population genetics, mating systems, and hybridization.

  17. Ash in the Soil System

    Science.gov (United States)

    Pereira, P.

    2012-04-01

    Ash is the organic and inorganic residue produced by combustion, under laboratory and field conditions. This definition is far away to be accepted. Some researchers consider ash only as the inorganic part, others include also the material not completely combusted as charcoal or biochar. There is a need to have a convergence about this question and define clear "what means ash". After the fire and after spread ash onto soil surface, soil properties can be substantially changed depending on ash properties, that can be different according to the burned residue (e.g wood, coal, solid waste, peppermill, animal residues), material treatment before burning, time of exposition and storage conditions. Ash produced in boilers is different from the produced in fires because of the material diferent propertie and burning conditions. In addition, the ash produced in boilers is frequently treated (e.g pelletization, granulation, self curing) previously to application, to reduce the negative effects on soil (e.g rapid increase of pH, mycorrhiza, fine roots of trees and microfauna). These treatments normally reduce the rate of nutrients dissolution. In fires this does not happen. Thus the implications on soil properties are logically different. Depending on the combustion temperature and/or severity, ash could have different physical (e.g texture, wettability) and chemical properties (e.g amount and type of total and leached nutrients) and this will have implications on soil. Ash can increase and decrease soil aggregation, wettablity and water retention, bulk density, runoff and water infiltration. Normally, ash increases soil pH, Electrical Conductivity, and the amount of some basic nutrients as calcium, magnesium, sodium and potassium. However it is also a potential source of heavy metals, especially if ash pH is low. However the effect of ash on soil in space and time depends especially of the ash amount and characteristics, fire temperature, severity, topography, aspect

  18. Modeling and Analysis of Mesh Tree Hybrid Power/Ground Networks with Multiple Voltage Supply in Time Domain

    Institute of Scientific and Technical Information of China (English)

    Yi-Ci Cai; Jin Shi; Zu-Ying Luo; Xian-Long Hong

    2005-01-01

    This paper proposes a novel algorithm, which can be used to model and analyze mesh tree hybrid power/ground distribution networks with multiple voltage supply in time domain. Not only this algorithm enhances common method's ability on analysis of power/ground network with irregular topology, but also very high accuracy it keeps. The accuracy and stability of this algorithm is proved using strict math method in this paper. Also, the usage of both precondition technique based on Incomplete Choleskey Decomposition and fast variable elimination technique has improved the algorithm's efficiency a lot. Experimental results show that it can finish the analysis of power/ground network with enormous size within very short time. Also, this algorithm can be applied to analyze the clock network, bus network, and signal network without buffer under high working frequency because of the independence of the topology.

  19. A Hybrid Key Management Scheme for WSNs Based on PPBR and a Tree-Based Path Key Establishment Method.

    Science.gov (United States)

    Zhang, Ying; Liang, Jixing; Zheng, Bingxin; Chen, Wei

    2016-04-09

    With the development of wireless sensor networks (WSNs), in most application scenarios traditional WSNs with static sink nodes will be gradually replaced by Mobile Sinks (MSs), and the corresponding application requires a secure communication environment. Current key management researches pay less attention to the security of sensor networks with MS. This paper proposes a hybrid key management schemes based on a Polynomial Pool-based key pre-distribution and Basic Random key pre-distribution (PPBR) to be used in WSNs with MS. The scheme takes full advantages of these two kinds of methods to improve the cracking difficulty of the key system. The storage effectiveness and the network resilience can be significantly enhanced as well. The tree-based path key establishment method is introduced to effectively solve the problem of communication link connectivity. Simulation clearly shows that the proposed scheme performs better in terms of network resilience, connectivity and storage effectiveness compared to other widely used schemes.

  20. EAB induced tree mortality impacts ecosystem respiration and tree water use in an experimental forest

    Science.gov (United States)

    Charles E. Flower; Douglas J. Lynch; Kathleen S. Knight; Miquel A. Gonzales-Meler

    2011-01-01

    The invasive emerald ash borer (Agrilus planipennis Fairmaire, EAB) has been spreading across the forest landscape of the Midwest resulting in the rapid decline of ash trees (Fraxinus spp.). Ash trees represent a dominant riparian species in temperate deciduous forests of the Eastern United States (USDA FIA Database). Prior...

  1. Emerald ash borer biology and invasion history

    Science.gov (United States)

    Robert A. Haack; Yuri Baranchikov; Leah S. Bauer; Therese M. Poland

    2015-01-01

    The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is native to eastern Asia and is primarily a pest of ash (Fraxinus) trees (Fig. 1). Established populations of EAB were first detected in the United States and Canada in 2002 (Haack et al., 2002), and based on a dendrochronology study by Siegert...

  2. Specific gravity of hybrid poplars in the north-central region, USA: within-tree variability and site × genotype effects

    Science.gov (United States)

    William L. Headlee; Ronald S. Jr. Zalesny; Richard B. Hall; Edmund O. Bauer; Bradford Bender; Bruce A. Birr; Raymond O. Miller; Jesse A. Randall; Adam H. Wiese

    2013-01-01

    Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most...

  3. Emerald ash borer biological control release and recovery guidelines

    Science.gov (United States)

    Juli S. Gould; Leah S. Bauer; Jian. Duan

    2015-01-01

    Emerald ash borer (EAB), a beetle from Asia that feeds on ash trees, was discovered as the cause of extensive ash mortality in southeast Michigan and adjacent areas of Canada in 2002. It is thought that this destructive pest was introduced in the early 1990's in infested solid wood packing material originating in Asia. Shortly after EAB was discovered in North...

  4. Phasing Variants in Poplar Trees using a Hybrid of Short & Long Read Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Schackwitz, Wendy; Martin, Joel; Lipzen, Anna; Pennacchio, Len; Tuskan, Gerald

    2013-03-26

    Poplar grow throughout the West coast & are adapted to extremely variable conditions. To examine what allows for this wide range of growth conditions, Jerry Tuskan's team has collected 1000 different individuals from British Columbia to California. In 2009, three Common Gardens were established where each individual was cloned in triplicate. Nearly all of these trees have been sequenced using short read technology, revealing a huge degree of variation in genotype. Correlating this genomic variation to phenotype would be greatly be strengthened if the variants could be phased into long haplotype blocks.

  5. Photocatalytic enhancement of floating photocatalyst: Layer-by-layer hybrid carbonized chitosan and Fe-N- codoped TiO2 on fly ash cenospheres

    Science.gov (United States)

    Song, Jingke; Wang, Xuejiang; Bu, Yunjie; Wang, Xin; Zhang, Jing; Huang, Jiayu; Ma, RongRong; Zhao, Jianfu

    2017-01-01

    Due to the advantage of floating on water surface, floating photocatalysts show higher rates of radical formation and collection efficiencies. And they were expected to be used for solar remediation of non-stirred and non-oxygenated reservoirs. In this research, floating fly ash cenospheres (FAC) supported layer-by- layer hybrid carbonized chitosan and Fe-N-codoped TiO2 was prepared by a simple sol-gel method. The catalysts were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy(DRS), nitrogen adsorption analyses for Brunauer-Emmett-Teller (BET) specific surface area. It is indicated that Fe-N codoped narrowed the material's band gap, and the layer of carbonized chitosan (Cts) increased the catalyst's adsorption capacity and the absorption ability of visible light. Comparing with Fe-N-TiO2/FAC and N-TiO2/FAC, the composite photocatalyst show excellent performance on the degradation of RhB. Photodegradation rate of RhB by Fe-N-TiO2/FAC-Cts was 0.01018 min-1, which is about 1.5 and 2.09 times higher than Fe-N-TiO2/FAC and N-TiO2/FAC under visible light irradiation in 240 min, respectively. The dye photosentization, capture of holes and electrons by Fe3+ ion, and synergistic effect of adsorption and photodegradation were attributed to the results for the improvement of photocatalytic performance. The floating photocatalyst can be reused for at least three consecutive times without any significant decrease on the degradation of Rhodamin B after each reuse.

  6. 76 FR 5679 - Emerald Ash Borer; Addition of Quarantined Areas in Kentucky, Michigan, Minnesota, New York...

    Science.gov (United States)

    2011-02-02

    ... planipennis) is a destructive wood-boring insect that attacks ash trees (Fraxinus spp., including green ash.... Ash trees are valuable to the commercial timber industry and are commonly planted in urban areas. In... nurseries, timber operations, and landscaping. These potential economic impacts would likely be much...

  7. Evaluation of reference genes for expression studies in ash (Fraxinus spp.)

    Science.gov (United States)

    Loren Rivera-Vega; Praveen Mamidala; Jennifer L. Koch; Mary E. Mason; Omprakash. Mittapalli

    2012-01-01

    Ash (Fraxinus spp.) is a dominant tree species in North America, in both managed and natural landscapes. However, due to the rapid invasion by the emerald ash borer (Agrilus planipennis), an exotic invasive insect pest, millions of North American ash trees have been killed. Real-time quantitative polymerase chain reaction (RTq-PCR...

  8. A hybrid model using decision tree and neural network for credit scoring problem

    Directory of Open Access Journals (Sweden)

    Amir Arzy Soltan

    2012-08-01

    Full Text Available Nowadays credit scoring is an important issue for financial and monetary organizations that has substantial impact on reduction of customer attraction risks. Identification of high risk customer can reduce finished cost. An accurate classification of customer and low type 1 and type 2 errors have been investigated in many studies. The primary objective of this paper is to develop a new method, which chooses the best neural network architecture based on one column hidden layer MLP, multiple columns hidden layers MLP, RBFN and decision trees and ensembling them with voting methods. The proposed method of this paper is run on an Australian credit data and a private bank in Iran called Export Development Bank of Iran and the results are used for making solution in low customer attraction risks.

  9. Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

    Science.gov (United States)

    Chen, Yigen; Poland, Therese M

    2009-12-01

    The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

  10. Tree and stand water fluxes of hybrid poplar clone (Populus nigra x P. maximowiczii) in short rotation coppice culture

    Science.gov (United States)

    Fischer, M.; Trnka, M.; Kucera, J.; Zalud, Z.

    2010-09-01

    This study reports on evapotranspiration and tree water use in short rotation coppice culture of hybrid poplar (Populus nigra x P. maximowiczii) for biomass energy in the Czech Republic. The high density poplar plantation (10 000 trees per ha) was established in 2003 on arable land in Czech-Moravian Highland (49°32´ N, 16°15´ E, 530 m a.s.l.) and has been coppiced in rotation period of 7 years. Firstly, evapotranspiration of the stand has been estimated by applying the Bowen ratio-energy budget method, which is considered as reliable, robust, quite simple and inexpensive technique with comparable results to eddy covariance and lysimeters. The gaps in evapotranspiration diurnal patterns caused by limitation of the bowen ratio method were filled with simple linear regression model based on relation between potential and actual evapotranspiration with regard to soil water availability and leaf area index and thus the daily, monthly and seasonal totals could be calculated. The amount of evapotranspiration during the growing season 2009 (1 March - 31 October) was 593 mm with highest monthly total 116 mm in June. Mean daily water loss over the season reached 2.43 mm per day. During the hot summer day, the maximal value 5.73 mm per day, which presented 89 % of potential evapotranspiration calculated by Penman equation, was recorded with a peak rate 0.94 mm per hour. Secondly, the transpiration was measured by sap flow tissue heat balance techniques on four individual trees with greatest stem diameters (11 - 12 cm d.b.h.) and height of 12 - 12.5 m. Relatively high transpiration values by the poplars were found during the measured part of growing season (18 June - 31 October), with maximum and mean daily transpiration of 44.41 dm3 and 16.69 dm3 per day, respectively. The seasonal transpiration of the most vigorous from the investigated individuals amounted 2542 dm3. Because in this study we didńt evaluate the transpiration of thinner trees (technical features of sap

  11. Hybridizing rapidly exploring random trees and basin hopping yields an improved exploration of energy landscapes.

    Science.gov (United States)

    Roth, Christine-Andrea; Dreyfus, Tom; Robert, Charles H; Cazals, Frédéric

    2016-03-30

    The number of local minima of the potential energy landscape (PEL) of molecular systems generally grows exponentially with the number of degrees of freedom, so that a crucial property of PEL exploration algorithms is their ability to identify local minima, which are low lying and diverse. In this work, we present a new exploration algorithm, retaining the ability of basin hopping (BH) to identify local minima, and that of transition based rapidly exploring random trees (T-RRT) to foster the exploration of yet unexplored regions. This ability is obtained by interleaving calls to the extension procedures of BH and T-RRT, and we show tuning the balance between these two types of calls allows the algorithm to focus on low lying regions. Computational efficiency is obtained using state-of-the art data structures, in particular for searching approximate nearest neighbors in metric spaces. We present results for the BLN69, a protein model whose conformational space has dimension 207 and whose PEL has been studied exhaustively. On this system, we show that the propensity of our algorithm to explore low lying regions of the landscape significantly outperforms those of BH and T-RRT.

  12. Topological incongruence between nuclear and chloroplast DNA trees suggesting hybridization in the urophyllum group of the genus Fagopyrum (Polygonaceae).

    Science.gov (United States)

    Nishimoto, Yuriko; Ohnishi, Ohmi; Hasegawa, Masami

    2003-04-01

    We performed phylogenetic analyses of Fagopyrum species in the urophyllum group based on nucleotide sequences of two nuclear genes, FLORICAULA/LEAFY (FLO/LFY) and AGAMOUS (AG), and three segments of chloroplast DNA (cpDNA), rbcL-accD, trnK intron, and trnC-rpoB spacer. The FLO/LFY and AG sequences turned out to be phylogenetically more informative at the intrageneric level than the cpDNA sequences. Congruence among these gene trees, inferred by a maximum-likelihood (ML) method, demonstrated that topologies were partially incongruent between the nuclear and chloroplast DNA phylogenies. The nuclear DNA sequence data supported a monophyletic relation of F. statice, F. gilesii, and F. jinshaense, whereas the former two species formed another monophyletic relation with the F. capillatum-F. gracilipes-F. gracilipedoides-F. rubifolium clade excluding F. jinshaense in the synthetic cpDNA phylogeny. In addition, two divergent sequences of FLO/LFY were found in F. rubifolium (tetraploid). One of these was sister to F. gracilipedoides and another was sister to F. statice, and a monophyletic relation of these two genes was rejected by a bootstrap analysis. These results suggest that hybridization may have occurred during diversification of Fagopyrum species in the urophyllum group, and that F. rubifolium is possibly allotetraploid species.

  13. Addition of ash and PK with or without N on a peatland in southern Sweden. Effects on tree growth and needle element concentrate; Tillfoersel av aska och PK med eller utan N paa en torvmark i soedra Sverige. Effekter paa traedtillvaext och aemneshalter i barr

    Energy Technology Data Exchange (ETDEWEB)

    Sikstroem, Ulf (Forestry Research Inst. of Sweden, Uppsala (Sweden))

    2008-04-15

    In Sweden, about 1.3 million tonnes of ash are produced annually. Out of that amount, 150 000 - 300 000 tonnes have been estimated to originate from forest fuels, i.e. ashes that potentially can be brought back to the forest. Apart from being a compensatory measure after intensive forest harvest (e.g. including tops and branches), the ash may be used to increase the tree growth on peat soils (ash fertilization). On peat soils, tree growth is generally increased after addition of ash or phosphorous (P) and potassium (K) fertilizers. However, in some cases also nitrogen (N) addition is required. On sparsely stocked mires, fertilization may promote the regeneration as well as increase the growth of the trees. Sufficient drainage and supply of plant-available N are some prerequisites for increasing tree growth by PK-addition. In 1982, Skogforsk established a field experiment (168 Perstorp) located in the province of Scania in a sparsely stocked Pinus Sylvestris (L.) sapling stand on a ditched mire where different nutrient regimes were tested. The experiment had a randomized block design including four blocks and seven treatments. Ash and different dozes of P (raw phosphate) and K (potassium chloride), with or without simultaneous N addition, were included as well as un untreated control. The aim of the present study was to evaluate the effects on tree growth and needle elemental concentrations 26 years after treatment. The addition of similar dozes of P (approx. 40 kg P/ha), as ash (2.5 tonnes/ha) or as PK-fertilizer rendered similar growth responses. The increase in stem-wood growth was in the order of 1,6 - 1,9 m3/ha/yr during the 26-year period. The N-addition had no additional effect. On the control plots, the growth was more or less negligible (approx. 0,04 m3sk/ha/yr). On average, the high dozes of raw-phosphate and potassium chloride (40 kg P/ha and 80 kg K/ha) gave a higher growth increase than the low dozes (20 kg P/ha and 40 kg K/ha), although this effect was

  14. Subtyping of renal cortical neoplasms in fine needle aspiration biopsies using a decision tree based on genomic alterations detected by fluorescence in situ hybridization

    OpenAIRE

    Gowrishankar, Banumathy; Cahill, Lynnette; Arndt, Alexandra E; Al-Ahmadie, Hikmat; Lin, Oscar; Chadalavada, Kalyani; Chaganti, Seeta; Nanjangud, Gouri J; Murty, Vundavalli V; Chaganti, Raju S K; Reuter, Victor E.; Houldsworth, Jane

    2014-01-01

    Objectives To improve the overall accuracy of diagnosis in needle biopsies of renal masses, especially small renal masses (SRMs), using fluorescence in situ hybridization (FISH), and to develop a renal cortical neoplasm classification decision tree based on genomic alterations detected by FISH. Patients and Methods Ex vivo fine needle aspiration biopsies of 122 resected renal cortical neoplasms were subjected to FISH using a series of seven-probe sets to assess gain or loss of 10 chromosomes ...

  15. Unravelling aspects of spatial and temporal distribution of Verticillium dahliae in olive, maple and ash trees and improvement of detection methods

    NARCIS (Netherlands)

    Keykhasaber, Mojtaba

    2017-01-01

    Vascular wilts caused by xylem-colonizing pathogens are among the most devastating plant diseases that affect a wide range of plant species worldwide. Information on the distribution of V. dahliae in infected trees helps to design an appropriate and efficient sampling method for reliable detection o

  16. Transgenic hybrid aspen trees with increased gibberellin (GA) concentrations suggest that GA acts in parallel with FLOWERING LOCUS T2 to control shoot elongation.

    Science.gov (United States)

    Eriksson, Maria E; Hoffman, Daniel; Kaduk, Mateusz; Mauriat, Mélanie; Moritz, Thomas

    2015-02-01

    Bioactive gibberellins (GAs) have been implicated in short day (SD)-induced growth cessation in Populus, because exogenous applications of bioactive GAs to hybrid aspens (Populus tremula × tremuloides) under SD conditions delay growth cessation. However, this effect diminishes with time, suggesting that plants may cease growth following exposure to SDs due to a reduction in sensitivity to GAs. In order to validate and further explore the role of GAs in growth cessation, we perturbed GA biosynthesis or signalling in hybrid aspen plants by overexpressing AtGA20ox1, AtGA2ox2 and PttGID1.3 (encoding GA biosynthesis enzymes and a GA receptor). We found trees with elevated concentrations of bioactive GA, due to overexpression of AtGA20ox1, continued to grow in SD conditions and were insensitive to the level of FLOWERING LOCUS T2 (FT2) expression. As transgenic plants overexpressing the PttGID1.3 GA receptor responded in a wild-type (WT) manner to SD conditions, this insensitivity did not result from limited receptor availability. As high concentrations of bioactive GA during SD conditions were sufficient to sustain shoot elongation growth in hybrid aspen trees, independent of FT2 expression levels, we conclude elongation growth in trees is regulated by both GA- and long day-responsive pathways, similar to the regulation of flowering in Arabidopsis thaliana.

  17. Predicting future trends in stock market by decision tree rough-set based hybrid system with HHMM

    Directory of Open Access Journals (Sweden)

    Shweta Tiwari

    2012-06-01

    Full Text Available Around the world, trading in the stock market has gained huge attractiveness as a means through which, one can obtain vast profits. Attempting to profitably and precisely predict the financial market has long engrossed the interests and attention of bankers, economists and scientists alike. Stock market prediction is the act of trying, to determine the future value of a company’s stock or other financial instrument traded on a financial exchange. Accurate stock market predictions are important for many reasons. Chief among all is the need for investors, to hedge against potential market risks and the opportunities for arbitrators and speculators, to make profits by trading indexes. Stock Market is a place, where shares are issued and traded. These shares are either traded through Stock exchanges or Overthe-Counter in physical or electronic form. Data mining, as a process of discovering useful patterns, correlations has its own role in financial modeling. Data mining is a discipline in computational intelligence that deals with knowledge discovery, data analysis and full and semi-autonomous decision making. Prediction of stock market by data mining techniques has been receiving a lot of attention recently. This paper presents a hybrid system based on decision tree- rough set, for predicting the trends in the Bombay Stock Exchange (BSESENSEX with the combination of Hierarchical Hidden Markov Model. In this paper we present future trends on the bases of price earnings and dividend. The data on accounting earnings when averaged over many years help to predict the present value of future dividends.

  18. Tree age-dependent changes in photosynthetic and respiratory CO2 exchange in leaves of micropropagated diploid, triploid and hybrid aspen.

    Science.gov (United States)

    Pärnik, Tiit; Ivanova, Hiie; Keerberg, Olav; Vardja, Rael; Niinemets, Ulo

    2014-06-01

    The growth rate of triploid European aspen (Populus tremula L.) and hybrid aspen (P. tremula × Populus tremuloides Michx.) significantly exceeds that of diploid aspen, but the underlying physiological controls of the superior growth rates of these genotypes are not known. We tested the hypothesis that the superior growth rate of triploid and hybrid aspen reflects their greater net photosynthesis rate. Micropropagated clonal plants varying in age from 2.5 to 19 months were used to investigate the ploidy and plant age interaction. The quantum yield of net CO2 fixation (Φ) in leaves of young 2.5-month-old hybrid aspen was lower than that of diploid and triploid trees. However, Φ in 19-month-old hybrid aspen was equal to that in triploid aspen and higher than that in diploid aspen. Φ and the rate of light-saturated net photosynthesis (ANS) increased with plant age, largely due to higher leaf dry mass per unit area in older plants. ANS in leaves of 19-month-old trees was highest in hybrid, medium in triploid and lowest in diploid aspen. Light-saturated photosynthesis had a broad temperature optimum between 20 and 35 °C. Rate of respiration in the dark (RDS) did not vary among the genotypes in 2.5-month-old plants, and the shape of the temperature response was also similar. RDS increased with plant age, but RDS was still not significantly different among the leaves of 19-month-old diploid and triploid aspen, but it was significantly lower in leaves of 19-month-old hybrid plants. The initial differences in the growth of plants with different ploidy were minor up to the age of 19 months, but during the next 2 years, the growth rate of hybrid aspen exceeded that of triploid plants by 2.7 times and of diploid plants by five times, in line with differences in ANS of 19-month-old plants of these species. It is suggested that differences in photosynthesis and growth became more pronounced with tree aging, indicating that ontogeny plays a key role in the expression of

  19. Specific Gravity of Hybrid Poplars in the North-Central Region, USA: Within-Tree Variability and Site × Genotype Effects

    Directory of Open Access Journals (Sweden)

    Jesse A. Randall

    2013-04-01

    Full Text Available Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most specific gravity reports are for a limited number of locations, resulting in a lack of information about the interactions between clones and sites over a wide range of climate and soil conditions. The objective of the current study was to characterize the effects of bole position, site, clone, and site × clone interactions for twelve hybrid poplar genotypes grown in Iowa, Minnesota, Wisconsin, and Michigan, USA. Observed specific gravities ranged from 0.267 to 0.495 (mean = 0.352 ± 0.001 for 612 samples taken from 204 trees, with bole position and site × clone interactions having significant effects on specific gravity. Further investigation of the site × clone interactions indicated that environmental conditions related to water stress were key predictors of specific gravity. These data are important for informing genotypic selection and silvicultural management decisions associated with growing hybrid poplars.

  20. The Phylogeny and Biogeographic History of Ashes (Fraxinus, Oleaceae) Highlight the Roles of Migration and Vicariance in the Diversification of Temperate Trees

    Science.gov (United States)

    Hinsinger, Damien Daniel; Basak, Jolly; Gaudeul, Myriam; Cruaud, Corinne; Bertolino, Paola; Frascaria-Lacoste, Nathalie; Bousquet, Jean

    2013-01-01

    The cosmopolitan genus Fraxinus, which comprises about 40 species of temperate trees and shrubs occupying various habitats in the Northern Hemisphere, represents a useful model to study speciation in long-lived angiosperms. We used nuclear external transcribed spacers (nETS), phantastica gene sequences, and two chloroplast loci (trnH-psbA and rpl32-trnL) in combination with previously published and newly obtained nITS sequences to produce a time-calibrated multi-locus phylogeny of the genus. We then inferred the biogeographic history and evolution of floral morphology. An early dispersal event could be inferred from North America to Asia during the Oligocene, leading to the diversification of the section Melioides sensus lato. Another intercontinental dispersal originating from the Eurasian section of Fraxinus could be dated from the Miocene and resulted in the speciation of F. nigra in North America. In addition, vicariance was inferred to account for the distribution of the other Old World species (sections Sciadanthus, Fraxinus and Ornus). Geographic speciation likely involving dispersal and vicariance could also be inferred from the phylogenetic grouping of geographically close taxa. Molecular dating suggested that the initial divergence of the taxonomical sections occurred during the middle and late Eocene and Oligocene periods, whereas diversification within sections occurred mostly during the late Oligocene and Miocene, which is consistent with the climate warming and accompanying large distributional changes observed during these periods. These various results underline the importance of dispersal and vicariance in promoting geographic speciation and diversification in Fraxinus. Similarities in life history, reproductive and demographic attributes as well as geographical distribution patterns suggest that many other temperate trees should exhibit similar speciation patterns. On the other hand, the observed parallel evolution and reversions in floral

  1. Potential effects of foundation species loss on wetland communities: A case study of black ash wetlands threatened by emerald ash borer

    Science.gov (United States)

    Melissa B. Youngquist; Sue L. Eggert; Anthony W. D' Amato; Brian J. Palik; Robert A. Slesak

    2017-01-01

    The emerald ash borer (EAB; Agrilus planipennis) is an invasive beetle that causes almost complete mortality of ash trees (Fraxinus spp.) in North America and Europe. Northern temperate wetlands, where black ash (F. nigra) is a dominant and foundation species, will likely undergo dramatic shifts after EAB...

  2. Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

    Directory of Open Access Journals (Sweden)

    Justin G A Whitehill

    Full Text Available The emerald ash borer (Agrilus planipennis is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp. that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica, which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER, and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

  3. Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

    Science.gov (United States)

    Whitehill, Justin G A; Popova-Butler, Alexandra; Green-Church, Kari B; Koch, Jennifer L; Herms, Daniel A; Bonello, Pierluigi

    2011-01-01

    The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

  4. Anonymization of big data based on hybrid tree%基于混合式子树算法的大数据匿名化

    Institute of Scientific and Technical Information of China (English)

    孙炯宁

    2015-01-01

    The top-down specialization( TDS) and the bottom-up generalization( BUG) are two ways to fulfill the sub-tree anonymization. However,existing approaches for sub-tree anonymization fall short of parallelization capability,thereby lacking scalability in handling big data on cloud. Still,both the TDS and the BUG suffer from poor performances for certain value of the K anonymity parameter when they are utilized individually. In view of that,a hybrid approach combining the TDS and the BUG for efficient sub-tree anonymization over big data is proposed. Further,the MapReduce is designed based algorithms for two components ( TDS and BUG ) to gain the high scalability by exploiting powerful computation capability of cloud. Experiment evaluations demonstrate that the hybrid approach significantly improves the scalability and the efficiency of the sub-tree anonymization scheme over existing approaches.%自顶而下具体化( TDS)和自底向上泛化( BUG)是子树匿名化的主要方法,但其并行能力不足,易导致在云数据处理中缺乏可扩展性。当TDS和BUG分开使用时,很难准确确定K匿名参数。针对这一问题,该文提出一种在大数据中进行有效数据匿名化的基于TDS和BUG的混合方法,设计了基于该混合方法的MapReduce模型,以提高云计算能力的可扩展性。实验表明,与现有方法相比,该混合法可以显著提高扩展性和子树匿名化的效率。

  5. Estimating biomass of mixed and uneven-aged forests using spectral data and a hybrid model combining regression trees and linear models

    Directory of Open Access Journals (Sweden)

    López-Serrano PM

    2016-04-01

    Full Text Available The Sierra Madre Occidental mountain range (Durango, Mexico is of great ecological interest because of the high degree of environmental heterogeneity in the area. The objective of the present study was to estimate the biomass of mixed and uneven-aged forests in the Sierra Madre Occidental by using Landsat-5 TM spectral data and forest inventory data. We used the ATCOR3® atmospheric and topographic correction module to convert remotely sensed imagery digital signals to surface reflectance values. The usual approach of modeling stand variables by using multiple linear regression was compared with a hybrid model developed in two steps: in the first step a regression tree was used to obtain an initial classification of homogeneous biomass groups, and multiple linear regression models were then fitted to each node of the pruned regression tree. Cross-validation of the hybrid model explained 72.96% of the observed stand biomass variation, with a reduction in the RMSE of 25.47% with respect to the estimates yielded by the linear model fitted to the complete database. The most important variables for the binary classification process in the regression tree were the albedo, the corrected readings of the short-wave infrared band of the satellite (2.08-2.35 µm and the topographic moisture index. We used the model output to construct a map for estimating biomass in the study area, which yielded values of between 51 and 235 Mg ha-1. The use of regression trees in combination with stepwise regression of corrected satellite imagery proved a reliable method for estimating forest biomass.

  6. Partition-Based Hybrid Decoding (PHD: A Class of ML Decoding Schemes for MIMO Signals Based on Tree Partitioning and Combined Depth- and Breadth-First Search

    Directory of Open Access Journals (Sweden)

    J. I. Park

    2013-03-01

    Full Text Available In this paper, we propose a hybrid maximum likelihood (ML decoding scheme for multiple-input multiple-output(MIMO systems. After partitioning the searching tree into several stages, the proposed scheme adopts thecombination of depth- and breadth-first search methods in an organized way. Taking the number of stages, the size ofsignal constellation, and the number of antennas as the parameter of the scheme, we provide extensive simulationresults for various MIMO communication conditions. Numerical results indicate that, when the depth- and breadth-firstsearch methods are employed appropriately, the proposed scheme exhibits substantially lower computationalcomplexity than conventional ML decoders while maintaining the ML bit error performance.

  7. Fast decision tree-based method to index large DNA-protein sequence databases using hybrid distributed-shared memory programming model.

    Science.gov (United States)

    Jaber, Khalid Mohammad; Abdullah, Rosni; Rashid, Nur'Aini Abdul

    2014-01-01

    In recent times, the size of biological databases has increased significantly, with the continuous growth in the number of users and rate of queries; such that some databases have reached the terabyte size. There is therefore, the increasing need to access databases at the fastest rates possible. In this paper, the decision tree indexing model (PDTIM) was parallelised, using a hybrid of distributed and shared memory on resident database; with horizontal and vertical growth through Message Passing Interface (MPI) and POSIX Thread (PThread), to accelerate the index building time. The PDTIM was implemented using 1, 2, 4 and 5 processors on 1, 2, 3 and 4 threads respectively. The results show that the hybrid technique improved the speedup, compared to a sequential version. It could be concluded from results that the proposed PDTIM is appropriate for large data sets, in terms of index building time.

  8. Management tactics for emerald ash borer: chemical and biological control

    Science.gov (United States)

    Therese M. Poland; Deborah G. McCullough; Daniel A. Herms; Leah S. Bauer; Juli R. Gould; Andrew R. Tluczek

    2011-01-01

    Emerald ash borer (EAB) (Agrilus planipennis), an invasive buprestid native to northeast Asia, has killed tens of millions of ash (Fraxinus) trees in infested areas of eastern North America. EAB apparently arrived in infested solid wood packaging materials from China in the early 1990s near Detroit, MI, but was not identified as...

  9. Can ash communities and their dependent species be partially protected through biological control of emerald ash borer

    Science.gov (United States)

    Ash trees were once relatively free of serious, major diseases and insect pests in North America until the arrival of the emerald ash borer (EAB), Agrilus planipennis Fairmaire, which was first detected in North America in Michigan in 2002 and has been detected in 32 U.S. states and two Canadian pro...

  10. Quantifying change in riparian ash forests following the introduction of EAB in Michigan and Indiana

    Science.gov (United States)

    Susan J. Crocker; Dacia M. Meneguzzo

    2012-01-01

    The emerald ash borer (Agrilus planipennis Fairmaire; Coleoptera: Buprestidae; EAB) is an introduced beetle that kills ash (Fraxinus spp.) trees. While most EAB-related ash mortality has been documented in urban areas, the effects of EAB in forested settings, particularly in riparian forests, are not well known. This study utilizes...

  11. A hybrid 3D spatial access method based on quadtrees and R-trees for globe data

    Science.gov (United States)

    Gong, Jun; Ke, Shengnan; Li, Xiaomin; Qi, Shuhua

    2009-10-01

    3D spatial access method for globe data is very crucial technique for virtual earth. This paper presents a brand-new maintenance method to index 3d objects distributed on the whole surface of the earth, which integrates the 1:1,000,000- scale topographic map tiles, Quad-tree and R-tree. Furthermore, when traditional methods are extended into 3d space, the performance of spatial index deteriorates badly, for example 3D R-tree. In order to effectively solve this difficult problem, a new algorithm of dynamic R-tree is put forward, which includes two sub-procedures, namely node-choosing and node-split. In the node-choosing algorithm, a new strategy is adopted, not like the traditional mode which is from top to bottom, but firstly from bottom to top then from top to bottom. This strategy can effectively solve the negative influence of node overlap. In the node-split algorithm, 2-to-3 split mode substitutes the traditional 1-to-2 mode, which can better concern the shape and size of nodes. Because of the rational tree shape, this R-tree method can easily integrate the concept of LOD. Therefore, it will be later implemented in commercial DBMS and adopted in time-crucial 3d GIS system.

  12. Multiple-geographic-scale genetic structure of two mangrove tree species: the roles of mating system, hybridization, limited dispersal and extrinsic factors.

    Directory of Open Access Journals (Sweden)

    Gustavo M Mori

    Full Text Available Mangrove plants comprise a unique group of organisms that grow within the intertidal zones of tropical and subtropical regions and whose distributions are influenced by both biotic and abiotic factors. To understand how these extrinsic and intrinsic processes influence a more fundamental level of the biological hierarchy of mangroves, we studied the genetic diversity of two Neotropical mangrove trees, Avicenniagerminans and A. schaueriana, using microsatellites markers. As reported for other sea-dispersed species, there was a strong differentiation between A. germinans and A. schaueriana populations sampled north and south of the northeastern extremity of South America, likely due to the influence of marine superficial currents. Moreover, we observed fine-scale genetic structures even when no obvious physical barriers were present, indicating pollen and propagule dispersal limitation, which could be explained by isolation-by-distance coupled with mating system differences. We report the first evidence of ongoing hybridization between Avicennia species and that these hybrids are fertile, although this interspecific crossing has not contributed to an increase in the genetic diversity the populations where A. germinans and A. schaueriana hybridize. These findings highlight the complex interplay between intrinsic and extrinsic factors that shape the distribution of the genetic diversity in these sea-dispersed colonizer species.

  13. Corrosion behaviour of groundnut shell ash and silicon carbide hybrid reinforced Al-Mg-Si alloy matrix composites in 3.5% NaCl and 0.3M H2SO4 solutions

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo ALANEME

    2015-05-01

    Full Text Available The corrosion behaviour of Al-Mg-Si alloy based composites reinforced with groundnut shell ash (GSA and silicon carbide (SiC was investigated. The aim is to assess the corrosion properties of Al-Mg-Si alloy based hybrid reinforced composites developed using different mix ratios of GSA (a cheaply processed agro waste derivative which served as partial replacement for SiC and SiC as reinforcing materials. GSA and SiC mixed in weight ratios 0:1, 1:3, 1:1, 3:1, and 1:0 were utilized to prepare 6 and 10 wt% of the reinforcing phase with Al‐Mg‐Si alloy as matrix using two‐step stir casting method. Mass loss and corrosion rate measurement was used to study the corrosion behaviour of the produced composites in 3.5% NaCl and 0.3M H2SO4 solutions. The results show that the Al-Mg-Si alloy based composites containing 6 and 10 wt% GSA and SiC in varied weight ratios were resistant to corrosion in 3.5% NaCl solution. The composites were however more susceptible to corrosion in 0.3M H2SO4 solution (in comparison with the 3.5% NaCl solution. It was noted that the Al-Mg-Si/6 wt% GSA-SiC hybrid composite grades containing GSA and SiC in weight ratio 1:3 and 3:1 respectively exhibited superior corrosion resistance in the 0.3M H2SO4 solution compared to other composites produced for this series. In the case of the Al-Mg-Si/10 wt% GSA-SiC hybrid composite grades, the corrosion resistance was relatively superior for the composites containing a greater weight ratio of GSA (75% and 100% in 0.3M H2SO4 solution.

  14. Natural enemies implicated in the regulation of an invasive pest: a life table analysis of the population dynamics of the emerald ash Borer

    Science.gov (United States)

    The emerald ash borer (EAB), Agrilus planipennis Fairmaire, is a serious invasive forest pest that has killed tens of millions of ash (Fraxinus) trees in the United States and Canada. By caging EAB adults on trunks of healthy ash trees, we established three generations of experimental cohorts from ...

  15. Spectral analysis of white ash response to emerald ash borer infestations

    Science.gov (United States)

    Calandra, Laura

    The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) is an invasive insect that has killed over 50 million ash trees in the US. The goal of this research was to establish a method to identify ash trees infested with EAB using remote sensing techniques at the leaf-level and tree crown level. First, a field-based study at the leaf-level used the range of spectral bands from the WorldView-2 sensor to determine if there was a significant difference between EAB-infested white ash (Fraxinus americana) and healthy leaves. Binary logistic regression models were developed using individual and combinations of wavelengths; the most successful model included 545 and 950 nm bands. The second half of this research employed imagery to identify healthy and EAB-infested trees, comparing pixel- and object-based methods by applying an unsupervised classification approach and a tree crown delineation algorithm, respectively. The pixel-based models attained the highest overall accuracies.

  16. Analysis on the Hybridization Affinity among Tree Peony Varieties%牡丹品种间杂交亲和性分析

    Institute of Scientific and Technical Information of China (English)

    宋升德; 李一龙; 杨善明; 鞠志新

    2012-01-01

    In the test,using the method of Cross-pollination to discuss the hybridization affinity among tree peony varieties.Taking 'FengDan' and 'Zibanmudan' as the female parent,developing 13 varieties hybrid combinations,and taking single rosette seed quantity as the evaluation indicator of affinity,the results showed that taking 'FengDan' as the female parent,13 male varieties that selected were all affinity to hybrid with 'FengDan',however,the affinity of different paternal species had big difference,and the affinity of 'Wulongpengsheng'was the highest;taking 'Zibanmudan' as the female parent,12 male varieties that selected were all affinity to hybrid with 'FengDan' except 'Yinhongqiaodui',However,also the affinity of different paternal species had big difference, the affinity of 'Qingchun' was the highest;By determination of pollen viability and analysis of hybrid combinations,paternal pollen viability had some effect on the hybrid sterility,but not significant.%采用杂交授粉方法对牡丹品种间杂交的亲和性进行探索,分别以‘凤丹’和‘紫斑牡丹’作母本,共开展了13个品种间的杂交组合,以单花结种量作为亲和性的评价指标。结果表明:以‘凤丹’做母本时,所选的13个父本品种与‘凤丹’杂交均亲和,但不同的父本品种的亲和性有很大的差异,其中父本‘乌龙捧盛’亲和性最高;以紫斑牡丹做母本时,所选的13个父本品种除了‘银红巧对’表现不亲和,其它12个品种均亲和,但不同的父本品种的亲和性也存在差异,其中父本‘青春’亲和性最高;通过花粉活力测定及杂交组合分析,父本花粉活力对杂交育性有一定影响,但不显著。

  17. Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

    Science.gov (United States)

    Chakraborty, Sourav; Whitehill, Justin G A; Hill, Amy L; Opiyo, Stephen O; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

    2014-04-01

    The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability.

  18. Fertile fruit trees obtained by somatic hybridization: navel orange (Citrus sinensis) and Troyer citrange (C. sinensis x Poncirus trifoliata).

    Science.gov (United States)

    Ohgawara, T; Kobayashi, S; Ishii, S; Yoshinaga, K; Oiyama, I

    1991-02-01

    Nucellar cell suspension protoplasts of navel orange (Citrus sinsensis Osb.) were chemically fused with mesophyll protoplasts of Troyer citrange (C. sinensis x Poncirus trifoliata) and cultured in hormone-free Murashige and Tucker medium containing 0.6 M sucrose. Two types of plant were regenerated through embryogenesis. One type showed intermediate mono-and difoliate leaves and the other types was identical to Troyer citrange. The regenerated plants with intermediate morphology were demonstrated by chromosome counts and rDNA analysis to be amphidiploid somatic hybrids. Five clones of these somatic hybrids were grafted in the field. After 4 years, they set flowers having a morphology intermediate between those of the two parents. The pollen grains showed high stainability and sufficient germinability, and were larger than those of Troyer citrange. The fruits of the somatic hybrids were large and spherical with thick rinds. Most of them contained seeds with normal germinability. These results indicate that somatic hybridization is a useful tool for Citrus breeding.

  19. All European Ash Species are Susceptible to Emerald Ash Borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae – a Far Eastern Invader

    Directory of Open Access Journals (Sweden)

    Yu. N. Baranchikov

    2014-12-01

    Full Text Available Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae – an example of a destructive invasive insect which abruptly enlarged its initially East-Asian area in 80–90s of the previous century. Nowadays this species is the main pest of ash (Fraxinus trees in USA and Canada and is quickly spreading over 11 administrative regions of Russia. It is very important to determine a list of possible host plants of A. planipennis for the pest risk assessment of invasion of this pest over the territory of Central and Western Europe. In its native area – North-Eastern Asia – this buprestid is a secondary consumer of dying trees of East-Asian ash species F. сhinensis and F. mandshurica. Healthy trees of these species are highly resistant to the pest. No examples of resistant ash species were found at North American continent. Documentary data are presented for the first time on infestation of three European ash species at the territory of the Main Botanical Garden of the Russian Academy of Sciences in Moscow, Russia by the emerald ash borer. At the first time this pest was registered at the garden in 2011. During the period of 2010–2014 EAB killed from 70 to 100 % of trees of European ash species: Fraxinus excelsior, F. angustifolia (= F. oxycarpa and F. ornus. At the same period from 81 to 90 % of specimens of North American ash species (F. pennsylvanica and F. americana were killed by this buprestid. Simultaneously dead trees of Asian species F. mandshurica and F. chinensis (= F. rhynchophyla did not carry any trace of EAB infestation. This case study is a good example of the «sentinel trees» concept’s usefulness. Arboretums with collections of non-native plants may serve as «ecological traps» for the local pests and pathogens – potential invasive organisms in the source regions of introduced plants.

  20. A Hybrid Approach of Stepwise Regression, Logistic Regression, Support Vector Machine, and Decision Tree for Forecasting Fraudulent Financial Statements

    Directory of Open Access Journals (Sweden)

    Suduan Chen

    2014-01-01

    Full Text Available As the fraudulent financial statement of an enterprise is increasingly serious with each passing day, establishing a valid forecasting fraudulent financial statement model of an enterprise has become an important question for academic research and financial practice. After screening the important variables using the stepwise regression, the study also matches the logistic regression, support vector machine, and decision tree to construct the classification models to make a comparison. The study adopts financial and nonfinancial variables to assist in establishment of the forecasting fraudulent financial statement model. Research objects are the companies to which the fraudulent and nonfraudulent financial statement happened between years 1998 to 2012. The findings are that financial and nonfinancial information are effectively used to distinguish the fraudulent financial statement, and decision tree C5.0 has the best classification effect 85.71%.

  1. Climate change and the ash dieback crisis

    Science.gov (United States)

    Goberville, Eric; Hautekèete, Nina-Coralie; Kirby, Richard R.; Piquot, Yves; Luczak, Christophe; Beaugrand, Grégory

    2016-01-01

    Beyond the direct influence of climate change on species distribution and phenology, indirect effects may also arise from perturbations in species interactions. Infectious diseases are strong biotic forces that can precipitate population declines and lead to biodiversity loss. It has been shown in forest ecosystems worldwide that at least 10% of trees are vulnerable to extinction and pathogens are increasingly implicated. In Europe, the emerging ash dieback disease caused by the fungus Hymenoscyphus fraxineus, commonly called Chalara fraxinea, is causing a severe mortality of common ash trees (Fraxinus excelsior); this is raising concerns for the persistence of this widespread tree, which is both a key component of forest ecosystems and economically important for timber production. Here, we show how the pathogen and climate change may interact to affect the future spatial distribution of the common ash. Using two presence-only models, seven General Circulation Models and four emission scenarios, we show that climate change, by affecting the host and the pathogen separately, may uncouple their spatial distribution to create a mismatch in species interaction and so a lowering of disease transmission. Consequently, as climate change expands the ranges of both species polewards it may alleviate the ash dieback crisis in southern and occidental regions at the same time. PMID:27739483

  2. [Ash Meadows Purchase Proposal

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A proposal sent to the Richard King Mellon Foundation for a loan to fund the purchase of Ash Meadows by the Nature Conservancy. Ash Meadows, set outside of Las Vegas...

  3. Nest site characteristics of the Great-spotted Woodpecker in a bottomland riparian forest in the presence of invasive tree species

    Directory of Open Access Journals (Sweden)

    Ónodi Gábor

    2016-06-01

    Full Text Available This study was carried out in Hungary, in an old unmanaged riparian poplar-willow forest during the breeding seasons of 2014 and 2015. The occurrence of two invasive tree species, the green ash and boxelder, is significant in the study area, which influences negatively the populations of native riparian tree species in Central Europe. We studied Great-spotted Woodpecker nest sites in the presence of these invasive species. Throughout the study period, eight and twelve nesting cavity trees were mapped. Trees were recorded in 20-20 circular plots of 0.05 ha both for each mapped nest trees and random plots as well. Species, diameter at breast height and condition were recorded for each tree. Composition and diversity of nest site and random plots were compared. Distributions and preferences were calculated for nest tree use. Most of the recorded trees were invasive. Nest site plots had more native trees compared to random plots. Nest site showed higher diversity in terms of all three variables. Decayed and dead willow and white poplar hybrid trees were preferred for nesting. Diameter at breast height of nest trees was between 30-90 cm. Studies about cavity excavators in transformed habitats have high importance for nature conservation of riparian forests.

  4. A Study of the Distribution of Apple stem pitting virus in Tissues of Pear Tree sing In Situ Hybridization and In Situ RT-PCR

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ying; LIU Na; NIU Jian-xin

    2009-01-01

    To understand the distribution of Apple stem pitting virus (ASPV) in tissues of pear tree and provide directly theorical and technical support for shoot tips detoxication, leaves and shoot tips of Korla pear were used as the materials, cDNA probe for ASPV was synthesized through RT-PCR reaction system using the unradioactive digoxigenin-labeled probe, and the specificity and sensitivity of probe were verified by blot hybridization method. Paraffin slice for in situ PCR and in situ hybridization was made and the location and distribution of ASPV RNA were detected in paraffin slices using in situ reverse transcription polymerase chain reaction, and the important factors which influenced the experiment results were optimized. ASPV mainly distributed in palisade tissue of mesophyll cells, external cortex of the tip, and the corresponding newborn vascular bundles. 20 min was the suitable digestive time for proteinase K. For the better amplication, RT reaction system should be above 0.2 U μL-1 and 0.4 mmol L-1 for RNasin and dNTPs respectively, 0.1-1.3 U μL-1 SuperScript Ⅱ, 0.6-0.8 μmol L-1 primer concentration, and above 0.5 U 100 μL-1 LA Taq DNA polymerase. The suitable annealing temperature in PCR reaction was 60℃ with 35 cycles. The apical meristem of 0.25 mm was the region of virus-free.

  5. Effects of trap type, placement and ash distribution on emerald ash borer captures in a low density site.

    Science.gov (United States)

    McCullough, Deborah G; Siegert, Nathan W; Poland, Therese M; Pierce, Steven J; Ahn, Su Zie

    2011-10-01

    Effective methods for early detection of newly established, low density emerald ash borer (Agrilus planipennis Fairmaire) infestations are critically needed in North America. We assessed adult A. planipennis captures on four types of traps in a 16-ha site in central Michigan. The site was divided into 16 blocks, each comprised of four 50- by 50-m cells. Green ash trees (Fraxinus pennsylvanica Marshall) were inventoried by diameter class and ash phloem area was estimated for each cell. One trap type was randomly assigned to each cell in each block. Because initial sampling showed that A. planipennis density was extremely low, infested ash logs were introduced into the center of the site. In total, 87 beetles were captured during the summer. Purple double-decker traps baited with a blend of ash leaf volatiles, Manuka oil, and ethanol captured 65% of all A. planipennis beetles. Similarly baited, green double-decker traps captured 18% of the beetles, whereas sticky bands on girdled trees captured 11% of the beetles. Purple traps baited with Manuka oil and suspended in the canopies of live ash trees captured only 5% of the beetles. At least one beetle was captured on 81% of the purple double-decker traps, 56% of the green double-decker traps, 42% of sticky bands, and 25% of the canopy traps. Abundance of ash phloem near traps had no effect on captures and trap location and sun exposure had only weak effects on captures. Twelve girdled and 29 nongirdled trees were felled and sampled in winter. Current-year larvae were present in 100% of the girdled trees and 72% of the nongirdled trees, but larval density was five times higher on girdled than nongirdled trees.

  6. Comparison of galled trees.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2011-01-01

    Galled trees, directed acyclic graphs that model evolutionary histories with isolated hybridization events, have become very popular due to both their biological significance and the existence of polynomial-time algorithms for their reconstruction. In this paper, we establish to which extent several distance measures for the comparison of evolutionary networks are metrics for galled trees, and hence, when they can be safely used to evaluate galled tree reconstruction methods.

  7. Occurrence of emerald ash borer (Coleoptera: Buprestidae) and biotic factors affecting its immature stages in the Russian Far East.

    Science.gov (United States)

    Duan, Jian J; Yurchenko, Galina; Fuester, Roger

    2012-04-01

    Field surveys were conducted from 2008 to 2011 in the Khabarovsk and Vladivostok regions of Russia to investigate the occurrence of emerald ash borer, Agrilus planipennis Fairmaire, and mortality factors affecting its immature stages. We found emerald ash borer infesting both introduced North American green ash (Fraxinus pennsylvanica Marshall) and native oriental ashes (F. mandshurica Rupr. and F. rhynchophylla Hance) in both regions. Emerald ash borer densities (larvae/m(2) of phloem area) were markedly higher on green ash (11.3-76.7 in the Khabarovsk area and 77-245 in the Vladivostok area) than on artificially stressed Manchurian ash (2.2) or Oriental ash (10-59). Mortality of emerald ash borer larvae caused by different biotic factors (woodpecker predation, host plant resistance and/or undetermined diseases, and parasitism) varied with date, site, and ash species. In general, predation of emerald ash borer larvae by woodpeckers was low. While low rates (3-27%) of emerald ash borer larval mortality were caused by undetermined biotic factors on green ash between 2009 and 2011, higher rates (26-95%) of emerald ash borer larval mortality were caused by putative plant resistance in Oriental ash species in both regions. Little (emerald ash borer larvae was observed in Khabarovsk; however, three hymenopteran parasitoids (Spathius sp., Atanycolus nigriventris Vojnovskaja-Krieger, and Tetrastichus planipennisi Yang) were observed attacking third - fourth instars of emerald ash borer in the Vladivostok area, parasitizing 0-8.3% of emerald ash borer larvae infesting Oriental ash trees and 7.3-62.7% of those on green ash trees (primarily by Spathius sp.) in two of the three study sites. Relevance of these findings to the classical biological control of emerald ash borer in newly invaded regions is discussed.

  8. Simulated Impacts of Emerald Ash Borer on Throughfall and Stemflow Inputs of Water and Nitrogen in Black Ash Wetlands in Northern Michigan

    Science.gov (United States)

    Pypker, T. G.; Davis, J.; Van Grinsven, M. J.; Bolton, N. W.; Shannon, J.; Kolka, R. K.; Nelson, J.; Wagenbrenner, J. W.

    2014-12-01

    Emerald ash borer (Agrilus planipennis Fairmaire (EAB)) is an invasive insect that effectively kills ash trees (genus: Fraxinus) greater than 2.5 cm in diameter, resulting in near-complete stand mortality within 3-4 years. Black ash wetlands occupy approximately 270,000 ha in Michigan, and have 40 to 90% of the basal area occupied by black ash (F. nigra Marshall); hence the loss of black ash may result in dramatic changes in the canopy hydrology and nutrient deposition. We assessed the impact of a simulated EAB invasion on throughfall and stemflow quantity and nitrogen (N) content in 9 uninfected black ash wetlands located in the Upper Peninsula of Michigan. Within the 9 stands, 3 stands were left untreated ('Control'), 3 stands had all the black ash trees manually girdled ('Girdled') and 3 had all the black ash trees felled by chainsaw ('Clearcut'). We measured the quantity and inorganic-N content of throughfall using an array of randomly placed collectors (n = 16 per site). Stemflow was monitored at 2 sites (n = 12 trees) on the 3 most common tree species (black ash, yellow birch (Betula alleghaniensis Britt.) and red maple (Acer rubra L.)). Preliminary results indicate that relative to the Control, average monthly throughfall was 25% and 1% greater in the Clearcut and Girdled sites, respectively. While the loss of the ash trees resulted in greater throughfall inputs in the Clearcut sites, water table heights did not significantly change as a result of the treatments. Stemflow from live black ash trees was lower than from the yellow birch and red maple trees. As a result, we predict stemflow will increase over time as species with smoother bark and less upright branching begin replacing the black ash. Hence, the change in tree species may result in a greater concentration of inorganic-N inputs to the base of the trees, thereby altering the distribution of inorganic-N inputs into the wetland. Our preliminary results show no significant change in the total

  9. Evaluating the economic costs and benefits of slowing the spread of emerald ash borer in Ohio and Michigan

    Science.gov (United States)

    Jonathan Bossenbroek; Audra Croskey; David Finnoff; Louis Iverson; Shana M. McDermott; Anantha Prasad; Charles Sims; Davis. Sydnor

    2015-01-01

    The emerald ash borer (Agrilus planipennis; EAB) is poised to wipe out native ashes (Fraxinus spp.) in North America with expected catastrophic losses to ash tree forestry (MacFarlane and Meyer 2005). EAB was first discovered in Detroit in 2002. Most scientists hypothesize that it entered the United States through solid wood...

  10. Identification of differentially expressed genes associated with bud dormancy release in tree peony (Paeonia suffruticosa) by suppression subtractive hybridization

    Institute of Scientific and Technical Information of China (English)

    HUANG Xin; ZHENG Guo-sheng; DAI Si-lan; GAI Shu-peng

    2008-01-01

    A subtractive cDNA library was developed to study genes associated with bud dormancy release in tree peonies. In order to identify genes that are highly expressed in buds released from dormancy, 588 clones were examined by differential screening. Of these, 185 clones were selected to be sequenced. A total of 37 unique sequences were obtained of which only 31 sequences have matches in the NCBI database or the Arabidopsis thaliana protein database. Semi-quantitative RT-PCR was used to confirm further the expression profiles for 12 transcripts identified within the subtraetive cDNA library. Gene ontology analyses indicated that many of the different genes identified have unknown or hypothetical functions while it is speculated that other genes play different molecular roles. In our study, genes involved in bud dormancy release were growth-related or stress-responsive, while low-temperature-induced ribosomal proteins may also play a role in bud dormancy release. Our results provide interesting information for further understanding of the molecular mechanism of bud dormancy release in tree peonies.

  11. Multi-year residual activity of Arborjet's IMA-jet (imidacloprid 5% SL) against emerald ash borer [Agrilus planipennis Fairemaire (Coleoptera: Buprestidae)] in green ash (Fraxinus pennsylvanica Marsh) in Troy, MI.

    Science.gov (United States)

    Joseph J. Doccola; Peter M. Wild; Eric J. Bristol; Joseph Lojko; Xin Li

    2007-01-01

    In cooperative university studies, IMA-jet treated green ash were effectively protected for 2 years to date in Troy, MI against emerald ash borer (EAB). Trees were infested at the time of treatment, exhibiting epicormic sprouting and thinning canopies. Twenty trees were injected with IMA-jet alone or with a diluent to aid uptake and translocation within the vascular...

  12. Tree Growth-Hybrid Genetic Algorithm for Predicting the Structure of Small (TiO2)n, n = 2-13, Nanoclusters.

    Science.gov (United States)

    Chen, Mingyang; Dixon, David A

    2013-07-09

    The initial structures for the search for the global minimum of TiO2 nanoclusters were generated by combining a tree growth (TG) algorithm with a hybrid genetic algorithm (HGA). In the TG algorithm, the clusters grow from a small seed to the size of interest stepwise. New atoms are added to the smaller cluster from the previous step, by analogy to new leaves grown by a tree. The addition of the new atoms is controlled by predefined geometry parameters to reduce the computational cost and to provide physically meaningful structures. In each step, the energies for the various generated structures are evaluated, and those with the lowest energies are carried into the next step. The structures that match the formulas of interest are collected as HGA candidates during the various steps. Low energy candidates are fed to the HGA component to search for the global minimum for each formula of interest. The lowest energy structures from the HGA are then optimized by using density functional theory to study the dissociation energies of the clusters and the evolution in the structure as the size of the cluster increases. The optimized geometries of the (TiO2)n nanoclusters for n = 2-13, do not show the character of a TiO2 bulk crystal with a hexacoordinate Ti. The average clustering energy ⟨ΔEn⟩ converges slowly to the bulk value for rutile. The TiO2 dissociation energies for (TiO2)n clusters approach the bulk value for rutile more quickly but show larger variations. The (TiO2)12 cluster appears to be quite stable, and the (TiO2)13 cluster is quite unstable on a relative scale.

  13. Fly ash carbon passivation

    Science.gov (United States)

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  14. Soil food web structure after wood ash application

    DEFF Research Database (Denmark)

    Mortensen, Louise Hindborg; Qin, Jiayi; Cruz-Paredes, Carla

    the consequences of returning wood ash to biofuel producing coniferous forest. We that the change in pH and increased availability of nutrients after ash application to forest floor can facilitate an increase in the bacteria to fungi ratio with possible effects for the soil food by applying ash of different......In 2006, the European Council established a mandatory target of 20 % renewable energy of consumption by 2020. Part of the replacement is burning biomass for heating and electricity. ~ Whole tree biomass harvesting for biofuel combustion intensifies removal of nutrients from the by applying ash from...... the combustion back to the system and thus recycle the besides being rich in inorganic nutrients, ash is also very alkaline and contains heavy metals. The ASHBACK project (www.ashback.dk) is a cooperation between three Danish universities other research institutions and stake-holders that aims to investigate...

  15. Molecular markers for tolerance of European ash (Fraxinus excelsior) to dieback disease identified using Associative Transcriptomics

    DEFF Research Database (Denmark)

    Harper, Andrea L.; McKinney, Lea Vig; Nielsen, Lene Rostgaard

    2016-01-01

    Tree disease epidemics are a global problem, impacting food security, biodiversity and national economies. The potential for conservation and breeding in trees is hampered by complex genomes and long lifecycles, with most species lacking genomic resources. The European Ash tree Fraxinus excelsior...

  16. 自适应Tree-Mesh结构的大棚无线监测网络设计%Design of adaptive tree-mesh hybrid wireless sensor networks for greenhouses

    Institute of Scientific and Technical Information of China (English)

    石繁荣; 黄玉清; 任珍文; 伍春

    2013-01-01

    Wireless sensor networks have been widely utilized in agricultural production in such as crop information monitoring systems, agricultural facilities’wireless control systems, etc. The wireless sensor networks could promote the development of agricultural information and intelligence, and more research has been focused on using ZigBee wireless technology to build the networks in recent years. To collect the base crop status and environmental information of greenhouses in a wireless way, a wireless sensor monitoring network system was designed. The basic work of this paper was the software and hardware system design; further work is projected to be low-power adaptive mechanism design. In analyzing the distribution characteristics of the greenhouse base, it could be seen that the greenhouses were concentrated in their distribution, but independent from each other. So the network topology architecture was designed as clustering Tree-Mesh hybrid topology architecture, and the nodes of the cluster belonged to the same greenhouse. The network was built up by a coordinator, and a large number of routers and sensor nodes were joined in. The coordinator was a sink node, it was designed as a gateway, and there were some routers which played the role of cluster head in the network. The clustering Tree-Mesh hybrid network was built in two steps: First, the mesh network was established by the coordinator and cluster head. Then, the tree network was built by the cluster head, and the tree was a cluster with routers and sensor nodes. The system utilized ZigBee to build the wireless sensor network and multi-hop communication, and the hardware of a single chip multi-sensor wireless node based CC2530 was designed. The modular design of the hardware subsystem was composed of a radio module, sensor module and power module. The finite state machine node software and the low-power improvement were designed based on Z-Stack. The stack ran on a task allocation mechanism that was similar

  17. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt;

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  18. Indirect effects of emerald ash borer-induced ash mortality and canopy gap formation on epigaeic beetles.

    Science.gov (United States)

    Gandhi, Kamal J K; Smith, Annemarie; Hartzler, Diane M; Herms, Daniel A

    2014-06-01

    Exotic herbivorous insects have drastically and irreversibly altered forest structure and composition of North American forests. For example, emerald ash borer (Agrilus planipennis Fairmaire) from Asia has caused wide-scale mortality of ash trees (Fraxinus spp.) in eastern United States and Canada. We studied the effects of forest changes resulting from emerald ash borer invasion on epigaeic or ground beetles (Coleoptera: Carabidae) along a gradient of ash dieback and gap sizes in southeastern Michigan. Ground beetles were sampled in hydric, mesic, and xeric habitats in which black (Fraxinus nigra Marshall), green (Fraxinus pennsylvanica Marshall), and white (Fraxinus americana L.) ash were the most common species, respectively. During 2006-2007, we trapped 2,545 adult ground beetles comprising 52 species. There was a negative correlation between percent ash tree mortality in 2006 and catches of all beetles. Catches of Agonum melanarium Dejean (in 2006) and Pterostichus mutus (Say) (in 2006-2007) were negatively correlated with tree mortality and gap size, respectively. However, catches of Pterostichus corvinus Dejean were positively correlated with gap size in 2006. As ash mortality and average gap size increased from 2006 to 2007, catches of all beetles as well as P. mutus and Pterostichus stygicus (Say) increased (1.3-3.9 times), while species diversity decreased, especially in mesic and xeric stands. Cluster analysis revealed that beetle assemblages in hydric and mesic stand diverged (25 and 40%, respectively) in their composition from 2006 to 2007, and that hydric stands had the most unique beetle assemblages. Overall, epigaeic beetle assemblages were altered in ash stands impacted by emerald ash borer; however, these impacts may dissipate as canopy gaps close.

  19. Effectiveness of differing trap types for the detection of emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Marshall, Jordan M; Storer, Andrew J; Fraser, Ivich; Beachy, Jessica A; Mastro, Victor C

    2009-08-01

    The early detection of populations of a forest pest is important to begin initial control efforts, minimizing the risk of further spread and impact. Emerald ash borer (Agrilus planipennis Fairmaire) is an introduced pestiferous insect of ash (Fraxinus spp. L.) in North America. The effectiveness of trapping techniques, including girdled trap trees with sticky bands and purple prism traps, was tested in areas with low- and high-density populations of emerald ash borer. At both densities, large girdled trap trees (>30 cm diameter at breast height [dbh], 1.37 m in height) captured a higher rate of adult beetles per day than smaller trees. However, the odds of detecting emerald ash borer increased as the dbh of the tree increased by 1 cm for trap trees 15-25 cm dbh. Ash species used for the traps differed in the number of larvae per cubic centimeter of phloem. Emerald ash borer larvae were more likely to be detected below, compared with above, the crown base of the trap tree. While larval densities within a trap tree were related to the species of ash, adult capture rates were not. These results provide support for focusing state and regional detection programs on the detection of emerald ash borer adults. If bark peeling for larvae is incorporated into these programs, peeling efforts focused below the crown base may increase likelihood of identifying new infestations while reducing labor costs. Associating traps with larger trees ( approximately 25 cm dbh) may increase the odds of detecting low-density populations of emerald ash borer, possibly reducing the time between infestation establishment and implementing management strategies.

  20. Molecular evidence of cryptic speciation, historical range expansion, and recent intraspecific hybridization in the Neotropical seasonal forest tree Cedrela fissilis (Meliaceae).

    Science.gov (United States)

    Garcia, Magali Gonçalves; Silva, Roberta Santos; Carniello, Maria Antonia; Veldman, Joseph William; Rossi, Ana Aparecida Bandini; de Oliveira, Luiz Orlando

    2011-12-01

    Molecular phylogeography can lead to a better understanding of the interaction between past climate events, large-scale vegetation shifts, and the evolutionary history of Neotropical seasonal forests. The endangered timber tree species Cedrela fissilis is associated with seasonal forests and occurs throughout South America. We sampled C. fissilis from 56 sites across the species' range in Brazil and Bolivia and obtained sequence data for nuclear and chloroplast DNA. Most specimens (149 out of 169) exhibited intraindividual polymorphism for the nuclear internal transcribed spacer (ITS). Cloning and an array of complementary sequence analyses indicated that the multiple copies of ITS were functional paralogs--concerted evolution in C. fissilis appeared to be incomplete. Independent Bayesian analyses using either ITS or cpDNA data revealed two separate phylogenetic lineages within C. fissilis that corresponded to populations located in separate geographic regions. The divergence occurred in the Early Pliocene and Late Miocene. We argue that climate-mediated events triggered dispersal events and split ancestral populations into at least two large refugial areas of seasonal forest that were located to the east and west of the present day Cerrado. Upon recent climate amelioration, formerly isolated lineages reconnected and intraspecific hybridization gave rise to intraindividual polymorphism and incomplete concerted evolution in C. fissilis. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Understanding the role of the cytoskeleton in wood formation in angiosperm trees: hybrid aspen (Populus tremula x P. tremuloides) as a model species

    Energy Technology Data Exchange (ETDEWEB)

    Chaffey, N.; Barlow, P. [Bristol Univ., Dept. of Agricultural Sciences, Long Ashton, (United Kingdom); Sundberg, B. [Swedish Univ. of Agricultural Sciences, Dept. of Forest Genetics and Plant Physiology, Umea (Sweden)

    2002-03-01

    The involvement of microfilaments (MFs) and microtubules (MTs) in the development of the radial and axial components of secondary wood in hybrid aspen (Populus tremula X P. tremuloides) was studied by indirect immunofluorescent localization techniques in order to elucidate a consensus view of the roles of the cytoskeleton during wood formation in angiosperm trees. Early and late vessel elements, axial parenchyma, normal-wood fibres and contact and isolation cells were included in addition to cambial cells. Microfilaments were found to be rare in cambial cells, but were abundant and axially arranged in their derivatives once cell elongation begun. Microtubules were randomly oriented in ray and fusiform cells of the cambial zone. Ellipses of microfilaments were associated with pit development in fiber cells and isolation ray cells. Rings of localized microtubules and microfilaments were associated with developing inter-vessel bordered pits and vessel-contact ray cell contact pits. Although only microtubules were seen in the periphery of the perforation plate of vessel elements, a prominent meshwork of microfilaments overlaid the perforation plate itself. These observations indicate that there are corresponding subcellular control points whose manipulation could lead to the development of 'designer wood'. However, such development would require a better understanding of the physiological basis for the behaviour of microtubule and microfibre cytoskeletons during wood formation. 44 refs., 6 figs.

  2. Nutritional attributes of ash (Fraxinus spp.) outer bark and phloem and their relationships to resistance against the emerald ash borer.

    Science.gov (United States)

    Hill, Amy L; Whitehill, Justin G A; Opiyo, Stephen O; Phelan, P Larry; Bonello, Pierluigi

    2012-12-01

    The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an alien, invasive wood-boring insect that is responsible for killing millions of ash trees since its discovery in North America in 2002. All North American ash species (Fraxinus spp.) that EAB has encountered have shown various degrees of susceptibility, while Manchurian ash (Fraxinus mandshurica Ruprecht), which shares a co-evolutionary history with this insect, is resistant. Recent studies have looked into constitutive resistance mechanisms in Manchurian ash, concentrating on the secondary phloem, which is the feeding substrate for the insect. In addition to specialized metabolism and defense-related components, primary metabolites and nutritional summaries can also be important to understand the feeding behavior of insect herbivores. Here, we have compared the nutritional characteristics (water content, total protein, free amino acids, total soluble sugars and starch, percent carbon and nitrogen, and macro- and micronutrients) of outer bark and phloem from black, green, white and Manchurian ash to determine their relevance to resistance or susceptibility to EAB. Water content and concentrations of Al, Ba, Cu, Fe, K, Li, tryptophan and an unknown compound were found to separate black and Manchurian ash from green and white ash in a principal component analysis (PCA), confirming their phylogenetic placements into two distinct clades. The traits that distinguished Manchurian ash from black ash in the PCA were water content and concentrations of total soluble sugars, histidine, lysine, methionine, ornithine, proline, sarcosine, tyramine, tyrosol, Al, Fe, K, Na, V and an unknown compound. However, only proline, tyramine and tyrosol were significantly different, and higher, in Manchurian ash than in black ash.

  3. Urban trees and forests of the Chicago region

    Science.gov (United States)

    David J. Nowak; Robert E. III Hoehn; Allison R. Bodine; Daniel E. Crane; John F. Dwyer; Veta Bonnewell; Gary. Watson

    2013-01-01

    An analysis of trees in the Chicago region of Illinois reveals that this area has about 157,142,000 trees with tree and shrub canopy that covers 21.0 percent of the region. The most common tree species are European buckthorn, green ash, boxelder, black cherry, and American elm. Trees in the Chicago region currently store about 16.9 million tons of carbon (61.9 million...

  4. Bio energy production in birch and hybrid aspen after addition of residue based fertilizers - establishment of fertilization trials; Bioenergiproduktion hos bjoerk och hybridasp vid tillfoersel av restproduktbaserade goedselmedel - etablering av goedslingsfoersoek

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar (EkoBalans Fenix AB, Malmoe (Sweden))

    2009-03-15

    Sewage sludge and wood ashes could be used as fertilizers in order to increase forest tree production. In southern Sweden forest growth normally increases with approximately 10 % after ash recycling due to increased N and/or P availability. P is added with the ashes and the pH-increasing effect of the wood ash can lead to increased N net mineralization. Other positive effects of wood ash recycling are improved nutrient sustainability and less acid run-off water. Possible negative effects are heavy metal accumulation, if the content of one or more heavy metals of the recycled ash exceeds the heavy metal content of the harvested biomass, and nitrate leaching if the vegetation cannot take up nitrified N. It is important to evaluate the sustainability of fertilization systems based on residues such as sludge and wood ash. Wood ash does not contain N and the P concentration often is too low for the ashes to function as an NP fertilizer. Thus N and sometimes P must be added. Sludge is an interesting alternative. The main purpose of the project is to study sustainable production of forest bio energy in intensively cultivated birch and hybrid aspen stands. Another purpose is to establish experiments that can be used for long term studies and as demonstration objects. In the first few years the goal is to study the short term effects of residue based fertilization compared to conventional NPK fertilization on tree nutrient uptake, nutrient leaching, sustainability and economy. In the long term the goal is to design appropriate fertilization strategies in a residue based fertilization system for the intensive cultivation of birch and hybrid aspen without negative side effects such as large scale nutrient leaching. Four field experiments were established in 2008 and one additional experiment in hybrid aspen will be established in the spring of 2009. Elevated bud N and P concentrations after fertilization with both Ashes+N and NPK means good possibilities for future growth

  5. Trace elements in coal ash

    Science.gov (United States)

    Deonarine, Amrika; Kolker, Allan; Doughten, Michael W.

    2015-01-01

    Coal ash is a residual waste product primarily produced by coal combustion for electric power generation. Coal ash includes fly ash, bottom ash, and flue-gas desulfurization products (at powerplants equipped with flue-gas desulfurization systems). Fly ash, the most common form of coal ash, is used in a range of products, especially construction materials. A new Environmental Protection Agency ruling upholds designation of coal ash as a non-hazardous waste under Subtitle D of the Resource Conservation and Recovery Act, allowing for the continued beneficial use of coal ash and also designating procedures and requirements for its storage.

  6. Hybrid poplar and forest soil response to municipal and industrial by-products: a greenhouse study.

    Science.gov (United States)

    Cavaleri, Molly A; Gilmore, Daniel W; Mozaffari, Morteza; Rosen, Carl J; Halbach, Thomas R

    2004-01-01

    Little research has been conducted in the Lake States (Minnesota, Wisconsin, and Michigan) to evaluate the effects of municipal and industrial by-product applications on the early growth of short rotation woody crops such as hybrid poplar. Anticipated shortages of harvestable-age aspen in the next decade can be alleviated and rural development can be enhanced through the application of by-products to forest soils. This study was conducted to evaluate the effects of inorganic fertilizer, boiler ash, biosolids, and the co-application of ash and biosolids application on tree growth and soil properties by measuring hybrid poplar clone NM-6 (Populus nigra L. x P. maximowiczii A. Henry) yield, nutrient uptake, and select post-harvest soil properties after 15 wk of greenhouse growth. Treatments included a control of no amendment; agricultural lime; inorganic N, P, and K; three types of boiler ash; biosolids application rates equivalent to 70, 140, 210, and 280 kg available N ha(-1); and boiler ash co-applied with biosolids. All of the by-products treatments showed biomass production that was equal to or greater than inorganic fertilizer and lime treatments. A trend of increased biomass with increasing rates of biosolids was observed. Soil P concentration increased with increasing rates of biosolids application. None of the by-products treatments resulted in plant tissue metal concentrations greater than metal concentrations of plant tissue amended with inorganic amendments. Biosolids, boiler ash, and the co-application of biosolids and boiler ash together on forest soils were as beneficial to plant growth as inorganic fertilizers.

  7. Suitability of immature emerald ash borers to Tetrastichus planipennisi (Hymenoptera: Eulophidae)

    Science.gov (United States)

    Since first detected in Michigan in 2002, the emerald ash borer (EAB) (Agrilus planipennis Fairmaire), a buprestid native to Asia, has killed millions of ash trees in northeastern North America and continues to expand into new areas. Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), a gregar...

  8. Evaluation of recovery and monitoring methods for parasitoids released against Emerald Ash Borer

    Science.gov (United States)

    The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an invasive insect pest, and the target of an extensive biological control campaign designed to mitigate EAB driven ash tree (Fraxinus spp.) mortality. Since 2007, environmental releases of three species of hymenopteran parasitoids of EA...

  9. Population biology of emerald ash borer and its natural enemies in China

    Science.gov (United States)

    Houping Liu; Leah S. Bauer; Tonghai Zhao; Ruitong Gao

    2008-01-01

    Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), also known as emerald ash borer (EAB), was first discovered in Michigan and Ontario, Canada, in 2002 following investigations of declining and dying ash trees (Fraxinus spp.). Agrilus planipennis has also spread to Ohio, Indiana, Maryland, Virginia,...

  10. In-situ genetic conservation of white ash (Fraxinus americana) at the Allegheny national forest

    Science.gov (United States)

    Charles E. Flower; Elijah Aubihl; Jeremie Fant; Stephen Forry; Andrea Hille; Kathleen S. Knight; William K. Oldland; Alejandro A. Royo; Richard M. Turcotte

    2017-01-01

    The emerald ash borer (EAB, Agrilus planipennis) is a non-native forest pest that has been sweeping across North America causing widespread mortality of trees in the genus Fraxinus, which includes the economically valuable white ash (F. americana). The rapid spread and lethality of EAB, paired with low levels of natural...

  11. Core RNAi machinery and gene knockdown in the emerald ash borer (Agrilus planipennis)

    Science.gov (United States)

    Chaoyang Zhao; Miguel A. Alvarez Gonzales; Therese M. Poland; Omprakash. Mittapalli

    2015-01-01

    The RNA interference (RNAi) technology has been widely used in insect functional genomics research and provides an alternative approach for insect pest management. To understand whether the emerald ash borer (Agrilus planipennis), an invasive and destructive coleopteran insect pest of ash tree (Fraxinus spp.), possesses a strong...

  12. Melting and Sintering of Ashes

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug

    1997-01-01

    The thesis contains an experimental study of the fusion and sintering of ashes collected during straw and coal/straw co-firing.A laboratory technique for quantitative determination of ash fusion has been developed based on Simultaneous Thermal Analysis (STA). By means of this method the fraction...... of melt in the investigated ashes has been determined as a function of temperature. Ash fusion results have been correlated to the chemical and mineralogical composition of the ashes, to results from a standard ash fusion test and to results from sintering experiments. Furthermore, the ash fusion results......-firing, the model only had a qualitative agreement with the measured ash deposit formation rates.Sintering measurements were carried out by means of compression strength testing of ash pellets. This method showed to not be applicable for the salt rich fly ash derived from straw combustion. For the fly ashes...

  13. Larval Survival and Growth of Emerald Ash Borer (Coleoptera: Buprestidae) on White Ash and White Fringetree Saplings Under Well-Watered and Water-Deficit Conditions.

    Science.gov (United States)

    Rutledge, Claire E; Arango-Velez, Adriana

    2017-04-01

    Emerald ash borer (Agrilus planipennis Fairmaire) was recently found on a novel host in North America, white fringetree (Chionanthus virginicus L.) (Oleaceae). In this study, we artificially infested 4-yr-old, naïve white fringetree and white ash (Fraxinus americana L.) saplings under well-watered and water-deficit conditions with emerald ash borer eggs. We used physiological and phenotypical approaches to investigate both plant response to emerald ash borer and insect development at 21, 36, and 61 d postinfestation. Photosynthesis was reduced in both tree species by larval feeding, but not by water deficits. Emerald ash borer larvae established and survived successfully on white ash. Both establishment and survival were lower on white fringetree than on white ash. Larvae were larger, and had reached higher instars at all three time points on white ash than on white fringetrees. Larvae grew faster in white ash under water-deficit conditions; however, water-deficit conditions negatively impacted survival of larvae at 61 d postinfestation in white fringetrees, although head size did not differ among surviving larvae. White ash showed higher callus formation in well-watered trees, but no impact on larval survival was observed. In white fringetree, callus formation was not affected by water treatment, and was inversely related to larval survival. The higher rate of mortality and slow growth rate of larvae in white fringetree as compared to white ash suggest that populations of emerald ash borer may be sustained by white fringetree, but may grow more slowly than in white ash. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Crowdsourcing genomic analyses of ash and ash dieback – power to the people

    Directory of Open Access Journals (Sweden)

    MacLean Dan

    2013-02-01

    Full Text Available Abstract Ash dieback is a devastating fungal disease of ash trees that has swept across Europe and recently reached the UK. This emergent pathogen has received little study in the past and its effect threatens to overwhelm the ash population. In response to this we have produced some initial genomics datasets and taken the unusual step of releasing them to the scientific community for analysis without first performing our own. In this manner we hope to ‘crowdsource’ analyses and bring the expertise of the community to bear on this problem as quickly as possible. Our data has been released through our website at oadb.tsl.ac.uk and a public GitHub repository.

  15. Feeding by emerald ash borer larvae induces systemic changes in black ash foliar chemistry.

    Science.gov (United States)

    Chen, Yigen; Whitehill, Justin G A; Bonello, Pierluigi; Poland, Therese M

    2011-11-01

    The exotic wood-boring pest, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has been threatening North American ash (Fraxinus spp.) resources, this being recognized since its first detection in Michigan, USA and Ontario, Canada in 2002. Ash trees are killed by larval feeding in the cambial region, which results in disruption of photosynthate and nutrient translocation. In this study, changes in volatile and non-volatile foliar phytochemicals of potted 2-yr-old black ash, Fraxinus nigra Marshall, seedlings were observed in response to EAB larval feeding in the main stem. EAB larval feeding affected levels of six compounds [hexanal, (E)-2-hexenal, (Z)-3-hexenyl acetate, (E)-β-ocimene, methyl salicylate, and (Z,E)-α-farnesene] with patterns of interaction depending upon compounds of interest and time of observation. Increased methyl salicylate emission suggests similarity in responses induced by EAB larval feeding and other phloem-feeding herbivores. Overall, EAB larval feeding suppressed (Z)-3-hexenyl acetate emission, elevated (E)-β-ocimene emission in the first 30days, but emissions leveled off thereafter, and generally increased the emission of (Z,E)-α-farnesene. Levels of carbohydrates and phenolics increased overall, while levels of proteins and most amino acids decreased in response to larval feeding. Twenty-three amino acids were consistently detected in the foliage of black ash. The three most abundant amino acids were aspartic acid, glutamic acid, glutamine, while the four least abundant were α-aminobutyric acid, β-aminoisobutyric acid, methionine, and sarcosine. Most (16) foliar free amino acids and 6 of the 9 detected essential amino acids decreased with EAB larval feeding. The ecological consequences of these dynamic phytochemical changes on herbivores harbored by ash trees and potential natural enemies of these herbivores are discussed.

  16. Ash properties of some dominant Greek forest species

    Energy Technology Data Exchange (ETDEWEB)

    Liodakis, S. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)]. E-mail: liodakis@central.ntua.gr; Katsigiannis, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece); Kakali, G. [Laboratory of Inorganic and Analytical Chemistry, Department of Chemical Engineering, National Technical University of Athens (NTUA), 9 Iroon Polytechniou Street, Athens 157 73 (Greece)

    2005-10-15

    The elemental and chemical wood ash compositions of six dominant Greek fuels was investigated using a variety of techniques, including thermal gravimetric analysis (TG), differential thermal analysis (DTA), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). In addition, the alkalinity of wood ash was determined by titration. The ash was prepared by combustion at low (600 deg. C), middle (800 deg. C) and high temperatures (1000 deg. C). The ash composition is very important because thousands of hectares of wildlands are burned annually in Greece. The resulting deposits affect soil properties (i.e., pH) and provide a source of inorganic constituents (i.e., Ca, K, Na, Mg, etc.), while the most soluble compounds (i.e., sodium and potassium hydroxides and carbonates) do not persist through the wet season. The samples selected were: Pinus halepensis (Aleppo pine), Pinus brutia (Calabrian pine), Olea europaea (Olive), Cupressus sempervirens (Italian cypress), Pistacia lentiscus (Mastic tree), Quercus coccifera (Holly oak)

  17. Physiological responses of emerald ash borer larvae to feeding on different ash species reveal putative resistance mechanisms and insect counter-adaptations.

    Science.gov (United States)

    Rigsby, C M; Showalter, D N; Herms, D A; Koch, J L; Bonello, P; Cipollini, D

    2015-07-01

    Emerald ash borer, Agrilus planipennis Fairmaire, an Asian wood-boring beetle, has devastated ash (Fraxinus spp.) trees in North American forests and landscapes since its discovery there in 2002. In this study, we collected living larvae from EAB-resistant Manchurian ash (Fraxinus mandschurica), and susceptible white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash hosts, and quantified the activity and production of selected detoxification, digestive, and antioxidant enzymes. We hypothesized that differences in larval physiology could be used to infer resistance mechanisms of ash. We found no differences in cytochrome P450, glutathione-S-transferase, carboxylesterase, sulfotransferase, and tryptic BApNAase activities between larvae feeding on different hosts. Despite this, Manchurian ash-fed larvae produced a single isozyme of low electrophoretic mobility that was not produced in white or green ash-fed larvae. Additionally, larvae feeding on white and green ash produced two serine protease isozymes of high electrophoretic mobility that were not observed in Manchurian ash-fed larvae. We also found lower activity of β-glucosidase and higher activities of monoamine oxidase, ortho-quinone reductase, catalase, superoxide dismutase, and glutathione reductase in Manchurian ash-fed larvae compared to larvae that had fed on susceptible ash. A single isozyme was detected for both catalase and superoxide dismutase in all larval groups. The activities of the quinone-protective and antioxidant enzymes are consistent with the resistance phenotype of the host species, with the highest activities measured in larvae feeding on resistant Manchurian ash. We conclude that larvae feeding on Manchurian ash could be under quinone and oxidative stress, suggesting these may be potential mechanisms of resistance of Manchurian ash to EAB larvae, and that quinone-protective and antioxidant enzymes are important counter-adaptations of larvae for dealing with these resistance

  18. Ash cloud aviation advisories

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.J.; Ellis, J.S. [Lawrence Livermore National Lab., CA (United States); Schalk, W.W.; Nasstrom, J.S. [EG and G, Inc., Pleasanton, CA (United States)

    1992-06-25

    During the recent (12--22 June 1991) Mount Pinatubo volcano eruptions, the US Air Force Global Weather Central (AFGWC) requested assistance of the US Department of Energy`s Atmospheric Release Advisory Capability (ARAC) in creating volcanic ash cloud aviation advisories for the region of the Philippine Islands. Through application of its three-dimensional material transport and diffusion models using AFGWC meteorological analysis and forecast wind fields ARAC developed extensive analysis and 12-hourly forecast ash cloud position advisories extending to 48 hours for a period of five days. The advisories consisted of ``relative`` ash cloud concentrations in ten layers (surface-5,000 feet, 5,000--10,000 feet and every 10,000 feet to 90,000 feet). The ash was represented as a log-normal size distribution of 10--200 {mu}m diameter solid particles. Size-dependent ``ashfall`` was simulated over time as the eruption clouds dispersed. Except for an internal experimental attempt to model one of the Mount Redoubt, Alaska, eruptions (12/89), ARAC had no prior experience in modeling volcanic eruption ash hazards. For the cataclysmic eruption of 15--16 June, the complex three-dimensional atmospheric structure of the region produced dramatically divergent ash cloud patterns. The large eruptions (> 7--10 km) produced ash plume clouds with strong westward transport over the South China Sea, Southeast Asia, India and beyond. The low-level eruptions (< 7 km) and quasi-steady-state venting produced a plume which generally dispersed to the north and east throughout the support period. Modeling the sequence of eruptions presented a unique challenge. Although the initial approach proved viable, further refinement is necessary and possible. A distinct need exists to quantify eruptions consistently such that ``relative`` ash concentrations relate to specific aviation hazard categories.

  19. Temperature Effects on the Ash Colour of Forest Litter

    Directory of Open Access Journals (Sweden)

    Jolita Dūdaitė

    2011-12-01

    Full Text Available Abstract. Research was carried out to identify the influence of temperature (150, 250, 350, 450, 550ºC on the ash colour of Acer platanoides L. leaf litter and Pinus sylvestris L. needle litter samples collected from deciduous coniferous mixed forest in Lithuania (54º43‘ N 25º19‘ E in April 2010. To achieve the objective, a laboratory experiment was conducted to determine ash samples using the Munsell Colour Chart. The analysis of colours has demonstrated that considering all litter samples, an increase in the temperature of litter heating was found to increase ash colour values (r = 0.92; p = 0.01. All the samples (n = 50 of both litter species were divided into categories 2.5Y (5 samples, 7.5YR (10 samples and 10YR (35 samples. The total black Munsell colour was observed at a temperature of 350ºC for both litter species. Needle ash started turning bright at a temperature of 550ºC while the complete consumption of leaf litter was visible at a temperature of 450ºC. We conclude that the Munsell Colour Chart used for predicting the colour of ash is an informative feature to have the primary classification of ash. It is imperative to analyse the colour of the litter ash of the selected tree species in order to quickly and easily assess and predict their possible impact on the surrounding environment.

  20. Fire severity effects on ash extractable Total Phosphorous

    Science.gov (United States)

    Pereira, Paulo; Úbeda, Xavier; Martin, Deborah

    2010-05-01

    Phosphorous (P) is a crucial element to plant nutrition and limits vegetal production. The amounts of P in soil are lower and great part of this nutrient is absorbed or precipitated. It is well known that fire has important implications on P cycle, that can be lost throughout volatilization, evacuated with the smoke, but also more available to transport after organic matter mineralization imposed by the fire. The release of P depends on ash pH and their chemical and physical characteristics. Fire temperatures impose different severities, according to the specie affected and contact time. Fire severity is often evaluated by ash colour and this is a low-cost and excellent methodology to assess the fire effects on ecosystems. The aim of this work is study the ash properties physical and chemical properties on ash extractable Total Phosphorous (TP), collected in three wildfires, occured in Portugal, (named, (1) Quinta do Conde, (2) Quinta da Areia and (3) Casal do Sapo) composed mainly by Quercus suber and Pinus pinaster trees. The ash colour was assessed using the Munsell color chart. From all three plots we analyzed a total of 102 ash samples and we identified 5 different ash colours, ordered in an increasing order of severity, Very Dark Brown, Black, Dark Grey, Very Dark Grey and Light Grey. In order to observe significant differences between extractable TP and ash colours, we applied an ANOVA One Way test, and considered the differences significant at a p<0.05. The results showed that significant differences in the extractable TP among the different ash colours. Hence, to identify specific differences between each ash colour, we applied a post-hoc Fisher LSD test, significant at a p<0.05. The results obtained showed significant differences between the extractable TP from Very dark Brown and Black ash, produced at lower severities, in relation to Dark Grey, Very Dark Grey and Light Grey ash, generated at higher severities. The means of the first group were higher

  1. Comparison of Ash from PF and CFB Boilers and Behaviour of Ash in Ash Fields

    Science.gov (United States)

    Arro, H.; Pihu, T.; Prikk, A.; Rootamm, R.; Konist, A.

    Over 90% of electricity produced in Estonia is made by power plants firing local oil shale and 25% of the boilers are of the circulating fluidised bed (CFB) variety. In 2007 approximately 6.5 million tons of ash was acquired as a byproduct of using oil shale for energy production. Approximately 1.5 million tons of that was ash from CFB boilers. Such ash is deposited in ash fields by means ofhydro ash removal.

  2. Interactive influence of leaf age, light intensity, and girdling on green ash foliar chemistry and emerald ash borer development.

    Science.gov (United States)

    Chen, Yigen; Poland, Therese M

    2009-07-01

    Biotic and abiotic environmental factors affect plant nutritional quality and defensive compounds that confer plant resistance to herbivory. Influence of leaf age, light availability, and girdling on foliar nutrition and defense of green ash (Fraxinus pennsylvanica Marsh) was examined in this study. Longevity of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), adults reared on green ash foliage subjected to these factors was assayed. Mature leaves generally were more nutritious with greater amino acids and a greater ratio of protein to non-structural carbohydrate (P:C) than young leaves, in particular when trees were grown in shade. On the other hand, mature leaves had lower amounts of trypsin and chymotrypsin inhibitors, and total phenolics compared to young leaves. Lower defense of mature leaves alone, or along with higher nutritional quality may lead to increased survival and longevity of emerald ash borer feeding on mature leaves. Sunlight reduced amino acids and P:C ratio, irrespective of leaf age and girdling, and elevated total protein of young foliage, but not protein of mature leaves. Sunlight also dramatically increased all investigated defensive compounds of young, but not mature leaves. Girdling reduced green ash foliar nutrition, especially, of young leaves grown in shade and of mature leaves grown in sun. However emerald ash borer performance did not differ when fed leaves from trees grown in sun or shade, or from girdled or control trees. One explanation is that emerald ash borer reared on lower nutritional quality food may compensate for nutrient deficiency by increasing its consumption rate. The strong interactions among leaf age, light intensity, and girdling on nutrition and defense highlight the need for caution when interpreting data without considering possible interactions.

  3. Spatial distribution of fine roots of larch and ash in the mixed plantation stand

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The spatial distribution of standing fine roots in tree rows of different species in a 12-year-old mixed stand of ash (Fraxinus mandshurica Rupr.) and larch (Larix olgensis Henry) was studied by soil core sampling in early spring, 2001. It is found that ash and larch differ greatly in their belowground biomass distribution. Ash has much higher fine root biomass density in the soil than l arch at stand level (with the max value of 4442.3 vs. 2234.9 g@m-3). Both tree species deployed more fine roots in their neighboring zone, suggesting a less in tensive competition between roots of the two species. Both fine root biomass den sity and root length density of ash in the zone between larch tree rows are greater than that of larch in zone between ash tree rows, indicating that ash is more powerful than larch in belowground competition. The spatial distribution feature of roots favors the growth of ash in the mixed stand.

  4. Emerald ash borer invasion of North America: history, biology, ecology, impacts, and management.

    Science.gov (United States)

    Herms, Daniel A; McCullough, Deborah G

    2014-01-01

    Since its accidental introduction from Asia, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has killed millions of ash trees in North America. As it continues to spread, it could functionally extirpate ash with devastating economic and ecological impacts. Little was known about EAB when it was first discovered in North America in 2002, but substantial advances in understanding of EAB biology, ecology, and management have occurred since. Ash species indigenous to China are generally resistant to EAB and may eventually provide resistance genes for introgression into North American species. EAB is characterized by stratified dispersal resulting from natural and human-assisted spread, and substantial effort has been devoted to the development of survey methods. Early eradication efforts were abandoned largely because of the difficulty of detecting and delineating infestations. Current management is focused on biological control, insecticide protection of high-value trees, and integrated efforts to slow ash mortality.

  5. Distribution, Predictors, and Impacts of Emerald Ash Borer (Agrilus planipennis) (Coleoptera: Buprestidae) Infestation of White Fringetree (Chionanthus virginicus).

    Science.gov (United States)

    Peterson, Donnie L; Cipollini, Don

    2017-02-01

    Emerald ash borer, Agrilus planipennis (Fairmaire), is an invasive pest of ash trees (Fraxinus spp.) in North America that was recently found infesting white fringetree (Chionanthus virginicus L.). Initial reports of the infestation of white fringetree by emerald ash borer occurred in southwestern Ohio and Chicago, IL. We examined white fringetrees at additional sites in Illinois, Indiana, Ohio, and Pennsylvania in Summer and Fall 2015 and Winter 2016 for emerald ash borer infestation. Our aim was to examine white fringetrees at a limited number of sites with emerald ash borer infestation and to relate tree size, crown dieback, epicormic sprouting, tree sex, and adjacency to ash or white fringetrees with the likelihood of beetle infestation. A higher proportion of infested trees exhibited epicormic sprouting and the likelihood that a tree was infested increased with increasing crown dieback, variables that may be both predictors and responses to attack. The proportion of trees infested with emerald ash borer increased with increasing tree size. Signs consistent with emerald ash borer infestation were found in 26% of 178 white fringetrees, with at least one host infested at each site in all states. Infestation rates of white fringetrees increased with the density of white fringetrees at each site. The Chicago Botanic Garden site had a significantly lower infestation (3.7%) than other sites, which may be due to proactive management of ash. Overall, these data indicate white fringetree has been utilized by emerald ash borer throughout their overlapping ranges in the United States in ornamental settings likely due to ecological fitting. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Fusion characterization of biomass ash

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang

    2016-01-01

    The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two...... stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, Tm, is proposed to represent the severe melting temperature of biomass ash. The fusion...... characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates....

  7. Hybrid regression trees applied to the monitoring of dynamic safety of isolated networks with large eolic production contribution; Utilizacao de arvores de regressao hibridas na monitorizacao da seguranca dinamica de redes isoladas com grande producao eolica

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, J.A Pecas; Vasconcelos, Maria Helena O.P. de [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal). E-mail: jpl@riff.fe.up.pt; hvasconcelos@inescn.pt

    1999-07-01

    This paper describes in a synthetic manner the technology adopted to define structures used in the fast evaluation of dynamic safety of isolated network with high level of eolic production contribution. This methodology uses hybrid regression trees, which allows the quantification the endurance connected to the dynamic behavior of these networks by emulating the frequency minimum deviation that will be experienced by the system when submitted toa pre-defined perturbation. Also, new procedures for data automatic generation are presented, which will be used for construction and measurements of the evaluation structures performance. The paper describes the Terceira island - Acores archipelago network study case.

  8. Effect of Salt Stress on Transpiration and Ion Distribution in Seedlings of Four Tree Species

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Transpiration rate and ion distribution of pagoda tree, walnut, velvet ash and poplar seedlings treated by NaCl solution of 0, 50, 100, 200 mmol·L-1 were studied. The results showed that there were significant differences in the response to NaCl among the four tree species. Na+ exclusion capacity of pagoda tree was the largest among the four species. The Na+ exclusion capacity of velvet ash was less than that of pagoda tree. Salt excretion capacity of velvet ash was limited. Its salt-tolerance was bigge...

  9. National volcanic ash operations plan for aviation

    Science.gov (United States)

    ,; ,

    2007-01-01

    International Civil Aviation Organization’s (ICAO) International Airways Volcano Watch. This plan defines agency responsibilities, provides a comprehensive description of an interagency standard for volcanic ash products and their formats, describes the agency backup procedures for operational products, and outlines the actions to be taken by each agency following an occurrence of a volcanic eruption that subsequently affects and impacts aviation services. Since our most recent International Conference on Volcanic Ash and Aviation Safety, volcanic ash-related product and service activities have grown considerably along with partnerships and alliances throughout the aviation community. In January 2005, the National Oceanic and Atmospheric Administration’s National Centers for Environment Prediction began running the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model in place of the Volcanic Ash Forecast Transport and Dispersion (VAFTAD) model, upgrading support to the volcanic ash advisory community. Today, improvements to the HYSPLIT model are ongoing based on recommendations by the OFCM-sponsored Joint Action Group for the Selection and Evaluation of Atmospheric Transport and Diffusion Models and the Joint Action Group for Atmospheric Transport and Diffusion Modeling (Research and Development Plan). Two international workshops on volcanic ash have already taken place, noticeable improvements and innovations in education, training, and outreach have been made, and federal and public education and training programs on volcanic ash-related products, services, and procedures iv continue to evolve. For example, in partnership with Embry-Riddle Aeronautical University and other academic institutions, volcanic ash hazard and mitigation training has been incorporated into aviation meteorology courses. As an essential next step, our volcanic ash-related efforts in the near term will be centered on the development of an interagency implementation plan to

  10. Ash Properties of Alternative Biomass

    DEFF Research Database (Denmark)

    Capablo, Joaquin; Jensen, Peter Arendt; Pedersen, Kim Hougaard

    2009-01-01

    The ash behavior during suspension firing of 12 alternative solid biofuels, such as pectin waste, mash from a beer brewery, or waste from cigarette production have been studied and compared to wood and straw ash behavior. Laboratory suspension firing tests were performed on an entrained flow...... analysis into three main groups depending upon their ash content of silica, alkali metal, and calcium and magnesium. To further detail the biomass classification, the relative molar ratio of Cl, S, and P to alkali were included. The study has led to knowledge on biomass fuel ash composition influence...... on ash transformation, ash deposit flux, and deposit chlorine content when biomass fuels are applied for suspension combustion....

  11. MAT 126 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    stylia

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MAT 126 Week 1 DQ 1 (Ash) MAT 126 Week 1 Quiz (Ash) MAT 126 Week 1 Written Assignment (Arithmetic and geometric sequence) (Ash) MAT 126 Week 2 DQ 1 (Ash) MAT 126 Week 2 DQ 2 (Ash) MAT 126 Week 2 Assignment Is It Fat Free (Ash) MAT 126 Week 2 Quiz (Ash) MAT 126 Week 3 DQ 1 (Ash) MAT 126 Week 3 DQ 2 (Ash) MAT 126 Week 3 Assignment Quadratic Equations (Ash) MAT 126 Week 3 Quiz (Ash) MAT 126...

  12. Microsatellite population genetics of the emerald ash borer (Agrilus planipennis Fairmaire): comparisons between Asian and North American populations

    Science.gov (United States)

    Carson C. Keever; Christal Nieman; Larissa Ramsay; Carol E. Ritland; Leah S. Bauer; D. Barry Lyons; Jenny S. Cory

    2013-01-01

    The emerald ash borer (EAB) (Agrilus planipennis Fairmaire) (Coleoptera; Buprestidae), is an invasive wood-boring beetle native to northeast Asia. This species was first detected in Michigan USA in 2002, and is a significant threat to native and ornamental ash tree species (Fraxinus spp.) throughout North America. We...

  13. Developing rearing methods for Tetrastichus planipennisi (Hymenoptera: Eulophidae), a larval endoparasitoid of the emerald ash borer (Coleoptera: Buprestidae)

    Science.gov (United States)

    Tetrastichus planipennisi Yong, a gregarious koinobiont endoparasitoid, is one of three hymenopteran parasitoids being released in the U.S. for biological control of the emerald ash borer (Agrilus planipennis Fairmair, EAB), an invasive beetle from Asia causing mortality of the ash trees (Fraxinus s...

  14. Hydration of fly ash cement

    Energy Technology Data Exchange (ETDEWEB)

    Etsuo Sakai; Shigeyoshi Miyahara; Shigenari Ohsawa; Seung-Heun Lee; Masaki Daimon [Tokyo Institute of Technology, Tokyo (Japan). Department of Metallurgy and Ceramics Science, Graduate School of Science and Engineering

    2005-06-01

    It is necessary to establish the material design system for the utilization of large amounts of fly ash as blended cement instead of disposing of it as a waste. Cement blended with fly ash is also required as a countermeasure to reduce the amount of CO{sub 2} generation. In this study, the influences of the glass content and the basicity of glass phase on the hydration of fly ash cement were clarified and hydration over a long curing time was characterized. Two kinds of fly ash with different glass content, one with 38.2% and another with 76.6%, were used. The hydration ratio of fly ash was increased by increasing the glass content in fly ash in the specimens cured for 270 days. When the glass content of fly ash is low, the basicity of glass phase tends to decrease. Reactivity of fly ash is controlled by the basicity of the glass phase in fly ash during a period from 28 to 270 days. However, at an age of 360 days, the reaction ratios of fly ash show almost identical values with different glass contents. Fly ash also affected the hydration of cement clinker minerals in fly ash cement. While the hydration of alite was accelerated, that of belite was retarded at a late stage.

  15. Fusion characterization of biomass ash

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Teng [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Sino-Danish Center for Education and Research, Beijing, 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Fan, Chuigang; Hao, Lifang [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Li, Songgeng, E-mail: sgli@ipe.ac.cn [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Song, Wenli [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Lin, Weigang [State Key Laboratory ofMultiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Zhongguancun North Second Street, Beijing 100190 (China); Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)

    2016-08-20

    Highlights: • A novel method is proposed to analyze fusion characteristics of biomass ash. • T{sub m} can represent the severe melting temperature of biomass ash. • Compared with AFT, TMA is the better choice to analyze the fusion characteristics of biomass ash. - Abstract: The ash fusion characteristics are important parameters for thermochemical utilization of biomass. In this research, a method for measuring the fusion characteristics of biomass ash by Thermo-mechanical Analyzer, TMA, is described. The typical TMA shrinking ratio curve can be divided into two stages, which are closely related to ash melting behaviors. Several characteristics temperatures based on the TMA curves are used to assess the ash fusion characteristics. A new characteristics temperature, T{sub m}, is proposed to represent the severe melting temperature of biomass ash. The fusion characteristics of six types of biomass ash have been measured by TMA. Compared with standard ash fusibility temperatures (AFT) test, TMA is more suitable for measuring the fusion characteristics of biomass ash. The glassy molten areas of the ash samples are sticky and mainly consist of K-Ca-silicates.

  16. Electrodialytic treatment of fly ash

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Pedersen, Anne Juul; Kirkelund, Gunvor Marie

    Heavy metals are removed from the fly ashes by an electrodialytic treatment with the aim of up-grading the ashes for reuse in stead of disposal in landfill.A great potential for upgrading of bio- and waste incineration ashes by electrodialytic treatment exists. In the future, the applicability...

  17. The Early Detection of the Emerald Ash Borer (EAB) Using Advanced Geospacial Technologies

    Science.gov (United States)

    Hu, B.; Li, J.; Wang, J.; Hall, B.

    2014-11-01

    The objectives of this study were to exploit Light Detection And Ranging (LiDAR) and very high spatial resolution (VHR) data and their synergy with hyperspectral imagery in the early detection of the EAB presence in trees within urban areas and to develop a framework to combine information extracted from multiple data sources. To achieve these, an object-oriented framework was developed to combine information derived from available data sets to characterize ash trees. Within this framework, individual trees were first extracted and then classified into different species based on their spectral information derived from hyperspectral imagery, spatial information from VHR imagery, and for each ash tree its health state and EAB infestation stage were determined based on hyperspectral imagery. The developed framework and methods were demonstrated to be effective according to the results obtained on two study sites in the city of Toronto, Ontario Canada. The individual tree delineation method provided satisfactory results with an overall accuracy of 78 % and 19 % commission and 23 % omission errors when used on the combined very high-spatial resolution imagery and LiDAR data. In terms of the identification of ash trees, given sufficient representative training data, our classification model was able to predict tree species with above 75 % overall accuracy, and mis-classification occurred mainly between ash and maple trees. The hypothesis that a strong correlation exists between general tree stress and EAB infestation was confirmed. Vegetation indices sensitive to leaf chlorophyll content derived from hyperspectral imagery can be used to predict the EAB infestation levels for each ash tree.

  18. Recycling of ash - an important factor in the forest fuel cycle; Askaaterfoering - en viktig faktor i skogsbraenslets kretslopp

    Energy Technology Data Exchange (ETDEWEB)

    Lundborg, A.

    1997-12-31

    If energy sources are to be called renewable, they must be used on the conditions set by nature and natural balance must be maintained. The ash from biofuels from forests contains almost all the minerals and nutrients (except nitrogen) which were present in the fuel and should be recycled to the forest. This conference paper describes the composition and properties of ash, its production and handling, and its ecological effects when recycled. The chemical properties of ash depend largely on the content of minerals, nutrients and heavy metals in the fuel, and on how the combustion process is conducted. Ash from bioforests or from waste combustion may contain heavy metals and may be unsuitable for recycling. Ash is strongly alkaline and needs processing before recycling. In forests that grow on peat the addition of ash causes a strong growth of trees. On firm ground, however, the effect of adding ash is more in the nature of long-time forest care. 4 refs.

  19. Interaction mechanisms of organic contaminants with burned straw ash charcoal

    Institute of Scientific and Technical Information of China (English)

    Wenhai Huang; Baoliang Chen

    2010-01-01

    Black carbons (e.g.,charcoal) have a great impact on the transport of organic contaminants in soil and water because of its strong affinity and ubiquity in the environment.To further elucidate their interaction mechanism,sorption of polar (p-nitrotoluene,m-dinitrobenzene and nitrobenzene) and nonpolar (naphthalene) aromatic contaminants to burned straw ash charcoal under different de-ashed treatments were investigated.The sorption isotherms fitted well with Freundlich equation,and the Freundlich N values were all around 0.31-0.38,being independent of the sorbate properties and sorbent types.After sequential removal of ashes by acid treatments (HCl and HCl-HF),both adsorption and partition were enhanced due to the enrichment of charcoal component.The separated contribution of adsorption and partition to total sorption were quantified.The effective carbon content in ash charcoal functioned as adsorption sites,partition phases,and hybrid regions with adsorption and partition were conceptualized and calculated.The hybrid regions increased obviously after de-ashed treatment.The linear relationships of Freundlich N values with the charring-temperature of charcoal or biochar (the charred byproduct in biomass pyrolysis) were observed based on the current study and the cited publications which included 15 different temperatures (100-850℃),10 kinds of precursors of charcoal/biochar,and 10 organic sorbates.

  20. Interaction mechanisms of organic contaminants with burned straw ash charcoal.

    Science.gov (United States)

    Huang, Wenhai; Chen, Baoliang

    2010-01-01

    Black carbons (e.g., charcoal) have a great impact on the transport of organic contaminants in soil and water because of its strong affinity and ubiquity in the environment. To further elucidate their interaction mechanism, sorption of polar (p-nitrotoluene, m-dinitrobenzene and nitrobenzene) and nonpolar (naphthalene) aromatic contaminants to burned straw ash charcoal under different de-ashed treatments were investigated. The sorption isotherms fitted well with Freundlich equation, and the Freundlich N values were all around 0.31-0.38, being independent of the sorbate properties and sorbent types. After sequential removal of ashes by acid treatments (HCl and HCl-HF), both adsorption and partition were enhanced due to the enrichment of charcoal component. The separated contribution of adsorption and partition to total sorption were quantified. The effective carbon content in ash charcoal functioned as adsorption sites, partition phases, and hybrid regions with adsorption and partition were conceptualized and calculated. The hybrid regions increased obviously after de-ashed treatment. The linear relationships of Freundlich N values with the charring-temperature of charcoal or biochar (the charred byproduct in biomass pyrolysis) were observed based on the current study and the cited publications which included 15 different temperatures (100-850 degrees C), 10 kinds of precursors of charcoal/biochar, and 10 organic sorbates.

  1. Emerald ash borer and the urban forest: Changes in landslide potential due to canopy loss scenarios in the City of Pittsburgh, PA.

    Science.gov (United States)

    Pfeil-McCullough, Erin; Bain, Daniel J; Bergman, Jeffery; Crumrine, Danielle

    2015-12-01

    Emerald ash borer is expected to kill thousands of ash trees in the eastern U.S. This research develops tools to predict the effect of ash tree loss from the urban canopy on landslide susceptibility in Pittsburgh, PA. A spatial model was built using the SINMAP (Stability INdex MAPping) model coupled with spatially explicit scenarios of tree loss (0%, 25%, 50%, and 75% loss of ash trees from the canopy). Ash spatial distributions were estimated via Monte Carlo methods and available vegetation plot data. Ash trees are most prevalent on steeper slopes, likely due to urban development patterns. Therefore, ash loss disproportionately increases hillslope instability. A 75% loss of ash resulted in roughly 800 new potential landslide initiation locations. Sensitivity testing reveals that variations in rainfall rates, and friction angles produce minor changes to model results relative to the magnitude of parameter variation, but reveal high model sensitivity to soil density and root cohesion values. The model predictions demonstrate the importance of large canopy species to urban hillslope stability, particularly on steep slopes and in areas where soils tend to retain water. To improve instability predictions, better characterization of urban soils, particularly spatial patterns of compaction and species specific root cohesion is necessary. The modeling framework developed in this research will enhance assessment of changes in landslide risk due to tree mortality, improving our ability to design economically and ecologically sustainable urban systems.

  2. MGT 330 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    alfoniz

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 330 Week 1 Individual Assignment Functions of Management Paper (Ash) MGT 330 Week 1 DQ 1 (Ash) MGT 330 Week 1 DQ 2 (Ash) MGT 330 Week 1 DQ 3 (Ash) MGT 330 Week 1 Summary (Ash) MGT 330 Week 2 Team Assignment External Internal Factors Paper (Ash) MGT 330 Week 2 Individual Assignment Delegation (Ash) MGT 330 Week 2 Summary (Ash) MGT 330 Week 2 DQ 1 (Ash) MGT 330 Week 2 DQ 2 (Ash) MGT 330 W...

  3. ePHM System Development, Hardware-in-the-Loop Testing, Fault Tree, and FMECA Applied to and Integrated on NASA Hybrid Electric Testbeds Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hybrid-Electric distributed propulsion (HEDP) is becoming widely accepted and new tools will be required for future development with validation and demonstrations...

  4. Ash pollen allergy: reliable detection of sensitization on the basis of IgE to Ole e 1.

    Science.gov (United States)

    Imhof, Konrad; Probst, Elisabeth; Seifert, Burkhardt; Regenass, Stephan; Schmid-Grendelmeier, Peter

    Background: Alongside hazel, alder and birch pollen allergies, ash pollen allergy is a relevant cause of hay fever during spring in the European region. For some considerable time, ash pollen allergy was not routinely investigated and its clinical relevance may well have been underestimated, particularly since ash and birch tree pollination times are largely the same. Ash pollen extracts are not yet well standardized and diagnosis is therefore sometimes unreliable. Olive pollen, on the other hand, is strongly cross-reactive with ash pollen and is apparently better standardized. Therefore, the main allergen of olive pollen, Ole e 1, has been postulated as a reliable alternative for the detection of ash pollen sensitization. Methods: To determine to what extent specific IgE against Ole e 1 in patients with ash pollen allergy is relevant, we included 183 subjects with ash pollen allergy displaying typical symptoms in March/April and positive skin prick test specific IgE against Ole e 1 (t224) and ash pollen (t25) and various birch allergens (Bet v 1, Bet v 2/v 4) in a retrospective study. Results: A significant correlation was seen between specific IgE against Ole e 1 and ash pollen, but also to a slightly lesser extent between IgE against Ole e 1 and skin prick test with ash pollen, the latter being even higher than IgE and skin prick test both with ash pollen. No relevant correlation was found with birch pollen allergens, demonstrating the very limited cross-reactivity between ash and birch pollen. Conclusion: It appears appropriate to determine specific IgE against Ole e 1 instead of IgE against ash pollen to detect persons with ash pollen allergy. Our findings may also support the idea of using possibly better standardized or more widely available olive pollen extracts instead of ash pollen extract for allergen-specific immunotherapy.

  5. Properties and flammability of major tree species in the Beijing area

    Institute of Scientific and Technical Information of China (English)

    Xiaoli WANG; Shukui NIU; Zhenguo KAN

    2009-01-01

    In order to examine correlations among the properties of tree species and to quantify the relationships between these properties and flammability, the properties of 20 tree species, consisting of heat of combustion, extractive contents, ash content, moisture content and basic density, were measured via experimental methods. In the first instance, the results show that, there are significant correlations between heat of combustion and extractive contents, ash content and basic density. Second, heat of combustion can be presented effectively in terms of linear regression models with extractive contents and ash content as independent variables. Third, a flammable model was developed based on four properties of tree species as independent variables, i.e., heat of combustion, extractive contents, ash content and moisture content. Finally, the flammability of 20 tree species is compared, ordered and ranked based on this flammable model. The conclusion is that flammability can be predicted from properties of tree species, which are significantly correlated among themselves.

  6. Emerald Ash Borer Threat Reveals Ecohydrologic Feedbacks in Northern U.S. Black Ash Wetlands

    Science.gov (United States)

    Diamond, J.; Mclaughlin, D. L.; Slesak, R.

    2016-12-01

    Hydrology is a primary driver of wetland structure and process that can be modified by abiotic and biotic feedbacks, leading to self-organization of wetland systems. Large-scale disturbance to these feedbacks, such as loss of vegetation, can thus be expected to impact wetland hydrology. The Emerald Ash Borer is an invasive beetle that is expected to cause widespread-loss of ash trees throughout the northern U.S. and Canada. To predict ecosystem response to this threat of vegetation loss, we ask if and how Black Ash (Fraxinus nigra), a ubiquitous facultative-wetland ash species, actively controls wetland hydrology to determine if Black Ash creates favorable hydrologic regimes for growth (i.e., evidence for ecohydrologic feedbacks). We do this by taking advantage of plot-level tree removal experiments in Black Ash-dominated (75-100% basal area) wetlands in the Chippewa National Forest, Minnesota. The monospecies dominance in these systems minimizes variation associated with species-specific effects, allowing for clearer interpretation of results regarding ecohydrologic feedbacks. Here, we present an analysis of six years of water table and soil moisture time series in experimental plots with the following treatments: 1) clear cut, 2) girdling, 3) group-selection thinning, and 4) control. We also present evapotranspiration (ET) time series estimates for each experimental plot using analysis of diel water level variation. Results show elevated water tables in treatment plots relative to control plots for all treatments for several years after treatments were applied, with differences as great as 50 cm. Some recovery of water table to pre-treatment levels was observed over time, but only the group-selection thinning treatment showed near-complete recovery to pre-treatment levels, and clear-cut treatments indicate sustained elevated water tables over five years. Differences among treatments are directly attributed to variably reduced ET relative to controls. Results also

  7. Multispectral airborne imagery in the field reveals genetic determinisms of morphological and transpiration traits of an apple tree hybrid population in response to water deficit.

    Science.gov (United States)

    Virlet, Nicolas; Costes, Evelyne; Martinez, Sébastien; Kelner, Jean-Jacques; Regnard, Jean-Luc

    2015-09-01

    Genetic studies of response to water deficit in adult trees are limited by low throughput of the usual phenotyping methods in the field. Here, we aimed at overcoming this bottleneck, applying a new methodology using airborne multispectral imagery and in planta measurements to compare a high number of individuals.An apple tree population, grafted on the same rootstock, was submitted to contrasting summer water regimes over two years. Aerial images acquired in visible, near- and thermal-infrared at three dates each year allowed calculation of vegetation and water stress indices. Tree vigour and fruit production were also assessed. Linear mixed models were built accounting for date and year effects on several variables and including the differential response of genotypes between control and drought conditions.Broad-sense heritability of most variables was high and 18 quantitative trait loci (QTLs) independent of the dates were detected on nine linkage groups of the consensus apple genetic map. For vegetation and stress indices, QTLs were related to the means, the intra-crown heterogeneity, and differences induced by water regimes. Most QTLs explained 15-20% of variance.Airborne multispectral imaging proved relevant to acquire simultaneous information on a whole tree population and to decipher genetic determinisms involved in response to water deficit.

  8. Effect of wood ash and K-fertilization on {sup 137}Cs uptake by selected forest plants

    Energy Technology Data Exchange (ETDEWEB)

    Mandro, Yrii N. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Rosen, Klas [Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden); Vinichuk, Mykhailo M. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden)

    2014-07-01

    Accumulation {sup 137}Cs by different forest plants and trees after fertilization of soil with potassium and wood ash ({sup 137}Cs-contaminated and non-contaminated) in forest ecosystems of Ukraine contaminated by radionuclides after Chernobyl accident in 1986 was studied. Experiment is performed in Bazar forestry, Zhytomyr region, Ukraine, located about 70 km (51 deg. 5'35'' N, 29 deg. 18'56'' E) from Chernobyl NPP. Potassium fertilizer (KCl, wooden ash (Ash), and {sup 137}Cs-contaminated ash ({sup 137}CsAsh) in different combinations) were spread on the forest floor in April 2012 at a rate corresponding 100 kg/ha potassium. The experiment layout was as follows: 1- Control (no fertilizers were applied), 2- KCl, 3- Ash + KCl, 4- Ash + {sup 137}CsAsh, 5- Ash, 6- {sup 137}CsAsh + KCl. Samples (leaves and annual shoots) of blueberry (Vaccinium myrtillus), cowberry (Vaccinium vitis-idaea), rowan (Sorbus aucuparia), birch (Betula), buckthorn (Frangula) and oak (Quercus robur) and also mushrooms (fruit bodies of Russula, Lactarius, Cantharellus, Collybia etc.) and berries (blueberry and cowberry) were taken monthly from each treatment. Samples were measured for {sup 137}Cs with calibrated HPGe detectors. The results of the first year studies show variation of Transfer Factors (TF) for different plants and for the same plants on different treatments. The effect of fertilization was found for blueberry on Ash-applicated (TF = 0.0085 ± 0.0025), {sup 137}CsAsh + KCl-applicated (TF = 0.0105 ± 0.0060) and Ash + KCl-applicated (TF = 0.0123 ± 0.0058) treatments compared to Control (TF = 0.0163 ± 0.0092). Also good effect for rowan on Ash + KCl-applicated treatment (TF = 0.0067 ± 0.0024) compared to Control (TF = 0.0100 ± 0.0064). Effect was less obvious for birch on Ash + KCl-applicated treatment and for cowberry on Ash + KCl-applicated treatment. There was not found an obvious effect of fertilization for buckthorn. Positive effect of

  9. Volcanic ash melting under conditions relevant to ash turbine interactions.

    Science.gov (United States)

    Song, Wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado; Dingwell, Donald B

    2016-03-02

    The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200-2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines.

  10. Ash Management Review—Applications of Biomass Bottom Ash

    Directory of Open Access Journals (Sweden)

    Harpuneet S. Ghuman

    2012-10-01

    Full Text Available In industrialized countries, it is expected that the future generation of bioenergy will be from the direct combustion of residues and wastes obtained from biomass. Bioenergy production using woody biomass is a fast developing application since this fuel source is considered to be carbon neutral. The harnessing of bioenergy from these sources produces residue in the form of ash. As the demand for bioenergy production increases, ash and residue volumes will increase. Major challenges will arise relating to the efficient management of these byproducts. The primary concerns for ash are its storage, disposal, use and the presence of unburned carbon. The continual increase in ash volume will result in decreased ash storage facilities (in cases of limited room for landfill expansion, as well as increased handling, transporting and spreading costs. The utilization of ash has been the focus of many studies, hence this review investigates the likely environmental and technological challenges that increased ash generation may cause. The presence of alkali metals, alkaline earth metals, chlorine, sulphur and silicon influences the reactivity and leaching to the inorganic phases which may have significant impacts on soils and the recycling of soil nutrient. Discussed are some of the existing technologies for the processing of ash. Unburned carbon present in ash allows for the exploration of using ash as a fuel. The paper proposes sieve fractionation as a suitable method for the separation of unburnt carbon present in bottom ash obtained from a fixed-bed combustion system, followed by the application of the gasification technology to particle sizes of energy importance. It is hoped that this process will significantly reduce the volume of ash disposed at landfills.

  11. Enumerating Trees

    CERN Document Server

    Kucharczyk, Robert A

    2012-01-01

    In this note we discuss trees similar to the Calkin-Wilf tree, a binary tree that enumerates all positive rational numbers in a simple way. The original construction of Calkin and Wilf is reformulated in a more algebraic language, and an elementary application of methods from analytic number theory gives restrictions on possible analogues.

  12. MGT 401 ASH Course Tutorial / Tutorialoutlet

    OpenAIRE

    kennith

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   MGT 401 Week 1 Individual Assignment Strategic Management Process Paper (Ash) MGT 401 Week 1 Class Activity Week 1 (Ash) MGT 401 Week 1 DQ 1 (Ash) MGT 401 Week 1 DQ 2 (Ash) MGT 401 Week 2 Learning Team Business Model Comparison Example (Ash) MGT 401 Week 2 DQ 1 (Ash) MGT 401 Week 2 DQ 2 (Ash) MGT 401 Week 2 Class Activity (Ash) MGT 401 Week 3 Individual Assignment Business Plan Evaluation (Ash) ...

  13. Influence of trap placement and design on capture of the emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Francese, Joseph A; Oliver, Jason B; Fraser, Ivich; Lance, David R; Youssef, Nadeer; Sawyer, Alan J; Mastro, Victor C

    2008-12-01

    The key to an effective pest management program for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera Buprestidae), is a survey program equipped with tools for detecting and delimiting populations. We studied the effects of trap design, color, and placement on the efficacy of sticky traps for capturing the emerald ash borer. There were significant differences in trap catch along a transect gradient from wooded to open field conditions, with most beetles being caught along the edge, or in open fields, 15-25 m outside an ash (Fraxinus spp. L.) (Oleaceae) woodlot. Greater emerald ash borer catch occurred on purple traps than on red or white traps. Traps placed in the mid-canopy of ash trees (13 m) caught significantly more beetles than those placed at ground level. We also describe a new trap design, a three-sided prism trap, which is relatively easy to assemble and deploy.

  14. Melting Behavior of Volcanic Ash relevant to Aviation Ash Hazard

    Science.gov (United States)

    Song, W.; Hess, K.; Lavallee, Y.; Cimarelli, C.; Dingwell, D. B.

    2013-12-01

    Volcanic ash is one of the major hazards caused by volcanic eruptions. In particular, the threat to aviation from airborne volcanic ash has been widely recognized and documented. In the past 12 years, more than 60 modern jet airplanes, mostly jumbo jets, have been damaged by drifting clouds of volcanic ash that have contaminated air routes and airport facilities. Seven of these encounters are known to have caused in-flight loss of engine power to jumbo jets carrying a total of more than 2000 passengers. The primary cause of engine thrust loss is that the glass in volcanic ash particles is generated at temperatures far lower than the temperatures in the combustion chamber of a jet engine ( i.e. > 1600 oC) and when the molten volcanic ash particles leave this hottest section of the engine, the resolidified molten volcanic ash particles will be accumulated on the turbine nozzle guide vanes, which reduced the effective flow of air through the engine ultimately causing failure. Thus, it is essential to investigate the melting process and subsequent deposition behavior of volcanic ash under gas turbine conditions. Although few research studies that investigated the deposition behavior of volcanic ash at the high temperature are to be found in public domain, to the best our knowledge, no work addresses the formation of molten volcanic ash. In this work, volcanic ash produced by Santiaguito volcano in Guatemala in November 8, 2012 was selected for study because of their recent activity and potential hazard to aircraft safety. We used the method of accessing the behavior of deposit-forming impurities in high temperature boiler plants on the basis of observations of the change in shape and size of a cylindrical coal ash to study the sintering and fusion phenomena as well as determine the volcanic ash melting behavior by using characteristic temperatures by means of hot stage microscope (HSM), different thermal analysis (DTA) and Thermal Gravimetric Analysis (TGA) to

  15. Papermill sludge amendments, tree protection and tree establishment on an abandoned coal minesoil

    Energy Technology Data Exchange (ETDEWEB)

    Kost, D.A.; Boutelle, D.A.; Larson, M.M.; Smith, W.D.; Vimmerstedt, J.P. [Ohio State University, Wooster, OH (United States). School of Natural Resources

    1997-09-01

    The authors measured survival, growth, and foliar nutrition of white ash (Fraxinus americana L.), sycamore (Platanus occidentalis L.), and black walnut (Juglans nigra L.) on a regraded minesoil (Typic Udorthent, pH 2.9) treated with four combinations of papermill sludge depth by incorporation methods. They also compared tree performance when protected from mammal damage by tube, netting, or no shelters. Sludge rates were approximately 860 Mg ha{sup -1} for a 15-cm depth and 3450 Mg ha{sup -1} for a 60-cm depth. After 4 yr, tree survival was 65% when either 15 or 60 -cm depth. After 4 yr, tree survival was 65% when either 15 or 60 cm of sludge was deep incorporated by a backhole. Survival was 43% if 15 cm of sludge was rototill incorporated and 3% if 45 cm of sludge was surface applied over the rotoiller-incorporated sludge (60 cm total sludge depth). Trees were tallest (236 cm) on 15 cm-backhoed, intermediate (204 cm) on 60 cm backhoed, and shortest (130 cm) on 15 cm rotilled treatments. Ash (56% survival) survived better than sycamore (40%) and walnut (36%). Tree survival was best (61%) in tubes, intermediate (43%) in nets, and worst (28%) with no protection. Ash and walnut were tallest (177 cm) in tubes, intermediate (124 cm) in nets, and shortest (103 cm) with no protection. Sycamore height (305 cm) was not affected by the shelters. Foliar nutrition of trees was adequate except for possible low P in ash. In summary, tree survival and growth were good if sludge was incorporated by backhoeing and trees were protected by tube shelters. 38 refs., 5 tabs.

  16. Thermal constraints on the emerald ash borer invasion of North America

    Science.gov (United States)

    DeSantis, R.; Moser, W. K.; Gormanson, D. D.; Bartlett, M. G.

    2012-12-01

    Emerald ash borer (Agrilus planipennis Fairmaire; EAB), a non-native invasive beetle, has caused substantial damage to green (Fraxinus pennsylvanica Marsh.), white (Fraxinus americana L.), and black ash (Fraxinus nigra Marsh.), the major ash species of North America. In the absence of effective methods for controlling or eradicating the beetle, EAB continues to spread unimpeded across North America. Evidence indicates the mortality rate for EAB-infested trees near the epicenter of the infestation in southeast Michigan exceeds 99 percent for the major ash species. One possible climatic limitation on the spread of the infestation is suggested by recent work indicating that beetles cannot survive exposure to temperatures below -35.3 degrees Celsius. We considered whether this thermal constraint will limit the spread and distribution of EAB in North America. Historical climatic data for the United States and Canada were employed along with thermal models of the conditions beneath likely winter snowpack and beneath tree bark to predict the potential geographic distribution of the invasion. Results suggested the thermal mortality constraint will not lead to the protection of ash stands across most of North America. However, recent work indicates the majority of beetles cannot survive exposure to temperatures below -30 degrees Celsius. Along with our results, this suggests thermal constraints near the northern and western edges of the ranges of ash might limit EAB survival to some extent, thereby reducing the EAB population, the likelihood of EAB infestation, and subsequent ash mortality.

  17. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  18. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2013-01-01

    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  19. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  20. Ash Aggregates in Proximal Settings

    Science.gov (United States)

    Porritt, L. A.; Russell, K.

    2012-12-01

    Ash aggregates are thought to have formed within and been deposited by the eruption column and plume and dilute density currents and their associated ash clouds. Moist, turbulent ash clouds are considered critical to ash aggregate formation by facilitating both collision and adhesion of particles. Consequently, they are most commonly found in distal deposits. Proximal deposits containing ash aggregates are less commonly observed but do occur. Here we describe two occurrences of vent proximal ash aggregate-rich deposits; the first within a kimberlite pipe where coated ash pellets and accretionary lapilli are found within the intra-vent sequence; and the second in a glaciovolcanic setting where cored pellets (armoured lapilli) occur within Diamond Mine, Canada, are the residual deposits within the conduit and vent of the volcano and are characterised by an abundance of ash aggregates. Coated ash pellets are dominant but are followed in abundance by ash pellets, accretionary lapilli and rare cored pellets. The coated ash pellets typically range from 1 - 5 mm in diameter and have core to rim ratios of approximately 10:1. The formation and preservation of these aggregates elucidates the style and nature of the explosive phase of kimberlite eruption at A418 (and other pipes?). First, these pyroclasts dictate the intensity of the kimberlite eruption; it must be energetic enough to cause intense fragmentation of the kimberlite to produce a substantial volume of very fine ash (sustained plume attended by concomitant production of pyroclastic density currents. The size and internal structure of the armoured lapilli provide constraints on the nature of the initial explosive phase of eruption at Kima'Kho. Their proximity to the vent also indicates rapid aggregation within the eruption plume. Within both sequences rapid aggregation of ash particles occurred in proximity to the vent. However, the conditions were substantially different leading to the production of armoured

  1. Dielectric properties of fly ash

    Indian Academy of Sciences (India)

    S C Raghavendra; R L Raibagkar; A B Kulkarni

    2002-02-01

    This paper reports the dielectric properties of fly ash. The dielectric measurements were performed as a function of frequency and temperature. The sample of fly ash shows almost similar behaviour in the frequency and temperature range studied. The large value of dielectric constant in the typical frequency range is because of orientation polarization and tight binding force between the ions or atoms in the fly ash. The sample of fly ash is of great scientific and technological interest because of its high value of dielectric constant (104).

  2. Volcanic ash infrared signature: realistic ash particle shapes compared to spherical ash particles

    Directory of Open Access Journals (Sweden)

    A. Kylling

    2013-10-01

    Full Text Available The reverse absorption technique is often used to detect volcanic clouds from thermal infrared satellite measurements. From these measurements particle size and mass loading may also be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculate thermal infrared optical properties of highly irregular and porous ash particles and compare these with mass- and volume-equivalent spherical models. Furthermore, brightness temperatures pertinent to satellite observing geometry are calculated for the different ash particle shapes. Non-spherical shapes and volume-equivalent spheres are found to produce a detectable ash signal for larger particle sizes than mass-equivalent spheres. The assumption of mass-equivalent spheres for ash mass loading estimates will underestimate the mass loading by several tens of percent compared to morphologically complex inhomogeneous ash particles.

  3. Volcanic ash infrared signature: realistic ash particle shapes compared to spherical ash particles

    Science.gov (United States)

    Kylling, A.; Kahnert, M.; Lindqvist, H.; Nousiainen, T.

    2013-10-01

    The reverse absorption technique is often used to detect volcanic clouds from thermal infrared satellite measurements. From these measurements particle size and mass loading may also be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculate thermal infrared optical properties of highly irregular and porous ash particles and compare these with mass- and volume-equivalent spherical models. Furthermore, brightness temperatures pertinent to satellite observing geometry are calculated for the different ash particle shapes. Non-spherical shapes and volume-equivalent spheres are found to produce a detectable ash signal for larger particle sizes than mass-equivalent spheres. The assumption of mass-equivalent spheres for ash mass loading estimates will underestimate the mass loading by several tens of percent compared to morphologically complex inhomogeneous ash particles.

  4. Automatic volcanic ash detection from MODIS observations using a back-propagation neural network

    Directory of Open Access Journals (Sweden)

    T. M. Gray

    2015-12-01

    Full Text Available Due to the climate effects and aviation threats of volcanic eruptions, it is important to accurately locate ash in the atmosphere. This study aims to explore the accuracy and reliability of training a neural network to identify cases of ash using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS. Satellite images were obtained for the following eruptions: Kasatochi, Aleutian Islands, 2008; Okmok, Aleutian Islands, 2008; Grímsvötn, northeastern Iceland, 2011; Chaitén, southern Chile, 2008; Puyehue-Cordón Caulle, central Chile, 2011; Sangeang Api, Indonesia, 2014; and Kelut, Indonesia, 2014. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT model was used to obtain ash concentrations for the same archived eruptions. Two back-propagation neural networks were then trained using brightness temperature differences as inputs obtained via the following band combinations: 12–11, 11–8.6, 11–7.3, and 11 μm. Using the ash concentrations determined via HYSPLIT, flags were created to differentiate between ash (1 and no ash (0 and SO2-rich ash (1 and no SO2-rich ash (0 and used as output. When neural network output was compared to the test data set, 93 % of pixels containing ash were correctly identified and 7 % were missed. Nearly 100 % of pixels containing SO2-rich ash were correctly identified. The optimal thresholds, determined using Heidke skill scores, for ash retrieval and SO2-rich ash retrieval were 0.48 and 0.47, respectively. The networks show significantly less accuracy in the presence of high water vapor, liquid water, ice, or dust concentrations. Significant errors are also observed at the edge of the MODIS swath.

  5. Automatic volcanic ash detection from MODIS observations using a back-propagation neural network

    Directory of Open Access Journals (Sweden)

    T. M. Gray

    2015-08-01

    Full Text Available Due to the climate effects and aviation threats of volcanic eruptions, it is important to accurately locate ash in the atmosphere. This study aims to explore the accuracy and reliability of training a neural network to identify cases of ash using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS. Satellite images were obtained for the following eruptions: Kasatochi, Aleutian Islands, 2008; Okmok, Aleutian Islands, 2008; Grímsvötn, northeastern Iceland, 2011; Chaiteìn, southern Chile, 2008; Puyehue-Cordoìn Caulle, central Chile, 2011; Sangeang Api, Indonesia, 2014; and Kelut, Indonesia, 2014. The Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT was used to obtain ash concentrations for the same archived eruptions. Two back-propagation neural networks were then trained using brightness temperature differences as inputs obtained via the following band combinations: 12-11, 11-8.6, 11-7.3, and 11 μm. Using the ash concentrations determined via HYSPLIT, flags were created to differentiate between ash (1 and no ash (0 and SO2-rich ash (1 and no SO2-rich ash (0 and used as output. When neural network output was compared to the test dataset, 93 % of pixels containing ash were correctly identified and 7 % were missed. Nearly 100 % of pixels containing SO2-rich ash were correctly identified. The optimal thresholds, determined using Heidke skill scores, for ash retrieval and SO2-rich ash retrieval were 0.48 and 0.47, respectively. The networks show significantly less accuracy in the presence of high water vapor, liquid water, ice, or dust concentrations. Significant errors are also observed at the edge of the MODIS swath.

  6. Influence of Bed Ash and Fly Ash Replacement in Mortars

    Directory of Open Access Journals (Sweden)

    S. L. Summoogum-Utchanah

    2015-03-01

    Full Text Available The study evaluates the influence of fly ash and bottom ash as partial cement substitutes in mortars by studying the particle size distribution, consistency, flow, fresh density, air content, compressive strength and flexural strength characteristics. The results revealed that fly ash and cement had relatively the same particle size distribution unlike bottom ash. In the fresh state, as the amount of pozzolans increased in the mixtures, the mortars showed an enhancement in workability, were susceptible to water loss by bleeding, and exhibited a decline in fresh density. The early strength gains of the fly ash samples were low but reached higher than the control after 28 days of curing. The flexural strength increased as the fly ash content rose to reach a maximum at 20 % replacement. However, the 2-day compressive strength of bottom ash samples was higher than the control but decreased after 28 days of curing while the flexural strength declined with addition of bottom ash except at 5 % substitution.

  7. Fly ash quality and utilization

    Energy Technology Data Exchange (ETDEWEB)

    Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  8. HIS 103 ASH course tutorial/tutorialoutlet

    OpenAIRE

    NARESH 1

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com   HIS 103 Week 1 DQ 1 (Transition to Agriculture) (Ash) HIS 103 Week 1 DQ 2 (Early Complex Societies) (Ash) HIS 103 Week 1 Quiz (Ash) HIS 103 Week 1 Assignment (Ash) HIS 103 Week 2 Assignment Greco Roman Influence Paper (Ash) HIS 103 Week 2 DQ 1 Chinese Social and Political Order Systems (Ash) HIS 103 Week 2 DQ 2 Caste System (Ash) HIS 103 Week 2 Quiz (Ash) HIS 103 Week 3 Assignment Black Death Dra...

  9. Impact of Beauveria bassiana and imidacloprid, alone and in combination, used against emerald ash borer in a newly-infested ash nursery

    Science.gov (United States)

    We are investigating the potential of Beauveria bassiana (strain GHA), alone or in combination with imidacloprid, for use against the emerald ash borer (EAB), Agrilus planipennis. We treated approximately 400 Fraxinus pennsylvanica and F. americana (height ca. 5-6 m) at a commercial tree nursery wit...

  10. Quantifying the impact of woodpecker predation on population dynamics of the emerald ash borer (Agrilus planipennis.

    Directory of Open Access Journals (Sweden)

    David E Jennings

    Full Text Available The emerald ash borer (EAB, Agrilus planipennis, is an invasive beetle that has killed millions of ash trees (Fraxinus spp. since it was accidentally introduced to North America in the 1990s. Understanding how predators such as woodpeckers (Picidae affect the population dynamics of EAB should enable us to more effectively manage the spread of this beetle, and toward this end we combined two experimental approaches to elucidate the relative importance of woodpecker predation on EAB populations. First, we examined wild populations of EAB in ash trees in New York, with each tree having a section screened to exclude woodpeckers. Second, we established experimental cohorts of EAB in ash trees in Maryland, and the cohorts on half of these trees were caged to exclude woodpeckers. The following spring these trees were debarked and the fates of the EAB larvae were determined. We found that trees from which woodpeckers were excluded consistently had significantly lower levels of predation, and that woodpecker predation comprised a greater source of mortality at sites with a more established wild infestation of EAB. Additionally, there was a considerable difference between New York and Maryland in the effect that woodpecker predation had on EAB population growth, suggesting that predation alone may not be a substantial factor in controlling EAB. In our experimental cohorts we also observed that trees from which woodpeckers were excluded had a significantly higher level of parasitism. The lower level of parasitism on EAB larvae found when exposed to woodpeckers has implications for EAB biological control, suggesting that it might be prudent to exclude woodpeckers from trees when attempting to establish parasitoid populations. Future studies may include utilizing EAB larval cohorts with a range of densities to explore the functional response of woodpeckers.

  11. Quantifying the impact of woodpecker predation on population dynamics of the emerald ash borer (Agrilus planipennis).

    Science.gov (United States)

    Jennings, David E; Gould, Juli R; Vandenberg, John D; Duan, Jian J; Shrewsbury, Paula M

    2013-01-01

    The emerald ash borer (EAB), Agrilus planipennis, is an invasive beetle that has killed millions of ash trees (Fraxinus spp.) since it was accidentally introduced to North America in the 1990s. Understanding how predators such as woodpeckers (Picidae) affect the population dynamics of EAB should enable us to more effectively manage the spread of this beetle, and toward this end we combined two experimental approaches to elucidate the relative importance of woodpecker predation on EAB populations. First, we examined wild populations of EAB in ash trees in New York, with each tree having a section screened to exclude woodpeckers. Second, we established experimental cohorts of EAB in ash trees in Maryland, and the cohorts on half of these trees were caged to exclude woodpeckers. The following spring these trees were debarked and the fates of the EAB larvae were determined. We found that trees from which woodpeckers were excluded consistently had significantly lower levels of predation, and that woodpecker predation comprised a greater source of mortality at sites with a more established wild infestation of EAB. Additionally, there was a considerable difference between New York and Maryland in the effect that woodpecker predation had on EAB population growth, suggesting that predation alone may not be a substantial factor in controlling EAB. In our experimental cohorts we also observed that trees from which woodpeckers were excluded had a significantly higher level of parasitism. The lower level of parasitism on EAB larvae found when exposed to woodpeckers has implications for EAB biological control, suggesting that it might be prudent to exclude woodpeckers from trees when attempting to establish parasitoid populations. Future studies may include utilizing EAB larval cohorts with a range of densities to explore the functional response of woodpeckers.

  12. White Fringetree as a Novel Larval Host for Emerald Ash Borer.

    Science.gov (United States)

    Cipollini, Don

    2015-02-01

    Emerald ash borer is an invasive Asian pest of ash species in North America. All North American species of ash tested so far are susceptible to it, but there are no published reports of this insect developing fully in non-ash hosts in the field in North America. I report here evidence that emerald ash borer can attack and complete development in white fringetree, Chionanthus virginicus L., a species native to the southeastern United States that is also planted ornamentally. Four of 20 mature ornamental white fringetrees examined in the Dayton, Ohio area showed external symptoms of emerald ash borer attack, including the presence of adult exit holes, canopy dieback, and bark splitting and other deformities. Removal of bark from one of these trees yielded evidence of at least three generations of usage by emerald ash borer larvae, several actively feeding live larvae, and a dead adult confirmed as emerald ash borer. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Emerald Ash Borer (Coleoptera: Buprestidae)

    Science.gov (United States)

    The emerald ash borer, Agrilus planipennis Fairmaire, is an invasive beetle from Asia that has caused large scale ash (Fraxinus spp.) mortality in North America. This book chapter reviews the taxonomy, biology, life history of this invasive pest and its associated natural enemies in both its native ...

  14. Leaching from biomass combustion ash

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2014-01-01

    The use of biomass combustion ashes for fertilizing and liming purposes has been widely addressed in scientific literature. Nevertheless, the content of potentially toxic compounds raises concerns for a possible contamination of the soil. During this study five ash samples generated at four...

  15. Context trees

    OpenAIRE

    Ganzinger, Harald; Nieuwenhuis, Robert; Nivela, Pilar

    2001-01-01

    Indexing data structures are well-known to be crucial for the efficiency of the current state-of-the-art theorem provers. Examples are \\emph{discrimination trees}, which are like tries where terms are seen as strings and common prefixes are shared, and \\emph{substitution trees}, where terms keep their tree structure and all common \\emph{contexts} can be shared. Here we describe a new indexing data structure, \\emph{context trees}, where, by means of a limited kind of conte...

  16. Two Trees

    OpenAIRE

    Cochrane, John. H.; Longstaff, Francis A.; Santa-Clara, Pedro

    2004-01-01

    We solve a model with two “Lucas trees.†Each tree has i.i.d. dividend growth. The investor has log utility and consumes the sum of the two trees’ dividends. This model produces interesting asset-pricing dynamics, despite its simple ingredients. Investors want to rebalance their portfolios after any change in value. Since the size of the trees is fixed, however, prices must adjust to offset this desire. As a result, expected returns, excess returns, and return volatility all vary throug...

  17. Biology, life history, and laboratory rearing of Atanycolus cappaerti (Hymenoptera:Braconidae), a larval parasitoid of the invasive Emerald Ash Borer (Coleoptera: Buprestidae)

    Science.gov (United States)

    Atanycolus cappaerti Marsh and Strazanac is a native North American parasitoid that has been found to parasitize the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire, which has killed millions of ash trees since it was first detected in Michigan. A native parasitoid like A. cappaerti...

  18. Biology and Life History of Atanycolus cappaerti (Hymenoptera: Braconidae), a North American Larval Parasitoid Attacking the Invasive Emerald Ash Borer (Coleoptera: Buprestidae)

    Science.gov (United States)

    Atanycolus cappaerti Marsh and Strazanac is a native North American parasitoid that has been found to parasitize the emerald ash borer, Agrilus planipennis Fairmaire, a serious invasive pests of North American ash trees (Fraxinus spp.). To facilitate the development of potential augmentative biocon...

  19. Monitoring the establishment and flight phenology of egg and larval parasitoids of emerald ash borer (Coleoptera: Buprestidae) in Michigan, USA using sentinel eggs and larvae

    Science.gov (United States)

    Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an important invasive pest of ash (Fraxinus) trees in North America. Two larval parasitoids, Tetrastichus planipennisi Yang and Spathius agrili Yang, and one egg parasitoid, Oobius agrili Zhang and Huang, were introduced into the United Sta...

  20. Oviposition and development of emerald ash borer (Agrilus planipennis) (Coleoptera: Buprestidae) on hosts and potential hosts in no-choice bioassays

    Science.gov (United States)

    Andrea C. Anulewicz; Deborah G. McCullough; Deborah L. Miller

    2006-01-01

    Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is an invasive phloem-feeding pest native to Asia. It was first identified in North America in 2002 and has killed millions of ash (Fraxinus spp.) trees in southeast Michigan and Essex County, Ontario. Since then, additional populations have been discovered...

  1. Implementation of routine ash predictions using a general purpose atmospheric dispersion model (HYSPLIT) adapted for calculating ash thickness on the ground.

    Science.gov (United States)

    Hurst, Tony; Davis, Cory; Deligne, Natalia

    2016-04-01

    GNS Science currently produces twice-daily forecasts of the likely ash deposition if any of the active or recently active volcanoes in New Zealand was to erupt, with a number of alternative possible eruptions for each volcano. These use our ASHFALL program for calculating ash thickness, which uses 1-D wind profiles at the location of each volcano derived from Numerical Weather Prediction (NWP) model output supplied by MetService. HYSPLIT is a hybrid Lagrangian dispersion model, developed by NOAA/ARL, which is used by MetService in its role as a Volcanic Ash Advisory Centre, to model airborne volcanic ash, with meteorological data provided by external and in-house NWP models. A by-product of the HYSPLIT volcanic ash dispersion simulations is the deposition rate at the ground surface. Comparison of HYSPLIT with ASHFALL showed that alterations to the standard fall velocity model were required to deal with ash particles larger than about 50 microns, which make up the bulk of ash deposits near a volcano. It also required the ash injected into the dispersion model to have a concentration based on a typical umbrella-shaped eruption column, rather than uniform across all levels. The different parameters used in HYSPLIT also caused us to revisit what possible combinations of eruption size and column height were appropriate to model as a likely eruption. We are now running HYSPLIT to produce alternative ash forecasts. It is apparent that there are many times at which the 3-D wind model used in HYSPLIT gives a substantially different ash deposition pattern to the 1-D wind model of ASHFALL, and the use of HYSPLIT will give more accurate predictions. ASHFALL is likely still to be used for probabilistic hazard forecasting, in which very large numbers of runs are required, as HYSPLIT takes much more computer time.

  2. Talking Trees

    Science.gov (United States)

    Tolman, Marvin

    2005-01-01

    Students love outdoor activities and will love them even more when they build confidence in their tree identification and measurement skills. Through these activities, students will learn to identify the major characteristics of trees and discover how the pace--a nonstandard measuring unit--can be used to estimate not only distances but also the…

  3. Pathological Condition of Trees and Shrubs of Forest Plantations in the Middle and Lower Volga Region

    Directory of Open Access Journals (Sweden)

    Kolmukidi Svetlana Valeryevna

    2015-09-01

    Full Text Available The materials on the study of the characteristics of pathologies common in the protective forest plantations are presented. The basic factors of deterioration of woody species pathological conditions are identified. The most common and harmful diseases of the major tree species of the Lower and Middle Volga region are determined. The comparative tolerance of systematic structure of the main forest-forming species to diseases are revealed. The complex research of modern pathological condition of trees and shrubs agroforestry plantations in the steppe and dry steppe regions of Lower and Middle Volga is carried out. Arid climate and harsh growing conditions contribute to the weakening of the stability of trees and shrubs and the deterioration of the pathological state plantations. Abnormal weather conditions (high temperatures, insufficiency or lack of precipitation, strong winds, hot winds, careless use of fire were the reason of forest plantations death. The varying degrees of resistance to pathogens among systematic composition rocks of artificial planting: elm, poplar, birch, ash, maple and others are revealed. The diseases of various etiologies, aggressiveness and severity leading to partial or complete loss of epiphytotics are identified. The most harmful are the vascular pathology (Dutch elm disease, Verticillium of maple, necrotic and cancerous disease of poplar, rot, bacterial diseases. The Middle Volga region Submucusracemosa is the most immune to pathogens, but Ribesaureum is quite resistant to anthracnose and powdery mildew, meanwhile it is subject to Verticillium wilt (Fungi of the genus Verticillium. In the Lower Volga region Cotinuscoggygria and Loniceratatarica are resistant to pathogens. Ribesaureum is subject to anthracnose and Verticillium wilt, on the branches of shadberry necrosis sore meets. Leaves of pea tree suffer from Septoria and rust, branch necrosis and cancer. The use of more sustainable, fast-growing species, hybrids

  4. Laboratory Evaluation of the Toxicity of Systemic Insecticides to Emerald Ash Borer Larvae.

    Science.gov (United States)

    Poland, Therese M; Ciaramitaro, Tina M; McCullough, Deborah G

    2016-04-01

    Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae), an invasive phloem-feeding insect native to Asia, threatens at least 16 North American ash (Fraxinus) species and has killed hundreds of millions of ash trees in landscapes and forests. We conducted laboratory bioassays to assess the relative efficacy of systemic insecticides to control emerald ash borer larvae in winter 2009 and 2010. Second- and third-instar larvae were reared on artificial diet treated with varying doses of emamectin benzoate (TREE-äge, Arborjet, Inc., Woburn, MA), imidacloprid (Imicide, J. J Mauget Co., Arcadia, CA), dinotefuran (Safari, Valent Professional Products, Walnut Creek, CA), and azadirachtin (TreeAzin, BioForest Technologies, Inc., Sault Ste. Marie, Ontario, and Azasol, Arborjet, Inc., Woburn, MA). All of the insecticides were toxic to emerald ash borer larvae, but lethal concentrations needed to kill 50% of the larvae (LC50), standardized by larval weight, varied with insecticide and time. On the earliest date with a significant fit of the probit model, LC50 values were 0.024 ppm/g at day 29 for TREE-äge, 0.015 ppm/g at day 63 for Imicide, 0.030 ppm/g at day 46 for Safari, 0.025 ppm/g at day 24 for TreeAzin, and 0.027 ppm/g at day 27 for Azasol. The median lethal time to kill 50% (LT50) of the tested larvae also varied with insecticide product and dose, and was longer for Imicide and Safari than for TREE-äge or the azadirachtin products. Insecticide efficacy in the field will depend on adult and larval mortality as well as leaf and phloem insecticide residues.

  5. 49 CFR 230.69 - Ash pans.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Ash pans. 230.69 Section 230.69 Transportation... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Ash Pans § 230.69 Ash pans. Ash pans shall be securely supported from mud-rings or frames with no part less than...

  6. Hybrid Model of Content Extraction

    DEFF Research Database (Denmark)

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah

    2012-01-01

    We present a hybrid model for content extraction from HTML documents. The model operates on Document Object Model (DOM) tree of the corresponding HTML document. It evaluates each tree node and associated statistical features like link density and text distribution across the node to predict signi...

  7. Improved hybrid query tree anti-collision algorithm in RFID system%改进的RFID混合查询树防碰撞算法

    Institute of Scientific and Technical Information of China (English)

    周清; 蔡明

    2012-01-01

    为了改善射频识别(radio frequency identification,RFID)系统中大量无源标签识别时,普通算法识别速度慢、性能不稳定等的问题,在混合查询树算法的基础上提出了一种改进型的混合查询树防碰撞算法.在原有查询队列的基础上,由每个符合前缀标签的除去前缀后高三位比特中“1”的个数来决定其延时多少个时隙再进行对阅读器的应答;应答过程中,采用曼彻斯特编码进行数据的发送,有效地识别了碰撞位.仿真结果表明,改进算法在大量标签识别的场合比混合查询树算法更具有效性和稳定性.%To resolve the problem of performing slowly and lacking of steadiness for traditional anti-collision algorithms in the case where there are hundreds of tags identifying simultaneously in the RFID system, a new algorithm is suggested based on hy-brid QT. In this algorithm, the tag which matches prefix sent by reader delays slots depending on their count of value 1 of upper 3 bit based on query queue. Manchester code is used in the process for tags' responding to detect collision effectively. The simula-tion performance shows the algorithm is more effective and steady than hybrid QT in the situation for a large number of tags for identifying.

  8. Knowledge Transfer from the Forestry Sector to the Agricultural Sector concerning Ash Recycling; Kunskapsoeverfoering fraan skogssektorn till jordbrukssektorn angaaende askaaterfoering

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Johanna; Salomon, Eva

    2009-02-15

    cultivation period, which is generally 70-80 years for trees (25 years for willow), but 1-3 years for arable crops. Nutrients are supplied more continuously in agriculture than in forestry, which is rarely fertilised. There is an existing quality assurance system for ash application in forestry, and the knowledge available there could be applied in a corresponding system for agriculture. Different types of biofuels are combusted together today, e.g. forest trash and willow chippings. It is important to determine how mixing different ash types can affect ash recycling, e.g. by increasing the levels of Cd in the product. To enable ash recycling to arable land, the relevant authorities, e.g. the Swedish Board of Agriculture and the Swedish Environmental Protection Agency, will have to formulate requirements or recommendations for all ash recycling, including mixed ash. One quality assurance approach for ash recycling is to have a declaration of content system for ash intended for application on arable land. The authorities should also promote the development of circulation systems where biofuel ash is returned to the land where the biofuel crops were grown

  9. Phylogenetic trees

    OpenAIRE

    Baños, Hector; Bushek, Nathaniel; Davidson, Ruth; Gross, Elizabeth; Harris, Pamela E.; Krone, Robert; Long, Colby; Stewart, Allen; WALKER, Robert

    2016-01-01

    We introduce the package PhylogeneticTrees for Macaulay2 which allows users to compute phylogenetic invariants for group-based tree models. We provide some background information on phylogenetic algebraic geometry and show how the package PhylogeneticTrees can be used to calculate a generating set for a phylogenetic ideal as well as a lower bound for its dimension. Finally, we show how methods within the package can be used to compute a generating set for the join of any two ideals.

  10. A review of European ash (Fraxinus excelsior L.): implications for silviculture

    NARCIS (Netherlands)

    Dobrowolska, D.; Hein, S.; Oosterbaan, A.; Wagner, S.; Clark, J.; Skovsgaard, J.P.

    2011-01-01

    European ash (Fraxinus excelsior L.) is common throughout much of Europe and is a valuable broadleaved tree due to its ecological characteristics, outstanding wood properties and high economic value. It is a fast growing species, associated with several forest types and with a scattered distribution

  11. The overwintering physiology of the emerald ash borer, Agrilus planipennis fairmaire (coleoptera: buprestidae).

    Science.gov (United States)

    Crosthwaite, Jill C; Sobek, Stephanie; Lyons, D Barry; Bernards, Mark A; Sinclair, Brent J

    2011-01-01

    Ability to survive cold is an important factor in determining northern range limits of insects. The emerald ash borer (Agrilus planipennis) is an invasive beetle introduced from Asia that is causing extensive damage to ash trees in North America, but little is known about its cold tolerance. Herein, the cold tolerance strategy and mechanisms involved in the cold tolerance of the emerald ash borer were investigated, and seasonal changes in these mechanisms monitored. The majority of emerald ash borers survive winter as freeze-intolerant prepupae. In winter, A. planipennis prepupae have low supercooling points (approximately -30°C), which they achieve by accumulating high concentrations of glycerol (approximately 4M) in their body fluids and by the synthesis of antifreeze agents. Cuticular waxes reduce inoculation from external ice. This is the first comprehensive study of seasonal changes in cold tolerance in a buprestid beetle.

  12. AshMeadowsNaucorid_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Naucorid (Ambrysus amargosus) occur. "Nevada, Nye County. Point of Rocks Springs and...

  13. AshMeadowsNaucorid_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Naucorid (Ambrysus amargosus) occur. "Nevada, Nye County. Point of Rocks Springs and...

  14. Game tree algorithms and solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie)

    1998-01-01

    textabstractIn this paper, a theory of game tree algorithms is presented, entirely based upon the concept of solution tree. Two types of solution trees are distinguished: max and min trees. Every game tree algorithm tries to prune nodes as many as possible from the game tree. A cut-off criterion in

  15. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  16. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  17. Fly ash. Quality recycling material

    Energy Technology Data Exchange (ETDEWEB)

    Blomster, D.; Leisio, C.

    1996-11-01

    Imatran Voima`s coal-fired power plants not only generate power and heat but also produce fly ash which is suitable raw material for recycling. This material for recycling is produced in the flue gas cleaning process. It is economical and, thanks to close quality control, is suitable for use as a raw material in the building materials industry, in asphalt production, and in earthworks. Structures made from fly ash are also safe from an environmental point of view. (orig.)

  18. Fly ash. Quality recycling material

    Energy Technology Data Exchange (ETDEWEB)

    Blomster, D.; Leisio, C.

    1996-11-01

    Imatran Voima`s coal-fired power plants not only generate power and heat but also produce fly ash which is suitable raw material for recycling. This material for recycling is produced in the flue gas cleaning process. It is economical and, thanks to close quality control, is suitable for use as a raw material in the building materials industry, in asphalt production, and in earthworks. Structures made from fly ash are also safe from an environmental point of view. (orig.)

  19. 几种苹果砧木杂交后代对红富士苹果树体生长及早花特性的影响%Effects of different apple rootstock hybrids on the growth and early flowering of Fuji apple tree

    Institute of Scientific and Technical Information of China (English)

    隗晓雯; 郭静; 史娟; 郭兴科; 张学英; 徐继忠

    2015-01-01

    为苹果矮化砧木杂交育种亲本选择与选配提供依据,以‘西府海棠’、‘珠美海棠’、‘77‐34’、‘P22’、‘S H38’、‘S19’等苹果砧木的杂交后代嫁接红富士为试材,研究不同砧木杂交后代对树体大小、枝类组成、新梢生长等与树体生长相关的性状及早花特性的影响。结果表明:以不同组合杂交后代为砧木的红富士苹果在树高方面无显著差异;77‐34× S H38的杂交后代嫁接红富士植株短枝+叶丛枝所占总枝量的比率显著高于其他组合;77‐34× S H38杂交后代、西府海棠× S19杂交后代嫁接红富士植株的早花比例明显高于其他组合。供试材料中,‘77‐34’是矮砧杂交育种中较为适宜的母本,‘S19’是较为适宜的父本。%To select suitable parents for apple dwarf rootstock breeding ,the experiment was carried out with Fuji apple trees grafted onto different apple rootstock hybrids .Effects of dif‐ferent apple rootstock hybrids on tree characters ,including tree size ,composition of shoot types ,new shoot growth and early flowering were studied .The results showed that the ratio of leafage shoot + dwarf shoot to total number of shoots on 77‐34 × SH38 hybrids was markedly higher than that of other trees ;the early flowering habit of Fuji apple trees grafted onto 77‐34 × SH38 hybrids ,Midget crabapple × S19 hybrids were obviously higher than that of other trees .‘77‐34’was a suitable mother parent and ‘S19’was a suitable father parent for breeding of dwarf and early flowering rootstocks in the test materials .

  20. Decreased emergence of emerald ash borer from ash treated with methyl jasmonate is associated with induction of general defense traits and the toxic phenolic compound verbascoside.

    Science.gov (United States)

    Whitehill, Justin G A; Rigsby, Chad; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

    2014-12-01

    The emerald ash borer (EAB; Agrilus planipennis Fairmaire) is causing widespread mortality of ash (Fraxinus spp.) in North America. To date, no mechanisms of host resistance have been identified against this pest. Methyl jasmonate was applied to susceptible North American and resistant Asian ash species to determine if it can elicit induced responses in bark that enhance resistance to EAB. In particular, phenolic compounds, lignin, and defense-related proteins were quantified, and compounds associated with resistance were subsequently tested directly against EAB larvae in bioassays with artificial diet. MeJA application decreased adult emergence in susceptible ash species, comparable to levels achieved by insecticide application. Concentration of the phenolic compound verbascoside sharply increased after MeJA application to green and white ash. When incorporated in an artificial diet, verbascoside decreased survival and growth of EAB neonates in a dose-dependent fashion. Lignin and trypsin inhibitors were also induced by MeJA, and analogs of both compounds reduced growth of EAB larvae in artificial diets. We conclude that the application of MeJA prior to EAB attack has the ability to enhance resistance of susceptible ash trees by inducing endogenous plant defenses, and report evidence that induction of verbascoside is a mechanism of resistance to EAB.

  1. The use of cover crops to control tree invasion on a right-of-way near Tobermory. IV. Crop persistance and tree invasion in the third growing season

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.

    1992-04-08

    A study was carried out to determine the ability of grasses, legumes, and the natural right-of-way vegetation cover to interfere with tree invasion. The location, in the Tobermory area of the Bruce Peninsula, was used to test 6 treatments at 6 sites, consisting of: soil scarification and seeding with creeping red fescue (Festuca rubra); soil scarification and seeding with juno orchard grass (Dactylis glomerata); soil scarification and seeding with birdsfoot trefoil (Lotus corniculatus); soil scarification and seeding with a mixture of penngift crown vetch (Coronilla varia) and perennial ryegrass (Lolium multiflorum); soil scarification with no seeding; and no soil scarification and no seeding. A design change in 1991 involved the addition of a slow release fertilizer and planting of green ash (Flaxinus pennsylvanica), sugar maple (Acer saccharum) and hybrid poplar (Populus sp.) to directly measure the interference potential of the crops. Orchard grass had the highest frequency (93[plus minus]3%), the largest cover (32[plus minus]7%) and the tallest canopy. Red fescue was present with a similarly high frequency and cover but did not appear to be as vigorous as the orchard grass. The frequencies of birdsfoot trefoil and crown vetch declined, and had extremely poor covers. The density of incompatible trees varied at each site but was not affected by the treatments. 41 refs., 6 figs., 7 tabs.

  2. ITER helium ash accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, J.T.; Hillis, D.L.; Galambos, J.; Uckan, N.A. (Oak Ridge National Lab., TN (USA)); Dippel, K.H.; Finken, K.H. (Forschungszentrum Juelich GmbH (Germany, F.R.). Inst. fuer Plasmaphysik); Hulse, R.A.; Budny, R.V. (Princeton Univ., NJ (USA). Plasma Physics Lab.)

    1990-01-01

    Many studies have shown the importance of the ratio {upsilon}{sub He}/{upsilon}{sub E} in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analysed, and a first estimate of the ratio {upsilon}{sub He}/{upsilon}{sub E} to be expected for future reactor systems has been made. The experiments were carried out for neutral beam heated plasmas in the TEXTOR tokamak, at KFA/Julich. Helium was injected both as a short puff and continuously, and subsequently extracted with the Advanced Limiter Test-II pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge exchange spectroscopy, and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with PPPL TRANSP code, to distinguish beam from thermal confinement, especially for low density cases. The ALT-II pump limiter system is found to exhaust the He with maximum exhaust efficiency (8 pumps) of {approximately}8%. We find 1<{upsilon}{sub He}/{upsilon}{sub E}<3.3 for the database of cases analysed to date. Analysis with the ITER TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.

  3. Influência de uma árvore isolada de freixo (Fraxinus angustifolia Vahl no microclima num lameiro em Trás-os-Montes Modification of microclimate by an isolated ash-tree (Fraxinus angustifolia Vahl in natural pastures of Northeastern Portugal

    Directory of Open Access Journals (Sweden)

    E. Pereira

    2007-07-01

    Full Text Available Estudaram-se as alterações microclimáticas decorrentes da presença de árvores isoladas de freixo (Fraxinus angustifolia Vahl num lameiro próximo de Alfaião (41º 46’ 55’’ N; 6º 24’ 51’’ W; 510m de altitude, no distrito de Bragança (Nordeste de Portugal, em que o clima é do tipo Csb de Köppen. O lameiro localiza-se no fundo de um pequeno vale, cujos solos correspondem a Fluvissolos êutricos. Durante três anos mediu-se a radiação solar global incidente em campo aberto e a transmitida através da copa da árvore, a temperatura do ar e do solo sob e fora do coberto e a precipitação incidente sob a copa e em campo aberto. Em todas as estações do ano a presença da árvore alterou significativamente o microclima sob a mesma devido à intercepção de radiação solar (cerca de 25 a 35% no Inverno e de 55 a 65% no Verão e de cerca de 40% do total anual da precipitação bruta (52-56% no período de Maio-Setembro e 35% no período de ausência de folhagem. As temperaturas médias do ar sob a influência da copa (SIC da árvore foram superiores às observadas fora da influência da copa (FIC, com as diferenças máximas ocorrendo durante o período nocturno e sendo da ordem de 3ºC no Verão e de 5ºC no Inverno. Os valores médios da temperatura do solo foram superiores na área SIC durante o Inverno (1,1ºC à profundidade de 20 cm e no Verão na área FIC (1ºC à profundidade de 2 cm. As amplitudes térmicas no ar e no solo da área SIC foram inferiores às observadas na FIC. As condições microclimáticas observadas sob coberto poderão favorecer o desenvolvimento da vegetação herbácea no fim do Inverno, o que pode afectar a produção de biomassa das herbáceas.Changes in microclimate caused by an isolated ash tree (Fraxinus angustifolia Vahl were assessed in a pasture land close to Bragança (41º 46’ 55’’ N; 6º 24’ 51’’ W; 510m de altitude, in Northeastern Portugal, where climate is Csb according

  4. Volcanic ash infrared signature: realistic ash particle shapes compared to spherical ash particles

    OpenAIRE

    A. Kylling; Kahnert, M.; Lindqvist, H.; T. Nousiainen

    2013-01-01

    The reverse absorption technique is often used to detect volcanic clouds from thermal infrared satellite measurements. From these measurements particle size and mass loading may also be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculate thermal infrared optical properties of highly irregular and porous ash particles and compare these with mass- and volume-equivalent spherical models. Furtherm...

  5. Accumulation of metals in vegetation established in wood ash; Upptag av metaller i vegetation som etablerats i vedaska

    Energy Technology Data Exchange (ETDEWEB)

    Hemstroem, Kristian; Fransson, Sara; Wik, Ola

    2009-04-15

    the study are only representative for the specific materials and circumstances that existed in the studied systems, but are assumed to be useful as basic data in future discussions of relevant systems for assessment of risks related to ash materials in constructions that are left behind in the post operational phase. Although the total metal content in wood ash was much higher than in crushed stone, this was not reflected in the accumulation of metals in the vegetation. With the exception of As and Sb, no, or only small, differences in metal content in grazable parts of birch and Salix between trees grown in wood ash and trees grown in crushed stone was observed The translocation factors (i.e. the quota between concentration in leaves and total concentration in the wood ash and crushed stone) for Cr, Cu, Ni, Pb, Sb and Zn were higher in the trees that had grown in crushed stone than in those grown in wood ash. The leaves of the trees that had grown in crushed stone had thus accumulated a larger part of the material's total content of these metals than the trees grown in wood ash. In the trees grown in wood ash accumulated As, Cr, Pb and Sb was to a large extent concentrated in the roots of the trees, and a relatively large part of the As and Sb was concentrated in the leaves. In Salix, Cd and Zn was to a large extent accumulated in the leaves of the trees, both in those grown in wood ash and in those grown in crushed stone. The risk to herbivores is greatest when toxic metals are allocated to grazable parts of the plant. The Zn concentration in Salix leaves, both in the trees grown in wood ash and in trees grown in crushed stone, exceeded the lower limit of tolerable daily intake (TDI) for domestic animals and may thus pose a risk to herbivores. No other metal exceeded TDI in grazable parts of the trees. The mobility of Cd, Cr, Cu, Ni, Sb and Zn, estimated as leachability (the quota between leachable concentration and total concentration), was lower in the

  6. 三维欧氏 Steiner 最小树的 Delaunay 四面体网格混合智能算法%A Hybrid Intelligent Algorithm Based on Delaunay Tetrahedron Mesh Generation for Euclidean Steiner Minimum Tree Problem in 3-space

    Institute of Scientific and Technical Information of China (English)

    王家桢; 马良; 张惠珍

    2015-01-01

    Euclidean Steiner minimum tree problem , a classical NP-hard problem in combination optimization , has been widely studied in many fields .Euclidean Steiner minimal tree problem in 3-space is the generalization of Euclidean Steiner minimum tree problem in 2-space .The research results on Euclidean Steiner minimal tree problem in 3-space have been rarely published because of their difficulties .In this paper , a hybrid intelligent method is designed by using Delaunay tetrahedron mesh generation technology to solve the Euclidean Steiner min -imal tree problem in 3-space , which can not only avoid falling into local optima , but also has good effects in solving large scale problems .Promising results are obtained by using this hybrid method coded in MATLAB to solve series of Euclidean Steiner minimum tree problem instances in 3-space .%Steiner最小树问题是组合优化中经典的NP难题,在许多实际问题中有着广泛的应用,而三维欧氏Stei-ner最小树问题是对二维欧氏Steiner最小树问题的推广。由于三维欧氏Steiner树问题的求解非常困难,至今为止的相关成果较为少见。本文针对该问题,利用Delaunay四面体网格剖分技术,提出了一种混合型智能求解方法,不仅可以尽量避免拓扑结构陷入局部最优,且对较大规模的问题求解亦有良好的效果。算法在Matlab环境下编程实现,经实例测试,获得了满意的效果。

  7. Measuring the impact of biotic factors on populations of immature emerald ash borers (Coleoptera: Buprestidae).

    Science.gov (United States)

    Duan, Jian J; Ulyshen, Michael D; Bauer, Leah S; Gould, Juli; Van Driesche, Roy

    2010-10-01

    Cohorts of emerald ash borer larvae, Agrilus planipennis Fairmaire, were experimentally established in July of 2008 on healthy green ash (Fraxinus pennsylvanica) trees in two wooded plots at each of three sites near Lansing, MI, by caging gravid emerald ash borer females or placing laboratory-reared eggs on trunks (0.5-2 m above the ground) of selected trees. One plot at each site was randomly chosen for release of two introduced larval parasitoids, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), whereas the other served as the control. Stage-specific mortality factors and rates were measured for all experimentally established cohorts and for associated wild (i.e., naturally occurring) emerald ash borer immature stages via destructive sampling of 2.5 m (above the ground) trunk sections of cohort-bearing trees in the spring and fall of 2009. Host tree defense was the most important mortality factor, causing 32.0 to 41.1% mortality in the experimental cohorts and 17.5 to 21.5% in wild emerald ash borer stages by spring 2009, and 16.1 to 29% for the remaining experimental cohorts, and 9.9 to 11.8% for wild immature emerald ash borer stages by fall 2009. Woodpecker predation was the second most important factor, inflicting no mortality in the experimental cohorts but causing 5.0 to 5.6% mortality to associated wild emerald ash borer stages by spring 2009 and 9.2 to 12.8% and 3.2 to 17.7%, respectively, for experimental cohorts and wild emerald ash borer stages by fall 2009. Mortality from disease in both the experimental and wild cohorts was low (emerald ash borer stages were parasitized by T. planipennisi. While there were no significant differences in mortality rates because of parasitism between parasitoid-release and control plots, T. planipennisi was detected in each of the three release sites by the end of the study but was not detected in the experimental cohorts or associated wild larvae in any of the

  8. Effects of host plant and larval density on intraspecific competition in larvae of the emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Duan, Jian J; Larson, Kristi; Watt, Tim; Gould, Juli; Lelito, Jonathan P

    2013-12-01

    Competition for food, mates, and space among different individuals of the same insect species can affect density-dependent regulation of insect abundance or population dynamics. The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of North American ash (Fraxinus spp.) trees, with its larvae feeding in serpentine galleries between the interface of sapwood and phloem tissues of ash trees. Using artificial infestation of freshly cut logs of green ash (Fraxinus pennsylvanica Marshall) and tropical ash (Fraxinus uhdei [Wenzig] Lingelsh) with a series of egg densities, we evaluated the mechanism and outcome of intraspecific competition in larvae of A. planipennis in relation to larval density and host plant species. Results from our study showed that as the egg densities on each log (1.5-6.5 cm in diameter and 22-25 cm in length) increased from 200 to 1,600 eggs per square meter of surface area, larval survivorship declined from ≍68 to 10% for the green ash logs, and 86 to 55% for tropical ash logs. Accordingly, larval mortality resulting from cannibalism, starvation, or both, significantly increased as egg density increased, and the biomass of surviving larvae significantly decreased on both ash species. When larval density was adjusted to the same level, however, larval mortality from intraspecific competition was significantly higher and mean biomasses of surviving larvae was significantly lower in green ash than in tropical ash. The role of intraspecific competition of A. planipennis larvae in density-dependent regulation of its natural population dynamics is discussed.

  9. Pre-treatment and recirculation of wood ashes; Forbehandling og recirkulering af flisaske

    Energy Technology Data Exchange (ETDEWEB)

    Skov, S.; Ingerslev, M.

    2011-07-01

    Harvest of forest biomass for energy production may lead to a significant export of nutrients from the forest. Ash spreading and recycling of nutrients from wood chip combustion to the forest has come into focus as a means for counteracting the nutrient export. A study was carried out to examine the retention of various elements in the different ash fractions and utilize the nutrient recovery to evaluate the fertilizer quality of the examined ash. The mass and element flux of wood chips, bottom ash, cyclone fly ash and condensation sludge at Ebeltoft central heating plant was studied over a four-day period in spring 2005. Substantial amounts of nutrients were retained in the fly ash (P, Ca, Mg, Mn and Cu have a recovery higher than 60 % and K, S and Fe have a recovery higher than 30 %). The recovery of elements in the bottom ash was smaller. The added recovery of the usable fractions of ashes (both fly ash and bottom ash) exceeded 75 % for the nutrients P, Ca, Mn and Mg. Both these ash fractions should be considered for fertilization. To examine how ash application affects the forest and Christmas tree stand ecosystem and especially the element budget field experiments were established and monitored intensively. Wood ash is alkaline and by spreading ash in the forest ecosystem, the chemistry of soil water and soil is affected. This introduces a risk of scorching the organisms, eg. mosses but also of root damaging and thereby an impaired water and nutrient uptake as a result. The ash contains salts. Some of these salts, especially metal chlorides and metal sulfates can be dissolved quickly and causes a pH decrease in soil water. There may be a risk that the geochemical conditions in the soil changed dramatically within a relatively short period. These changes can affect nutrient concentrations in soil water and mineralization of organic matter in soil. This increases the risk of leaching and permanent loss of nutrients. These adverse effects of wood ash application

  10. Characterization of ashes from biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.J.; Hansen, L.A. [Technical Univ. of Denmark. Dept. of Chemical Engineering (Denmark); Soerensen, H.S. [Geological Survey of Denmark and Greenland (Denmark); Hjuler, K. [dk-TEKNIK. Energy and Environment (Denmark)

    1998-02-01

    One motivation for initiating the present project was that the international standard method of estimating the deposit propensity of solid fuels, of which a number of variants exist (e.g. ISO, ASTM, SD, DIN), has shown to be unsuitable for biomass ashes. This goal was addressed by the development of two new methods for the detection of ash fusibility behaviour based on Simultaneous Thermal Analysis (STA) and High Temperature Light Microscopy (HTLM), respectively. The methods were developed specifically for ashes from biofuels, but are suitable for coal ashes as well. They have been tested using simple salt mixtures, geological standards and samples from straw CHP and coal-straw PF combustion plants. All samples were run in a nitrogen atmosphere at a heating rate of 10 deg. C/min. In comparison with the standard method, the new methods are objective and have superior repeatability and sensitivity. Furthermore, the two methods enable the melting behavior to be characterized by a continuous measurement of melt fraction versus temperature. Due to this two-dimensional resolution of the results, the STA and HTLM methods provide more information than the standard method. The study of bottom ash and fly ash as well as deposit samples from straw test firings at the Haslev and Slagelse Combined Heat and Power plants resulted in a better understanding of mineral behaviour during straw grate firing. In these tests a number of straws were fired which had been carefully selected for having different qualities with respect to sort and potassium and chlorine contents. By studying bottom ashes from Slagelse it was found that the melting behaviour correlated with the deposition rate on a probe situated at the outlet part of the combustion zone. (EG)

  11. Interpreting Tree Ensembles with inTrees

    OpenAIRE

    Deng, Houtao

    2014-01-01

    Tree ensembles such as random forests and boosted trees are accurate but difficult to understand, debug and deploy. In this work, we provide the inTrees (interpretable trees) framework that extracts, measures, prunes and selects rules from a tree ensemble, and calculates frequent variable interactions. An rule-based learner, referred to as the simplified tree ensemble learner (STEL), can also be formed and used for future prediction. The inTrees framework can applied to both classification an...

  12. Controlling formaldehyde emissions with boiler ash.

    Science.gov (United States)

    Cowan, Jennifer; Abu-Daabes, Malyuba; Banerjee, Sujit

    2005-07-01

    Fluidized wood ash reduces formaldehyde in air from about 20 to formaldehyde reduction increases with increasing moisture content of the ash. Sorption of formaldehyde to ash can be substantially accounted for by partitioning to the water contained in the ash followed by rate-controlling binding to the ash solids. Adsorption occurs at temperatures of up to 165 degrees C; oxidation predominates thereafter. It is proposed that formaldehyde could be stripped from an air stream in a fluidized bed containing ash, which could then be returned to a boiler to incinerate the formaldehyde.

  13. The Natural Evolutionary Potential of Tree Populations to Cope with Newly Introduced Pests and Pathogens

    DEFF Research Database (Denmark)

    Budde, Katharina Birgit; Nielsen, Lene Rostgaard; Ravn, Hans Peter

    2016-01-01

    and the heritability of resistance traits varies substantially among the cases. While chestnut blight wilt combined with ink disease has virtually eliminated mature Castanea dentata trees from North America, other severe emerging diseases, such as the ash dieback, have left many surviving trees and genetic variation...

  14. Audubon Tree Study Program.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Trees," a leaders' guide, and a large tree chart with 37 colored pictures. The student reader reviews several aspects of trees: a definition of a tree; where and how trees grow; flowers, pollination and seed production; how trees make their food; how to recognize trees; seasonal changes;…

  15. Pre-treatment and recirculation of wood ashes; Forbehandling og recirkulering af flisaske

    Energy Technology Data Exchange (ETDEWEB)

    Skov, S.; Ingerslev, M.

    2011-07-01

    Harvest of forest biomass for energy production may lead to a significant export of nutrients from the forest. Ash spreading and recycling of nutrients from wood chip combustion to the forest has come into focus as a means for counteracting the nutrient export. A study was carried out to examine the retention of various elements in the different ash fractions and utilize the nutrient recovery to evaluate the fertilizer quality of the examined ash. The mass and element flux of wood chips, bottom ash, cyclone fly ash and condensation sludge at Ebeltoft central heating plant was studied over a four-day period in spring 2005. Substantial amounts of nutrients were retained in the fly ash (P, Ca, Mg, Mn and Cu have a recovery higher than 60 % and K, S and Fe have a recovery higher than 30 %). The recovery of elements in the bottom ash was smaller. The added recovery of the usable fractions of ashes (both fly ash and bottom ash) exceeded 75 % for the nutrients P, Ca, Mn and Mg. Both these ash fractions should be considered for fertilization. To examine how ash application affects the forest and Christmas tree stand ecosystem and especially the element budget field experiments were established and monitored intensively. Wood ash is alkaline and by spreading ash in the forest ecosystem, the chemistry of soil water and soil is affected. This introduces a risk of scorching the organisms, eg. mosses but also of root damaging and thereby an impaired water and nutrient uptake as a result. The ash contains salts. Some of these salts, especially metal chlorides and metal sulfates can be dissolved quickly and causes a pH decrease in soil water. There may be a risk that the geochemical conditions in the soil changed dramatically within a relatively short period. These changes can affect nutrient concentrations in soil water and mineralization of organic matter in soil. This increases the risk of leaching and permanent loss of nutrients. These adverse effects of wood ash application

  16. Ash in fire affected ecosystems

    Science.gov (United States)

    Pereira, Paulo; Jordan, Antonio; Cerda, Artemi; Martin, Deborah

    2015-04-01

    Ash in fire affected ecosystems Ash lefts an important footprint in the ecosystems and has a key role in the immediate period after the fire (Bodi et al., 2014; Pereira et al., 2015). It is an important source of nutrients for plant recover (Pereira et al., 2014a), protects soil from erosion and controls soil hydrological process as runoff, infiltration and water repellency (Cerda and Doerr, 2008; Bodi et al., 2012, Pereira et al., 2014b). Despite the recognition of ash impact and contribution to ecosystems recuperation, it is assumed that we still have little knowledge about the implications of ash in fire affected areas. Regarding this situation we wanted to improve our knowledge in this field and understand the state of the research about fire ash around world. The special issue about "The role of ash in fire affected ecosystems" currently in publication in CATENA born from the necessity of joint efforts, identify research gaps, and discuss future cooperation in this interdisciplinary field. This is the first special issue about fire ash in the international literature. In total it will be published 10 papers focused in different aspects of the impacts of ash in fire affected ecosystems from several parts of the world: • Fire reconstruction using charcoal particles (Burjachs and Espositio, in press) • Ash slurries impact on rheological properties of Runoff (Burns and Gabet, in press) • Methods to analyse ash conductivity and sorbtivity in the laboratory and in the field (Balfour et al., in press) • Termogravimetric and hydrological properties of ash (Dlapa et al. in press) • Effects of ash cover in water infiltration (Leon et al., in press) • Impact of ash in volcanic soils (Dorta Almenar et al., in press; Escuday et al., in press) • Ash PAH and Chemical extracts (Silva et al., in press) • Microbiology (Barreiro et al., in press; Lombao et al., in press) We believe that this special issue will contribute importantly to the better understanding of

  17. The biology and ecology of the emerald ash borer, Agrilus planipennis, in China.

    Science.gov (United States)

    Wang, Xiao-Yi; Yang, Zhong-Qi; Gould, Juli R; Zhang, Yi-Nan; Liu, Gui-Jun; Liu, En-shan

    2010-01-01

    The biology, ecology, and life cycle of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), were studied using regular inspection in the forest and observations in the laboratory. Results indicated that A. planipennis are mostly univoltine in Tianjin, China. They overwintered individually as mature larvae in shallow chambers excavated in the outer sapwood. In late July, some full-grown larvae began to build overwintering chambers, and all larvae entered the sapwood for dormancy by early November. A. planipennis pupated in the overwintering chamber from early April to mid May the following year, and the average pupal duration was about 20 days. In late April, some newly eclosed adults could be found in the pupal cells, but they had not yet emerged from the tree. Adults began to emerge in early May, with peak flight occurring in mid May. The average longevity of adults was about 21 days and the adult stage lasted through early July. The adults fed on ash foliage as a source of nutrition. Mating was usually conducted and completed on the leaf or trunk surfaces of ash trees. Oviposition began in mid May and eggs hatched on average in 15.7 days. The first instar larvae appeared in early June. The larval stage lasted about 300 days to complete an entire generation. The emerald ash borer had four larval instars on velvet ash, Fraxinus velutina (Scrophulariales: Oleaceae). The major natural control factors of A. planipennis were also investigated, and preliminary suggestions for its integrated management are proposed.

  18. Aspen Trees.

    Science.gov (United States)

    Canfield, Elaine

    2002-01-01

    Describes a fifth-grade art activity that offers a new approach to creating pictures of Aspen trees. Explains that the students learned about art concepts, such as line and balance, in this lesson. Discusses the process in detail for creating the pictures. (CMK)

  19. The History of Attack and Success of Emerald Ash Borer (Coleoptera: Buprestidae) on White Fringetree in Southwestern Ohio.

    Science.gov (United States)

    Thiemann, Danielle; Lopez, Vanessa; Ray, Ann M; Cipollini, Don

    2016-08-01

    Emerald ash borer, Agrilus planipennis Fairmaire, is an invasive insect that has caused widespread mortality of ash species in North America. The ability of emerald ash borer to utilize white fringetree as an alternate host was reported recently. We aimed to determine how long white fringetree has been under attack from emerald ash borer, the degree of attack, and the overall success of this beetle on this novel host. Stems from three of nine infested white fringetrees collected from the Dayton and Cincinnati, OH, areas in the winter of 2015 yielded four live adult emerald ash borers after being held in rearing containers, and numerous older exit holes were observed. Measurement and aging of feeding galleries on these stems indicated that emerald ash borer has been using this species since 2011, at least, with peak gallery densities reached in 2012 and 2013 on most of the harvested trees. On average, 32 galleries per square meter were found in these stems with about one-third of them being indicative of fourth-instar larvae. This supports the assertion that emerald ash borer has been using white fringetree as a host plant with moderate to good success for as long as ash species in these particular areas have been utilized.

  20. Carbon and nitrogen in forest floor and mineral soil under six common European tree species

    DEFF Research Database (Denmark)

    Vesterdal, Lars; Schmidt, Inger K.; Callesen, Ingeborg;

    2007-01-01

    The knowledge of tree species effects on soil C and N pools is scarce, particularly for European deciduous tree species. We studied forest floor and mineral soil carbon and nitrogen under six common European tree species in a common garden design replicated at six sites in Denmark. Three decades...... after planting the six tree species had different profiles in terms of litterfall, forest floor and mineral soil C and N attributes. Three groups were identified: (1) ash, maple and lime, (2) beech and oak, and (3) spruce. There were significant differences in forest floor and soil C and N contents...... and C/N ratios, also among the five deciduous tree species. The influence of tree species was most pronounced in the forest floor, where C and N contents increased in the order ash = lime = maple

  1. Settling characteristics of some Indian fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.; Sastry, B.S. [Indian Institute of Technology, Kharapur (India). Dept. of Mining Engineering

    2003-07-01

    The paper examines the aspects of the solid liquid separation (settling characteristics) of some of the fly ash obtained from coal-fired power plants in India. The application of a coagulating or flocculating agent (polymer) to improve the two properties as indicated is a typical industrial practice. The sources for this study comprise of fly ash, pond ash, and bottom ash and the settling characteristics are studied in conjunction with the flocculating agent polyacrylamide. 4 refs., 4 figs., 3 tabs.

  2. Gasification of high ash, high ash fusion temperature bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  3. Gasification of high ash, high ash fusion temperature bituminous coals

    Science.gov (United States)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  4. Long-term monitoring of the introduced emerald ash borer (Coleoptera: Buprestidae) egg parasitoid, oobius agrili (Hymenoptera: Encyridae), in Michigan, USA and evaluation of a newly developed monitoring technique

    Science.gov (United States)

    Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of ash trees (Fraxinus spp.) in North America. The egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) was introduced as a biological control agent of this pest in Michiga...

  5. DURABILITY OF HARDENED FLY ASH PASTE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The mechanical properties and durability ( mainly frost-resistance and carbonation resistance ) of fly ash-CaO-CaSO4 .2H2O hardened paste are studied. The relationship among durability of harden ed fly ash paste, the quantity and distribution of hydrates and the initial p aste texture of hardened fly ash paste is presented.

  6. A method for treating bottom ash

    NARCIS (Netherlands)

    Rem, P.C.; Van Craaikamp, H.; Berkhout, S.P.M.; Sierhuis, W.; Van Kooy, L.A.

    2007-01-01

    A method for treating bottom ash from a waste incineration plant. The invention relates in particular to a method for treating bottom ash from a domestic waste incineration plant. In accordance with the invention bottom ash having a size ranging up to 2 mm is treated by removing a previously determi

  7. Fuelwood quality of promising tree species for alkaline soil sites in relation to tree age

    Energy Technology Data Exchange (ETDEWEB)

    Goel, V.L.; Behl, H.M. [National Botanical Research Inst., Lucknow (India). Biomass Research Center

    1996-06-01

    The fuelwood quality of five tree species suitable for afforestation of alkaline soil sites was investigated in relation to tree age for establishing harvest rotation cycles. Prosopis juliflora and Acacia nilotica were found to be the most suitable species for short rotation fuel wood forestry programmes because of their high wood density, biomass yield, low ash and moisture content, and good heat of combustion at the juvenile stage. The performance of other species like Acacia auriculiformis, Terminalia arjuna and Sesbania formosa is discussed. (author)

  8. Biology and damage traits of emerald ash borer (Agrilus planipennis Fairmaire) in China

    Institute of Scientific and Technical Information of China (English)

    XIA WEI; YUN WU; RICHARD REARDON; TIE-HUAN SUN; MIN LU; JIANG-HUA SUN

    2007-01-01

    Emerald ash borer (Agrilusplanipennis Fairmaire)(Coleoptera: Buprestidae) is a major stem borer of ash (Fraxinus spp.). It is univoltine in Tianjin, while it is semivoltine in Heilongjiang Province, and both univoltine and semivoltine in Changchun, Jilin Province,where the majority is univoltine. The longevity of emerald ash borer adults is 17.2 ± 4.6 days (n = 45), eggs 9.0 ± 1.1 days (n = 103), univoltine larvae 308 days, semivoltine larvae 673 days, and pupae 61.2± 1.6 days (n = 45). It takes about 100 days from the time larvae bore into the phloem to when they complete the pupal cell. In a 10-year-old velvet ash (Fraxinus velutina Torr.) plantation in Tianjin, emerald ash borer preferred to oviposit on the regions of boles from 50-150 cm above ground, accounting for 76.7% of the total girdling.Girdling on the south side of the tree boles accounted for 43.40% of the total girdling. The emerald ash borer population density is higher at the edge of the plantation compared with the center.

  9. Leaching of wood ash - Laboratory and field studies; Lakning av vedaska - Laboratorie- och faeltstudier

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Per-Erik

    2012-02-15

    High forest production leads to diminishing amounts of base cations and micro nutrients in forest soils. This is due to uptake in, and harvest of, the trees. Losses can be compensated for by spreading stabilized wood ash on the forest ground, which means recycling of base cations and micro nutrients. Chemical composition of wood ash can easily be described by standard methods in the laboratory. However, this does not include the process of leaching in nature, such as which components and leaching rate for different compounds. During field conditions several factors are added, which are not available in the laboratory. After almost 10 years in the forest soils there still remains large quantities of the original product. Only 10-30 % of the wood ash products and 5 % of the lime product has been leached. In the laboratory study the leached amount was slightly larger, at the most 35 % for wood ash and 20 % for lime. Both studies indicate long time for weathering of the products in forest soils. Slower leaching rate from pellets of wood ash compared to leaching rate from crushed wood ash in the laboratory study is not verified by the field study. This indicates limited possibilities to control rates of leaching in the environment

  10. Ectomycorrhizal community structure and function in relation to forest residue harvesting and wood ash applications

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, Shahid

    2000-05-01

    Ectomycorrhizal fungi form symbiotic associations with tree roots and assist in nutrient-uptake and -cycling in forest ecosystems, thereby constituting a most significant part of the microbial community. The aims of the studies described in this thesis were to evaluate the potential of DNA-based molecular methods in below-ground ectomycorrhizal community studies and to investigate changes in ectomycorrhizal communities on spruce roots in sites with different N deposition, and in sites subjected to harvesting of forest residues or application of wood ash. The ability of selected ectomycorrhizal fungi to mobilise nutrients from wood ash and to colonise root systems in the presence and absence of ash was also studied. In total 39 ectomycorrhizal species were detected in the experimental forests located in southern Sweden. At each site five to six species colonised around 60% of the root tips. The dominant species, common to the sites, were Tylospora fibrillosa, Thelephora terrestris and Cenococcum geophilum. Differences between two sites with differing levels of N deposition suggested that community structure may be influenced by N deposition, although site history, location and degree of isolation may also influence species composition. Repeated harvesting of forest residues reduced numbers of mycorrhizal roots in the humus layer to approximately 50% of that in control plots but no shift in the ectomycorrhizal community could be detected. At another site, application of granulated wood ash induced a shift in ectomycorrhizal community structure and three ectomycorrhizal fungi ('ash fungi') were found to colonise ash granules. Two 'ash fungi' showed a superior ability to solubilise stabilised wood ash in laboratory experiments compared to other ectomycorrhizal isolates from the same site. In laboratory microcosms containing intact mycorrhizal mycelia, colonisation of wood ash patches by one 'ash fungus' was good whereas colonisation by

  11. Unimodular trees versus Einstein trees

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Enrique; Gonzalez-Martin, Sergio [Universidad Autonoma, Instituto de Fisica Teorica, IFT-UAM/CSIC, Madrid (Spain); Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Martin, Carmelo P. [Universidad Complutense de Madrid (UCM), Departamento de Fisica Teorica I Facultad de Ciencias Fisicas, Madrid (Spain)

    2016-10-15

    The maximally helicity violating tree-level scattering amplitudes involving three, four or five gravitons are worked out in Unimodular Gravity. They are found to coincide with the corresponding amplitudes in General Relativity. This a remarkable result, insofar as both the propagators and the vertices are quite different in the two theories. (orig.)

  12. Unimodular Trees versus Einstein Trees

    CERN Document Server

    Alvarez, Enrique; Martin, Carmelo P

    2016-01-01

    The maximally helicity violating (MHV) tree level scattering amplitudes involving three, four or five gravitons are worked out in Unimodular Gravity. They are found to coincide with the corresponding amplitudes in General Relativity. This a remarkable result, insofar as both the propagators and the vertices are quite different in both theories.

  13. Unimodular trees versus Einstein trees

    Science.gov (United States)

    Álvarez, Enrique; González-Martín, Sergio; Martín, Carmelo P.

    2016-10-01

    The maximally helicity violating tree-level scattering amplitudes involving three, four or five gravitons are worked out in Unimodular Gravity. They are found to coincide with the corresponding amplitudes in General Relativity. This a remarkable result, insofar as both the propagators and the vertices are quite different in the two theories.

  14. Radioactivity of wood ash; Puun tuhkan radioaktiivisuus

    Energy Technology Data Exchange (ETDEWEB)

    Rantavaara, A.; Moring, M

    2000-01-01

    STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg{sup -1}, in decreasing order: {sup 137}Cs, {sup 40}K, {sup 90}Sr, {sup 210}Pb,{sup 226}Ra, {sup 232}Th, {sup 134}Cs, {sup 235}U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and {sup 210}Pb was hardly detectable. The NH{sub 4}Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

  15. Radioactivity of wood ash; Puun tuhkan radioaktiivisuus

    Energy Technology Data Exchange (ETDEWEB)

    Rantavaara, A.; Moring, M

    2000-01-01

    STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg{sup -1}, in decreasing order: {sup 137}Cs, {sup 40}K, {sup 90}Sr, {sup 210}Pb,{sup 226}Ra, {sup 232}Th, {sup 134}Cs, {sup 235}U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and {sup 210}Pb was hardly detectable. The NH{sub 4}Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

  16. 1999 international ash utilization symposium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    112 papers were presented covering various aspects of the utilization of coal and other combustion products. Topics included fundamental chemistry and mineralogy, new products, health and environmental aspects, economic development issues, agricultural and mine reclamation applications, concrete and cement, and fly ash beneficiation technologies. Selected papers will be published in the journal 'Fuel'.

  17. Tree Species Identity Shapes Earthworm Communities

    DEFF Research Database (Denmark)

    Schelfhout, Stephanie; Mertens, Jan; Verheyen, Kris

    2017-01-01

    Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden...... experiment, replicated six times over Denmark, six tree species were planted in blocks: sycamore maple (Acer pseudoplatanus), beech (Fagus sylvatica), ash (Fraxinus excelsior), Norway spruce (Picea abies), pedunculate oak (Quercus robur) and lime (Tilia cordata). We studied the chemical characteristics...... of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer...

  18. Use of Incineration MSW Ash: A Review

    Directory of Open Access Journals (Sweden)

    Charles H. K. Lam

    2010-07-01

    Full Text Available This study reviews the characteristics of municipal solid waste incineration (MSWI ashes, with a main focus on the chemical properties of the ashes. Furthermore, the possible treatment methods for the utilization of ash, namely, separation processes, solidification/stabilization and thermal processes, are also discussed. Seven types of MSWI ash utilization are reviewed, namely, cement and concrete production, road pavement, glasses and ceramics, agriculture, stabilizing agent, adsorbents and zeolite production. The practical use of MSWI ash shows a great contribution to waste minimization as well as resources conservation.

  19. Wildfires and water chemistry: effect of metals associated with wood ash.

    Science.gov (United States)

    Cerrato, José M; Blake, Johanna M; Hirani, Chris; Clark, Alexander L; Ali, Abdul-Mehdi S; Artyushkova, Kateryna; Peterson, Eric; Bixby, Rebecca J

    2016-08-10

    The reactivity of metals associated with ash from wood collected from the Valles Caldera National Preserve, Jemez Mountains, New Mexico, was assessed through a series of laboratory experiments. Microscopy, spectroscopy, diffraction, and aqueous chemistry measurements were integrated to determine the chemical composition of wood ash and its effect on water chemistry. Climate change has caused dramatic impacts and stresses that have resulted in large-scale increases in wildfire activity in semi-arid areas of the world. Metals and other constituents associated with wildfire ash can be transported by storm event runoff and negatively affect the water quality in streams and rivers. Differences among ash from six tree species based on total concentrations of metals such as Ca, Al, Mg, Fe, and Mn were identified using non-metric multidimensional analysis. Metal-bearing carbonate and oxide phases were quantified by X-ray diffraction analyses and X-ray spectroscopy analyses. These metal-bearing carbonate phases were readily dissolved in the first 30 minutes of reaction with 18 MΩ water and 10 mM HCO3(-) in laboratory batch experiments which resulted in the release of metals and carbonates in the ash, causing water alkalinity to increase. However, metal concentrations decreased over the course of the experiment, suggesting that metals re-adsorb to ash. Our results suggest that the dissolution of metal-bearing carbonate and oxide phases in ash and metal re-adsorption to ash are relevant processes affecting water chemistry after wildfire events. These results have important implications to better understand the impact of wildfire events on water quality.

  20. Symbolic Algorithmic Analysis of Rectangular Hybrid Systems

    Institute of Scientific and Technical Information of China (English)

    Hai-Bin Zhang; Zhen-Hua Duan

    2009-01-01

    This paper investigates symbolic algorithmic analysis of rectangular hybrid systems. To deal with the symbolic reachability problem, a restricted constraint system called hybrid zone is formalized for the representation and manipulation of rectangular automata state-spaces. Hybrid zones are proved to be closed over symbolic reachability operations of rectangular hybrid systems. They are also applied to model-checking procedures for verifying some important classes of timed computation tree logic formulas. To represent hybrid zones, a data structure called difference constraint matrix is defined.These enable us to deal with the symbolic algorithmic analysis of rectangular hybrid systems in an efficient way.

  1. Combining four dimensional variational data assimilation and particle filtering for estimating volcanic ash emissions

    Science.gov (United States)

    Franke, Philipp; Elbern, Hendrik

    2016-04-01

    Estimating volcanic ash emissions is a very challenging task due to limited monitoring capacities of the ash plume and nonlinear processes in the atmosphere, which renders application of source strength and injection height estimations difficult. Most models, which estimate volcanic ash emissions, make strong simplifications of the dispersion of volcanic ash and corresponding atmospheric processes. The objective of this work is to estimate volcanic ash emissions and simulate the ensuing dispersion applying a full chemistry transport model in a hybrid approach by using its adjoint as well as an ensemble of model runs to quantify forecast uncertainties. Therefore, the four dimensional variational data assimilation version of the EURAD-IM chemistry transport model is extended to include a Sequential Importance Resampling Smoother (SIRS), introducing novel weighting and resampling strategies. In the main SIRS step the ensemble members exchange high rated emission patterns while rejecting emission patterns with low value for the forecast. The emission profiles of the ensemble members are perturbed afterwards to guarantee different emissions for all ensemble members. First identical twin experiments show the ability of the system to estimate the temporal and vertical distribution of volcanic ash emissions. The 4D-var data assimilation algorithm of the new system additionally provides quantitative emission estimation.

  2. Trace elements in soils and plants in temperate forest plantations subjected to single and multiple applications of mixed wood ash

    Energy Technology Data Exchange (ETDEWEB)

    Omil, Beatriz; Merino, Agustin [Department of Soil Science and Agricultural Chemistry, Escuela Politecnica Superior, University of Santiago de Compostela, E-27002 Lugo (Spain); Pineiro, Veronica [Centro de Apoyo Tecnologico (CACTUS), University of Santiago de Compostela, E-27002 Lugo (Spain)

    2007-08-01

    Wood ash, a by-product generated in power plants, can be used to fertilize forest plantations to replenish nutrients lost during harvesting. Although wood ash generally contains low levels of trace metals, release of some of these may occur soon after ash application in acid soils. The risk of heavy metal contamination associated with application of mixed wood ash was assessed in six Pinus radiata D. Don plantations, on two types of mineral soil differing in texture, drainage and CECe. Four of the stands received a single application of 4500 kg ha{sup -} {sup 1} (March 2003), and in the other two stands the same treatment was applied over three consecutive years (2003-2005). Trace metal (Cd, Cr, Cu, Mn, Ni, Pb, Zn) concentrations were monitored throughout the 3 years in different components of the forest ecosystem - soil solid fraction, soil solution, tree needles, ground vegetation and different mushroom species. Repeated applications of wood ash led to moderate increases in soil extractable Mn and Zn, and Mn in all mushrooms species. However, the maximum concentrations did not reach levels potentially harmful to organisms. Concentrations of Zn, Cu and Cd decreased in some mushroom species, probably because of increased soil pH caused by the treatment. Heavy metal concentrations in tree needles and ground vegetation were not altered. Although the risk of heavy metal contamination appears to be low, the long-term effects of wood ash application must be assessed. (author)

  3. Trace elements in soils and plants in temperate forest plantations subjected to single and multiple applications of mixed wood ash.

    Science.gov (United States)

    Omil, Beatriz; Piñeiro, Verónica; Merino, Agustín

    2007-08-01

    Wood ash, a by-product generated in power plants, can be used to fertilize forest plantations to replenish nutrients lost during harvesting. Although wood ash generally contains low levels of trace metals, release of some of these may occur soon after ash application in acid soils. The risk of heavy metal contamination associated with application of mixed wood ash was assessed in six Pinus radiata D. Don plantations, on two types of mineral soil differing in texture, drainage and CECe. Four of the stands received a single application of 4500 kg ha(-1) (March 2003), and in the other two stands the same treatment was applied over three consecutive years (2003-2005). Trace metal (Cd, Cr, Cu, Mn, Ni, Pb, Zn) concentrations were monitored throughout the 3 years in different components of the forest ecosystem--soil solid fraction, soil solution, tree needles, ground vegetation and different mushroom species. Repeated applications of wood ash led to moderate increases in soil extractable Mn and Zn, and Mn in all mushrooms species. However, the maximum concentrations did not reach levels potentially harmful to organisms. Concentrations of Zn, Cu and Cd decreased in some mushroom species, probably because of increased soil pH caused by the treatment. Heavy metal concentrations in tree needles and ground vegetation were not altered. Although the risk of heavy metal contamination appears to be low, the long-term effects of wood ash application must be assessed.

  4. Identifying glass compositions in fly ash

    Directory of Open Access Journals (Sweden)

    Katherine eAughenbaugh

    2016-01-01

    Full Text Available In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS, calcium aluminosilicate glasses (CAS, a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

  5. Geotechnical engineering properties of incinerator ash mixes.

    Science.gov (United States)

    Muhunthan, B; Taha, R; Said, J

    2004-08-01

    The incineration of solid waste produces large quantities of bottom and fly ash. Landfilling has been the primary mode of disposal of these waste materials. Shortage in landfill space and the high cost of treatment have, however, prompted the search for alternative uses of these waste materials. This study presents an experimental program that was conducted to determine the engineering properties of incinerator ash mixes for use as construction materials. Incinerator ash mixes were tested as received and around optimum compacted conditions. Compaction curves, shear strength, and permeability values of fly ash, bottom ash, and their various blends were investigated. Bottom ash tends to achieve maximum dry density at much lower water content than does fly ash. The mixes displayed a change in their cohesion and friction angle values when one of the two mix components was altered or as a result of the addition of water. The permeability of bottom ash is quite comparable to that of sand. The permeability of fly ash lies in the range of those values obtained for silts and clays. A 100% bottom ash compacted at the optimum water content has a lower density value and yields a higher friction angle and cohesion values than most construction fills. This would encourage the use of bottom ash as a fill or embankment material because free drainage of water will prevent the buildup of pore water pressures.

  6. Interacting factors driving a major loss of large trees with cavities in a forest ecosystem.

    Science.gov (United States)

    Lindenmayer, David B; Blanchard, Wade; McBurney, Lachlan; Blair, David; Banks, Sam; Likens, Gene E; Franklin, Jerry F; Laurance, William F; Stein, John A R; Gibbons, Philip

    2012-01-01

    Large trees with cavities provide critical ecological functions in forests worldwide, including vital nesting and denning resources for many species. However, many ecosystems are experiencing increasingly rapid loss of large trees or a failure to recruit new large trees or both. We quantify this problem in a globally iconic ecosystem in southeastern Australia--forests dominated by the world's tallest angiosperms, Mountain Ash (Eucalyptus regnans). Tree, stand and landscape-level factors influencing the death and collapse of large living cavity trees and the decay and collapse of dead trees with cavities are documented using a suite of long-term datasets gathered between 1983 and 2011. The historical rate of tree mortality on unburned sites between 1997 and 2011 was >14% with a mortality spike in the driest period (2006-2009). Following a major wildfire in 2009, 79% of large living trees with cavities died and 57-100% of large dead trees were destroyed on burned sites. Repeated measurements between 1997 and 2011 revealed no recruitment of any new large trees with cavities on any of our unburned or burned sites. Transition probability matrices of large trees with cavities through increasingly decayed condition states projects a severe shortage of large trees with cavities by 2039 that will continue until at least 2067. This large cavity tree crisis in Mountain Ash forests is a product of: (1) the prolonged time required (>120 years) for initiation of cavities; and (2) repeated past wildfires and widespread logging operations. These latter factors have resulted in all landscapes being dominated by stands ≤72 years and just 1.16% of forest being unburned and unlogged. We discuss how the features that make Mountain Ash forests vulnerable to a decline in large tree abundance are shared with many forest types worldwide.

  7. Chemical Composition and Amount of Macro and Microelements .of Pine (Pinus silvestris L and Larch (Larix sibirica Ldb Trees in Mongolia

    Directory of Open Access Journals (Sweden)

    J. Sukhdolgor

    2003-06-01

    Full Text Available One thousand seed weight of pine and larch trees taken from district Bugant of province Selenge and district Mungen Mort, Tuv province and the bark, other mixture and the items still with bark were defined and comored. Chemical composition of the seeds of pine and larch trees was defined. The dry substance in pine seeds was 94.6%, protein 45.1 %, oil 22.1 %, ash 1.5%, respectively. In the seeds of larch trees dry substance was 93.8%, protein 18.7% and ash 2.1 %, respectively. The amount of macro and microelements in the ash samples of above tree seeds is determined in a spectrum laboratory. There were 20 elements in the seeds of pine trees and 19 elements in the seeds of larch trees.

  8. Development of ricehusk ash reinforced bismaleimide toughened epoxy nanocomposites.

    Directory of Open Access Journals (Sweden)

    Kanimozhi eK

    2014-09-01

    Full Text Available AbstractRecent past decades have witnessed remarkable advances in composites with potentialapplications in biomedical devices, aerospace, textiles, civil engineering, energy, electronicengineering, and household products. Thermoset polymer composites have further enhancedand broadened the area of applications of composites. In the present work epoxy-BMItoughened-silica hybrid (RHA/DGEBA-BMI was prepared using bismaleimide astoughener, bisphenol-A as matrix and a silica precursor derived from rice husk ash asreinforcement with glycidoxypropyltrimethoxysilane as coupling agent. Differential scanningcalorimetry, electron microscopy, thermogravimetric analysis, and goniometry were used tocharacterize RHA/DGEBA-BMI composites developed in the present work. Tensile, impactand flexural strength, tensile and flexural modulus, hardness, dielectric properties were alsostudied and discussed. The hybrid nanocomposites possess the higher values of the glasstransition temperature (Tg and mechanical properties than those of neat epoxy matrix.

  9. Development of ricehusk ash reinforced bismaleimide toughened epoxy nanocomposites.

    Science.gov (United States)

    K, Kanimozhi; Sethuraman, K.; V, Selvaraj; Alagar, Muthukaruppan

    2014-09-01

    Abstract Recent past decades have witnessed remarkable advances in composites with potential applications in biomedical devices, aerospace, textiles, civil engineering, energy, electronic engineering, and household products. Thermoset polymer composites have further enhanced and broadened the area of applications of composites. In the present work epoxy-BMI toughened-silica hybrid (RHA/DGEBA-BMI) was prepared using bismaleimide as toughener, bisphenol-A as matrix and a silica precursor derived from rice husk ash as reinforcement with glycidoxypropyltrimethoxysilane as coupling agent. Differential scanning calorimetry, electron microscopy, thermogravimetric analysis, and goniometry were used to characterize RHA/DGEBA-BMI composites developed in the present work. Tensile, impact and flexural strength, tensile and flexural modulus, hardness, dielectric properties were also studied and discussed. The hybrid nanocomposites possess the higher values of the glass transition temperature (Tg) and mechanical properties than those of neat epoxy matrix.

  10. Finite Sholander Trees, Trees, and their Betweenness

    CERN Document Server

    Chvátal, Vašek; Schäfer, Philipp Matthias

    2011-01-01

    We provide a proof of Sholander's claim (Trees, lattices, order, and betweenness, Proc. Amer. Math. Soc. 3, 369-381 (1952)) concerning the representability of collections of so-called segments by trees, which yields a characterization of the interval function of a tree. Furthermore, we streamline Burigana's characterization (Tree representations of betweenness relations defined by intersection and inclusion, Mathematics and Social Sciences 185, 5-36 (2009)) of tree betweenness and provide a relatively short proof.

  11. Ultrasonic ash/pyrite liberation

    Energy Technology Data Exchange (ETDEWEB)

    Yungman, B.A.; Buban, K.S.; Stotts, W.F.

    1990-06-01

    The objective of this project was to develop a coal preparation concept which employed ultrasonics to precondition coal prior to conventional or advanced physical beneficiation processes such that ash and pyrite separation were enhanced with improved combustible recovery. Research activities involved a series of experiments that subjected three different test coals, Illinois No. 6, Pittsburgh No. 8, and Upper Freeport, ground to three different size fractions (28 mesh [times] 0, 200 mesh [times] 0, and 325 mesh [times] 0), to a fixed (20 kHz) frequency ultrasonic signal prior to processing by conventional and microbubble flotation. The samples were also processed by conventional and microbubble flotation without ultrasonic pretreatment to establish baseline conditions. Product ash, sulfur and combustible recovery data were determined for both beneficiation processes.

  12. Utilization Of Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    S. D. Nagrale

    2012-07-01

    Full Text Available India is a major rice producing country, and the husk generated during milling is mostly used as a fuel in the boilers for processing paddy, producing energy through direct combustion and / or by gasification. About 20 million tones of Rice Husk Ash (RHA is produced annually. This RHA is a great environment threat causing damage to the land and the surrounding area in which it is dumped. Lots of ways are being thought of for disposing them by making commercial use of this RHA. RHA can be used as a replacement for concrete (15 to 25%.This paper evaluates how different contents of Rice Husk Ash added to concrete may influence its physical and mechanical properties. Sample Cubes were tested with different percentage of RHA and different w/c ratio, replacing in mass the cement. Properties like Compressive strength, Water absorption and Slump retention were evaluated.

  13. The Ashes of Marci Shore

    Directory of Open Access Journals (Sweden)

    Zbigniew Kopeć

    2013-01-01

    Full Text Available The article discusses Marci Shore’s social and historical thought, as presented in her books: Caviar and Ashes: A Warsaw Generation’s Life and Death in Marxism, 1918-1968 (2006, The Taste of Ashes (2013, and her essays recently published in Polish translation. The author follows the American historian, presenting her concept of modernity, but focuses on the main theme of her research: the contribution of Jewish writers, poets, artists, and intellectuals to the creation of Marxism. The author acknowledges the great value of Marci Shore’s writings, but argues that her panorama of the 20th century would be fuller if her discussion included a reflection on the religious attitude of many Jewish thinkers to Marxism and the USSR. This topic was discussed by Nikolai Berdyaev and Polish thinkers who published in pre-war social journals.

  14. Geopolymer Mortar with Fly Ash

    Directory of Open Access Journals (Sweden)

    Saloma

    2016-01-01

    Full Text Available The cement industry accounts for about 7% of all CO2 emissions caused by humans. Therefore, it is necessary to find another material in order to support sustainable material. An alternative way is replacing cement material with alternative material as fly ash. Fly ash as binder need to be added alkaline activator in the form of sodium silicate (Na2SiO3 or potassium silicate (K2SiO3 and sodium hydroxide (NaOH or potassium hydroxide (KOH. The purpose of this research is to analyze the effect of activator liquid concentration on geopolymer mortar properties and to know the value of compressive strength. Molarity variation of NaOH are 8, 12, 14, and 16 M with ratio of Na2SiO3/NaOH = 1.0. Ratio of sand/fly ash = 2.75 and ratio of activator/fly ash = 0.8. The cube-shaped specimen 50 × 50 × 50 mm is cured by steam curing with a temperature of 60°C for 48 hours. The experimental result of fresh mortar reported that the molarity of NaOH affect the slump flow and setting time, higher of NaOH produces the smaller value of slump and the faster time of setting. The experimental of density results reported that the increase of specific gravity when the molarity of NaOH increased. The experimental results of the compressive strength are showed that the maximum compressive strength of geopolymer mortar 14 M is 10.06 MPa and the lowest compressive strength produced by geopolymer mortar 8 M is 3.95 MPa. Testing the compressive strength of geopolymer mortar 16 M produces compressive strength lower than 14 M geopolymer mortar is 9.16 MPa.

  15. Vitrification of municipal solid waste incineration fly ash using biomass ash as additives.

    Science.gov (United States)

    Alhadj-Mallah, Moussa-Mallaye; Huang, Qunxing; Cai, Xu; Chi, Yong; Yan, JianHua

    2015-01-01

    Thermal melting is an energy-costing solution for stabilizing toxic fly ash discharged from the air pollution control system in the municipal solid waste incineration (MSWI) plant. In this paper, two different types of biomass ashes are used as additives to co-melt with the MSWI fly ash for reducing the melting temperature and energy cost. The effects of biomass ashes on the MSWI fly ash melting characteristics are investigated. A new mathematical model has been proposed to estimate the melting heat reduction based on the mass ratios of major ash components and measured melting temperature. Experimental and calculation results show that the melting temperatures for samples mixed with biomass ash are lower than those of the original MSWI fly ash and when the mass ratio of wood ash reaches 50%, the deformation temperature (DT), the softening, hemisphere temperature (HT) and fluid temperature (FT) are, respectively, reduced by 189°C, 207°C, 229°C, and 247°C. The melting heat of mixed ash samples ranges between 1650 and 2650 kJ/kg. When 50% wood ash is mixed, the melting heat is reduced by more than 700 kJ/kg for the samples studied in this paper. Therefore, for the vitrification treatment of the fly ash from MSW or other waste incineration plants, wood ash is a potential fluxing assistant.

  16. False deformation temperatures for ash fusibility associated with the conditions for ash preparation

    Energy Technology Data Exchange (ETDEWEB)

    Wall, T.F.; Gupta, S.K.; Gupta, R.P.; Sanders, R.H.; Creelman, R.A.; Bryant, G.W. [University of Newcastle, Callaghan, NSW (Australia). Cooperative Research Centre for Black Coal Utilization, Dept. of Chemical Engineering

    1999-07-01

    A study was made to investigate the fusibility behaviour of coal ashes of high ash fusion temperatures. Coals and ashes formed in the boiler were sampled in several Australian power stations, with laboratory ashes being prepared from the coals. The laboratory ashes gave lower values for the deformation temperature (DT) than the combustion ashes when the ash had low levels of basic oxide components. Thermo-mechanical analysis, quantitative X-ray diffraction and scanning electron microscopy were used to establish the mechanisms responsible for the difference. Laboratory ash is finer than combustion ash and it includes unreacted minerals (such as quartz, kaolinite and illite) and anhydrite (CaSO{sub 4}). Fusion events which appear to be characteristic of reacting illite, at temperatures from 900 to 1200{degree}C, were observed for the laboratory ashes, these being associated with the formation of melt phase and substantial shrinkage. The combustion ashes did not contain this mineral and their fusion events were observed at temperatures exceeding 1300{degree}C. The low DTs of coal ashes with low levels of basic oxides are therefore a characteristic of laboratory ash rather than that found in practical combustion systems. These low temperatures are not expected to be associated with slagging in pulverised coal fired systems. 10 refs., 3 figs., 2 tabs.

  17. Volcanic ash infrared signature: porous non-spherical ash particle shapes compared to homogeneous spherical ash particles

    OpenAIRE

    A. Kylling; Kahnert, M.; Lindqvist, H.; T. Nousiainen

    2014-01-01

    The reverse absorption technique is often used to detect volcanic ash clouds from thermal infrared satellite measurements. From these measurements effective particle radius and mass loading may be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculated thermal infrared optical properties of highly irregular and porous ash particles and compared these with mass- and volume-equivalent sp...

  18. Volcanic ash infrared signature: porous non-spherical ash particle shapes compared to homogeneous spherical ash particles

    Science.gov (United States)

    Kylling, A.; Kahnert, M.; Lindqvist, H.; Nousiainen, T.

    2014-04-01

    The reverse absorption technique is often used to detect volcanic ash clouds from thermal infrared satellite measurements. From these measurements effective particle radius and mass loading may be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculated thermal infrared optical properties of highly irregular and porous ash particles and compared these with mass- and volume-equivalent spherical models. Furthermore, brightness temperatures pertinent to satellite observing geometry were calculated for the different ash particle shapes. Non-spherical shapes and volume-equivalent spheres were found to produce a detectable ash signal for larger particle sizes than mass-equivalent spheres. The assumption of mass-equivalent spheres for ash mass loading estimates was found to underestimate mass loading compared to morphologically complex inhomogeneous ash particles. The underestimate increases with the mass loading. For an ash cloud recorded during the Eyjafjallajökull 2010 eruption, the mass-equivalent spheres underestimate the total mass of the ash cloud by approximately 30% compared to the morphologically complex inhomogeneous particles.

  19. Modular Tree Automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular r...

  20. Simple street tree sampling

    Science.gov (United States)

    David J. Nowak; Jeffrey T. Walton; James Baldwin; Jerry. Bond

    2015-01-01

    Information on street trees is critical for management of this important resource. Sampling of street tree populations provides an efficient means to obtain street tree population information. Long-term repeat measures of street tree samples supply additional information on street tree changes and can be used to report damages from catastrophic events. Analyses of...

  1. Modular tree automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular...

  2. [Caloric value and ash content of dominant plants in plantation communities in Heshan of Guangdong, China].

    Science.gov (United States)

    Zeng, Xiao-ping; Cai, Xi-an; Zhao, Ping; Rao, Xing-quan

    2009-03-01

    Different parts of twenty dominant plant species in five plantation communities on the subtropical hilly lands in Heshan of Gunagdong as well as the litters from three of the five plantation communities were sampled, and their gross caloric value (GCV) and ash content were measured by using a PARR-1281 oxygen bomb calorimeter and a muffle furnace. Based on the measurements, the ash-free caloric value (AFCV) of the samples was calculated, and the characteristics of caloric value and ash content of the samples, according to plant part, individual, and plant growth form, were analyzed. The results showed that the GCV and AFCV of leaf, branch, stem wood, stem bark, and root were in the range of 10.7-22.17 kJ x g(-1) and 13.89-23.04 kJ x g(-1), respectively. The GCV and AFCV of leaf were significantly higher than those of other parts (P shrub layer (19.46 kJ x g(-1) > herb layer (18.77 kJ x g(-1)), with indigenous coniferous tree (19.86 kJ x g(-1)) > indigenous broad-leaved tree (19.55 kJ x g(-1)) > exotic eucalyptus (19.18 kJ x g(-1)), while the mean ash content was just the opposite. In Acacia mangium, coniferous, and Schima plantation communities, the GCV and AFCV of litters were higher than those of various plant parts (P mangium and coniferous plantations had higher mean GCV and AFCV than the litters and fresh leaves of tree layer, while the fresh leaves of tree layer in Schima plantation showed higher mean GCV and AFCV.

  3. Possibilities of utilizing power plant fly ashes

    Directory of Open Access Journals (Sweden)

    Mezencevová Andrea

    2003-09-01

    Full Text Available The burning of fossil fuels in industrial power stations plays a significant role in the production of thermal and electrical energy. Modern thermal power plants are producing large amounts of solid waste, mainly fly ashes. The disposal of power plant waste is a large environmental problem at the present time. In this paper, possibilities of utilization of power plant fly ashes in industry, especially in civil engineering, are presented. The fly ash is a heterogeneous material with various physical, chemical and mineralogical properties, depending on the mineralogical composition of burned coal and on the used combustion technology. The utilization of fly ashes is determined of their properties. The fineness, specific surface area, particle shape, density, hardness, freeze-thaw resistance, etc. are decisive. The building trade is a branch of industry, which employs fly ash in large quantities for several decades.The best utilization of fluid fly ashes is mainly in the production of cement and concrete, due to the excellent pozzolanic and cementitious properties of this waste. In the concrete processing, the fly ash is utilized as a replacement of the fine aggregate (fine filler or a partial replacement for cement (active admixture. In addition to economic and ecological benefits, the use of fly ash in concrete improves its workability and durability, increases compressive and flexural strength, reduces segregation, bleeding, shrinkage, heat evolution and permeability and enhances sulfate resistance of concrete.The aim of current research is to search for new technologies for the fly ash utilization. The very interesting are biotechnological methods to recovery useful components of fly ashes and unconventional methods of modification of fly ash properties such as hydrothermal zeolitization and mechanochemical modification of its properties. Mechanochemistry deals with physico - chemical transformations and chemical reactions of solids induced by

  4. Volcanic ash impacts on critical infrastructure

    Science.gov (United States)

    Wilson, Thomas M.; Stewart, Carol; Sword-Daniels, Victoria; Leonard, Graham S.; Johnston, David M.; Cole, Jim W.; Wardman, Johnny; Wilson, Grant; Barnard, Scott T.

    2012-01-01

    Volcanic eruptions can produce a wide range of hazards. Although phenomena such as pyroclastic flows and surges, sector collapses, lahars and ballistic blocks are the most destructive and dangerous, volcanic ash is by far the most widely distributed eruption product. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to significant societal impacts. Even relatively small eruptions can cause widespread disruption, damage and economic loss. Volcanic eruptions are, in general, infrequent and somewhat exotic occurrences, and consequently in many parts of the world, the management of critical infrastructure during volcanic crises can be improved with greater knowledge of the likely impacts. This article presents an overview of volcanic ash impacts on critical infrastructure, other than aviation and fuel supply, illustrated by findings from impact assessment reconnaissance trips carried out to a wide range of locations worldwide by our international research group and local collaborators. ‘Critical infrastructure’ includes those assets, frequently taken for granted, which are essential for the functioning of a society and economy. Electricity networks are very vulnerable to disruption from volcanic ash falls. This is particularly the case when fine ash is erupted because it has a greater tendency to adhere to line and substation insulators, where it can cause flashover (unintended electrical discharge) which can in turn cause widespread and disruptive outages. Weather conditions are a major determinant of flashover risk. Dry ash is not conductive, and heavy rain will wash ash from insulators, but light rain/mist will mobilise readily-soluble salts on the surface of the ash grains and lower the ash layer’s resistivity. Wet ash is also heavier than dry ash, increasing the risk of line breakage or tower/pole collapse. Particular issues for water

  5. Accumulation of metals in vegetation established in ash constructions; Ackumulering av metaller i vegetation paa geotekniska askkonstruktioner

    Energy Technology Data Exchange (ETDEWEB)

    Hemstroem, Kristian; Wik, Ola (SGI, Statens geotekniska institut (Sweden)); Bramryd, Torleif; Johansson, Michael (Lunds Universitet, Miljoestrategi (Sweden)); Jaegerbrand, Annika (VTI, Statens Vaeg och transportforskningsinstitut (Sweden))

    2012-02-15

    The overall aim of this study was to investigate how the use of ash in a long-term perspective affects the surrounding flora and fauna with regard to the accumulation of metals in the ecosystem through plant uptake and exposure to grazing animals. The study included a field study and a cultivation experiment. In the field study, the accumulation of metals and metalloids in leaves of trees and shrubs that had self established and grown in lysimeters with aged MSWI bottom ash and aged biofuel ash was determined. In the cultivation experiment, the accumulation of metals and metalloids from the studied materials in ryegrass was determined. Reference materials in the cultivation experiment were two conventional geotechnical materials, crushed rock and excavated soil. Leaves from trees and bushes in the vicinity of the ash lysimeters were used as reference materials in the field study. Contamination of plant samples with particles, through splashing during rain, dusting, or in connection with sampling, proved to have had a major impact on the measured metal and metalloid concentrations in several grass samples in the cultivation experiment. The results also indicate that contamination of plant samples with particles occurred in the field study. In this case, probably due to atmospheric deposition. The particle contamination complicated the evaluation of some of the results in the project since the intention was to study accumulation by roots from the studied ash materials, but, on the other hand, the particle contamination showed the importance of taking into account the spreading of contaminants through particles as an exposure route for grazing animals. In the field study, only Cd and Zn in aspen, willow and birch exhibited elevated levels in the leaves due to root uptake from MSWI bottom ash compared to the reference samples. In addition, elevated levels of As was observed in leaves from trees in the biofuel ash. The total content of As was similar in all studied

  6. COAL ASH RESOURCES RESEARCH CONSORTIUM

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The Coal Ash Resources Research Consortium (CARRC, pronounced �cars�) is the core coal combustion by-product (CCB) research group at the Energy & Environmental Research Center (EERC). CARRC focuses on performing fundamental and applied scientific and engineering research emphasizing the environmentally safe, economical use of CCBs. CARRC member organizations, which include utilities and marketers, are key to developing industry-driven research in the area of CCB utilization and ensuring its successful application. CARRC continued the partnership of industry partners, university researchers, and the U.S. Department of Energy (DOE) addressing needs in the CCB industry through technical research and development projects. Technology transfer also continued through distribution and presentation of the results of research activities to appropriate audiences, with emphasis on reaching government agency representatives and end users of CCBs. CARRC partners have evolved technically and have jointly developed an understanding of the layers of social, regulatory, legal, and competition issues that impact the success of CCB utilization as applies to the CCB industry in general and to individual companies. Many CARRC tasks are designed to provide information on CCB performance including environmental performance, engineering performance, favorable economics, and improved life cycle of products and projects. CARRC activities from 1993�1998 included a variety of research tasks, with primary work performed in laboratory tasks developed to answer specific questions or evaluate important fundamental properties of CCBs. The tasks summarized in this report are 1) The Demonstration of CCB Use in Small Construction Projects, 2) Application of CCSEM (computer-controlled scanning electron microscopy) for Coal Combustion By-Product Characterization, 3) Development of a Procedure to Determine Heat of Hydration for Coal Combustion By-Products, 4) Investigation of the Behavior of High

  7. Rapid toxicity screening of gasification ashes.

    Science.gov (United States)

    Zhen, Xu; Rong, Le; Ng, Wei Cheng; Ong, Cynthia; Baeg, Gyeong Hun; Zhang, Wenlin; Lee, Si Ni; Li, Sam Fong Yau; Dai, Yanjun; Tong, Yen Wah; Neoh, Koon Gee; Wang, Chi-Hwa

    2016-04-01

    The solid residues including bottom ashes and fly ashes produced by waste gasification technology could be reused as secondary raw materials. However, the applications and utilizations of these ashes are very often restricted by their toxicity. Therefore, toxicity screening of ash is the primary condition for reusing the ash. In this manuscript, we establish a standard for rapid screening of gasification ashes on the basis of in vitro and in vivo testing, and henceforth guide the proper disposal of the ashes. We used three different test models comprising human cell lines (liver and lung cells), Drosophila melanogaster and Daphnia magna to examine the toxicity of six different types of ashes. For each ash, different leachate concentrations were used to examine the toxicity, with C0 being the original extracted leachate concentration, while C/C0 being subsequent diluted concentrations. The IC50 for each leachate was also quantified for use as an index to classify toxicity levels. The results demonstrated that the toxicity evaluation of different types of ashes using different models is consistent with each other. As the different models show consistent qualitative results, we chose one or two of the models (liver cells or lung cells models) as the standard for rapid toxicity screening of gasification ashes. We may classify the gasification ashes into three categories according to the IC50, 24h value on liver cells or lung cells models, namely "toxic level I" (IC50, 24h>C/C0=0.5), "toxic level II" (C/C0=0.05gasification plants every day. Subsequently, appropriate disposal methods can be recommended for each toxicity category. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Toxicity of waste gasification bottom ash leachate.

    Science.gov (United States)

    Sivula, Leena; Oikari, Aimo; Rintala, Jukka

    2012-06-01

    Toxicity of waste gasification bottom ash leachate from landfill lysimeters (112 m(3)) was studied over three years. The leachate of grate incineration bottom ash from a parallel setup was used as reference material. Three aquatic organisms (bioluminescent bacteria, green algae and water flea) were used to study acute toxicity. In addition, an ethoxyresorufin-O-deethylase (EROD) assay was performed with mouse hepatoma cells to indicate the presence of organic contaminants. Concentrations of 14 elements and 15 PAH compounds were determined to characterise leachate. Gasification ash leachate had a high pH (9.2-12.4) and assays with and without pH adjustment to neutral were used. Gasification ash leachate was acutely toxic (EC(50) 0.09-62 vol-%) in all assays except in the algae assay with pH adjustment. The gasification ash toxicity lasted the entire study period and was at maximum after two years of disposal both in water flea (EC(50) 0.09 vol-%) and in algae assays (EC(50) 7.5 vol-%). The grate ash leachate showed decreasing toxicity during the first two years of disposal in water flea and algae assays, which then tapered off. Both in the grate ash and in the gasification ash leachates EROD-activity increased during the first two years of disposal and then tapered off, the highest inductions were observed with the gasification ash leachate. The higher toxicity of the gasification ash leachate was probably related to direct and indirect effects of high pH and to lower levels of TOC and DOC compared to the grate ash leachate. The grate ash leachate toxicity was similar to that previously reported in literature, therefore, confirming that used setup was both comparable and reliable. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. As and Se interactions with fly ashes

    Directory of Open Access Journals (Sweden)

    M. Díaz-Somoano

    2012-03-01

    Full Text Available Arsenic and selenium are toxic elements present incoal in trace concentrations that may be emitted tothe environment during coal conversion processes.However, it is possible to retain volatile arsenic andselenium compounds in the fly ashes originated bythe process, the proportions retained depending onthe characteristics of the ashes and processconditions. This work is focused on the capture ofthese elements in fly ashes in simulated coalcombustion and gasification atmospheres inlaboratory scale reactors.

  10. Characterization and valorization of biomass ashes.

    Science.gov (United States)

    Trivedi, Nikhilesh S; Mandavgane, Sachin A; Mehetre, Sayaji; Kulkarni, Bhaskar D

    2016-10-01

    In India, farming is the primary source of income for many families. Following each harvest, a huge amount of biomass is generated. These are generally discarded as "agrowaste," but recent reports have indicated several beneficial uses for these biomasses and their ashes. However, before the utilization of biomass ashes (BMAs), their chemical and physical properties need to be investigated (characterized) so as to utilize their potential benefit to the fullest. In this paper, eight different biomass ashes (soybean plant ash, mustard plant ash, maize ash, groundnut plant ash, cotton plant ash, wheat plant ash, pigeon peas ash, and groundnut shell ash) were characterized, and their chemical properties are discussed. Surface chemical composition analysis, proximate analysis, and ultimate analysis were performed on all BMA samples, and properties such as porosity, particle density, bulk density, point of zero charge, BET surface area, water-absorption capacity, and bulk parameters such as surface pH and surface charges were determined. BMAs were characterized by SEM and FTIR. The surface areas of biomass ashes vary from 1.9 to 46 m(2)/g, and point of zero charge for all BMAs exceed 9.8, which confirmed the alkaline nature of these samples. Based on the chemical composition, BMAs are categorized into four types (S, C, K, and CK), and their utilization is proposed based on the type. BMAs find applications in agriculture and construction industries; glass, rubber, and zeolite manufacturing; and in adsorption (as a source of silica/zeolites). The paper also discusses the research challenges and opportunities in utilization of BMAs.

  11. Ash wettability conditions splash erosion in the postfire

    Science.gov (United States)

    Gordillo-Rivero, Ángel J.; de Celis, Reyes; García-Moreno, Jorge; Jiménez-Compán, Elizabeth; Alanís, Nancy; Cerdà, Artemi; Pereira, Paulo; Zavala, Lorena M.; Jordán, Antonio

    2015-04-01

    at each point of study were collected monthly and determined gravimetrically after oven drying between November 2012 and May 2013. 3. RESULTS AND DISCUSSION Depending on the intensity of the water repellency, the ash layer fluctuated between wettable and very strongly water repellent. The ash has a high permeability and water storage. However, its hydrophilic character has been emphasized rarely (Cerdà and Doerr, 2008). Different authors have described hydrophobic behaviors depending on the burned vegetation such as oak (Gabet and Sternberg, 2008) or pine forest (Stark, 1977) in the United States, eucalyptus forest in Australia (Khanna et al., 1996 ) or Mediterranean tree and shrub species in Spain (Bodí et al., 2011). In the latter case, Bodí et al. (2011) observed that ash has different properties depending on the combustion conditions, organic carbon content and color. This variability of behavior agrees with the results obtained in the present work. Significant differences between splash erosion from wettable and water-repellent ash zones were found (p charred litter reduces susceptibility to rain splash erosion post-wildfire Earth Surface Processes and Landforms, 34, 1522-1532. Zavala LM, De Celis R, Jordán A. 2014. How wildfires affect soil properties. A brief review Cuadernos de Investigación Geográfica 40, 311-331. AKNOWLEDGEMENTS This research is part of the POSTFIRE Project (ref. CGL2013-47862-C2-1-R), funded by the Spanish Ministry of Economy and Competitiveness. The authors are also grateful to the Environmental Management Centre (Mykolas Romeris University, Lithuania) and the Michoacan University (Morelia, Mexico) for their support.

  12. Some durability aspects of hybrid alkaline cements

    Directory of Open Access Journals (Sweden)

    Donatello S.

    2014-04-01

    Full Text Available Blended cements that contain a high content of fly ash and a low content of Portland cement typically suffer from low early strength development and long setting times. Recently, one method of overcoming these problems has been to use an alkali activator to enhance the reactivity of fly ash particles at early ages. Such cements can be grouped under the generic term “hybrid alkaline cements”, where both cement clinker and fly ash, encouraged by the presence of alkalis, are expected to contribute to cementitious gel formation. The work presented here examines some of the durability aspects of high fly ash content hybrid alkaline cement. Specifically, the aspects investigated were: exposure at high temperatures (up to 1000°C, resistance to immersion in aggressive solutions and susceptibility to the alkali aggregate reaction. All tests were repeated with a commercially available sulfate resistant Portland cement for comparison. When exposed to high temperatures, the hybrid alkaline cement showed strikingly different behaviour compared to the control Portland cement, showing fewer micro-cracks and maintaining residual compressive strengths at least equal to original strengths. Beyond 700°C, the hybrid alkaline cement began to sinter, which resulted in shrinkage of around 5% and a 100% increase in residual compressive strengths. No such sintering event was noted in the control Portland cement, which showed a drastic loss in residual compressive strengths upon heating. In immersion tests, the hybrid alkaline cement possessed excellent resistance to sulfate and seawater attack, similar to the control sulfate resistant cement. Both cements were however severely degraded by immersion in 0.1M HCl for 90 days. Both binders complied with the accelerated alkali-aggregate test but when this test was extended, the hybrid alkaline binder showed much greater dimensional stability. Possible reasons for the differences in durability behaviour in both cements

  13. Combustion of stoker ash in a CFBC

    Energy Technology Data Exchange (ETDEWEB)

    Jia, L.; Anthony, E.J. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2002-07-01

    The ash generated from petroleum coke fired stokers at Georgia Pacific in Wisconsin has an elevated carbon content and a higher fuel value. This paper presents results of a study in which the stoker ash was test fired at the CANMET Energy Technology Centre in a bench scale circulating fluidized bed combustor (CFBC). The objective was to determine if firing the stoker ash in its 'as received' state (with a 40 per cent moisture content) is a viable fuel option for Georgia Pacific's FBC boiler to save fuel costs, or if it should be co-fired with petroleum coke. Mixtures of the stoker ash and petroleum coke were also test fired. Results indicate that the stoker ash alone cannot sustain combustion. However, good ignition and even bed temperature is possible with premixed coke and 10 per cent less moisture content. Emissions of sulphur dioxides, nitrogen oxides carbon monoxide were the same as for firing petroleum coke alone. In addition, the co-firing of stoker ash and petroleum coke did not negatively affect the tendency to foul, compared to firing coke alone. The amount of ash generated from the FBC boiler was high due to the high ash content. An economic evaluation showed that firing a 20/80 coke/stoker ash mixture can save approximately 22 per cent of the limestone usage compared to coke firing alone, if the Ca/S molar ratio remain the same. 8 refs., 2 tabs., 1 fig.

  14. Volcanic ash at Santiaguito dome complex, Guatemala

    Science.gov (United States)

    Hornby, Adrian; Kendrick, Jackie; Lavallée, Yan; Cimarelli, Corrado; von Aulock, Felix; Rhodes, Emma; Kennedy, Ben; Wadsworth, Fabian

    2015-04-01

    Dome-building volcanoes often suffer episodic explosions. Examination of eruptive activity at Santiaguito dome complex (Guatemala) reveals that gas-and-ash explosions are concordant with rapid inflation/ deflation cycles of the active dome. During these explosions strain is accommodated along marginal faults, where tensional fracture mechanisms and friction dominate, complicating the model of ash generation by bubble rupture in magma. Here, we describe textural features, morphology and petrology of ash collected before, during and after a dome collapse event at Santiaguito dome complex on the 28th November 2012. We use QEM-scan (on more than 35000 grains), laser diffraction granulometry and optical and scanning microscopy to characterise the samples. The ash samples show a bimodal size distribution and a range of textures, crystal content and morphologies. The ash particles are angular to sub-angular and are relatively dense, so do not appear to comprise of pore walls. Instead the ash is generally blocky (>70%), similar to the products of shear magma failure. The ash samples show minor variation before, during and after dome collapse, specifically having a smaller grain size and a higher fraction of phenocrysts fragments before collapse. Textural analysis shows vestiges of chemically heterogeneous glass (melt) filaments originating from the crystals and crosscut by fragmentation during volcanic ash formation. High-velocity friction can induce melting of dome lavas, producing similar disequilibrium melting textures. This work shows the importance of deformation mechanisms in ash generation at lava domes and during Vulcanian activity.

  15. Solidification on fly ash, Yugoslav experiences

    Energy Technology Data Exchange (ETDEWEB)

    Knezevic, D. [Mining Institute, Belgrade (Yugoslavia); Popov, S.; Salatic, D. [Faculty of Mining and Geology, Belgrade (Yugoslavia)

    1997-12-31

    A study was performed on ashes produced in the combustion process of coal from the Kosovo coal basin, in order to determine the potential and conditions of ash self-solidification. Investigations showed that the ash properties allows for the transformation into a solid mass through a controlled mixing with water. The optimal concentration of ash is 50 percent and the hydro-mixture is behaving as a Bingham plastic fluid. Solidification is obtained in a relatively short period (within 3 to 5 days) without additives. The resulting solidified mass is very consistent and stable

  16. Comparison of leachable trace element levels in coal gasifier ash with levels in power plant ash

    Energy Technology Data Exchange (ETDEWEB)

    Bombaugh, K.J.; Milosavljevic, M.; Janes, T.K.

    1984-04-01

    The levels of 14 trace elements in leachates from three types of ash of a common origin coal were compared. The study was conducted over a one year period at the Kosovo plant in Obilic, Yugoslavia comparing coal gasifier ash with fly ash and bottom ash from a coal-fired power plant using lignite from the Dobro Solo mine. Results obtained indicate that levels of Sb, As, Be, Cr, Cu, Pb, Mo, Ni and Zn in gasifier ash leachate were similar to those in fly ash leachate. Barium levels in gasifier ash leachate averaged 2.7 times that in fly ash and selenium levels averaged 0.33 times. The average ratio for the total set was 0.99. The set average, relative to bottom ash, was 2.1 with the nickel ratio differing significantly from the average. Metal oxides, CaO, MgO, Na/SUB/2O, K/SUB/2O and MgO; in the Kosovo gasifier ash were found at levels similar to those in Kosovo fly ash, and except for K/SUB/2O, were approximately twice those in bottom ash. Concentration levels of all components showed relatively small variations averaging 50% of their mean annual concentration over the test period. (14 refs.)

  17. Self hardening property of Botswana fly ash | Sahu | Botswana ...

    African Journals Online (AJOL)

    Self hardening property of Botswana fly ash. ... In the present investigation, an effort has been made to study the self hardening property of Botswana fly ash by ... This will encourage the use of fly ash economically as a construction material.

  18. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett [Park City, UT

    2012-05-15

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  19. Ash recycling to spruce and beech stands effects on nutrients, growth, nitrogen dynamics and carbon balance; Askaaterfoering till gran- och bokbestaand - effekter paa naering, tillvaext, kvaevedynamik och kolbalans

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar

    2006-03-15

    Ash recycling is an important part in a modern, sustainable forestry, especially in whole-tree harvest systems. Nutrients lost at harvest are returned to the forest with the wood-ash. In the project the effects of ash treatment on needle and leaf chemistry, tree growth, soil chemistry, soil water chemistry, and carbon and nitrogen dynamics were studied on 23 Norway spruce sites in south-western Sweden and in ten European beech sites in Scania, southern Sweden. On some of the sites there were previously established ash recycling experiments, but on a majority of the sites ash recycling was performed without experimental lay-out and ash and control plots were established afterwards. The most common dose was two tons of self hardened crushed wood-ash and two tons of Mg-lime. On average seven to eight years after ash recycling the results were 1. increased exchangeable stores of base cations in the soil in the beech and the spruce stands 2. increased base saturation in the beech and the spruce stands and increased BC/Al in the spruce stands 3. increased concentrations and ratios to N of P, Ca, Zn, and S in the needles, the increased P-values are especially important since P is close to or below deficiency levels in a majority of the spruce stands 4. decreased K-concentration in the beech leaves 5. increased tree growth with on average 14 % in the ash treated spruce stands compared to the control plots 6. increased carbon and nitrogen amounts in the biomass in the spruce stands 7. tendencies towards increased amounts of carbon and nitrogen in the soil in the beech stands and no effect in the soil in the spruce stands 8. increased concentrations of Ca, Mg, and SO{sub 4} and no effect on ANC in the soil water 9. no effect on potential net mineralization but increased potential nitrification rates 10. decreased concentration of nitrate in the soil water in the beech stands and no effect in the spruce stands 11. lower system N losses in the beech stands and possibly in the

  20. Effects of rearing conditions on reproduction of Spathius agrili (Hymenoptera: Braconidae), a parasitoid of the emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Gould, Juli R; Ayer, Tracy; Fraser, Ivich

    2011-04-01

    Spathius agrili Yang (Hymenoptera: Braconidae) can be successfully reared on emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), larvae feeding in chambers drilled in small ash twigs that are wrapped with floral tape. Females maintained in groups with males for one week can receive enough sperm for production of female progeny throughout their lives. Volatiles released by emerald ash borer adults feeding on ash foliage increased parasitoid fecundity over ash foliage alone or no stimulus. The temperature at which the parasitoids were reared ranged from 20 to 25 degrees C in a daily cycle; however, raising the daily maximum temperature to 28 degrees C did not affect parasitoid longevity or fecundity. Adult females lived between 12 and 127 d, with an average of 60.8 +/- 4.5 d. Males lived slightly longer, with an average of 66 +/- 4.5 d. The first clutch of eggs was laid when the female was between 2 and 42 d old, with the average preoviposition period lasting 11.4 +/- 1.4 or 19.5 +/- 2.0 d in 2007 and 2009 trials, respectively. A higher proportion of the emerald ash borer larvae were feeding and thus attractive to parasitoids in the 2009 trial, and female S. agrili laid an average of 9.5 +/- 1.0 clutches containing 5.4 +/- 0.2 eggs, for an average of 51.2 eggs per female. Approximately three quarters of the progeny were female. The number of eggs per clutch was significantly greater when deposited on larger emerald ash borer larvae, further highlighting the need for quality larvae in rearing. Chilling S. agrili pupae at 10 degrees C to stockpile them for summer release was not successful; chilling resulted in lower survival and lower fecundity of emerging progeny. Female S. agrili proved capable of attacking emerald ash borer larvae through even the thickest bark of an ash tree that was 30-cm diameter at breast height. Even emerald ash borer larvae that were creating overwintering chambers in the outer sapwood of the tree were successfully

  1. State of volcanic ash dispersion prediction

    Science.gov (United States)

    Eliasson, Jonas; Palsson, Thorgeir; Weber, Konradin

    2017-04-01

    The Eyjafjallajokull 2010 and Grimsvotn 2011 eruptions created great problems for commercial aviation in Western Europe and in the North Atlantic region. Comparison of satellite images of the visible and predicted ash clouds showed the VAAC prediction to be much larger than the actual ash clouds. No official explanation of this discrepancy exists apart from the definition of the ash cloud boundary. Papers on simulation of the Eyjafjallajökull ash cloud in peer reviewed journals, typically attempted to simulate the VAAC predictions rather than focusing on the satellite pictures. Sporadic measurements made in-situ showed much lower ash concentrations over Europe than the predicted values. Two of the weak points in ash cloud prediction have been studied in airborne measurements of volcanic ash by the Universities in Kyoto Japan, Iceland and Düsseldorf Germany of eruptions in Sakurajima, Japan. It turns out that gravitational deformation of the plume and a streak fallout process make estimated ash content of clouds larger than the actual, both features are not included in the simulation model. Tropospheric plumes tend to ride in stable inversions this causes gravitational flattening (pancaking) of the volcanic plume, while diffusion in the mixing layer is insignificant. New rules from ICAO, effective from November 2014, reiterate that jetliners should avoid visible ash, this makes information on visible ash important. A procedure developed by JMÁs Tokyo VAAC uses satellite images of visible ash to correct the prediction. This and the fact that meteorological data necessary to model gravitational dispersion and streak fallout do not exist in the international database available to the VAAĆs. This shows that close monitoring by airborne measurements and satellite and other photographic surveillance is necessary.

  2. Characteristics of spanish fly ashes

    Directory of Open Access Journals (Sweden)

    de Luxán, M. P.

    1988-03-01

    Full Text Available The purpose of this study is the characterization of fly ashes produced by Spanish thermoelectric power plants, according to sampling taken in 1981 and 1982. The study takes in the following characteristics: physical characteristics (size distribution of particles, ...; chemical ones (chemical analysis...; and mineralogical ones (application of instrumental techniques of X-ray diffraction and infrared absorption spectroscopy. From a general point of view, it can be said that the samples of Spanish fly ashes are similar to those produced in other countries. The results obtained are a contribution to the knowledge of Spanish fly ashes and form part of the antecedents of investigations carried out in subsequent years.

    Este trabajo tiene por objeto la caracterización de las cenizas volantes producidas en las Centrales Termoeléctricas españolas, según un muestreo realizado entre 1981 y 1982. El estudio comprende las siguientes características: físicas (distribución del tamaño de partículas,...; químicas (análisis químico, …; y mineralógicas (aplicación de las técnicas instrumentales de difracción de rayos X y espectroscopía de absorción infrarroja. Desde un punto de vista general, se puede afirmar que las muestras de ceniza volante estudiadas son semejantes a las producidas en otros países. Los resultados obtenidos son una aportación al conocimiento de las cenizas volantes españolas y forman parte de los antecedentes de las investigaciones llevadas a cabo en años posteriores.

  3. Characterization of fly ash from bio and municipal waste

    DEFF Research Database (Denmark)

    Lima, Ana T.; Ottosen, Lisbeth M.; Pedersen, Anne Juul

    2008-01-01

    Four different fly ashes are characterized in the present paper. The ashes differ in the original fuel type and were sampled at distinct plants. The investigation includes two different ashes from municipal solid waste incineration (with and without sorbents addition), a straw ash and an ash from...... potentiality to be valorized. The main conclusion of this paper regards fly ash’s profound dissimilarity, where each ash should be studied separately....

  4. Determination of some tree parameters using terrestrial laser scanner in urban green areas

    Directory of Open Access Journals (Sweden)

    Mustafa Akgül

    2016-07-01

    Full Text Available The aim of this study is to measure the parameters for modelling individual and street trees in urban areas using Terrestrial Laser Scanner (TLS data. Breast height diameter (d1.30, tree height, crown base height, distance between trees were measured in the roadside trees which are composed of Narrow-leaved ash (Fraxinus angustifolia Vahl. in Istanbul University Faculty of Forestry Campus. In addition, tree zone models of the trees were formed in order to express development process of trees with time in an integrated way and to make connections among different parts of trees. As a result of measurements, d1.30valuesvaried between 24 cm and 45,6 cm both from ground measurement and TLS. Statistically there were not a significant difference between d1.30 values, even though ground measurement values were higher than TLS measurements. According to regression analysis, a significant correlation was found between ground and TLS mesurements (R2=0,971, p<0,05. Objective values were derived from TLS data related to tree crown forms, tree zone model and tree architecture. The ratio of static and dynamic mass of trees and their relations were showed on 3D tree models. 3D tree models and measurements on this models, which were carried out in this study, can be used in maintenance and pruning application of individual and forests of Urban areas.

  5. Inference in hybrid Bayesian networks

    DEFF Research Database (Denmark)

    Lanseth, Helge; Nielsen, Thomas Dyhre; Rumí, Rafael

    2009-01-01

    Since the 1980s, Bayesian Networks (BNs) have become increasingly popular for building statistical models of complex systems. This is particularly true for boolean systems, where BNs often prove to be a more efficient modelling framework than traditional reliability-techniques (like fault trees...... decade's research on inference in hybrid Bayesian networks. The discussions are linked to an example model for estimating human reliability....

  6. The potential of utilizing wood ash and peat ash on organic soils in Sweden; Arealer foer skogsgoedsling med traeaska och torvaska paa organogena jordar i Sverige

    Energy Technology Data Exchange (ETDEWEB)

    Haanell, Bjoern [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Silviculture

    2004-01-01

    Nutrients removed from the forest when branches and treetops are harvested as fuel can be returned to the site by recycling the remaining wood ash after combustion. This compensation measure is presently not carried out to any appreciable extent, partly because there is no economic incentive for the landowner. In sites where this measure has been applied, only on mineral soils (e.g. moraine) until now, greater margins for sustainable maintenance of the long-term site productivity can be expected. The ash contains all elements required for tree growth except for nitrogen (N). Therefore the ash amendment does not result in increased stand growth on these soils because the most important element for a growth response (N) is missing. In contrast, on organic soils N is often abundant whereas the amounts of other mineral nutrients are small. Thus, the elements lacking in the soils of peatland forests are available in the ash. This is especially true for phosphorus (P) and potassium (K). This means that peatland forests provide an opportunity for ash amendment in order to increase forest production. Old fertilization trials using wood ash show that the growth increase can be very large. The aim of this study was to (i) calculate the area of peat covered land that with respect to stand growth responses could be regarded as most suitable for bio-ash (wood ash and peat ash) fertilization, and (ii) assess the amount of bio-ash needed for fertilizing this area. Peat ash, although not as much studied, also has potential to be used to provide nutrients for increasing peatland forest growth. Most of the area calculations were based on data from the National Forest Inventory (NFI) 1997-2001. Sites were selected with guidance from existing knowledge about ash fertilization effects on tree growth and with the aid of registrations made in NFI regarding peat depth, site productivity, drainage, condition of drains, dominating field vegetation, and degree of stand development

  7. Biomass fly ash in concrete: SEM, EDX and ESEM analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shuangzhen Wang; Larry Baxter; Fernando Fonseca [Brigham Young University, Provo, UT (USA). Department of Chemical Engineering

    2008-03-15

    This document summarizes microscopy study of concrete prepared from cement and fly ash (25% fly ash and 75% cement by weight), which covers coal fly ash and biomass fly ash. All the fly ash concrete has the statistical equal strength from one day to one year after mix. Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX) and environmental scanning electron microscopy (ESEM) analysis show that both coal and biomass fly ash particles undergo significant changes of morphology and chemical compositions in concrete due to pozzolanic reaction, although biomass fly ash differs substantially from coal fly ash in its fuel resources. 8 refs., 17 figs., 1 tab.

  8. Electrodialytic removal of heavy metals from fly ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul

    2002-01-01

    The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration.......The aim of the Ph.D. work was to develop the electrodialytic remediation method for removal of heavy metals from fly ashes. The work was focused on two types of fly ashes: fly ashes from wood combustion and fly ashes from municipal solid waste incineration....

  9. CHARACTERIZATION AND COMPARISON OF TREATED AND UNTREATED RICH HUSH ASH & FLY ASH FOR METAL MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    Ravinder Pal Singh

    2011-10-01

    Full Text Available Rice Husk ash and fly ash are agricultural and coal wastes respectively. These are produced in abundance globally and poses risk to health as well as environment. Thus their effective, conducive and eco-friendly utilization has always been a challenge for scientific community. The fly ash has been used as reinforcement for improved mechanical properties of composites (1,3-5,9. Rice husk ash can also be used for similar applications as its composition is almost similar to that of fly ash. This paper mainly deals with identification ofcharacteristics of both the fly ash and rice husk ash using spectroscopic and microscopic analysis. SEM, XRD,XRF and FTIR spectroscopic methods were used for the characterization of treated and untreated ashes. The results were compared and it was observed that both ashes possesses nearly same chemical phases and otherfunctional groups thus proposing the use of rice husk ash as reinforcement like fly ash in Metal Matrix Composites (MMCs specifically for wear resistance applications.

  10. Effects of colemanite waste, coal bottom ash, and fly ash on the properties of cement

    Energy Technology Data Exchange (ETDEWEB)

    Kula, I.; Olgun, A.; Erdogan, Y.; Sevinc, V. [Celal Bayar University, Manisa (Turkey)

    2001-03-01

    The physical and chemical properties of colemanite ore waste from concentrator, coal bottom ash, fly ash, cement+ash mixtures, cement+colemanite ore waste, and their effects on the mechanical properties of concrete were investigated. These materials with different proportion were substituted with Portland cement. Physical properties such as setting time, volume expansion, and compressive strength were determined and compared to reference mixture and Turkish standards (TS). The results showed that cement replacement materials had clear effects on the mechanical properties. The use of fly ash and bottom ash even at the concentration of 25% showed either comparable or better result compared to reference mixture. Although replacement of Portland cement by 9 wt.% of colemanite ore waste causes reduction in the compressive strength, the values obtained are within the limit of TS. As a result, colemanite ore waste, fly ash, and bottom ash may be used as cementitious materials.

  11. Wet physical separation of MSWI bottom ash

    NARCIS (Netherlands)

    Muchova, L.

    2010-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) has high potential for the recovery of valuable secondary materials. For example, the MSWI bottom ash produced by the incinerator at Amsterdam contains materials such as non-ferrous metals (2.3%), ferrous metals (8-13%), gold (0.4 ppm),

  12. Wet physical separation of MSWI bottom ash

    NARCIS (Netherlands)

    Muchova, L.

    2010-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) has high potential for the recovery of valuable secondary materials. For example, the MSWI bottom ash produced by the incinerator at Amsterdam contains materials such as non-ferrous metals (2.3%), ferrous metals (8-13%), gold (0.4 ppm),

  13. Biology of emerald ash borer parasitoids

    Science.gov (United States)

    Leah S. Bauer; Jian J. Duan; Jonathan P. Lelito; Houping Liu; Juli R. Gould

    2015-01-01

    The emerald ash borer (EAB) (Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive beetle introduced from China (Bray et al., 2011), was identified as the cause of ash (Fraxinus spp.) mortality in southeast Michigan and nearby Ontario in 2002 (Haack et al., 2002; Federal Register, 2003; Cappaert et al., 2005)....

  14. Fly ash-reinforced thermoplastic starch composites

    Energy Technology Data Exchange (ETDEWEB)

    Ma, X.F.; Yu, J.G.; Wang, N. [Tianjin University, Tianjin (China). School of Science

    2007-01-02

    As a by-product from the combustion of pulverized coal, fly ash was, respectively, used as the reinforcement for formamide and urea-plasticized thermoplastic starch (FUPTPS) and glycerol-plasticized thermoplastic starch (GPTPS). The introduction of fly ash improved tensile stress from 4.56 MPa to 7.78 MPa and Youngs modulus increased trebly from 26.8 MPa to 84.6 MPa for fly ash-reinforced FUPTPS (A-FUPTPS), while tensile stress increased from 4.55 MPa to 12.86 MPa and Youngs modulus increased six times from 76.4 MPa to 545 MPa for fly ash-reinforced GPTPS (A-GPTPS). X-ray diffractograms illustrated that fly ash destroyed the formation of starch ordered crystal structure, so both A-GPTPS and FUPTPS could resist the starch re-crystallization (retrogradation). Also fly ash improved water resistance of TPS. As shown by rheology, during the thermoplastic processing, the extruder screw speed effectively adjusted the flow behavior of A-FUPTPS, while the increasing of the processing temperature effectively ameliorated the flow behavior of A-GPTPS. However, superfluous ash contents (e.g., 20 wt%) worsened processing fluidity and resulted in the congregation of fly ash in FUPTPS matrix (tested by SEM) rather than in GPTPS matrix. This congregation decreased the mechanical properties and water resistance of the materials.

  15. Physicochemical characterization of Spanish fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Querol, X.; Umana, J.C.; Alastuey, A.; Bertrana, C.; Lopez-Soler, A.; Plana, F.

    1999-12-01

    This article summarizes the results obtained from the physical, chemical, and mineralogical characterization of 14 fly ash samples. Major features that influence the utilization of each fly ash for zeolite synthesis are evidenced, and several fly ash types were selected as potential high-quality starting material for zeolite synthesis and ceramic applications. The main parameters influencing this selection were relatively small grain size; high Al and Si contents; high glass content; low CaO, S, and Fe contents; and relatively low heavy metal concentration. The Compostilla and Cou He fly ashes have high potential applications because of the low content of major impurities (such as Ca, Fe, and S) and the low content of soluble hazardous elements. The Espiel, Escucha, Los Barrios, As Pontes, Soto de Ribera, Meirama, Narcea, and Teruel fly ashes have important application potential, but this potential is slightly limited by the intermediate content of nonreactive impurities, such as Fe and Ca. The La Robla fly ash is of moderate interest, since the relatively high Ca and Fe oxide contents may reduce its potential applications. Finally, the Puertollano fly ash also has limited application because of the very high concentration of some heavy metals such as As, Cd, Ge, Hg, Pb, and Zn. From a mineralogical point of view, the Compostilla, Espiel, and Soto de Ribera fly ashes show the highest aluminum-silicate glass content and, consequently, the highest industrial application potential.

  16. Physiochemical characterization of Spanish fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Querol, X.; Umana, J.C.; Alastuey, A.; Bertrana, C.; Lopez Soler, A.; Plana, F.

    1999-12-01

    This article summarizes the results obtained from the physical, chemical, and mineralogical characterization of 14 fly ash samples. Major features that influence the utilization of each fly ash for zeolite synthesis are evidenced, and several fly ash types were selected as potential high-quality starting material for zeolite synthesis and ceramic applications. The main parameters influencing this selection were relatively small grain size; high Al and Si contents; high glass content; low CaO, S, and Fe contents; and relatively low heavy metal concentration. The Compostilla and Dou He fly ashes have high potential applications because of the low content of major impurities (such as Ca, Fe, and S) and the low content of soluble hazardous elements. The Espiel, Escucha, Los Barrios, As Pontes, Soto de Ribera, Meirama, Narcea, and Teruel fly ashes have important application potential, but this potential is slightly limited by the intermediate content of nonreactive impurities, such as Fe and Ca. The La Robla fly ash is of moderate interest, since the relatively high Ca and Fe oxide contents may reduce its potential applications. Finally, the Puertollano fly ash also has limited application because of the very high concentration of some heavy metals such as As, Cd, Ge, Hg, Pb, and Zn. From a mineralogical point of view, the Compostilla, Espiel, and Soto de Ribera fly ashes show the highest aluminum-silicate glass content and, consequently, the highest industrial application potential. (author)

  17. Column leaching from biomass combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2015-01-01

    The utilization of biomass combustion ashes for forest soil liming and fertilizing has been addressed in literature. Though, a deep understanding of the ash chemical composition and leaching behavior is necessary to predict potential benefits and environmental risks related to this practice...

  18. Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

  19. Investigation on Leaching Behaviour of Fly Ash and Bottom Ash Replacement in Self-Compacting Concrete

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Fly ash and bottom ash are some of the waste generated by coal-fired power plants, which contains large quantities of toxic and heavy metals. In recent years, many researchers have been interested in studying on the properties of self-compacting concrete incorporated with fly ash and bottom ash but there was very limited research from the combination of fly ash and bottom ash towards the environmental needs. Therefore, this research was focused on investigating the leachability of heavy metals of SCC incorporated with fly ash and bottom ash by using Toxicity Characteristic Leaching Procedure, Synthetic Precipitation Leaching Procedure and Static Leaching Test. The samples obtained from the coal-fired power plant located at Peninsula, Malaysia. In this study, the potential heavy metals leached out from SCC that is produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a substitute for sand with the ratios from 10% to 30% respectively were designated and cast. There are eight heavy metals of concern such as As, Cr, Pb, Zn, Cu, Ni, Mn and Fe. The results indicated that most of the heavy metals leached below the permissible limits from the United States Environmental Protection Agency and World Health Organization limit for drinking water. As a conclusion, the minimum leaching of the heavy metals from the incorporation of fly ash and bottom ash in self-compacting concrete was found in 20% of fly ash and 20% of bottom ash replacement. The results also indicate that this incorporation could minimize the potential of environmental problems.

  20. Construction procedures using self hardening fly ash

    Science.gov (United States)

    Thornton, S. I.; Parker, D. G.

    1980-07-01

    Fly ash produced in Arkansas from burning Wyoming low sulfur coal is self-hardening and can be effective as a soil stabilizing agent for clays and sands. The strength of soil-self hardening fly ash develops rapidly when compacted immediately after mixing. Seven day unconfined compressive strengths up to 1800 psi were obtained from 20% fly ash and 80% sand mixtures. A time delay between mixing the fly ash with the soil and compaction of the mixture reduced the strength. With two hours delay, over a third of the strength was lost and with four hours delay, the loss was over half. Gypsum and some commercial concrete retarders were effective in reducing the detrimental effect of delayed compaction. Adequate mixing of the soil and fly ash and rapid compaction of the mixtures were found to be important parameters in field construction of stabilized bases.

  1. Ectomycorrhizal fungal diversity, tree diversity and root nutrient relations in a mixed Central European forest.

    Science.gov (United States)

    Lang, Christa; Polle, Andrea

    2011-05-01

    Knowledge is limited about whether root nutrient concentrations are affected by mixtures of tree species and interspecific root competition. The goal of this field study was to investigate root nutrient element concentrations in relation to root and ectomycorrhizal (EM) diversity in six different mixtures of beech (Fagus sylvatica), ash (Fraxinus excelsior) and lime (Tilia sp.) in an old-growth, undisturbed forest ecosystem. Root biomass and nutrient concentrations per tree taxon as well as the abundance and identity of all EM fungi were determined in soil cores of a volume of 1 L (r=40 mm, depth=200 mm). Stand-level nutrient concentrations in overall root biomass and H' (Shannon-Wiener diversity) were obtained by pooling the data per stand. At stand level, Shannon H' for roots and aboveground tree species abundance were correlated. H' for roots and EM fungi were not correlated because of the contribution of ash roots that form only arbuscular mycorrhizal but no EM associations. Nutrient element concentrations in roots showed taxon-related differences and increased in the following order: beech ≤ lime tree diversity because of two effects: increasing contribution of ash roots to the mixture and increasing Ca accumulation in beech roots with increasing root diversity. On a small scale, increasing root diversity, but not EM diversity, was correlated with decreasing P concentrations in beech roots pointing to interspecific tree competition. Nitrogen (N) concentrations of beech roots were unaltered in relation to root and EM diversity. Opposing behavior was observed for lime and ash: the N concentrations in lime roots increased, whereas those in ash roots decreased with increasing EM diversity in a given soil volume. This suggests that EM diversity facilitates N acquisition of lime roots at the expense of non-EM ash.

  2. Hybrid Baryons

    CERN Document Server

    Page, P R

    2003-01-01

    We review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modelled by both the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.

  3. 488-D Ash Basin Vegetative Cover Treatibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Christopher; Marx, Don; Blake, John; Adriano, Domy; Koo, Bon-Jun; Czapka, Stephen

    2003-01-01

    The 488-D Ash Basin is an unlined containment basin that received ash and coal reject material from the operation of a powerhouse at the USDOE's Savannah River Site, SC. They pyretic nature of the coal rejects has resulted in the formation of acidic drainage (AD), which has contributed to groundwater deterioration and threatens biota in down gradient wetlands. Establishment of a vegetative cover was examined as a remedial alternative for reducing AD generation within this system by enhanced utilization of rainwater and subsequent non-point source water pollution control. The low nutrient content, high acidity, and high salinity of the basin material, however, was deleterious to plant survivability. As such, studies to identify suitable plant species and potential adaptations, and pretreatment techniques in the form of amendments, tilling, and/or chemical stabilization were needed. A randomized block design consisting of three subsurface treatments (blocks) and five duplicated surface amendments (treatments) was developed. One hundred inoculated pine trees were planted on each plot. Herbaceous species were also planted on half of the plots in duplicated 1-m2 beds. After two growing seasons, deep ripping, subsurface amendments and surface covers were shown to be essential for the successful establishment of vegetation on the basin. This is the final report of the study.

  4. Healthy,Happy trees

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Healthy trees are important to us all. Trees provide shade, beauty, and homes for wildlife. Trees give us products like paper and wood. Trees can give us all this only if they are healthy.They must be well cared for to remain healthy.

  5. Laboratory Studies of Ice Nucleation on Volcanic Ash

    Science.gov (United States)

    Tolbert, M. A.; Schill, G. P.; Genareau, K. D.

    2014-12-01

    Ice nucleation on volcanic ash controls both ash aggregation and cloud glaciation, which affect human respiratory health, atmospheric transport, and global climate. We have performed laboratory studies of the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman Microscopy coupled to an environmental cell. Ash from the Fuego (Basaltic Ash, Guatemala), Soufriere Hills (Andesetic Ash, Montserrat), and Taupo (Rhyolitic Ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. We find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice at ice saturation ratios of 1.05 ± 0.1. For immersion freezing, however, only the Taupo ash exhibited efficient heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

  6. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2013-01-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  7. Treatment of fly ash for use in concrete

    Science.gov (United States)

    Boxley, Chett; Akash, Akash; Zhao, Qiang

    2012-05-08

    A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

  8. Factors influencing bird foraging preferences among conspecific fruit trees

    Science.gov (United States)

    Foster, M.S.

    1990-01-01

    The rates at which birds visit fruiting individuals of Allophylus edulis (Sapindaceae) differ substantially among trees. Such avian feeding preferences are well-known, but usually involve fruits and trees of different species. Factors controlling avian preferences for particular trees in a population of conspecifics are generally undocumented. To address this issue, I attempted to correlate rates at which individual birds and species fed in trees of Allophylus with 27 fruit or plant characteristics. Birds that swallow fruits whole were considered separately from those that feed in other ways. Plant characters were selected on the basis of their potential influence on feeding efficiency or predation risk, assuming that birds would select feeding trees so as to maximize the net rate of energy or nutrient intake and to minimize predation. Correlations were found between feeding visits by some groups of birds and percent water in the pulp, milligrams of mineral ash in the pulp, and crop size. No character was correlated with feeding visits by all groups of birds in both years of the study. The correlations with water and mineral ash are unexplained and may be artifacts. The correlation with crop size may represent a tactic to minimize predation.

  9. TreePM Method for Two-Dimensional Cosmological Simulations

    Indian Academy of Sciences (India)

    Suryadeep Ray

    2004-09-01

    We describe the two-dimensional TreePM method in this paper. The 2d TreePM code is an accurate and efficient technique to carry out large two-dimensional N-body simulations in cosmology. This hybrid code combines the 2d Barnes and Hut Tree method and the 2d Particle–Mesh method. We describe the splitting of force between the PM and the Tree parts. We also estimate error in force for a realistic configuration. Finally, we discuss some tests of the code.

  10. Comparison of tree-child phylogenetic networks.

    Science.gov (United States)

    Cardona, Gabriel; Rosselló, Francesc; Valiente, Gabriel

    2009-01-01

    Phylogenetic networks are a generalization of phylogenetic trees that allow for the representation of nontreelike evolutionary events, like recombination, hybridization, or lateral gene transfer. While much progress has been made to find practical algorithms for reconstructing a phylogenetic network from a set of sequences, all attempts to endorse a class of phylogenetic networks (strictly extending the class of phylogenetic trees) with a well-founded distance measure have, to the best of our knowledge and with the only exception of the bipartition distance on regular networks, failed so far. In this paper, we present and study a new meaningful class of phylogenetic networks, called tree-child phylogenetic networks, and we provide an injective representation of these networks as multisets of vectors of natural numbers, their path multiplicity vectors. We then use this representation to define a distance on this class that extends the well-known Robinson-Foulds distance for phylogenetic trees and to give an alignment method for pairs of networks in this class. Simple polynomial algorithms for reconstructing a tree-child phylogenetic network from its path multiplicity vectors, for computing the distance between two tree-child phylogenetic networks and for aligning a pair of tree-child phylogenetic networks, are provided. They have been implemented as a Perl package and a Java applet, which can be found at http://bioinfo.uib.es/~recerca/phylonetworks/mudistance/.

  11. Classification and regression trees

    CERN Document Server

    Breiman, Leo; Olshen, Richard A; Stone, Charles J

    1984-01-01

    The methodology used to construct tree structured rules is the focus of this monograph. Unlike many other statistical procedures, which moved from pencil and paper to calculators, this text's use of trees was unthinkable before computers. Both the practical and theoretical sides have been developed in the authors' study of tree methods. Classification and Regression Trees reflects these two sides, covering the use of trees as a data analysis method, and in a more mathematical framework, proving some of their fundamental properties.

  12. Selective catalytic reduction of NO by ammonia over oil shale ash and fly ash catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Changtao Yue; Shuyuan Li [University of Petroleum, Beijing (China). State Key Lab of Heavy Oil Processing

    2003-07-01

    Acid rain and urban air pollution, produced mainly by pollutants such as SOX and NOX and other volatile organic compounds, has become the most serious environmental problem. The selective catalytic reduction (SCR) of NO with NH{sub 3} in the presence of oxygen is a wellproven method to limit the NOX emissions. The work in this field has been the subject of much research in recent years. In this paper, NO reduction with NH{sub 3} over oil shale ash or fly ash catalysts was studied. Fe, Cu, V or Ni as active elements was loaded by adding aqueous solutions of the metal nitrate over the oil shale ash or fly ash support. The activities of the catalysts for NO removal were measured in a fixed-bed reactor. According to the results, oil shale ash or fly ash, after pre-treatment, can be reasonably used as the SCR catalyst support to remove NO from flue gas. Cu gave the highest catalytic activity and NO conversion for fly ash while V for oil shale ash. As the support, fly ash is more feasible than oil shale ash. Because of their low cost and high efficiency, the catalysts should be used in the SCR process. Further research on this subject is necessary in the future to understand more details of the SCR system and issue of pollution control. 9 refs., 2 figs., 2 tabs.

  13. Effect of wood ash on leaf and shoot anatomy, photosynthesis and carbohydrate concentrations in birch on a cutaway peatland.

    Science.gov (United States)

    Aguraijuja, Karin; Klõšeiko, Jaan; Ots, Katri; Lukjanova, Aljona

    2015-07-01

    Trees in cutaway peatland are growing in difficult conditions. Fertilization with nutrient-rich wood ash helps improve growth conditions. Photosynthesis and carbohydrate concentration along leaf anatomy were studied on plots treated with 10 and 5 t ha(-1) wood ash (WA10 and WA5) and on untreated (Control) plot to explain the physiological background of the differences in tree growth. The leaves from WA10 had the largest leaf area, total thickness, the thickest mesophyll and also significantly larger average values of all anatomical parameters of the shoots. The photosynthetic assimilation was significantly higher on treated plots at 200 and 400 ppm CO2 levels. In leaves on the treated plots, the sucrose concentration was lower while that of starch was higher than in trees on untreated soil. The differences in the maximum photosynthesis were relatively small. At unit ground, the leaf area provided for a wood ash-treated tree an efficient surface for CO2 assimilation, light interception and some starch storage during the growing period.

  14. Long term effects on water streams of wood ash recycling to a forest plantation; Laangtidsverkan paa avrinnande vatten av askaaterfoering till plantskog. Slutrapport foer en delstudie inom det av Energimyndigheten finansierade projektet 'Skogliga aatgaerder - effekter paa kol-, naering- och tungmetallfloeden'

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Hillevi; Nilsson, Torbjoern [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Soils

    2001-12-01

    The chemical composition of runoff from a wood ash fertilized catchment in central Sweden have been studied during eight years after the treatment. The effects of the ash treatment was compared with a 12ayear long reference period and a reference catchment close to the ash treated catchment. The ash treated area was earlier (winter 1980/81) whole-tree-harvested to 90 %. At the same time the reference area was stemwood harvested on 60 % of the area. Both areas were planted with spruce and pine. Granulated ash was spread on the whole-tree-harvested area, by helicopter, on two occasions (1aton per hectare in May 1989 and 2 tonnes per hectare in October 1991). During the first ash application a marked peak in K concentration was observed. The second ash application caused a high peak in K concentration. Short-lived peaks was also observed for pH, electric conductivity, ANC, Mg, Na and Cl. Significant increases of pH, electric conductivity, Ca, K and Cl was observed in runoff water from the ash treated area during the 8-year-period after the last ash spreading. However, during the same period concentrations of NH4-N, N03-N and total N have shown a relative decrease in runoff water from the ash treated area, compared to the reference area.

  15. Pozzolanic Reaction Kinetics of Coal Ashes

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hongwei; WANG Zhijuan; QIAN Jueshi; SONG Yuanming; WANG Zhi

    2009-01-01

    The pozzolanic reactivity was determined by the hydration kinetics of pozzolanic reaction based on the fact that the hydration products of active SiO_2 and Al_2O_3 with lime were soluble in dilute hydrochloric acid.The results show that the pozzolanic reaction of active SiO_2 and Al2O3 of coal ashes follows apparent first-order kinetics.The reaction rate constant of FBC ashes is greater than that of PC ashes,while the activation energy of the former is lower than that of the latter.It is confirmed that the pozzolanic activity of fluidized bed combustion(FBC)ashes is significantly higher than that of PC ashes,and the reaction barrier of the former is lower than that of the latter,because the microstructures of FBC ashes,such as mineralogical composition,morphology and polymerization degree of [SiO_4]and[AlO_6]are more favorable to the pozzolanic activity development than those of PC ashes.

  16. The climatic impact of supervolcanic ash blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Morgan T.; Sparks, R.S.J. [University of Bristol, Department of Earth Sciences, Bristol (United Kingdom); Valdes, Paul J. [University of Bristol, School of Geographical Sciences, Bristol (United Kingdom)

    2007-11-15

    Supervolcanoes are large caldera systems that can expel vast quantities of ash, volcanic gases in a single eruption, far larger than any recorded in recent history. These super-eruptions have been suggested as possible catalysts for long-term climate change and may be responsible for bottlenecks in human and animal populations. Here, we consider the previously neglected climatic effects of a continent-sized ash deposit with a high albedo and show that a decadal climate forcing is expected. We use a coupled atmosphere-ocean General Circulation Model (GCM) to simulate the effect of an ash blanket from Yellowstone volcano, USA, covering much of North America. Reflectivity measurements of dry volcanic ash show albedo values as high as snow, implying that the effects of an ash blanket would be severe. The modeling results indicate major disturbances to the climate, particularly to oscillatory patterns such as the El Nino Southern Oscillation (ENSO). Atmospheric disruptions would continue for decades after the eruption due to extended ash blanket longevity. The climatic response to an ash blanket is not significant enough to investigate a change to stadial periods at present day boundary conditions, though this is one of several impacts associated with a super-eruption which may induce long-term climatic change. (orig.)

  17. Marine mesocosm bacterial colonisation of volcanic ash

    Science.gov (United States)

    Witt, Verena; Cimarelli, Corrado; Ayris, Paul; Kueppers, Ulrich; Erpenbeck, Dirk; Dingwell, Donald; Woerheide, Gert

    2015-04-01

    Volcanic eruptions regularly eject large quantities of ash particles into the atmosphere, which can be deposited via fallout into oceanic environments. Such fallout has the potential to alter pH, light and nutrient availability at local scales. Shallow-water coral reef ecosystems - "rainforests of the sea" - are highly sensitive to disturbances, such as ocean acidification, sedimentation and eutrophication. Therefore, wind-delivered volcanic ash may lead to burial and mortality of such reefs. Coral reef ecosystem resilience may depend on pioneer bacterial colonisation of the ash layer, supporting subsequent establishment of the micro- and ultimately the macro-community. However, which bacteria are involved in pioneer colonisation remain unknown. We hypothesize that physico-chemical properties (i.e., morphology, mineralogy) of the ash may dictate bacterial colonisation. The effect of substrate properties on bacterial colonisation was tested by exposing five substrates: i) quartz sand ii) crystalline ash (Sakurajima, Japan) iii) volcanic glass iv) carbonate reef sand and v) calcite sand of similar grain size, in controlled marine coral reef aquaria under low light conditions for six months. Bacterial communities were screened every month by Automated Ribosomal Intergenic Spacer Analysis of the 16S-23S rRNA Internal Transcribed Spacer region. Multivariate statistics revealed discrete groupings of bacterial communities on substrates of volcanic origin (ash and glass) and reef origin (three sands). Analysis of Similarity supported significantly different communities associated with all substrates (p=0.0001), only quartz did not differ from both carbonate and calcite sands. The ash substrate exhibited the most diverse bacterial community with the most substrate-specific bacterial operational taxonomic units. Our findings suggest that bacterial diversity and community composition during colonisation of volcanic ash in a coral reef-like environment is controlled by the

  18. Photoperiodic growth control in perennial trees.

    Science.gov (United States)

    Azeez, Abdul; Sane, Aniruddha P

    2015-01-01

    Plants have to cope with changing seasons and adverse environmental conditions. Being sessile, plants have developed elaborate mechanisms for their survival that allow them to sense and adapt to the environment and reproduce successfully. A major adaptive trait for the survival of trees of temperate and boreal forests is the induction of growth cessation in anticipation of winters. In the last few years enormous progress has been made to elucidate the molecular mechanisms underlying SDs induced growth cessation in model perennial tree hybrid aspen (Populus tremula × P. tremuloides). In this review we discuss the molecular mechanism underlying photoperiodic control of growth cessation and adaptive responses.

  19. Seedling Growth and Phosphorus Cycling in Northern Forest Soils Amended With Biochar and Wood Ash

    Science.gov (United States)

    Noyce, G. L.; Jones, T.; Fulthorpe, R.; Basiliko, N.

    2015-12-01

    Biochar may be a powerful soil amendment to reduce nutrient depletion in North American forests where long-term nitrogen deposition has led to phosphorus (P) limitation, but many effects of biochar in these ecosystems are still unknown. We performed a 12-week growth chamber experiment in which red pine (Pinus resinosa) and sugar maple (Acer saccharum) seedlings were grown in pots with soil from three Ontario forests and varying amounts of sugar maple biochar. Additionally, biochar effects were compared with the effects of wood ash, a forest biomass bioenergy by-product that may also be a beneficial soil amendment in these ecosystems. We assessed plant biomass, soil microbial biomass and phosphatase activity; additional chemical analyses of plant tissue and soils are ongoing. Biochar effects on seedling growth were not consistent across tree species, soil type, and addition rate. For sugar maple seedlings grown in sand and sandy-loam textured soils, biochar additions of 20 t ha-1 significantly (p = 0.03) decreased root biomass by 25 %, and the root-to-shoot ratio correspondingly declined, but this effect was not observed in a silty soil. For red pine seedlings, the same biochar addition rate slightly increased root biomass. Wood ash effects on biomass were similarly variable. For example, in the sandy soil, sugar maple root biomass was significantly lower after application of 16 t ash ha-1, but unchanged by rates of 4 or 40 t ash ha-1. Microbial biomass and soil phosphatase activity also varied by soil type. Phosphatase activity was significantly lower (p = 0.02) in soils with sugar maple compared to red pine, but there were no consistent biochar or ash effects across all soils and species. However, for red pine seedlings grown in silt, biochar significantly (p = 0.04) reduced the phosphatase activity compared to the control and ash soils. Overall, biochar may lessen P-limitation in forested ecosystems, but the suitability of biochar, and wood ash, for increasing P

  20. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

    2015-01-01

    This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...... controlled arm. Higher sintering temperatures resulted in greater adhesion strengths, with a sharp increase observed near the melting point of the ash. Repetition of experiments with fixed operation conditions revealed considerable variation in the obtained adhesion strengths, portraying the stochastic...

  1. Fly Ash Disposal in Ash Ponds: A Threat to Ground Water Contamination

    Science.gov (United States)

    Singh, R. K.; Gupta, N. C.; Guha, B. K.

    2016-07-01

    Ground water contamination due to deposition of fly ash in ash ponds was assessed by simulating the disposal site conditions using batch leaching test with fly ash samples from three thermal power plants. The periodic analysis of leachates was performed for selected elements, Fe, Cu, Ni, Cr, Pb and Cd in three different extraction solutions to determine the maximum amount that can be leached from fly ash. It was observed that at low pH value, maximum metals are released from the surface of the ash into leachate. The average concentration of these elements found in ground water samples from the nearby area of ash ponds shows that almost all the metals except `Cr' are crossing the prescribed limits of drinking water. The concentration of these elements at this level can endanger public health and environment.

  2. Fly Ash Disposal in Ash Ponds: A Threat to Ground Water Contamination

    Science.gov (United States)

    Singh, R. K.; Gupta, N. C.; Guha, B. K.

    2016-09-01

    Ground water contamination due to deposition of fly ash in ash ponds was assessed by simulating the disposal site conditions using batch leaching test with fly ash samples from three thermal power plants. The periodic analysis of leachates was performed for selected elements, Fe, Cu, Ni, Cr, Pb and Cd in three different extraction solutions to determine the maximum amount that can be leached from fly ash. It was observed that at low pH value, maximum metals are released from the surface of the ash into leachate. The average concentration of these elements found in ground water samples from the nearby area of ash ponds shows that almost all the metals except `Cr' are crossing the prescribed limits of drinking water. The concentration of these elements at this level can endanger public health and environment.

  3. Individual Urban Tree Species Classification Using Very High Spatial Resolution Airborne Multi-Spectral Imagery Using Longitudinal Profiles

    Directory of Open Access Journals (Sweden)

    Baoxin Hu

    2012-06-01

    Full Text Available Individual tree species identification is important for urban forest inventory and ecology management. Recent advances in remote sensing technologies facilitate more detailed estimation of individual urban tree characteristics. This study presents an approach to improve the classification of individual tree species via longitudinal profiles from very high spatial resolution airborne imagery. The longitudinal profiles represent the side view tree shape, which play a very important role in individual tree species on-site identification. Decision tree classification was employed to conduct the final classification result. Using this profile approach, six major species (Maple, Ash, Birch, Oak, Spruce, Pine of trees on the York University (Ontario, Canada campus were successfully identified. Two decision trees were constructed, one knowledge-based and one derived from gain ratio criteria. The classification accuracy achieved were 84% and 86%, respectively.

  4. Effect of Fly Ash on the Electrical Conductivity of Concretes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The fly ash occasionally has high content of iron oxide and carbon that are good electrical conducting components. This paper investigates the effect of the fly ash used as mineral admixtures on the electrical conductivity of concretes. The electrical properties of concretes using 3 kinds of fly ash with different iron oxide contents have been studied. Experimental results show that at the same fly ash dosage the resistivity of concrete using fly ash with high content of iron oxide is slightly lower than that with low content of iron oxide. However, the concrete resistivity after 14d increases as fly ash dosage increases regardless of iron oxide content in fly ash.

  5. Biomass fly ash in concrete: Mixture proportioning and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Shuangzhen Wang; Amber Miller; Emilio Llamazos; Fernando Fonseca; Larry Baxter [Brigham Young University, Provo, UT (USA). Department of Chemical Engineering

    2008-03-15

    ASTM C 618 prohibits use of biomass fly ashes in concrete. This document compares the properties of biomass fly ashes from cofired (herbaceous with coal), pure wood combustion and blended (pure wood fly ash blended with coal fly ash) to those of coal fly ash in concrete. The results illustrate that with 25% replacement (wt%) of cement by fly ash, the compressive strength (one day to one year) and the flexure strength (at 56th day curing) of cofired and blended biomass fly ash concrete is statistically equal to that of two coal fly ash concrete in this investigation (at 95% confidence interval). This implies that biomass fly ash with co-firing concentration within the concentration interest to commercial coal-biomass co-firing operations at power plants and blended biomass fly ash within a certain blending ratio should be considered in concrete. 37 refs., 10 figs., 2 tabs.

  6. An Early-Warning System for Volcanic Ash Dispersal: The MAFALDA Procedure

    Science.gov (United States)

    Barsotti, S.; Nannipieri, L.; Neri, A.

    2006-12-01

    Forecasts of the dispersal of volcanic ash is a fundamental goal in order to mitigate its potential impact on urbanized areas and transport routes surrounding explosive volcanoes. To this aim we developed an early- warning procedure named MAFALDA (Modeling And Forecasting Ash Loading and Dispersal in the Atmosphere). Such tool is able to quantitatively forecast the atmospheric concentration of ash as well as the ground deposition as a function of time over a 3D spatial domain.\\The main features of MAFALDA are: (1) the use of the hybrid Lagrangian-Eulerian code VOL-CALPUFF able to describe both the rising column phase and the atmospheric dispersal as a function of weather conditions, (2) the use of high-resolution weather forecasting data, (3) the short execution time that allows to analyse a set of scenarios and (4) the web-based CGI software application (written in Perl programming language) that shows the results in a standard graphical web interface and makes it suitable as an early-warning system during volcanic crises.\\MAFALDA is composed by a computational part that simulates the ash cloud dynamics and a graphical interface for visualizing the modelling results. The computational part includes the codes for elaborating the meteorological data, the dispersal code and the post-processing programs. These produces hourly 2D maps of aerial ash concentration at several vertical levels, extension of "threat" area on air and 2D maps of ash deposit on the ground, in addition to graphs of hourly variations of column height.\\The processed results are available on the web by the graphical interface and the users can choose, by drop-down menu, which data to visualize. \\A first partial application of the procedure has been carried out for Mt. Etna (Italy). In this case, the procedure simulates four volcanological scenarios characterized by different plume intensities and uses 48-hrs weather forecasting data with a resolution of 7 km provided by the Italian Air Force.

  7. Rice Husk Ash Derived Zeolite Blended with Water Hyacinth Ash for Enhanced Adsorption of Cadmium Ions

    OpenAIRE

    G. W. Mbugua; H. M. Mbuvi; J. W. Muthengia

    2014-01-01

    In order to helpcurtail or imposesustained control to the offensive water hyacinth plant,it is essential to explore ways of generatingwater remediation materials from it. In the current study, the capacity and efficacy of water hyacinth ash (WHA),its insoluble residue (WHAR) and rice husk ash (RHA)to remove cadmium ionsand methylene blue from contaminated water was investigated. Mixtures of the two ashes were used to formulatezeolitic materialsby hydrothermal reactions. Material A, ZMA was pr...

  8. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

    Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

  9. Electrodialytic removal of heavy metals from different fly ashes. Influence of heavy metal speciation in the ashes

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

    2003-01-01

    Electrodialytic Remediation has recently been suggested as a potential method for removal of heavy metals from fly ashes. In this work electrodialytic remediation of three different fly ashes, i.e. two municipal solid waste incinerator (MSWI) fly ashes and one wood combustion fly ash was studied...

  10. Categorizing Ideas about Trees: A Tree of Trees

    Science.gov (United States)

    Fisler, Marie; Lecointre, Guillaume

    2013-01-01

    The aim of this study is to explore whether matrices and MP trees used to produce systematic categories of organisms could be useful to produce categories of ideas in history of science. We study the history of the use of trees in systematics to represent the diversity of life from 1766 to 1991. We apply to those ideas a method inspired from coding homologous parts of organisms. We discretize conceptual parts of ideas, writings and drawings about trees contained in 41 main writings; we detect shared parts among authors and code them into a 91-characters matrix and use a tree representation to show who shares what with whom. In other words, we propose a hierarchical representation of the shared ideas about trees among authors: this produces a “tree of trees.” Then, we categorize schools of tree-representations. Classical schools like “cladists” and “pheneticists” are recovered but others are not: “gradists” are separated into two blocks, one of them being called here “grade theoreticians.” We propose new interesting categories like the “buffonian school,” the “metaphoricians,” and those using “strictly genealogical classifications.” We consider that networks are not useful to represent shared ideas at the present step of the study. A cladogram is made for showing who is sharing what with whom, but also heterobathmy and homoplasy of characters. The present cladogram is not modelling processes of transmission of ideas about trees, and here it is mostly used to test for proximity of ideas of the same age and for categorization. PMID:23950877

  11. Fluidized bed gasification ash reduction and removal process

    Science.gov (United States)

    Schenone, Carl E.; Rosinski, Joseph

    1984-12-04

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  12. Fluidized bed gasification ash reduction and removal system

    Science.gov (United States)

    Schenone, Carl E.; Rosinski, Joseph

    1984-02-28

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  13. Analyzing and synthesizing phylogenies using tree alignment graphs.

    Directory of Open Access Journals (Sweden)

    Stephen A Smith

    Full Text Available Phylogenetic trees are used to analyze and visualize evolution. However, trees can be imperfect datatypes when summarizing multiple trees. This is especially problematic when accommodating for biological phenomena such as horizontal gene transfer, incomplete lineage sorting, and hybridization, as well as topological conflict between datasets. Additionally, researchers may want to combine information from sets of trees that have partially overlapping taxon sets. To address the problem of analyzing sets of trees with conflicting relationships and partially overlapping taxon sets, we introduce methods for aligning, synthesizing and analyzing rooted phylogenetic trees within a graph, called a tree alignment graph (TAG. The TAG can be queried and analyzed to explore uncertainty and conflict. It can also be synthesized to construct trees, presenting an alternative to supertrees approaches. We demonstrate these methods with two empirical datasets. In order to explore uncertainty, we constructed a TAG of the bootstrap trees from the Angiosperm Tree of Life project. Analysis of the resulting graph demonstrates that areas of the dataset that are unresolved in majority-rule consensus tree analyses can be understood in more detail within the context of a graph structure, using measures incorporating node degree and adjacency support. As an exercise in synthesis (i.e., summarization of a TAG constructed from the alignment trees, we also construct a TAG consisting of the taxonomy and source trees from a recent comprehensive bird study. We synthesized this graph into a tree that can be reconstructed in a repeatable fashion and where the underlying source information can be updated. The methods presented here are tractable for large scale analyses and serve as a basis for an alternative to consensus tree and supertree methods. Furthermore, the exploration of these graphs can expose structures and patterns within the dataset that are otherwise difficult to

  14. Emerald Ash Borer Pest Alert, (English version)El barrenador del fresno, el barrenador verde esmeralda del fresno o (Spanish version)

    Science.gov (United States)

    Deborah McCullough; Steven Katovich

    2008-01-01

    A beetle from Asia, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was identified in July 2002 as the cause of widespread ash (Fraxinus spp.) tree decline and mortality in southeastern Michigan and Windsor, Ontario, Canada. Larval feeding in the tissue between the bark and sapwood disrupts transport of nutrients and...

  15. Suggestion for a course of action on recycling wood ash to forests; Foerslag till handlingsplan foer askaaterfoering

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem, Henrik [AaF-Energi and Miljoe AB, Stockholm (Sweden)

    2002-10-01

    The purpose of the study reported here is a suggestion for a course of action that could be adopted by The Swedish Thermal Research Institute, within its program 'Environmentally correct utilization of ashes', with regard to recycling wood ashes to forest soils. Past and present activities concerning recycling to forests, incl. R and D, have been reviewed as a first step towards this goal. Thereafter, the present situation is discussed and some important actions are proposed. The assumption underlying the study is that wood ash shall be recycled, i.e. spread on forest soils, in order to compensate for the removal of mineral nutrients when whole trees are harvested. Account is taken neither of the discussion whether recycling ashes is necessary nor of alternative uses which might be more economically interesting. Actions that the producers of ashes might consider are the following: to establish a structured procedure to identify obstacles and actions to remove these. The question why ashes are recycled or not is complex, and it may be difficult to reduce it to a single question and answer. Actions that may be considered could be more information, improved organizational procedures, etc. depending on the obstacle: to try to build up more interest for recycling ashes by identifying areas where also a short term benefit for growth can be demonstrated and promoting the spreading of ashes there. It should be noted, though, reservations stated by the National Board of Forestry and the Swedish Energy Agency: spreading ash to peat soil is not recycling and spreading to nitrogen-burdened soil is not desirable; to develop methods for quality assurance, which would lead to consistent and better-known properties for the wood ashes. This includes standardization; to take part in the work aiming at the requirements on leaching properties that probably will be included in revised guidelines from 2005, or to perform parallel work in order to build up necessary know-how or

  16. AshMeadowsSpeckledDace_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each of...

  17. AshMeadowsAmargosaPupfish_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each of...

  18. Cementing Properties of Oil Shale Ash

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The oil crisis has prompted renewed interest in direct burning of oil shale as an alternative energy source.A major problem in this process is the large portion of ash produced.The cementing properties of this ash were investigated to determine its applicability as a building material.By means of XRD, IR, NMR and ICP, we have studied the effects of burning temperature on the reactivity of ash.Maximum reactivity was obtained with ash samples produced at 700 °C to 900 °C.In this range, the strength of oil-shale-based material, with properties similar to cement, which is composed of oil shale and several other kinds of solid wastes, can achieve the standard of 42.5# cement.Our study has provided an experimental foundation and theoretical base for a massive utilization of oil shale.

  19. Volcanic Ash Advisory Database, 1983-2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanic ash is a significant hazard to aviation and can also affect global climate patterns. To ensure safe navigation and monitor possible climatic impact, the...

  20. ASH External Web Portal (External Portal) -

    Data.gov (United States)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  1. AshMeadowsSpeckledDace_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each of...

  2. AshMeadowsAmargosaPupfish_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each of...

  3. Clay Improvement with Burned Olive Waste Ash

    Directory of Open Access Journals (Sweden)

    Utkan Mutman

    2013-01-01

    Full Text Available Olive oil is concentrated in the Mediterranean basin countries. Since the olive oil industries are incriminated for a high quantity of pollution, it has become imperative to solve this problem by developing optimized systems for the treatment of olive oil wastes. This study proposes a solution to the problem. Burned olive waste ash is evaluated for using it as clay stabilizer. In a laboratory, bentonite clay is used to improve olive waste ash. Before the laboratory, the olive waste is burned at 550°C in the high temperature oven. The burned olive waste ash was added to bentonite clay with increasing 1% by weight from 1% to 10%. The study consisted of the following tests on samples treated with burned olive waste ash: Atterberg Limits, Standard Proctor Density, and Unconfined Compressive Strength Tests. The test results show promise for this material to be used as stabilizer and to solve many of the problems associated with its accumulation.

  4. Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

    Energy Technology Data Exchange (ETDEWEB)

    Pourrut, Bertrand [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Lopareva-Pohu, Alena [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); Pruvot, Christelle [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Garcon, Guillaume; Verdin, Anthony [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); Waterlot, Christophe; Bidar, Geraldine [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Shirali, Pirouz [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); and others

    2011-10-01

    Aided phytostabilisation is a cost-efficient technique to manage metal-contaminated areas, particularly in the presence of extensive pollution. Plant establishment and survival in highly metal-contaminated soils are crucial for phytostabilisation success, as metal toxicity for plants is widely reported. A relevant phytostabilisation solution must limit metal transfer through the food chain. Therefore, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated by cadmium, lead, and zinc. The influence of afforestation and fly ash amendments on reducing metal phytoavailability was investigated as were their effects on plant development. Before being planted with a tree mix, the site was divided into three plots: a reference plot with no amendment, a plot amended with silico-aluminous fly ash and one with sulfo-calcic fly ash. Unlike Salix alba and Quercus robur, Alnus glutinosa, Acer pseudoplatanus and Robinia pseudoacacia grew well on the site and accumulated, overall, quite low concentrations of metals in their leaves and young twigs. This suggests that these three species have an excluder phenotype for Cd, Zn and Pb. After 8 years, metal availability to A. glutinosa, A. pseudoplatanus and R. pseudoacacia, and translocation to their above-ground parts, strongly decreased in fly ash-amended soils. Such decreases fit well together with the depletion of CaCl{sub 2}-extractable metals in amended soils. Although both fly ashes were effective to decrease Cd, Pb and Zn concentrations in above-ground parts of trees, the sulfo-calcic ash was more efficient.

  5. Spanning Tree Problem

    Directory of Open Access Journals (Sweden)

    Yen Hung Chen

    2012-01-01

    minimum cost spanning tree T in G such that the total weight in T is at most a given bound B. In this paper, we present two polynomial time approximation schemes (PTASs for the constrained minimum spanning tree problem.

  6. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  7. Stabilization/solidification of TSCA incinerator ash

    Energy Technology Data Exchange (ETDEWEB)

    Spence, R.D.; Trotter, D.R.; Francis, C.L.; Morgan, I.L.

    1994-06-01

    Stabilization/solidification is a well-known waste treatment technique that utilizes different additives and processes. The Phoenix Ash Technology of the Technical Innovation Development Engineering Company is such a technique that uses Cass C fly ash and mechanical pressure to make brick waste forms out of solid wastes, such as the bottom ash from the Toxic Substances Control Act incinerator at the Oak Ridge K-25 Site. One advantage of this technique is that no volume increase over the bulk volume of the bottom ash occurs. This technique should have the same high pH stabilization for Resource Conservation and Recovery Act metals as similar techniques. Also, consolidation of the bottom ash minimizes the potential problems of material dispersion and container corrosion. The bottom ash was spiked with {sup 99}{Tc} to test the effectiveness of the bricks as a physical barrier. The {sup 99}{Tc} leachability index measured for these bricks was 6.8, typical for the pertechnetate anion in cementitious waste forms, indicating that these bricks have accessible porosity as high as that of other cementitious waste forms, despite the mechanical compression, higher waste form density, and water resistant polymer coating.

  8. Flue gas desulfurization gypsum and fly ash

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The Cumberland Fossil Plant (CUF) is located in Stewart County, Tennessee, and began commercial operation in 1972. This is the Tennessee Valley Authority`s newest fossil (coal-burning) steam electric generating plant. Under current operating conditions, the plant burns approximately seven million tons of coal annually. By-products from the combustion of coal are fly ash, approximately 428,000 tons annually, and bottom ash, approximately 115,000 tons annually. Based on historical load and projected ash production rates, a study was initially undertaken to identify feasible alternatives for marketing, utilization and disposal of ash by-products. The preferred alternative to ensure that facilities are planned for all by-products which will potentially be generated at CUF is to plan facilities to handle wet FGD gypsum and dry fly ash. A number of different sites were evaluated for their suitability for development as FGD gypsum and ash storage facilities. LAW Engineering was contracted to conduct onsite explorations of sites to develop information on the general mature of subsurface soil, rock and groundwater conditions in the site areas. Surveys were also conducted on each site to assess the presence of endangered and threatened species, wetlands and floodplains, archaeological and cultural resources, prime farmland and other site characteristics which must be considered from an environmental perspective.

  9. Hybrid Model of Content Extraction

    DEFF Research Database (Denmark)

    Qureshi, Pir Abdul Rasool; Memon, Nasrullah

    2012-01-01

    We present a hybrid model for content extraction from HTML documents. The model operates on Document Object Model (DOM) tree of the corresponding HTML document. It evaluates each tree node and associated statistical features like link density and text distribution across the node to predict...... model outperformed other existing content extraction models. We present a browser based implementation of the proposed model as proof of concept and compare the implementation strategy with various state of art implementations. We also discuss various applications of the proposed model with special...

  10. Wildland fire ash: future research directions

    Science.gov (United States)

    Bodí, Merche B.; Martins, Deborah A.; Cerdà, Artemi; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Mataix-Solera, Jorge

    2014-05-01

    Ash is a key component of the forest fires affected land (Cerdà, 1998; Bodí et al., 2011; Pereira et al., 2013a). Ash controls the hydrological processes and determines the water repellency (Dlapa et al., 2012) and the infiltration rates (Cerdà and Doerr, 2008;). Moreover, ash is the key factor on runoff initiation and then on the soil erosion. Little is known about the impact of ash in different ecosystems, but during the last decade a substantial increase in the papers that show the role of ash in the Earth and Soil System were published (Bodí et al., 2012; Pereira et al., 2013b).. Ash is being found as the key component of the post-fire pedological, geomorphological and hydrological response after forest fires (Fernández et al., 2012; Martín et al., 2012; Bodí et al., 2013; Guénon et al., 2013; Pereira et al., 2013c). A recent State-of-the-Art review about wildland fire ash (Bodí et al., 2014) compiles the knowledge regarding the production, composition and eco-hydro-geomorphic effects of wildland fire ash. In the present paper we indicate the knowledge gaps detected and suggest topics that need more research effort concerning: i) data collection and analysis techniques: a) To develop standardized sampling techniques that allow cross comparison among sites and avoid inclusion of the underlying soil unless the burned surface soil forms part of the ash layer, b) To develop standardized methods to define and characterize ash, including its color, physical properties such as particle size distribution or density, proportion of pyrogenic C, chemical and biological reactivity and persistence in the environment, c) To validate, calibrate and test measurements collected through remote sensing with on-the-ground measurements. ii) ash production, deposition redistribution and fate: d) To untangle the significance of the effects of maximum temperature reached during combustion versus the duration of heating, e) To understand the production of ash by measuring its

  11. Feeding and Development of Emerald Ash Borer (Coleoptera: Buprestidae) on Cultivated Olive, Olea europaea.

    Science.gov (United States)

    Cipollini, Don; Rigsby, Chad M; Peterson, Donnie L

    2017-08-01

    We examined the suitability of cultivated olive, Olea europaea L., as a host for emerald ash borer, Agrilus planipennis Fairmaire. In a bioassay using cut stems from a field-grown olive tree (cv. 'Manzanilla') we found that 45% of larvae that had emerged from eggs used to inoculate stems, were recovered alive, many as larvae or prepupae, during periodic debarking of a subset of stems. Three intact stems that 19 larvae successfully entered were exposed to a simulated overwintering treatment. Four live adults emerged afterwards, and an additional pupa and several prepupae were discovered after debarking these stems. Cultivated olive joins white fringetree as one of the two species outside of the genus Fraxinus capable of supporting the development of emerald ash borer from neonate to adult. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Making Tree Ensembles Interpretable

    OpenAIRE

    Hara, Satoshi; Hayashi, Kohei

    2016-01-01

    Tree ensembles, such as random forest and boosted trees, are renowned for their high prediction performance, whereas their interpretability is critically limited. In this paper, we propose a post processing method that improves the model interpretability of tree ensembles. After learning a complex tree ensembles in a standard way, we approximate it by a simpler model that is interpretable for human. To obtain the simpler model, we derive the EM algorithm minimizing the KL divergence from the ...

  13. Embeddings of Iteration Trees

    OpenAIRE

    Mitchell, William

    1992-01-01

    This paper, dating from May 1991, contains preliminary (and unpublishable) notes on investigations about iteration trees. They will be of interest only to the specialist. In the first two sections I define notions of support and embeddings for tree iterations, proving for example that every tree iteration is a direct limit of finite tree iterations. This is a generalization to models with extenders of basic ideas of iterated ultrapowers using only ultrapowers. In the final section (which is m...

  14. Designing of Multiphase Fly Ash/MWCNT/PU Composite Sheet Against Electromagnetic Environmental Pollution

    Science.gov (United States)

    Gujral, Parth; Varshney, Swati; Dhawan, S. K.

    2016-06-01

    Fly ash and multiwalled carbon nanotubes (MWCNT) reinforced multiphase polyurethane (PU) composite sheets have been fabricated by using a solution casting technique. Utilization of fly ash was the prime objective in order to reduce environmental pollution and to enhance the shielding properties of PU polymer. Our study proves that fly ash particles with MWCNTs in a PU matrix leads to novel hybrid high performance electromagnetic shielding interference material. Scanning electron microscopy confirms the existence of fly ash particles along with MWCNTs in a PU matrix. This multiphase composite shows total shielding effectiveness of 35.8 dB (>99.99% attenuation) in the Ku-band (12.4-18 GHz) frequency range. This is attributed to high dielectric losses of reinforcement present in the polymers matrix. The Nicolson-Ross-Weir algorithm has been applied to calculate the electromagnetic attributes and dielectric parameters of the PU samples by using scattering parameters ( S 11, S 22, S 12, S 21). The synthesized multiphase composites were further characterized by using x-ray diffraction, Fourier transform infrared spectroscopy, and thermo gravimetric analysis.

  15. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  16. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  17. Macro tree transducers

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1985-01-01

    Macro tree transducers are a combination of top-down tree transducers and macro grammars. They serve as a model for syntax-directed semantics in which context information can be handled. In this paper the formal model of macro tree transducers is studied by investigating typical automata theoretical

  18. Winter Birch Trees

    Science.gov (United States)

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    Trees are great inspiration for artists. Many art teachers find themselves inspired and maybe somewhat obsessed with the natural beauty and elegance of the lofty tree, and how it changes through the seasons. One such tree that grows in several regions and always looks magnificent, regardless of the time of year, is the birch. In this article, the…

  19. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  20. The Wish Tree Project

    Science.gov (United States)

    Brooks, Sarah DeWitt

    2010-01-01

    This article describes the author's experience in implementing a Wish Tree project in her school in an effort to bring the school community together with a positive art-making experience during a potentially stressful time. The concept of a wish tree is simple: plant a tree; provide tags and pencils for writing wishes; and encourage everyone to…

  1. The Wish Tree Project

    Science.gov (United States)

    Brooks, Sarah DeWitt

    2010-01-01

    This article describes the author's experience in implementing a Wish Tree project in her school in an effort to bring the school community together with a positive art-making experience during a potentially stressful time. The concept of a wish tree is simple: plant a tree; provide tags and pencils for writing wishes; and encourage everyone to…

  2. Macro tree transducers

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1985-01-01

    Macro tree transducers are a combination of top-down tree transducers and macro grammars. They serve as a model for syntax-directed semantics in which context information can be handled. In this paper the formal model of macro tree transducers is studied by investigating typical automata theoretical

  3. Sulphation characteristics of paper sludge ash

    Energy Technology Data Exchange (ETDEWEB)

    Roh, S.A. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of); Kim, S.D. [Environmental Systems Research Center, Korea Inst. of Machinery and Materials, Daejeon (Korea, Republic of). Dept. of Chemical and Biomolecular Engineering

    2007-04-15

    Landfills are no longer a viable solution for the disposal of sludge produced from waste water treatment plants because of the decrease in available space, rising fees and growing environmental concerns. However, thermal utilization of this waste may be an economic and sustainable disposal solution. Co-combustion of low heating value sludge with fossil fuels has a positive effect for sulfur dioxide (SO{sub 2}) emissions due to the low sulphur content of biomass fuels and increased sulphur retention in the ash. The sulphur retention is attributed to the formation of sulphates, such as CaSO{sub 4}, K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4}. The amount of fuel-ash-related sulphur sorption increases during co-combustion. Therefore, sorbents for sulphur reduction may not be required if proper control of the biomass feed is maintained. This paper presented a study in which the sulphation characteristics of calcium-rich paper sludge ash were determined for the use of co-combustion of biomass and coal. The calcium in the paper sludge ash came from the limestone filler used in the manufacturing process to increase the density and whiteness of the paper at 2 paper mills in Korea. A thermobalance reactor along with XRD and SEM-EDX were used for the analysis of sulphated ash to determine the effects of sulphation temperature, particle size and SO{sub 2} concentration on sulphation conversion. The activation energy and pre-exponential factor of sulphation reaction of sludge ash were determined based on the uniform-reaction model. X-ray diffraction analysis revealed that most of the sulphation compounds were CaSO{sub 4}. The sulphation occurred uniformly throughout the ash and the CaSO{sub 4} did not block the outer pore of the sludge ash. The uniform distributions of CaO and other inert minerals in the ash resulted in uniform sulphation with good penetration of SO{sub 2} into pores of the sludge ash without pore blocking during sulphation of CaO. 13 refs., 1 tab., 9 figs.

  4. Scale-Up and Demonstration of Fly Ash Ozonation Technology

    Energy Technology Data Exchange (ETDEWEB)

    Rui Afonso; R. Hurt; I. Kulaots

    2006-03-01

    The disposal of fly ash from the combustion of coal has become increasingly important. When the fly ash does not meet the required specification for the product or market intended, it is necessary to beneficiate it to achieve the desired quality. This project, conducted at PPL's Montour SES, is the first near full-scale ({approx}10 ton/day), demonstration of ash ozonation technology. Bituminous and sub bituminous ashes, including two ash samples that contained activated carbon, were treated during the project. Results from the tests were very promising. The ashes were successfully treated with ozone, yielding concrete-suitable ash quality. Preliminary process cost estimates indicate that capital and operating costs to treat unburned carbon are competitive with other commercial ash beneficiation technologies at a fraction of the cost of lost sales and/or ash disposal costs. This is the final technical report under DOE Cooperative Agreement No.: DE-FC26-03NT41730.

  5. Ash transformation during co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn;

    2007-01-01

    Co-firing straw with coal in pulverized fuel boilers can cause problems related to fly ash utilization, deposit formation, corrosion and SCR catalyst deactivation due to the high contents of Cl and K in the ash. To investigate the interaction between coal and straw ash and the effect of coal...... quality on fly ash and deposit properties, straw was co-fired with three kinds of coal in an entrained flow reactor. The compositions of the produced ashes were compared to the available literature data to find suitable scaling parameters that can be used to predict the composition of ash from straw...... importantly, by reaction with Al and Si in the fly ash. About 70-80% K in the fly ash appears as alumina silicates while the remainder K is mainly present as sulphate. Lignite/straw co-firing produces fly ash with relatively high Cl content. This is probably because of the high content of calcium...

  6. Effect of ash components on the ignition and burnout of high ash coals

    Energy Technology Data Exchange (ETDEWEB)

    Feng, B.; Yan, R.; Zheng, C.G. [Huazhong University of Science and Technology, Wuhan (China). National Laboratory of Coal Combustion

    1998-11-01

    The effect of the ash components on the ignition and burnout of four Chinese high ash coals were studied by thermogravimetric analysis. To investigate the influence of the ash components, comparative experiments were carried out with original, deashed and impregnated coals. Eleven types of ash components, such as SiO{sub 2}, CaCO{sub 3}, MgO, Na{sub 2}CO{sub 3}, K{sub 2}CO{sub 3}, Al{sub 2}O{sub 3}, TiO{sub 2}, Fe{sub 2}O{sub 3}, FeS{sub 2}, NH{sub 4}Fe(SO{sub 4}){sub 2}{center_dot}12H{sub 2}O and FeSO{sub 4},(NH{sub 4}){center_dot}6H{sub 2}O were used in the present study. It was found that most of the ash components have negative effects. The strong influence of some ash components suggests that the combustion characteristics of high ash coal may be determined by the ash composition. 5 refs., 2 figs., 2 tabs.

  7. Modeling calcium dissolution from oil shale ash: Part 2.. Continuous washing of the ash layer

    Energy Technology Data Exchange (ETDEWEB)

    Velts, O.; Kallas, J. [Tallinn University of Technology, Laboratory of Inorganic Materials, 5 Ehitajate Str., Tallinn 19086 (Estonia); Lappeenranta University of Technology, Laboratory of Separation Technology, Skinnarilankatu 34, Lappeenranta 53851 (Finland); Hautaniemi, M.; Kuosa, M. [Lappeenranta University of Technology, Laboratory of Separation Technology, Skinnarilankatu 34, Lappeenranta 53851 (Finland); Kuusik, R. [Tallinn University of Technology, Laboratory of Inorganic Materials, 5 Ehitajate Str., Tallinn 19086 (Estonia)

    2010-05-15

    In the present work a possible approach to the utilization of oil shale ash containing free lime in precipitated calcium carbonate (PCC) production is elucidated. This paper investigates the Ca (calcium) dissolution process during continuous washing of pulverized firing (PF) and fluidized bed combustion (FBC) oil shale ash layers in a packed-bed leaching column. The main characteristics of the Ca dissolution process from ash are established. The effect of water flow rate is investigated by conducting leaching experiments of oil shale ashes formed in boilers operating with different combustion technologies. The values of the overall and liquid phase mass transfer coefficients are evaluated based on experiments using the developed ash layer washing model. The model is a set of partial differential equations that describe the changes in Ca content in the stagnant layer of ash and in the water flowing through the ash layer. An example in which the model is applied to environmental assessment and estimation of Ca leaching from industrial oil shale ash fields is provided. (author)

  8. Influence of Fly Ash, Bottom Ash, and Light Expanded Clay Aggregate on Concrete

    Directory of Open Access Journals (Sweden)

    S. Sivakumar

    2015-01-01

    Full Text Available Invention of new methods in strengthening concrete is under work for decades. Developing countries like India use the extensive reinforced construction works materials such as fly ash and bottom ash and other ingredients in RCC construction. In the construction industry, major attention has been devoted to the use of fly ash and bottom ash as cement and fine aggregate replacements. In addition, light expanded clay aggregate has been introduced instead of coarse aggregate to make concrete have light weight. This paper presents the results of a real-time work carried out to form light weight concrete made with fly ash, bottom ash, and light expanded clay aggregate as mineral admixtures. Experimental investigation on concrete mix M20 is done by replacement of cement with fly ash, fine aggregate with bottom ash, and coarse aggregate with light expanded clay aggregate at the rates of 5%, 10%, 15%, 20%, 25%, 30%, and 35% in each mix and their compressive strength and split tensile strength of concrete were discussed for 7, 28, and 56 days and flexural strength has been discussed for 7, 28, and 56 days depending on the optimum dosage of replacement in compressive strength and split tensile strength of concrete.

  9. Monitoring ash (Fraxinus spp.) decline and emerald ash borer (Agrilus planipennis) symptoms in infested areas

    Science.gov (United States)

    Kathleen S. Knight; Britton P. Flash; Rachel H. Kappler; Joel A. Throckmorton; Bernadette Grafton; Charles E. Flower

    2014-01-01

    Emerald ash borer (A. planipennis) (EAB) has had a devastating effect on ash (Fraxinus) species since its introduction to North America and has resulted in altered ecological processes across the area of infestation. Monitoring is an important tool for understanding and managing the impact of this threat, and the use of common...

  10. Comparative study on the characteristics of fly ash and bottom ash geopolymers.

    Science.gov (United States)

    Chindaprasirt, Prinya; Jaturapitakkul, Chai; Chalee, Wichian; Rattanasak, Ubolluk

    2009-02-01

    This research was conducted to compare geopolymers made from fly ash and ground bottom ash. Sodium hydroxide (NaOH) and sodium silicate (Na(2)SiO(3)) solutions were used as activators. A mass ratio of 1.5 Na(2)SiO(3)/NaOH and three concentrations of NaOH (5, 10, and 15M) were used; the geopolymers were cured at 65 degrees C for 48 h. A Fourier transform infrared spectrometer (FT-IR), differential scanning calorimeter (DSC), and scanning electron microscope (SEM) were used on the geopolymer pastes. Geopolymer mortars were also prepared in order to investigate compressive strength. The results show that both fly ash and bottom ash can be utilized as source materials for the production of geopolymers. The properties of the geopolymers are dependent on source materials and the NaOH concentration. Fly ash is more reactive and produces a higher degree of geopolymerization in comparison with bottom ash. The moderate NaOH concentration of 10 M is found to be suitable and gives fly ash and bottom ash geopolymer mortars with compressive strengths of 35 and 18 MPa.

  11. Trees in Lhasa

    Institute of Scientific and Technical Information of China (English)

    Degyi

    2008-01-01

    Trees are flourishing in Lhasa wherever the history exists. There is such a man. He has already been through cus-toms after his annual trek to Lhasa, which he has been doing for over twenty years in succession to visit his tree.Although he has been making this journey for so long,it is neither to visit friends or family,nor is it his hometown.It is a tree that is tied so profoundly to his heart.When the wind blows fiercely on the bare tree and winter snow falls,he stands be-fore the tree with tears of jo...

  12. Distributed Contour Trees

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy; Weber, Gunther H.

    2014-03-31

    Topological techniques provide robust tools for data analysis. They are used, for example, for feature extraction, for data de-noising, and for comparison of data sets. This chapter concerns contour trees, a topological descriptor that records the connectivity of the isosurfaces of scalar functions. These trees are fundamental to analysis and visualization of physical phenomena modeled by real-valued measurements. We study the parallel analysis of contour trees. After describing a particular representation of a contour tree, called local{global representation, we illustrate how di erent problems that rely on contour trees can be solved in parallel with minimal communication.

  13. Insight of the fusion behavior of volcanic ash: Implications for Volcanic ash Hazards to Aircraft Safety

    Science.gov (United States)

    Song, Wenjia; Hess, Kai-Uwe; Küppers, Ulrich; Scheu, Bettina; Cimarelli, Corrado; Lavallée, Yan; Sohyun, Park; Gattermann, Ulf; Müller, Dirk; Dingwell, Donald Bruce

    2014-05-01

    The interaction of volcanic ash with jet turbines during via ingestion of ash into engines operating at supra-volcanic temperatures is widely recognized as a potentially fatal hazard for jet aircraft. In the past 12 years, more than 60 modern jet airplanes, mostly jumbo jets, have been damaged by drifting clouds of volcanic ash that have contaminated air routes and airport facilities. Seven of these encounters are known to have caused in flight loss of engine power to jumbo jets carrying a total of more than 2000 passengers. The fusibility of volcanic ash is believed to impact strongly its deposition in the hotter parts of jet engines. Despite this, explicit investigation of ash sintering using standardized techniques is in its infancy. Volcanic ash may vary widely in its physical state and chemical composition between and even within explosive volcanic eruptions. Thus a comparative study of the fusibility of ash which involves a standard recognized techniques would be highly desirable. In this work, nine samples of fine ash, deposited from co-pyroclastic offrom nine different volcanoes which cover a broad range of chemical composition, were investigated. Eight of them were collected from 2001-2009 eruptions. Because of the currently elevated level of eruptive activity and its potential hazards to aircraft safety and the remaining one sample was collected from a 12,121 ± 114 yr B.P. eruption. We used the method of accessing the behavior of deposit-forming impurities in high temperature boiler plants on the basis of observations of the change in shape and size of a cylindrical coal ash to study the fusion phenomena as well as determine the volcanic ash melting behavior by defining four characteristic temperatures (shrinkage temperature, deformation temperature, hemispherical temperature, and flow temperature) by means of heating microscope instrument and different thermal analysis methods. Here, we find that there are similar sticking ability and flow behavior of

  14. Mechanical Properties of Concrete Using Eggshell Ash and Rice Husk Ash As Partial Replacement Of Cement

    Directory of Open Access Journals (Sweden)

    Afizah Asman Nurul Shahadahtul

    2017-01-01

    Full Text Available This research was carried out to determine the optimum percentage of eggshell ash and rice husk ash (RHA as partial cement replacement. The samples were tested for its mechanical properties by using concrete grade G30 with cube mould (100 mm × 100 mm × 100 mm and prisms (100 mm × 100 mm × 500 mm. The samples were mixed with eggshell ash and RHA admixture with different proportions (2%:8%, 4%:6%, 6%:4%. Several types of test were conducted towards the samples, which are the slump test, compressive and flexural test. Based on previous researches, the strength of concrete reduced as replaced with eggshells. Most of the researches show the similar trend when partial cement is replaced using eggshell ash. Thus, to increase the strength, an admixture which has pozzolanic reactivity called rice husk ash (RHA is introduced into mix design which has been proved can help to improve the strength of concrete.

  15. Ash fusion temperatures and the transformations of coal ash particles to slag

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S.K.; Wall, T.F.; Creelman, R.A.; Gupta, R.P. [University of Newcastle, Newcastle, NSW (Australia). CRC for Black Coal Utilisation

    1998-07-01

    A mechanistic study is detailed in which coal ash is heated with its shrinkage measured continuously up to a temperature of 1600{degree}C. The temperature corresponding to the rapid rate of shrinkage correspond to the formation of eutectics identified on phase diagrams. Samples were therefore heated to these temperatures, cooled rapidly and examined using a scanning electron microscope (SEM) to identify the associated chemical and physical changes. The progressive changes in the range of chemical composition (from SEM), the extent of undissolved ash particles and porosity were then quantified and related to homogenisation, viscosity and ash fusion mechanisms. Alternate ash fusion temperatures based on different levels of shrinkage have also been suggested to characterise the ash deposition tendency of the coals. 13 refs., 9 figs.

  16. International Database of Volcanic Ash Impacts

    Science.gov (United States)

    Wallace, K.; Cameron, C.; Wilson, T. M.; Jenkins, S.; Brown, S.; Leonard, G.; Deligne, N.; Stewart, C.

    2015-12-01

    Volcanic ash creates extensive impacts to people and property, yet we lack a global ash impacts catalog to organize, distribute, and archive this important information. Critical impact information is often stored in ephemeral news articles or other isolated resources, which cannot be queried or located easily. A global ash impacts database would improve 1) warning messages, 2) public and lifeline emergency preparation, and 3) eruption response and recovery. Ashfall can have varying consequences, such as disabling critical lifeline infrastructure (e.g. electrical generation and transmission, water supplies, telecommunications, aircraft and airports) or merely creating limited and expensive inconvenience to local communities. Impacts to the aviation sector can be a far-reaching global issue. The international volcanic ash impacts community formed a committee to develop a database to catalog the impacts of volcanic ash. We identify three user populations for this database: 1) research teams, who would use the database to assist in systematic collection, recording, and storage of ash impact data, and to prioritize impact assessment trips and lab experiments 2) volcanic risk assessment scientists who rely on impact data for assessments (especially vulnerability/fragility assessments); a complete dataset would have utility for global, regional, national and local scale risk assessments, and 3) citizen science volcanic hazard reporting. Publication of an international ash impacts database will encourage standardization and development of best practices for collecting and reporting impact information. Data entered will be highly categorized, searchable, and open source. Systematic cataloging of impact data will allow users to query the data and extract valuable information to aid in the development of improved emergency preparedness, response and recovery measures.

  17. Growth of a Pine Tree

    Science.gov (United States)

    Rollinson, Susan Wells

    2012-01-01

    The growth of a pine tree is examined by preparing "tree cookies" (cross-sectional disks) between whorls of branches. The use of Christmas trees allows the tree cookies to be obtained with inexpensive, commonly available tools. Students use the tree cookies to investigate the annual growth of the tree and how it corresponds to the number of whorls…

  18. Growth of a Pine Tree

    Science.gov (United States)

    Rollinson, Susan Wells

    2012-01-01

    The growth of a pine tree is examined by preparing "tree cookies" (cross-sectional disks) between whorls of branches. The use of Christmas trees allows the tree cookies to be obtained with inexpensive, commonly available tools. Students use the tree cookies to investigate the annual growth of the tree and how it corresponds to the number of whorls…

  19. Early detection of emerald ash borer infestation using multisourced data: a case study in the town of Oakville, Ontario, Canada

    Science.gov (United States)

    Zhang, Kongwen; Hu, Baoxin; Robinson, Justin

    2014-01-01

    The emerald ash borer (EAB) poses a significant economic and environmental threat to ash trees in southern Ontario, Canada, and the northern states of the USA. It is critical that effective technologies are urgently developed to detect, monitor, and control the spread of EAB. This paper presents a methodology using multisourced data to predict potential infestations of EAB in the town of Oakville, Ontario, Canada. The information combined in this study includes remotely sensed data, such as high spatial resolution aerial imagery, commercial ground and airborne hyperspectral data, and Google Earth imagery, in addition to nonremotely sensed data, such as archived paper maps and documents. This wide range of data provides extensive information that can be used for early detection of EAB, yet their effective employment and use remain a significant challenge. A prediction function was developed to estimate the EAB infestation states of individual ash trees using three major attributes: leaf chlorophyll content, tree crown spatial pattern, and prior knowledge. Comparison between these predicted values and a ground-based survey demonstrated an overall accuracy of 62.5%, with 22.5% omission and 18.5% commission errors.

  20. Tree Species Identity Shapes Earthworm Communities

    Directory of Open Access Journals (Sweden)

    Stephanie Schelfhout

    2017-03-01

    Full Text Available Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden experiment, replicated six times over Denmark, six tree species were planted in blocks: sycamore maple (Acer pseudoplatanus, beech (Fagus sylvatica, ash (Fraxinus excelsior, Norway spruce (Picea abies, pedunculate oak (Quercus robur and lime (Tilia cordata. We studied the chemical characteristics of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer and Tilia, which is related to calcium-rich litter and low soil acidification. Epigeic earthworms were indifferent to calcium content in leaf litter and were shown to be mainly related to soil moisture content and litter C:P ratios. Almost no earthworms were found in Picea stands, likely because of the combined effects of recalcitrant litter, low pH and low soil moisture content.

  1. Programming macro tree transducers

    DEFF Research Database (Denmark)

    Bahr, Patrick; Day, Laurence E.

    2013-01-01

    A tree transducer is a set of mutually recursive functions transforming an input tree into an output tree. Macro tree transducers extend this recursion scheme by allowing each function to be defined in terms of an arbitrary number of accumulation parameters. In this paper, we show how macro tree...... transducers can be concisely represented in Haskell, and demonstrate the benefits of utilising such an approach with a number of examples. In particular, tree transducers afford a modular programming style as they can be easily composed and manipulated. Our Haskell representation generalises the original...... definition of (macro) tree transducers, abolishing a restriction on finite state spaces. However, as we demonstrate, this generalisation does not affect compositionality....

  2. Programming macro tree transducers

    DEFF Research Database (Denmark)

    Bahr, Patrick; Day, Laurence E.

    2013-01-01

    A tree transducer is a set of mutually recursive functions transforming an input tree into an output tree. Macro tree transducers extend this recursion scheme by allowing each function to be defined in terms of an arbitrary number of accumulation parameters. In this paper, we show how macro tree...... transducers can be concisely represented in Haskell, and demonstrate the benefits of utilising such an approach with a number of examples. In particular, tree transducers afford a modular programming style as they can be easily composed and manipulated. Our Haskell representation generalises the original...... definition of (macro) tree transducers, abolishing a restriction on finite state spaces. However, as we demonstrate, this generalisation does not affect compositionality....

  3. Chemical characterization of ash from gasification of alfalfa stems: Implications for ash management

    Energy Technology Data Exchange (ETDEWEB)

    Mozaffari, M.; Rosen, C.J.; Russelle, M.P.; Nater, E.A.

    2000-06-01

    Electricity generation from biomass is an attractive option from an environmental perspective. Pilot studies have indicated that alfalfa (Medicago sativa L.) stems are suitable feedstock for energy generation via gasification. Detailed information on chemical characteristics of the ash generated from gasification of alfalfa stem is required to develop environmentally and economically sound ash management strategies. Alfalfa fly and bottom ashes were characterized with respect to chemical properties that are important in developing ash management practices with emphasis on beneficial utilization as a soil amendment. Mean concentrations of total C, K, Ca, and Cl were 424, 120, 85, and 26 g kg{sup {minus}1}, respectively, in fly ash. In bottom ash, the mean concentrations of C, K, and Ca, were 63, 61, and 193 g kg{sup {minus}1}. Concentrations of total Pb, As, Cd, Co, and Se were below detection limits in both ash types. Naphthalene ranged from 6.2 to 74 mg kg{sup {minus}1}, but concentrations of many other polyaromatic hydrocarbons were low or below mg kg{sup {minus}1} detection limits. Available K and P in fly ash were 90 to 120 and 8 to 10 g kg{sup {minus}1}, respectively. Mean CaCO{sub 3} equivalent value of fly ash was 400 g kg{sup {minus}1}, its electrical conductivity (EC) and pH were 127 dS m{sup {minus}1} and 11.5, respectively. These results suggest that when managed properly, gasified alfalfa ash could potentially be utilized as a beneficial soil amendment with few potential environmental concerns.

  4. Ash melting behavior by Fourier transform infrared spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LI Han-xu; QIU Xiao-sheng; TANG Yong-xin

    2008-01-01

    A Fourier Transform Infrared Spectroscopic (FTIR) method involving a Fe2O3 flux was used to learn how China's coal ash melts. The relationship between ash fusion temperature and chemical composition, as well as the effects of Fe2O3 flux on the ash fusion temperature were studied. The relationship between ash fusion temperature and chemical composition, mineralogical phases and functional groups was analyzed with the FTIR method. The results show that the ash fusion temperature is related to the location and transmittance of certain absorption peaks, which is of great significance for the study of ash behavior.

  5. Electrodialytic removal of Cd from biomass combustion fly ash

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

    2004-01-01

    Due to a high concentration of Cd, biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. In this work the potential of using the method Electrodialytic Remediation to reduce the concentration of Cd in different biomass combustion...... fly ashes was studied. Four fly ashes were investigated, originating from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. One of the straw ashes had been pre-washed and was obtained suspended in water, the other ashes were obtained naturally dry...

  6. Lipid peroxidation and oxidative status compared in workers at a bottom ash recovery plant and fly ash treatment plants.

    Science.gov (United States)

    Liu, Hung-Hsin; Shih, Tung-Sheng; Chen, I-Ju; Chen, Hsiu-Ling

    2008-01-01

    Fly ash and ambient emissions of municipal solid waste incinerators contain polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs), other organic compounds, metals, and gases. Hazardous substances such as PCDD/Fs, mercury vapors and other silicates, and the components of bottom ash and fly ash elevate the oxidative damage. We compared oxidative damage in workers exposed to hazardous substances at a bottom ash recovery plant and 3 fly ash treatment plants in Taiwan by measuring their levels of plasma malondialdehyde (MDA) and urine 8-hydroxydeoxyguanosine (8-OH-dG). Significantly higher MDA levels were found in fly ash treatment plant workers (3.20 microM) than in bottom ash plant workers (0.58 microM). There was a significant association between MDA levels in workers and their working environment, especially in the fly ash treatment plants. Levels of 8-OH-dG varied more widely in bottom ash workers than in fly ash workers. The association between occupational exposure and 8-OH-dG levels may be affected by the life style of the workers. Because more dioxins and metals may leach from fly ash than from bottom ash, fly ash treatment plant workers should, as much as possible, avoid exposing themselves to fly ash.

  7. Effects of the addition of oil shale ash and coal ash on physic-chemical properties of CPJ45 cement

    Directory of Open Access Journals (Sweden)

    Nabih K.

    2014-04-01

    Full Text Available We focused our research on recycling industrial wastes, fly ash (F.A, bottom ash (B.A and oil shale ash (S.A in cement production. The study concerns physico-chemical characterization of these products and the influence of their addition on the mechanical proprieties of the CPJ45 cement. XRF allowed us to rank the three additives used according to their contents on major oxides. Coal ashes belong to the class F, and thus possess poozzolanic properties and oil shale ash belongs to the class C and possesses hydraulic and poozolanic properties. The crystalline phases constituting each ash were analysed by XRD. We observe in bottom ash the presence of quartz and mullite. The same crystals are found in fly ash with hematite and magnetite. Oil shale ash is composed of quartz, anhydrite, gehlenite, wollastonite and periclase. The microstructures of fly ash and bottom ash were studied using SEM. The bottom ash was composed respectively of fine particles that are generally irregularly shaped, their dimensions are between 5 and 28μm and of big particles(300 μm. The EDX analysis coupled with an electronic microscope provided some information about the major elements that constitute our samples. The dehydrations of anhydrous and three days hydrated cement were examined by DSC. For hydrated cements we noticed endothermic peaks related to the dehydration of CSH, CH and decomposition of carbonates. The study of the mechanical properties of CPJ45 cement by adding different proportions of fly ash, bottom ash and oil shale ash helped clarifying the percentage of ash that leaded to improve the 28 days mechanical strength. The results show that the cements studied have their maximum mechanical resistance with the addition at 7% of fly ash or 10% of oil shale ash.

  8. Summer is the best time to thin hybrid poplar plantations

    Science.gov (United States)

    Harold F. Ford; Albert G., Jr. Snow

    1954-01-01

    Hybrid poplar plantations are established by planting dormant cuttings in close spacing, usually 4 x 4 feet. They are cultivated during the first growing season to eliminate competition from grasses and weeds. After the first year, the more vigorous trees effectively shade out lower vegetation. But rapid tree growth often makes thinning necessary after 2 or 3 growing...

  9. Characteristics of MSWI fly ash during vitrification

    Institute of Scientific and Technical Information of China (English)

    TIAN Shu-lei; WANG Qi; WANG Qun-hui; MA Hong-zhi

    2009-01-01

    The vitrification characteristics of municipal solid waste incinerator (MSWI) fly ash were investigated. Effects of temperature on the binding efficiency of heavy metals, the change of chemical compositions and the weight loss of fly ash in the range of 800 - 1350 ℃ were studied. Toxicity Characteristic Leaching Procedure (TCLP) of the United States was used to analyze the leaching characteristics of heavy metals in fly ash and molten slag. Results indicate that chemical compositions, the weight loss of fly ash and the binding efficiency of heavy metals in fly ash have a tremendous change in the range of 1150 - 1260 ℃. The percentage of CaO, SiO2and AI203 increases with the increasing temperature, whereas it is contrary for SO3 , K2O, Na20 and CI; especially when the temperature is 1260 ℃, the percentage of these four elements decreases sharply from 43.72%to 0. 71%. The weight loss occurs obviously in the range of 1150 - 1260 ℃. Heavy metals of Pb and Cd are almost vaporized above 1000 ℃. Cr is not volatile and its binding efficiency can reach 100% below 1000 ℃. Resuits of TCLP indicate that the heavy metal content of molten slag is beyond stipulated limit values.

  10. Manufacturing of aluminium nano hybrid composites: a state of review

    Science.gov (United States)

    Madhukar, P.; Selvaraj, N.; Rao, CSP

    2016-09-01

    This paper gives the details of hybrid composites, their fabrication methods and evaluation of mechanical, tribological behaviour and machining characteristics. Investigations on the various aspects of Hybrid composites furnish several conclusions regarding the influence of various parameters on the performance of the composites. Mostly micro structures of the hybrid composites fabricated through casting routes have been found to be stable with the distribution of uniformed reinforce particles. therefore, the hybrid composites can be constructed with various combinations of reinforcements to carry out desirable mechanical properties. The density of Hybrid composites increases with increasing reinforcements such as SiC, TiC, B4C....etc, while incorporation of partial reinforcements like fly ash, mica, rice husk, etc. reduces the density of composites. The study also reports that the hybrid composites can be treated as a replacement for regular composite materials in different advanced applications.

  11. Regular Recycling of Wood Ash to Prevent Waste Production (RecAsh). Technical Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Lars E-mail: lars.t.andersson@skogsstyreslen.se

    2007-03-15

    At present, the extraction of harvest residues is predicted to increase in Sweden and Finland. As an effect of the intensified harvesting, the export of nutrients and acid buffering substances from the growth site is also increased. Wood ash could be used to compensate forest soils for such losses. Most wood fuel ash is today often deposited in landfills. If the wood ash is recycled, wood energy is produced without any significant waste production. Ash recycling would therefore contribute to decreasing the production of waste, and to maintaining the chemical quality of forest waters and biological productivity of forest soils in the long term. The project has developed, analysed and demonstrated two regular ash-recycling systems. It has also distributed knowledge gathered about motives for ash recycling as well as technical and administrative solutions through a range of media (handbooks, workshops, field demonstrations, reports, web page and information videos). Hopefully, the project will contribute to decreasing waste problems related to bio-energy production in the EU at large. The project has been organised as a separate structure at the beneficiary and divided in four geographically defined subprojects, one in Finland and three in Sweden (Central Sweden, Northern Sweden, and South-western Sweden). The work in each subproject has been lead by a subproject leader. Each subproject has organised a regional reference group. A project steering committee has been established consisting of senior officials from all concerned partners. The project had nine main tasks with the following main expected deliverables and output: 1. Development of two complete full-scale ash-recycling systems; 2. Production of handbooks of the ash recycling system; 3. Ash classification study to support national actions for recommendations; 4. Organise regional demonstrations of various technical options for ash treatment and spreading; 5. Organise national seminars and demonstrations of

  12. Thermal treatment of ashes[Fly Ash from Municipal Waste Incineration]; Termisk rening av askor

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, Karin; Berg, Magnus; Bjurstroem, Henrik [AaF-Energi och Miljoe AB, Stockholm (Sweden); Nordin, Anders [Umeaa Univ. (Sweden). Dept. of Applied Physics and Electronics

    2003-04-01

    In this project descriptions of different processes for thermal treatment of ashes have been compiled. A technical and economic evaluation of the processes has been done to identify possibilities and problems. The focus in the project lays on treatment of fly ash from municipal waste incineration but the processes can also be used to treat other ashes. When the ash is heated in the thermal treatment reactor, with or without additives, the material is sintered or vitrified and at the same time volatile substances (Zn, Pb, Cd, Hg etc.) are separated. In general the separation is more effective in processes with reducing conditions compared to oxidizing conditions. Oxidizing processes have both worse separation capacity and require more energy. The oxidizing processes are mainly used to stabilize the ash through vitrification and they are in some cases developed for management of municipal sewage sludge and bottom ash. However, these processes are often not as complex as for example an electric arc melting furnace with reducing conditions. The research today aim to develop more effective electrical melting systems with reducing conditions such as plasma melting furnaces, electric resistance melting furnaces and low frequency induction furnaces. A central question in the evaluation of different thermal treatment processes for ash is how the residues from the treatment can be used. It is not certain that the vitrified material is stable enough to get a high economic value, but it can probably be used as construction material. How the remaining metals in the ash are bound is very important in a long-time perspective. Further studies with leaching tests are necessary to clarify this issue. The heavy metal concentrate from the processes contains impurities, such as chlorine, which makes it unprofitable to obtain the metals. Instead the heavy metal concentrate has to be land filled. However, the amount of material for land filling will be much smaller if only the heavy

  13. Preimaginal stages of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae: an invasive pest on ash trees (Fraxinus.

    Directory of Open Access Journals (Sweden)

    M Lourdes Chamorro

    Full Text Available This study provides the most detailed description of the immature stages of Agrilus planipennis Fairmaire to date and illustrates suites of larval characters useful in distinguishing among Agrilus Curtis species and instars. Immature stages of eight species of Agrilus were examined and imaged using light and scanning electron microscopy. For A. planipennis all preimaginal stages (egg, instars I-IV, prepupa and pupa were described. A combination of 14 character states were identified that serve to identify larvae of A. planipennis. Our results support the segregation of Agrilus larvae into two informal assemblages based on characters of the mouthparts, prothorax, and abdomen: the A. viridis and A. ater assemblages, with A. planipennis being more similar to the former. Additional evidence is provided in favor of excluding A. planipennis from the subgenus Uragrilus.

  14. Pattern Avoidance in Ternary Trees

    CERN Document Server

    Gabriel, Nathan; Pudwell, Lara; Tay, Samuel

    2011-01-01

    This paper considers the enumeration of ternary trees (i.e. rooted ordered trees in which each vertex has 0 or 3 children) avoiding a contiguous ternary tree pattern. We begin by finding recurrence relations for several simple tree patterns; then, for more complex trees, we compute generating functions by extending a known algorithm for pattern-avoiding binary trees. Next, we present an alternate one-dimensional notation for trees which we use to find bijections that explain why certain pairs of tree patterns yield the same avoidance generating function. Finally, we compare our bijections to known "replacement rules" for binary trees and generalize these bijections to a larger class of trees.

  15. Coal fly ash effluent affects the distributions of Brachionus calyciflorus sibling species.

    Science.gov (United States)

    Zhang, Gen; Xi, Yi-Long; Xue, Ying-Hao; Xiang, Xian-Ling; Wen, Xin-Li

    2015-02-01

    Fly ash, a coal combustion residue of thermal power plants and a source of multiple pollutants, has been recognized as an environmental hazard all over the world. Although it is known that fly ash effluent affects density, diversity and distribution of rotifers in drainage systems and receiving water bodies, the effect of fly ash effluent on the distributions of highly similar rotifer species remains unknown. In this study, the mtDNA COI genes of 90 individuals in Brachionus calyciflorus complex from Lake Hui (as a fly ash discharge water pond) and other two neighboring lakes (Lake Fengming and Lake Tingtang) were sequenced and analyzed, and the responses in selected life table demographic parameters (life expectancy at hatching, net reproductive rate, intrinsic rate of population increase and proportion of sexual offspring) of different rotifer populations to fly ash effluent were investigated. Overall, 72 mtDNA haplotypes were defined, and were split into two clades by the phylogenetic trees. The divergence of COI gene sequences between the two clades ranged from 11.8% to17.8%, indicating the occurrence of two sibling species (sibling species I and sibling species II). Sibling species I distributed in all the three lakes, showing strong capabilities for dispersal and colonization, which were supported by its higher level of gene flow (2.60-4.04) between the populations from Lake Hui and each of the other two lakes, longer life expectancy at hatching (101.6-148.2 h), and higher net reproductive rate (4.4-16.4 offspring/female) and intrinsic rate of population increase (0.60-0.98/d) when cultured in aerated tap water and fly ash effluent. Sibling species II distributed in both Lake Tingtang and Lake Fengming, showing that its dispersal existed between the two lakes. Considering that the distance between Lake Hui and Lake Fengming is shorter than that between Lake Tingtang and Lake Fengming, sibling species II is able to disperse at least from Lake Fengming to Lake

  16. Correlation between the critical viscosity and ash fusion temperatures of coal gasifier ashes

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Peter Y. [National Energy Technology Lab. (NETL), Albany, OR (United States); Kwong, Kyei-Sing [National Energy Technology Lab. (NETL), Albany, OR (United States); Bennett, James [National Energy Technology Lab. (NETL), Albany, OR (United States)

    2015-09-27

    Coal gasification yields synthesis gas, an important intermediate in chemical manufacturing. It is also vital to the production of liquid fuels through the Fischer-Tropsch process and electricity in Integrated Gasification Combined Cycle power generation. Minerals naturally present in coal become molten in entrained-flow slagging gasifiers. Molten coal ash slag penetrates and dissolves refractory bricks, leading to costly plant shutdowns. The extent of coal ash slag penetration and refractory brick dissolution depends on the slag viscosity, the gasification temperature, and the composition of slag and bricks. Here, we measured the viscosity of several synthetic coal ash slags with a high-temperature rotary viscometer and their ash fusion temperatures through optical image analysis. We made all measurements in a carbon monoxide-carbon dioxide reducing atmosphere that approximates coal gasification conditions. Empirical correlation models based on ash fusion temperatures were used to calculate critical viscosity temperatures based on the coal ash compositions. These values were then compared with those obtained from thermodynamic phase-transition models. Finally, an understanding of slag viscosity as a function of ash composition is important to reducing refractory wear in slagging coal gasifiers, which would help to reduce the cost and environmental impact of coal for chemical and electricity production.

  17. Effects of Wood Ash on Soil Fungi

    DEFF Research Database (Denmark)

    Cruz Paredes, Carla

    in agricultural and forest soils focusing on soil microbial communities’ composition and function, particularly mycorrhizal fungi. Two study sites were used for this study, one in an agricultural field where different biomass ashes were evaluated as replacements for P fertilizers in barley, and a second one...... in a Norway spruce forest where different amounts of wood ash were spread on the soil to study the effects on ectomycorrhizal (ECM) fungi, bioaccumulation of metals in sporocarps, and microbial communities. Laboratory microcosm experiments were run in parallel to the field studies, to compare the effects...... effects on barley or associated AM fungi. Furthermore, wood ash can also be re-distributed to the forest without representing any risks for ECM fungal communities, N leaching, Cd bioaccumulation in sporocarps or the general activity of the soil microbial community....

  18. Laboratory study of volcanic ash electrification

    Science.gov (United States)

    Alois, Stefano; Merrison, Jonathan

    2016-04-01

    Electrostatic forces play an important role in the dynamics of volcanic plumes, for example in ash dispersion and aggregation phenomena. Field measurements of ash electrification are often technically challenging due to poor access and there lacks an accepted physical theory to describe the electrical charge exchange which occurs during particle contact. The goal of the study is to investigate single particle electrification under controlled conditions using advanced laboratory facilities. A novel technique is presented, based on the use of a laser based velocimeter. Here an electric field is applied and the field-induced drift velocity of (micron-sized) ash grains is measured as well as the particles fall velocity. This allows the simultaneous determination of a suspended grains size and electrical charge. The experiments are performed in a unique environmental wind tunnel facility under controlled low-pressure conditions. Preliminary results of particle electrification will be presented.

  19. Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer.

    Science.gov (United States)

    Chindaprasirt, Prinya; Rattanasak, Ubolluk

    2010-04-01

    In this paper, synthesis of geopolymer from fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash was studied in order to effectively utilize both ashes. FBC-fly ash and bottom ash were inter-ground to three different finenesses. The ashes were mixed with as-received PCC-fly ash in various proportions and used as source material for synthesis of geopolymer. Sodium silicate (Na(2)SiO(3)) and 10M sodium hydroxide (NaOH) solutions at mass ratio of Na(2)SiO(3)/NaOH of 1.5 and curing temperature of 65 degrees C for 48h were used for making geopolymer. X-ray diffraction (XRD), scanning electron microscopy (SEM), degree of reaction, and thermal gravimetric analysis (TGA) were performed on the geopolymer pastes. Compressive strength was also tested on geopolymer mortars. The results show that high strength geopolymer mortars of 35.0-44.0MPa can be produced using mixture of ground FBC ash and as-received PCC-fly ash. Fine FBC ash is more reactive and results in higher degree of reaction and higher strength geopolymer as compared to the use of coarser FBC ash. Grinding increases reactivity of ash by means of increasing surface area and the amount of reactive phase of the ash. In addition, the packing effect due to fine particles also contributed to increase in strength of geopolymers.

  20. Fusion characteristics of volcanic ash relevant to aviation hazards

    Science.gov (United States)

    Song, Wenjia; Hess, Kai-Uwe; Damby, David E.; Wadsworth, Fabian B.; Lavallée, Yan; Cimarelli, Corrado; Dingwell, Donald B.

    2014-04-01

    The fusion dynamics of volcanic ash strongly impacts deposition in hot parts of jet engines. In this study, we investigate the sintering behavior of volcanic ash using natural ash of intermediate composition, erupted in 2012 at Santiaguito Volcano, Guatemala. A material science procedure was followed in which we monitored the geometrical evolution of cylindrical-shaped volcanic ash compact upon heating from 50 to 1400°C in a heating microscope. Combined morphological, mineralogical, and rheological analyses helped define the evolution of volcanic ash during fusion and sintering and constrain their sticking potential as well as their ability to flow at characteristic temperatures. For the ash investigated, 1240°C marks the onset of adhesion and flowability. The much higher fusibility of ash compared to that of typical test sands demonstrates for the need of a more extensive fusion characterization of volcanic ash in order to mitigate the risk posed on jet engine operation.

  1. Eco-friendly fly ash utilization: potential for land application

    Energy Technology Data Exchange (ETDEWEB)

    Malik, A.; Thapliyal, A. [Indian Institute of Technology Delhi, New Delhi (India)

    2009-07-01

    The increase in demand for power in domestic, agricultural, and industrial sectors has increased the pressure on coal combustion and aggravated the problem of fly ash generation/disposal. Consequently the research targeting effective utilization of fly ash has also gained momentum. Fly ash has proved to be an economical substitute for expensive adsorbents as well as a suitable raw material for brick manufacturing, zeolite synthesis, etc. Fly ash is a reservoir of essential minerals but is deficient in nitrogen and phosphorus. By amending fly ash with soil and/or various organic materials (sewage sludge, bioprocess materials) as well as microbial inoculants like mycorrhizae, enhanced plant growth can be realized. Based on the sound results of large scale studies, fly ash utilization has grown into prominent discipline supported by various internationally renowned organizations. This paper reviews attempts directed toward various utilization of fly ash, with an emphasis on land application of organic/microbial inoculants amended fly ash.

  2. Bayesian Rose Trees

    CERN Document Server

    Blundell, Charles; Heller, Katherine A

    2012-01-01

    Hierarchical structure is ubiquitous in data across many domains. There are many hier- archical clustering methods, frequently used by domain experts, which strive to discover this structure. However, most of these meth- ods limit discoverable hierarchies to those with binary branching structure. This lim- itation, while computationally convenient, is often undesirable. In this paper we ex- plore a Bayesian hierarchical clustering algo- rithm that can produce trees with arbitrary branching structure at each node, known as rose trees. We interpret these trees as mixtures over partitions of a data set, and use a computationally efficient, greedy ag- glomerative algorithm to find the rose trees which have high marginal likelihood given the data. Lastly, we perform experiments which demonstrate that rose trees are better models of data than the typical binary trees returned by other hierarchical clustering algorithms.

  3. Cleaner phosphogypsum, coal combustion ashes and waste incineration ashes for application in building materials: A review

    Energy Technology Data Exchange (ETDEWEB)

    L. Reijnders [University of Amsterdam, Amsterdam (Netherlands)

    2007-02-15

    Application of phosphogypsum, coal combustion ashes and waste incineration ashes in building materials has been limited by the presence of minor components that are hazardous, such as radioactive substances, chlorinated dioxins and heavy metals, or have a negative impact on product quality or production economics, such as phosphate, fluoride, carbon and chloride. Source reduction, destruction of persistent organics and separation techniques may reduce the concentrations of such components. With a few exceptions, separation techniques currently lead to significantly higher (private) costs. Higher waste disposal costs, tighter regulations and higher prices for competing virgin minerals could make the use of the purified phosphogypsum and ashes in building materials more attractive.

  4. Utilization options for fly ash, bottom ash, and slag in Eastern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Manz, O.E.

    1995-12-01

    Since 1967, at least six ash utilization symposiums have been held in the United States, with papers presented by several European authors on the utilization of coal by-products in Eastern Europe. There is currently over 80,000 megawatts of installed coal-fired capacity available in that region. Unfortunately, of the 117,778,000 tonnes of fly ash, bottom ash, and slag produced in Eastern Europe in 1989, only 13% was utilized. This paper outlines the research and levels and kinds of coal by-product utilization taking place in Eastern Europe since the late 1960s.

  5. Ash fusion temperatures and the transformations of coal ash particles to slag

    Energy Technology Data Exchange (ETDEWEB)

    Wall, T.F.; Creelman, R.A.; Gupta, R.; Gupta, S. [Univ. of Newcastle (Australia)

    1996-10-01

    A mechanistic study is detailed in which coal ash is heated with the shrinkage and electrical resistance measured continuously up to a temperature of 1600{degrees}C. The temperatures corresponding to rapid rates of shrinkage are shown to correspond to the formation of eutectics identified on phase diagrams. Samples where therefore heated to these temperatures, cooled rapidly and examined with an SEM to identify the associated chemical and physical changes. The progressive changes in the range of chemical analysis (from SEM), the extent of undissolved ash particles and porosity are then quantified and related to the shrinkage events and standard ash fusion temperatures.

  6. Ash fusion temperatures and the transformations of coal ash particles to slag

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S.; Wall, T.F.; Creelman, R.A.; Gupta, R. [Univ. of Newcastle, Callaghan (Australia)

    1996-12-31

    A mechanistic study is detailed in which coal ash is heated with its shrinkage measured continuously up to a temperature of 1600{degrees}C. The temperatures corresponding to the rapid rate of shrinkage are shown to correspond to the formation of eutectics identified on phase diagrams. Samples were therefore heated to these temperatures, cooled rapidly and examined with an SEM to identify the associated chemical and physical changes. The progressive changes in the range of chemical analysis (from SEM), the extent of undissolved ash particles and porosity were then quantified and related to homogenization, viscosity and ash fusion mechanisms.

  7. Changeing of fly ash leachability after grinding

    Science.gov (United States)

    Lakatos, J.; Szabo, R.; Racz, A.; Banhidi, O.; Mucsi, G.

    2016-04-01

    Effect of grinding on the reactivity of fly ash used for geopolymer production was tested. Extraction technique using different alkaline and acidic solutions were used for detect the change of the solubility of elements due to the physical and mechano-chemical transformation of minerals in function of grinding time. Both the extraction with alkaline and acidic solution have detected improvement in solubility in function of grinding time. The enhancement in alkaline solution was approx. 100% in case of Si and Al. The acidic medium able to dissolve the fly ash higher manner than the alkaline, therefore the effect of grinding was found less pronounced.

  8. Physical cleaning of high carbon fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Gray, McMahan L.; Champagne, Kenneth J.; Soong, Yee; Killmeyer, Richard P. [National Energy Technology Laboratory, US Department of Energy, P.O. Box 10940, Cochran Mills Roads, 15236 Pittsburgh, PA (United States); Maroto-Valer, M. Mercedes; Andresen, John M. [The Energy Institute, The Pennsylvania State University, 405 Academic Activities Building, 16802-2308 University Park, PA (United States); Ciocco, Michael V.; Zandhuis, Paul H. [Parson Project Services Inc, National Energy Technology Laboratory, P.O. Box 618, 15129 Library, Pittsburgh, PA (United States)

    2002-04-20

    An industrial fly ash sample was cleaned by three different processes, which were triboelectrostatic separation, ultrasonic column agglomeration, and column flotation. The unburned carbon concentrates were collected at purities ranging up to 62% at recoveries of 62%. In addition, optical microscopy studies were conducted on the final carbon concentrates to determine the carbon forms (inertinite, isotropic coke and anisotropic coke) collected from these various physical-cleaning processes. The effects of the various cleaning processes on the production of different carbon forms from high carbon fly ashes will be discussed.

  9. The valuative tree

    CERN Document Server

    Favre, Charles

    2004-01-01

    This volume is devoted to a beautiful object, called the valuative tree and designed as a powerful tool for the study of singularities in two complex dimensions. Its intricate yet manageable structure can be analyzed by both algebraic and geometric means. Many types of singularities, including those of curves, ideals, and plurisubharmonic functions, can be encoded in terms of positive measures on the valuative tree. The construction of these measures uses a natural tree Laplace operator of independent interest.

  10. Associative properties of {sup 137}Cs in biofuel ashes

    Energy Technology Data Exchange (ETDEWEB)

    Ravila, A.; Holm, E. [Lund Univ. (Sweden). Dept. of Radiation Physics

    1999-07-01

    The present study aims to reveal how radiocesium is associated to the ash particles derived from biofuel combustion. A sequential extraction procedure was carried out for the characterisation of radiocesium speciation in ash generated by different fuels and burner types. The ash types considered were fly ash and bottom ash collected from Swedish district heating plants using bark wood or peat as fuel. A fraction of the radiocesium in biofuel ash can easily become solubilised and mobilised by water and also, a significant fraction of the radionuclides can be bound to the ash particles in cation-exchangeable forms. Therefore, at using the ash derived from biofuels to recycle mineral nutrients for forestry or short rotation coppicing, radiocesium solubilised and leached from the ash by rains has a potential to rather quickly enter the rooting zone of forest vegetation or energy crops. On the other hand, radiocesium strongly bound to the ash will migrate slowly into the soil column with the successive accumulation of litter and in the process act to maintain the external dose rate at an elevated level for a long time. The results of the sequential extraction procedure and activity determination of the different extracted fractions implies that the bioavailable fraction of radiocesium in ash from bark, wood or peat is in the range between 20-85% of the total ash contents. Peat ash collected from a powder burner strongly retained a large fraction (70-90%) of its radiocesium content while the peat ash from a continuos fluidized bed type burner retained nearly 100% of the radiocesium in the bottom ash and only about 15% in the fly ash.

  11. A theory of game trees, based on solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie); A. Plaat (Aske)

    1996-01-01

    textabstractIn this paper a complete theory of game tree algorithms is presented, entirely based upon the notion of a solution tree. Two types of solution trees are distinguished: max and min solution trees respectively. We show that most game tree algorithms construct a superposition of a max and a

  12. A theory of game trees, based on solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie); A. Plaat (Aske)

    1996-01-01

    textabstractIn this paper a complete theory of game tree algorithms is presented, entirely based upon the notion of a solution tree. Two types of solution trees are distinguished: max and min solution trees respectively. We show that most game tree algorithms construct a superposition of a max and a

  13. D2-tree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Sioutas, Spyros; Pantazos, Kostas;

    2015-01-01

    We present a new overlay, called the Deterministic Decentralized tree (D2-tree). The D2-tree compares favorably to other overlays for the following reasons: (a) it provides matching and better complexities, which are deterministic for the supported operations; (b) the management of nodes (peers......-balancing scheme of elements into nodes is deterministic and general enough to be applied to other hierarchical tree-based overlays. This load-balancing mechanism is based on an innovative lazy weight-balancing mechanism, which is interesting in its own right....

  14. Symmetric M-tree

    CERN Document Server

    Sexton, Alan P

    2010-01-01

    The M-tree is a paged, dynamically balanced metric access method that responds gracefully to the insertion of new objects. To date, no algorithm has been published for the corresponding Delete operation. We believe this to be non-trivial because of the design of the M-tree's Insert algorithm. We propose a modification to Insert that overcomes this problem and give the corresponding Delete algorithm. The performance of the tree is comparable to the M-tree and offers additional benefits in terms of supported operations, which we briefly discuss.

  15. A parallel buffer tree

    DEFF Research Database (Denmark)

    Sitchinava, Nodar; Zeh, Norbert

    2012-01-01

    We present the parallel buffer tree, a parallel external memory (PEM) data structure for batched search problems. This data structure is a non-trivial extension of Arge's sequential buffer tree to a private-cache multiprocessor environment and reduces the number of I/O operations by the number...... of available processor cores compared to its sequential counterpart, thereby taking full advantage of multicore parallelism. The parallel buffer tree is a search tree data structure that supports the batched parallel processing of a sequence of N insertions, deletions, membership queries, and range queries...

  16. Hybridization and endangered species protection in the molecular era.

    Science.gov (United States)

    Wayne, Robert K; Shaffer, H Bradley

    2016-06-01

    After decades of discussion, there is little consensus on the extent to which hybrids between endangered and nonendangered species should be protected by US law. As increasingly larger, genome-scale data sets are developed, we can identify individuals and populations with even trace levels of genetic admixture, making the 'hybrid problem' all the more difficult. We developed a decision-tree framework for evaluating hybrid protection, including both the processes that produced hybrids (human-mediated or natural) and the ecological impact of hybrids on natural ecosystems. We then evaluated our decision tree for four case studies drawn from our own work and briefly discuss several other cases from the literature. Throughout, we highlight the management outcomes that our approach provides and the nuances of hybridization as a conservation problem.

  17. Ash Deposition Trials at Three Power Stations in Denmark

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming; Larsen, Ole Hede

    1998-01-01

    the probe temperature did influence the composition of deposits for coals with medium ash deposition propensities. These results may indicate that coals with medium to high ash deposition propensities in existing boilers may cause increasing ash deposit formation in future boilers with higher steam...

  18. Ashes from fluidized bed combustion of residual forest biomass

    NARCIS (Netherlands)

    Cruz, Nuno C.; Rodrigues, Sónia M.; Carvalho, Lina; Duarte, Armando C.; Pereira, Eduarda; Romkens, Paul; Tarelho, Luís A.C.

    2017-01-01

    Although bottom ash (BA) [or mixtures of bottom and fly ash (FA)] from clean biomass fuels is currently used as liming agent, additive for compost, and fertilizer on agricultural and forest soils in certain European countries, in several other countries most of the ashes are currently disposed in la

  19. Oil ash corrosion; A review of utility boiler experience

    Energy Technology Data Exchange (ETDEWEB)

    Paul, L.D. (Babcock and Wilcox Co., Alliance, OH (United States)); Seeley, R.R. (Babcock and Wilcox Canada Ltd., Cambridge, ON (Canada))

    1991-02-01

    In this paper a review of experience with oil ash corrosion is presented along with current design practices used to avoid excessive tube wastage. Factors influencing oil ash corrosion include fuel chemistry, boiler operation, and boiler design. These factors are interdependent and determine the corrosion behavior in utility boilers. Oil ash corrosion occurs when vanadium-containing ash deposits on boiler tube surfaces become molten. These molten ash deposits dissolve protective oxides and scales causing accelerated tube wastage. Vanadium is the major fuel constituent responsible for oil ash corrosion. Vanadium reacts with sodium, sulfur, and chlorine during combustion to produce lower melting temperature ash compositions, which accelerate tube wastage. Limiting tube metal temperatures will prevent ash deposits from becoming molten, thereby avoiding the onset of oil ash corrosion. Tube metal temperatures are limited by the use of a parallel stream flow and by limiting steam outlet temperatures. Operating a boiler with low excess air has helped avoid oil ash corrosion by altering the corrosive combustion products. Air mixing and distribution are essential to the success of this palliative action. High chromium alloys and coatings form more stable protective scaled on tubing surfaces, which result in lower oil ash corrosion rates. However, there is not material totally resistant to oil ash corrosion.

  20. The Rheology of Vegetative Ash-laden Debris Flows

    Science.gov (United States)

    Burns, K. A.; Gabet, E.

    2006-12-01

    There is mounting observational evidence that vegetative ash created in a forest fire may play a major role in reducing infiltration and leads to the generation of debris flows on these burned hillslopes. A viscometer was used to measure the viscosity of ash slurries of varying concentrations, as well as slurries containing both fine- grained clastic sediment (sand and silt sized) and vegetative ash at varying concentrations. Initial results from these experiments indicate that increasing the concentration of ash increases effective viscosity of the slurry. Increasing the ash concentration by 5% increases the effective viscosity of the slurry by 10-50% over a range of shear rates. Also, ash-only slurries appear to shear thin with increasing shear rate at all concentrations. For example, with a 60% ash concentration, increasing the shear rate from 5/s to 40/s reduces the effective viscosity by 90%. For the mixed ash and fine-grained sediment slurries, increasing the percentage of ash relative to the percentage of clastic sediment dramatically increases the viscosity of the slurry even though the ash and finest-grained sediment are approximately the same size. A 50% concentration slurry containing only silt-sized clastic particles has a 40-70% lower effective viscosity than a slurry of the same concentration containing only ash particles. Therefore, the ash particles behave differently than clastic sediment particles.

  1. 77 FR 55895 - Permanent Closure of Cincinnati Blue Ash Airport

    Science.gov (United States)

    2012-09-11

    ... Federal Aviation Administration Permanent Closure of Cincinnati Blue Ash Airport AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of permanent closure of Cincinnati Blue Ash Airport (ISZ). SUMMARY: The... Cincinnati advising that on August 29, 2012, it was permanently closing Cincinnati Blue Ash Airport...

  2. Observation of Eyjafjallajökull volcano ash over Poland

    Science.gov (United States)

    Zielinski, T.; Petelski, T.; Makuch, P.; Kowalczyk, J.; Rozwadowska, A.; Drozdowska, V.; Markowicz, K.; Malinowski, S.; Kardas, A.; Posyniak, M.; Jagodnicka, A. K.; Stacewicz, T.; Piskozub, J.

    2010-05-01

    The plume of Eyjafjallajökull volcano ash has been identified over Poland using three instruments (two lidars and a ceilometer) stationed in two locations: Sopot in northern Poland and Warsaw in central-eastern Poland. The observations made it possible to establish the base of the ash layer. However ash concentration could not be determined.

  3. Use of Unprocessed Coal Bottom Ash as Partial Fine Aggregate ...

    African Journals Online (AJOL)

    2012r

    Bottom ash, the solid residue from electric power ... consumption and greenhouse gas emissions (GHG). In addition, it helps ... economic sense; they are often less costly than the materials they replace. (American Coal Ash ... and Kim and Lee (2011), observed a decrease in density due to the low specific gravity of the ash.

  4. Product policies. characterization results ash by burning layer fluid

    OpenAIRE

    Neamtu, Ion; Achim, Marian Lucian

    2009-01-01

    By economical and at the same time ecological reasons, industrial refuses (ashes) are being transported in waste dumps like offal’s .To reduce the storage surfaces these offal’s are incinerated and results a new refuse - the ash.(Ex. paper factories, thermo power stations).It's very important to find solutions to turn to good account the ash.

  5. Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

    Science.gov (United States)

    Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

    2011-12-01

    By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

  6. Bio-restoration of wastelands/abandoned ash ponds/OB dumps in the vicinity of TPPS/coalfields on sustainable basis

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, N.K.; Tripathi, R.C.; Ram, L.C. (and others) [Central Fuel Research Institute, Dhanbad (India)

    2003-07-01

    Realizing the imperative need for the gainful utilisation of huge quantities of fly ash generated by 82 thermal power plants (TPPs) in India (about 100 million tons/annum) and taking a cue from the inherent pozzolanic and physico-chemical properties (alkalinity, negligible solubility and richness of nutrient elements) of fly ash, extensive R & D work on biorestoration of abandoned ash pond and OB dumps and large scale field trials/demonstrations in wasteland with different doses of pond ash in the vicinity of various TPPs under different agroclimatic conditions have been carried out. Based on these the Central Fuel Research Institute (CFRI) has developed fly ash-soil amendment technology, through which it is possible to amend the problematic abandoned ash pond, OB dumps and wasteland and improve their fertility, with promising growth performance of the planted species and the substantial increase in the yields of crops. Species grown included a wide range of trees and shrubs and cotton. 1 fig., 9 tabs.

  7. Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash

    Directory of Open Access Journals (Sweden)

    Martin Ernesto Kalaw

    2016-07-01

    Full Text Available Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC, which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1 their technical properties are comparable if not better; (2 they can be produced from industrial wastes; and (3 within reasonable constraints, their production requires less energy and emits significantly less CO2. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA and coal bottom ash (CBA, and rice hull ash (RHA. The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF for elemental and X-ray diffraction (XRD for mineralogical composition. The raw materials’ thermal stability and loss on ignition (LOI were determined using thermogravimetric analysis (TGA and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR

  8. Effect of ash circulation in gasification melting system on concentration and leachability of lead in melting furnace fly ash.

    Science.gov (United States)

    Okada, Takashi; Suzuki, Masaru

    2013-11-30

    In some gasification-melting plants, generated melting furnace fly ash is returned back to the melting furnace for converting the ash to slag. This study investigated the effect of such ash circulation in the gasification-melting system on the concentration and leachability of lead in the melting furnace fly ash. The ash circulation in the melting process was simulated by a thermodynamic calculation, and an elemental analysis and leaching tests were performed on a melting furnace fly ash sample collected from the gasification-melting plant with the ash circulation. It was found that by the ash circulation in the gasification-melting, lead was highly concentrated in the melting furnace fly ash to the level equal to the fly ash from the ash-melting process. The thermodynamic calculation predicted that the lead volatilization by the chlorination is promoted by the ash circulation resulting in the high lead concentration. In addition, the lead extraction from the melting furnace fly ash into a NaOH solution was also enhanced by the ash circulation, and over 90% of lead in the fly ash was extracted in 5 min when using 0.5 mol l(-1) NaOH solution with L/S ratio of 10 at 100 °C. Based on the results, a combination of the gasification-melting with the ash circulation and the NaOH leaching method is proposed for the high efficient lead recovery. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Assessment of Ziziphus mauritiana grown on fly ash dumps: Prospects for phytoremediation but concerns with the use of edible fruit.

    Science.gov (United States)

    Pandey, Vimal Chandra; Mishra, Tripti

    2016-12-12

    A field study was carried out on fly ash dumps of Panki Thermal Power Station to assess the phytoaccumulation of elements in various plant parts of edible fruit tree Ziziphus mauritiana. Out of the twelve analysed elements, the highest concentration was found for Fe followed by Mn > Se > Zn > Mo > Cu > Cr > Pb > Cd >Ni > As > Co in rhizospheric substrate of Z. mauritiana grown on fly ash dumps. Metal accumulation, bioconcentration factor and translocation factor for each metal was calculated in various parts of the edible fruit tree. Significant variations of metal accumulations were observed amongst various plant parts. Accumulation of toxic elements was higher in roots and it gradually declined towards the aerial parts of the plant corresponding to its distance from the ground. The concentration of some elements in fruit tree was found to be above prescribed limits in edible parts. Therefore, the present study suggested that additional care should be undertaken, if edible fruit trees are considered for phytoremediation or afforestation programs of FA dumps.

  10. Earthworm populations of highly metal-contaminated soils restored by fly ash-aided phytostabilisation.

    Science.gov (United States)

    Grumiaux, Fabien; Demuynck, Sylvain; Pernin, Céline; Leprêtre, Alain

    2015-03-01

    Highly metal contaminated soils found in the North of France are the result of intense industrial past. These soils are now unfit for the cultivation of agricultural products for human consumption. Solutions have to be found to improve the quality of these soils, and especially to reduce the availability of trace elements (TEs). Phytostabilisation and ash-aided phytostabilisation applied since 2000 to an experimental site located near a former metallurgical site (Metaleurop-Nord) was shown previously as efficacious in reducing TEs mobility in soils. The aim of the study was to check whether this ten years trial had influenced earthworm communities. This experimental site was compared to plots located in the surroundings and differing by the use of soils. Main results are that: (1) whatever the use of soils, earthworm communities are composed of few species with moderate abundance in comparison with communities found in similar habitats outside the TEs-contaminated area, (2) the highest abundance and specific richness (4-5 species) were observed in afforested plots with various tree species, (3) ash amendments in afforested plots did not increase the species richness and modified the communities favoring anecic worms but disfavoring epigeic ones. These findings raised the questions of when and how to perform the addition of ashes firstly, to avoid negative effects on soil fauna and secondly, to keep positive effects on metal immobilization.

  11. Vision of Spaces in the Paintings of the Asháninka sheripiare Noe Morales Silva

    Directory of Open Access Journals (Sweden)

    Luisa Elvira Belaunde

    2011-02-01

    Full Text Available Amazonian shamanic painting is a hybrid art born from the coming together of Western figurative techniques, indigenous body painting and visionary shamanic experiences. It is a testimonial art by which painters express their visionary experiences to a foreign public aiming to understand the Amazonian universe. In his watercolors and drawings, the Asháninka healer Noé Silva Morales bears witness to his life as a sheripiare through the construction of visionary spaces carefully painted with skins of luminous designs.

  12. Root secretion stimulating ash growth in larch-ash mixed forest

    Institute of Scientific and Technical Information of China (English)

    吴俊民; 刘广平; 王晓水; 吴保国

    2000-01-01

    Allelopathic effect of larch (Larix gmelini ) on the ash growth (Fraximus mandshurica) was studied in artificial cultivation tests. The results revealed that the larch root secretion obviously stimulated the ash growth. In order to determine the main stimulation allelochemicals, the chemical composition was analyzed. By contrasting the contents of carbohydrate and aminoacid in root secretion of larch and ash, it was concluded that the carbohydrate and aminoacid were not important stimulation allelochemicals. The organic acid and other components in root secretion of larch and ash were analyzed by GC and GC-MS analysis. The sand culture tests were carried out with selected model compounds. The results showed that benzeneacetic acid, benzenepropionic acid and phenolic acids in root secretion of larch were the main stimulation allelochemicals.

  13. Mössbauer characterization of feed coal, ash and fly ash from a thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Caballero, F.; Martínez Ovalle, S. A., E-mail: s.agustin.martinez@uptc.edu.co; Moreno Gutiérrez, M. [Universidad Pedagógica y Tecnológica de Colombia, UPTC, Grupo de Física Nuclear Aplicada y Simulación (Colombia)

    2015-06-15

    The aim of this work was apply {sup 57}Fe Transmission Mössbauer Spectroscopy at room temperature in order to study the occurrence of iron-containing mineral phases in: 1) feed coal; 2) coal ash, obtained in different stages of the ASTM D3174 standard method; and 3) fly ash, produced when coal is burned in the TERMOPAIPA IV thermal power plant localized in Boyacá, Colombia. According to obtained results, we can conclude the occurrence of pyrite and jarosite in the feed coal; Fe{sup 2+} and Fe{sup 3+} crystalline paramagnetic phases, superparamagnetic hematite and hematite in coal ash; Fe{sup 2+} and Fe{sup 3+} noncrystalline and crystalline phases, magnetite and hematite in fly ash. Precisely, for a basic understanding, this work discusses some the possible transformations that take place during coal combustion.

  14. Source water contributions and hydrologic responses to simulated emerald ash borer infestations in depressional black ash wetlands

    Science.gov (United States)

    Matthew J. Van Grinsven; Joseph P. Shannon; Joshua C. Davis; Nicholas W. Bolton; Joseph W. Wagenbrenner; Randall K. Kolka; Thomas Grant Pypker

    2017-01-01

    Forested wetlands dominated by black ash (Fraxinus nigra) are currently threatened by the rapid expansion of the exotic emerald ash borer (EAB) (Agrilus planipennis, Coleoptera: Buprestidae) in North America, and very little is known about the hydrology and ecology of black ash wetlands. The ecohydrological response of...

  15. Application of polymeric flocculant for enhancing settling of the pond ash particles and water drainage from hydraulically stowed pond ash

    Institute of Scientific and Technical Information of China (English)

    Mishra Devi Prasad; Das Samir Kumar

    2013-01-01

    Delayed settling of the ash particles and poor drainage of water from the pond ash are the major problems faced during the hydraulic stowing of pond ash.In this study the effect of polymeric flocculant on settling of the ash particles and drainage of water during pond ash stowing are investigated.In addition,the parameters,viz.drainage and absorption of water during pond ash stowing are quantified by stowing a mine goaf model with pond ash slurries of five different concentrations added with and without flocculant.The study revealed that addition of only 5 × 10-6 of Sodium Carboxymethyl Cellulose (Na-CMC)flocculant with the pond ash slurries during stowing offers best result in terms of quicker settling of the ash particles and enhanced water drainage from the hydraulically stowed pond ash.Besides,it resulted in drainage of more than 85% of the total water used in the initial 45 min of stowing.The improvement in drainage is caused due to coagulation and flocculation of the pond ash particles because of charge neutralization and particle-particle bridging.This study may provide a basis for estimating the drainage and absorption of water during the real pond ash stowing operation in underground mines.

  16. Transpiration and root development of urban trees in structural soil stormwater reservoirs.

    Science.gov (United States)

    Bartens, Julia; Day, Susan D; Harris, J Roger; Wynn, Theresa M; Dove, Joseph E

    2009-10-01

    Stormwater management that relies on ecosystem processes, such as tree canopy interception and rhizosphere biology, can be difficult to achieve in built environments because urban land is costly and urban soil inhospitable to vegetation. Yet such systems offer a potentially valuable tool for achieving both sustainable urban forests and stormwater management. We evaluated tree water uptake and root distribution in a novel stormwater mitigation facility that integrates trees directly into detention reservoirs under pavement. The system relies on structural soils: highly porous engineered mixes designed to support tree root growth and pavement. To evaluate tree performance under the peculiar conditions of such a stormwater detention reservoir (i.e., periodically inundated), we grew green ash (Fraxinus pennsylvanica Marsh.) and swamp white oak (Quercus bicolor Willd.) in either CUSoil or a Carolina Stalite-based mix subjected to three simulated below-system infiltration rates for two growing seasons. Infiltration rate affected both transpiration and rooting depth. In a factorial experiment with ash, rooting depth always increased with infiltration rate for Stalite, but this relation was less consistent for CUSoil. Slow-drainage rates reduced transpiration and restricted rooting depth for both species and soils, and trunk growth was restricted for oak, which grew the most in moderate infiltration. Transpiration rates under slow infiltration were 55% (oak) and 70% (ash) of the most rapidly transpiring treatment (moderate for oak and rapid for ash). We conclude this system is feasible and provides another tool to address runoff that integrates the function of urban green spaces with other urban needs.

  17. Transpiration and Root Development of Urban Trees in Structural Soil Stormwater Reservoirs

    Science.gov (United States)

    Bartens, Julia; Day, Susan D.; Harris, J. Roger; Wynn, Theresa M.; Dove, Joseph E.

    2009-10-01

    Stormwater management that relies on ecosystem processes, such as tree canopy interception and rhizosphere biology, can be difficult to achieve in built environments because urban land is costly and urban soil inhospitable to vegetation. Yet such systems offer a potentially valuable tool for achieving both sustainable urban forests and stormwater management. We evaluated tree water uptake and root distribution in a novel stormwater mitigation facility that integrates trees directly into detention reservoirs under pavement. The system relies on structural soils: highly porous engineered mixes designed to support tree root growth and pavement. To evaluate tree performance under the peculiar conditions of such a stormwater detention reservoir (i.e., periodically inundated), we grew green ash ( Fraxinus pennsylvanica Marsh.) and swamp white oak ( Quercus bicolor Willd.) in either CUSoil or a Carolina Stalite-based mix subjected to three simulated below-system infiltration rates for two growing seasons. Infiltration rate affected both transpiration and rooting depth. In a factorial experiment with ash, rooting depth always increased with infiltration rate for Stalite, but this relation was less consistent for CUSoil. Slow-drainage rates reduced transpiration and restricted rooting depth for both species and soils, and trunk growth was restricted for oak, which grew the most in moderate infiltration. Transpiration rates under slow infiltration were 55% (oak) and 70% (ash) of the most rapidly transpiring treatment (moderate for oak and rapid for ash). We conclude this system is feasible and provides another tool to address runoff that integrates the function of urban green spaces with other urban needs.

  18. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

    2016-01-01

    deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....

  19. Lixiviation of fly ash. Uitloging van vliegas

    Energy Technology Data Exchange (ETDEWEB)

    Verhagen, L.

    1988-01-01

    The lixiviation of a number of elements (Na, K, Ca, Mg, V, As, Sb and Hg) from different fly ash products (fired and cement bounded products) is investigated. A theoretical description of diffusion from a fly ash product is given as well as a standard test to determine the lixiviation rate. Lixiviation can be interpreted as a diffusion process. Diffusion of an element X from a fly ash product can be described with the following parameters: the effective diffusion coefficient, the fraction that is available for lixiviation and the tortuosity of the product. The physical meaning of the determined tortuosity is not clear. The behavior of tracers in the product is compared with the behavior of the corresponding element. Often this behavior deviates, sometimes even considerably. From a comparison of fly ash products it appears that cement bounded products are better able to combine with arsenicum and antimony than fired products. None of the investigated products caused concentrations of micro-elements way above the stated norm. Improvement as for lixiviation behavior of the products seems to be possible, in particular for bricks. 8 refs., 17 tabs., 26 figs.

  20. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

    Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, S.R.A.; Kootstra, A.M.J.

    2014-01-01

    Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching con