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Sample records for high ash indian

  1. Geotechnical characterization of some Indian fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.K.; Yudhbir [Indian Institute for Technology, Kanpur (India). Dept. of Civil Engineering

    2005-10-01

    This paper reports the findings of experimental studies with regard to some common engineering properties (e.g., grain size, specific gravity, compaction characteristics, and unconfined compression strength) of both low and high calcium fly ashes, to evaluate their suitability as embankment materials and reclamation fills. In addition, morphology, chemistry, and mineralogy of fly ashes are studied using scanning electron microscope, electron dispersive x-ray analyzer, x-ray diffractometer, and infrared absorption spectroscopy. In high calcium fly ash, mineralogical and chemical differences are observed for particles, {gt}75 {mu} m and the particles of {lt} 45 {mu} m size. The mode and duration of curing significantly affect the strength and stress-strain behavior of fly ashes. The geotechnical properties of fly ash are governed by factors like lime content (CaO), iron content (Fe{sub 2}O{sub 3}) and loss on ignition. The distinct difference between self-hardening and pozzolanic reactivity has been emphasized.

  2. 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.

  3. The chemical composition of tertiary Indian coal ash and its ...

    Indian Academy of Sciences (India)

    The regression analysis of high temperature ash (HTA) composition and initial deformation temperature (IDT) show a definite increasing or decreasing trend, which has been used to determine the predictive indices for slagging, fouling, and abrasion propensities during combustion practices. The increase or decrease of IDT ...

  4. Studies on sorption properties of zeolite derived from Indian fly ash.

    Science.gov (United States)

    Mishra, T; Tiwari, S K

    2006-09-01

    Indian fly ash has been completely converted to crystalline porous 13X zeolite by NaOH fusion at 600 degrees C followed by hydrothermal treatment at 105 degrees C for 20 h. Obtained materials were characterized by XRD, SEM and surface area measurement. Prepared material was used for the sorption study of different metal ions (Cu(2+), Co(2+) and Ni(2+)) at different pH, temperature. Thermodynamic data (DeltaS, DeltaH and DeltaG) corresponding to different metal ion uptake were evaluated from Langmuir equation. In all the experiment sorption capacity of prepared zeolite was found to be quite high than that of fly ash at acidic pH. However, the uptake selectivity order for both the materials is Cu(2+)>Co(2+)>Ni(2+).

  5. Mercury in coal ash and its fate in the Indian subcontinent: A synoptic review.

    Science.gov (United States)

    Mukherjee, Arun B; Zevenhoven, Ron

    2006-09-01

    In the Indian subcontinent power generation is mainly dependent upon the thermal power units and coal is burnt as a fuel for the production of heat and electricity. In India, bituminous and sub-bituminous coals are used which contain over 40% of ash. At present, 80-90 million tons of fly ashes are generated from 85 existing coal based thermal power plants. Coal contains trace metals of which mercury is most toxic for humans and aquatic fauna. The problem of mercury in the society is not new, but in recent years the Indian subcontinent has gained the reputation of being "a dumping ground for mercury". This study focuses on mercury in fly ash and its releases to the atmosphere and soils cross the country. The utilisation of coal ash in India is also addressed although it is still in its nascent stage. About 10% of produced fly ashes are used in India whereas in Western countries its use is typically over 70%. Regulations from India's Ministry of Environment and Forestry should increase coal fly ash utilisation, although this would require that cost-effective new technology is put to use. As to the release of Hg from ashes disposed of in the environment, the scarce literature suggests that this is negligible or zero, and less problematic than wet or dry deposition of Hg from flue gases.

  6. The chemical composition of tertiary Indian coal ash and its ...

    Indian Academy of Sciences (India)

    in marketing and furnace design. The abundance of hydroxides, sulphates, carbonates, phosphates, and trace elements present in coal may also affect .... mostly made considering the initial deformation temperature (IDT), where most of the melting takes place in this temperature range and therefore. Table 2. Ash fusion ...

  7. Properties of High-Volume Fly Ash Concrete Reinforced with Natural Fibres

    Directory of Open Access Journals (Sweden)

    Rafat SIDDIQUE

    2012-12-01

    Full Text Available Properties of high-volume fly ash concrete incorporating san fibres are presented in this paper. For this investigation, initially, three concrete mixtures were made with 35%, 45%, and 55% of Class F fly as partial replacement of cement. After this, three percentages (0.25, 0.50, and 0.75% of san fibres (25 mm length were added in each of the fly ash concrete mixtures. San is a natural bast fibre, and is also known as Sunn Hemp (Botanical name: Crotalaria Juncea. It is grown in Indian Sub-Continent, Brazil, Eastern and Southern Africa, and also in some parts of U.S.A. Tests were performed for compressive strength, splitting tensile strength, flexural strength, and impact strength at the ages of 28, 91 and 365 days. Tests were also performed for fresh concrete properties. 28 days test results indicated that san fibres reduced the compressive strength of high-volume fly ash concrete by 2 to 13%, increased splitting tensile strength by 6 to 26%, flexural strength by 5 to 14%, and enhanced impact strength tremendously (by 100 to 300% depending upon the fly ash content and fibre percentage. Later age (91 and 365 days results showed continuous increase in strength properties of high-volume fly ash concrete. This was probably be possible due to the pozzolanic action of fly ash, leading to more densification of the concrete matrix, and development of more effective bond between fibres and fly ash concrete matrix.

  8. Studies on synthesis and characteristics of zeolite prepared from Indian fly ash.

    Science.gov (United States)

    Prasad, Bably; Maity, Sudip; Sangita, Kumari; Mahato, Arun Kumar; Mortimer, Robert J G

    2012-01-01

    In the present study, samples of coal fly ash were obtained from seven major Indian thermal power plants. These samples were transformed into fly ash zeolite (FAZ) using hydrothermal activation by treatment with NaOH. All experiments were carried out at 100 degrees C, but with different solid:liquid ratios, different concentrations of alkali and different incubation times. The chemical composition, mineralogy and morphology of the fly ash and FAZ were determined by wet chemical method after Na2CO3 fusion, x-ray diffraction and scanning electron microscopy. The cation exchange capacity of fly ash and FAZ was determined using the ammonium acetate method (IS:2720). The ammonium exchange capacity was determined by the titrimetric method. The experiments demonstrate that zeolite can be synthesized at 100 degrees C using alkali. The cation exchange capacity and ammonium adsorption capacity of FAZ (up to 250 meq/100 g and 22.93 mg NH4+/g respectively) indicate that the FAZ may be potentially useful to reduce heavy metals and other pollutants from contaminated environments. Therefore, zeolitization at low temperature potentially allows waste fly ash to be used in an economically advantageous way.

  9. The Indian perspective of utilizing fly ash in phytoremediation, phytomanagement and biomass production.

    Science.gov (United States)

    Pandey, Vimal Chandra; Abhilash, P C; Singh, Nandita

    2009-07-01

    Coal-based power generation is a principal source of electricity in India and many other countries. About 15-30% of the total amount of residue generated during coal combustion is fly ash (FA). FA is generally alkaline in nature and contains many toxic metals like Cr, Pb, Hg, As and Cd along with many essential elements like S, B, Ca, Na, Fe, Zn, Mn and P. Dumped FA contaminates the biosphere by mobilization of its fine particles and hazardous metals. Despite the negative environmental impact of FA, coal continues to be a major source of power production in India and therefore FA disposal is a major environmental issue. To overcome this problem, FA dumping sites have been started as a potential resource for biomass production of tree species. Phytoremediation is a strategy that uses plants to degrade, stabilize, and remove contaminants from soils, water and waste FA. Phytomanagement of FA is based on the plants' root systems, high biomass, woody nature, native nature, and resistance to pH, salinity, and toxic metals. Recently Indian researchers mostly from the National Botanical Research Institute have been working on phytoremediation and revegetation of FA dykes, inoculation of bacterial strains for reducing FA stress and biomass production from FA dykes. Many international researchers have worked on reclamation, revegetation and utilization of FA. FA utilization saves resources, mainly land (topsoil), water, coal, limestone and chemical fertilizer. Safe utilization of FA is a major concern around the world and regulatory bodies are enforcing stringent rules for the proper management of FA. This article summarizes various viable avenues in India for FA utilization and environmental management.

  10. Effects of different treatments of fly ash and mining soil on growth and antioxidant protection of Indian wild rice.

    Science.gov (United States)

    Bisoi, Sidhanta Sekhar; Mishra, Swati S; Barik, Jijnasa; Panda, Debabrata

    2017-05-04

    The aim of the present study was investigation of the effects of fly ash and mining soil on growth and antioxidant protection of two cultivars of Indian wild rice (Oryza nivara and Oryza rufipogon) for possible phytoremediation and restoration of metal-contaminated site. In this study, Indian wild rice showed significant changes in germination, growth, and biochemical parameters after exposure to different ratio of fly ash and mining soil with garden soil. There was significant reduction of germination, fresh weight, dry weight, leaf chlorophyll content, leaf area, Special Analysis Device Chlorophyll (SPAD) Index, proteins, and activities of antioxidant enzymes in both cultivars of the wild rice grown in 100% fly ash and mining soil compared to the plants grown in 100% garden soil. Results from this study showed that in both cultivars of wild rice, all growth and antioxidant parameters increased when grown in 50% fly ash and mining soil. Taken together, Indian wild rice has the capacity to tolerate 50% of fly ash and mining soil, and can be considered as a good candidate for possible phytoremediation of contaminated soils.

  11. Durability properties of high volume fly ash self compacting concretes

    Energy Technology Data Exchange (ETDEWEB)

    P. Dinakar; K.G. Babu; Manu Santhanam [Indian Institute of Technology, Chennai (India). Building Technology Division

    2008-11-15

    This paper presents an experimental study on the durability properties of self compacting concretes (SCCs) with high volume replacements of fly ash. Eight fly ash self compacting concretes of various strength grades were designed at desired fly ash percentages of 0, 10, 30, 50, 70 and 85%, in comparison with five different mixtures of normal vibrated concretes (NCs) at equivalent strength grades. The durability properties were studied through the measurement of permeable voids, water absorption, acid attack and chloride permeation. The results indicated that the SCCs showed higher permeable voids and water absorption than the vibrated normal concretes of the same strength grades. However, in acid attack and chloride diffusion studies the high volume fly ash SCCs had significantly lower weight losses and chloride ion diffusion.

  12. Size fraction characterization of highly-calcareous fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Itskos, Grigorios; Koukouzas, Nikolaos [Institute for Solid Fuels Technology and Applications, Centre for Research and Technology Hellas, 357-359 Mesogeion Avenue, GR-152 31, Halandri, Athens (Greece); Itskos, Socrates [Department of Chemical Technology and the Environment, Steam Electric Station of Amynteon-Filotas, Public Power Corporation of Greece, GR-532 00, Amynteon (Greece)

    2010-11-15

    The chemical and mineralogical composition of lignite fly ash (FA) varies as a function of the prevalent conditions in both the processes of power production and lignite mining. The differentiation of the qualitative and quantitative composition of the highly-calcareous lignite fly ash, as a function of its particle size distribution, is verified in this paper. According to the results of the conducted research, a fine-grained fraction of considerable amount presents properties that obstruct the sustainable exploitation of calcareous lignite fly ash in cement industry applications. On the other hand, the same grain fraction (because of its hydraulic properties) can be utilized in other sort of applications, based on different criteria, i.e. in road constructions. The coarse-grained fraction (which reflects a low proportion to the total fly ash output) presents the same undesired characteristics as well. Rather, the intermediate grain fraction (75-150 {mu}m) presents the highly desirable properties when fly ash is utilized as a pozzolanic additive. In addition, the mechanism of the formation of the intermediate grain fraction strongly prevents the factors that cause the variation of fly ash-quality. It is therefore the optimum part of the whole amount of lignite FA, to be utilized as additive in cement manufacturing. The outcomes of this paper will hopefully contribute towards the crucial goal of the expansion of the utilization of calcareous lignite fly ash by proposing a more effective way of using this material, basically by taking advantage of its fundamental chemical and mineralogical properties. (author)

  13. Aluminum recovery from coal fly ash by high temperature chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Wijatno, Hendra [Iowa State Univ., Ames, IA (United States)

    1977-10-01

    A study of aluminum recovery from power plant fly ash by high temperature chlorination was undertaken to demonstrate that fly ash could be a potential source of aluminum, iron and possibly silicon. Magnetic separation of the iron oxide served as a first step to alleviate the iron contamination problem. However, the agglomeration of some iron oxide with alumina and silica made it difficult to completely separate the iron from the fly ash. Further iron separation was achieved by chlorinating the nonmagnetic ash fraction at 550°C for 30 minutes. This reduced the iron oxide content to less than 4 percent by weight. Chlorine flow rates affected the reaction rate much more drastically than temperatures. This suggested that diffusion was the major rate-controlling step. Besides Fe2O3, Al2O3 and SiO2, other oxides such as CaO, K2O, Na2O and MgO might have complicated the alumina recovery by forming individual chlorides or complexes. Investigating methods for separating more Fe2O3, and possibly CaO, K2O, Na2O and MgO from the nonmagnetic ash fraction before chlorinating it is highly recommended.

  14. SCC with high volume of fly ash content

    Directory of Open Access Journals (Sweden)

    Bakhrakh Anton

    2017-01-01

    Full Text Available Self-compacting concrete is a very perspective building material. It provides great benefits during the construction of heavily reinforced buildings. SCC has outstanding properties such as high flowability, dense structure and high strength due to specific quality of aggregates, fillers, their proportion in mix, use of polycarboxylate-based superplasticizers. Main disadvantages of SCC are high price and the difficulty of obtaining a proper mix. Use of fillers, such as fly ash type F, is a way to make SCC cheaper by replacing part of cement. Fly ash also provides some technological and operating advantages. In this paper the influence of high volume (60% from cement fly ash type F on the properties of concrete mixture and hardened concrete is investigated. The result of the work shows the possibility of reduction the cost of SCC using ordinary fillers and high amount of fly ash. The investigated SCC has low speed of hardening (7-day compressive strength at the range of 41.8 MPa and high volume of entrained air content (3.5%.

  15. Self compacting concrete incorporating high-volumes of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Bouzoubaa, N. [Natural Resources Canada, Ottawa, ON (Canada). International Centre for Sustainable Development of Cement and Concrete; Lachemi, M. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Civil Engineering

    2004-07-01

    Self-compacting concrete (SCC) is now widely used in reinforced concrete structures. Fine materials such as fly ash ensure that the concrete has the necessary properties of high fluidity and cohesiveness. An experimental study was conducted in which 9 SCC mixtures and one control concrete were produced in order to evaluate SCC made with high-volumes of fly ash. The content of the cementitious materials remained constant at 400 kg/cubic metre, but the ratio of water to cementitious material ranged from 0.35 to 0.45. The viscosity and stability of the fresh concrete was determined for self-compacting mixtures of 40, 50 and 60 per cent Class F fly ash. The compressive strength and drying shrinkage were also determined for the hardened concretes. Results showed that the SCCs developed a 28-day compressive strength ranging from 26 to 48 MPa. It was concluded that high-volumes of Class F fly ash could offer the following advantages to an SCC: reduced construction time and labour cost; eliminate the need for vibration; reduce noise pollution; improve the filling capacity of highly congested structural members; and, ensure good structural performance. 19 refs., 8 tabs., 2 figs.

  16. Fracture Toughness and Impact Strength of High-Volume Class-F Fly Ash Concrete Reinforced with Natural San Fibres

    Directory of Open Access Journals (Sweden)

    Rafat SIDDIQUE

    2008-06-01

    Full Text Available Results of experimental investigation carried out to study the effects of addition of natural san fibres on the fracture toughness and impact strength of high-volume fly ash concrete are presented in this paper. San fibres belong to the category of ‘Natural Bast Fibres’, also known as ‘Sunn Hemp’. Its scientific (botanical name is Crotalaria Juncea. It is mostly grown in the Indian Sub-Continent, Brazil, Eastern and Southern Africa, and in some parts of the U.S.A. Initially, a control mixture without fly ash was designed. Then, cement was replaced with three percentages (30, 40 and 50% of low-calcium (Class F fly ash. Three percentages of san fibres (0.30, 0.60 and 0.90%, having 25 mm length, were used. Tests were performed for compressive strength, fracture toughness, and impact strength at the ages of 28 and 91 days.The test results indicated that the replacement of cement with fly ash decreased the compressive strength and fracture toughness, and had no significant effect on the impact strength of plain (control concrete. Addition of san fibres did not affect significantly the compressive strength, increased the fracture toughness and impact strength of high-volume fly ash concrete as the percentage of fibres increased.

  17. Use of wood ash in the treatment of high tannin sorghum for poultry ...

    African Journals Online (AJOL)

    A study was conducted to investigate the effects of wood ash treatment on the nutritional value of high tannin sorghum. High tannin sorghum was either soaked in wood ash slurry and then germinated for four days or soaked in wood ash extract and germinated for 28 hours or germinated after soaking in water. Chemical ...

  18. Use of wood ash in the treatment of high tannin sorghum for poultry ...

    African Journals Online (AJOL)

    conniek

    Abstract. A study was conducted to investigate the effects of wood ash treatment on the nutritional value of high tannin sorghum. High tannin sorghum was either soaked in wood ash slurry and then germinated for four days or soaked in wood ash extract and germinated for 28 hours or germinated after soaking in water.

  19. Preventing ash agglomeration during gasification of high-sodium lignite

    Energy Technology Data Exchange (ETDEWEB)

    Robert S. Dahlin; Johnny R. Dorminey; WanWang Peng; Roxann F. Leonard; Pannalal Vimalchand [Southern Research Institute and Southern Company Services, Wilsonville, AL (USA). Power Systems Development Facility

    2009-01-15

    Various additives were evaluated to assess their ability to prevent ash agglomeration during the gasification of high-sodium lignite. Additives that showed promise in simple muffle furnace tests included meta-kaolin, vermiculite, two types of silica fume, and one type of bauxite. Additives that were tested and rejected included dolomite, calcite, sand flour, kaolinite, fine kaolin, and calcined bauxite. Based on the muffle furnace test results, the meta-kaolin was selected for a follow-on demonstration in a pilot-scale coal gasifier. Pilot-scale testing showed that the addition of coarse (minus 14-mesh, 920-{mu}m mean size) meta-kaolin at a feed rate roughly equivalent to the ash content of the lignite (10 wt %) successfully prevented agglomeration and deposition problems during gasification of high-sodium lignite at a maximum operating temperature of 927{sup o}C (1700{sup o}F). 13 refs., 24 figs., 1 tab.

  20. Ash Decline Assessment in Emerald Ash Borer Infested Natural Forests Using High Spatial Resolution Images

    Directory of Open Access Journals (Sweden)

    Justin Murfitt

    2016-03-01

    Full Text Available The invasive emerald ash borer (EAB, Agrilus planipennis Fairmaire infects and eventually kills endemic ash trees and is currently spreading across the Great Lakes region of North America. The need for early detection of EAB infestation is critical to managing the spread of this pest. Using WorldView-2 (WV2 imagery, the goal of this study was to establish a remote sensing-based method for mapping ash trees undergoing various infestation stages. Based on field data collected in Southeastern Ontario, Canada, an ash health score with an interval scale ranging from 0 to 10 was established and further related to multiple spectral indices. The WV2 image was segmented using multi-band watershed and multiresolution algorithms to identify individual tree crowns, with watershed achieving higher segmentation accuracy. Ash trees were classified using the random forest classifier, resulting in a user’s accuracy of 67.6% and a producer’s accuracy of 71.4% when watershed segmentation was utilized. The best ash health score-spectral index model was then applied to the ash tree crowns to map the ash health for the entire area. The ash health prediction map, with an overall accuracy of 70%, suggests that remote sensing has potential to provide a semi-automated and large-scale monitoring of EAB infestation.

  1. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    National Research Council Canada - National Science Library

    Mochamad Solikin; Budi Setiawan

    2017-01-01

    ...) and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly Ash Concrete...

  2. Radiological and material characterization of high volume fly ash concrete.

    Science.gov (United States)

    Ignjatović, I; Sas, Z; Dragaš, J; Somlai, J; Kovács, T

    2017-03-01

    The main goal of research presented in this paper was the material and radiological characterization of high volume fly ash concrete (HVFAC) in terms of determination of natural radionuclide content and radon emanation and exhalation coefficients. All concrete samples were made with a fly ash content between 50% and 70% of the total amount of cementitious materials from one coal burning power plant in Serbia. Physical (fresh and hardened concrete density) and mechanical properties (compressive strength, splitting tensile strength and modulus of elasticity) of concrete were tested. The radionuclide content (226Ra, 232Th and 40K) and radon massic exhalation of HVFAC samples were determined using gamma spectrometry. Determination of massic exhalation rates of HVFAC and its components using radon accumulation chamber techniques combined with a radon monitor was performed. The results show a beneficial effect of pozzolanic activity since the increase in fly ash content resulted in an increase in compressive strength of HVFAC by approximately 20% for the same mass of cement used in the mixtures. On the basis of the obtained radionuclide content of concrete components the I -indices of different HVFAC samples were calculated and compared with measured values (0.27-0.32), which were significantly below the recommended 1.0 index value. The prediction was relatively close to the measured values as the ratio between the calculated and measured I-index ranged between 0.89 and 1.14. Collected results of mechanical and radiological properties and performed calculations clearly prove that all 10 designed concretes with a certain type of fly ash are suitable for structural and non-structural applications both from a material and radiological point of view. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Mechanical behaviour and durability of high volume fly ash cementitious composites

    Directory of Open Access Journals (Sweden)

    Usman Haider

    2016-10-01

    Full Text Available The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles

  4. Some aspects of volcanic ash layers in the Central Indian Basin.

    Digital Repository Service at National Institute of Oceanography (India)

    Sukumaran, N.P.; Banerjee, R.; Borole, D.V.; Gupta, S.M.

    morphological structures and activation of seamounts during the geological past. The tentative correlation between depositional ages of the ash layer horizons and the period of global climatic cooling events reinforces the hypothesis that the suboceanic volcanic...

  5. Bench-scale synthesis of zeolite A from subbituminous coal ashes with high crystalline silica content

    Energy Technology Data Exchange (ETDEWEB)

    Chareonpanich, M.; Jullaphan, O.; Tang, C. [Kasetsart University, Bangkok (Thailand). Dept. of Chemical Engineering

    2011-01-15

    In this present work, fly ash and bottom ash with high crystalline silica content were obtained from the coal-fired boilers within the paper industries in Thailand. These coal ashes were used as the basic raw materials for synthetic zeolite production. The crystal type and crystallinity, specific surface area and pore size, and textural properties of zeolite products were characterized by using X-ray diffraction spectroscopy (XRD), N{sub 2} sorption analysis, and Scanning Electron Microscopy (SEM), respectively. It was found that sodalite octahydrate was selectively formed via the direct conventional (one-step) synthesis, whereas through a two-step, sodium silicate preparation and consecutive zeolite A synthesis process, 94 and 72 wt.% zeolite A products could be produced from the fly ash and bottom ash, respectively. The cation-exchange capacity (CEC) of fly ash and bottom ash-derived zeolite A products were closely similar to that of the commercial grade zeolite A.

  6. Using fume silica as heavy metals' stabilizer for high alkali and porous MSWI baghouse ash.

    Science.gov (United States)

    Huang, Wu-Jang; Huang, Hung-Shao

    2008-03-21

    In this study, we have proved that heavy metals in high porous and alkali baghouse ash could be fixed effectively by fume silica powder alone, or with the incorporation of colloidal aluminum oxide (CAO). The optimum amount is about 100g of fume silica per kilogram of baghouse ash. Results have indicated that fume silica has a better fixation efficiency of lead in high porous baghouse ash. In addition, the reaction mechanism of fume silica is also discussed.

  7. Characteristics variation of coal combustion residues in an Indian ash pond.

    Science.gov (United States)

    Asokan, Pappu; Saxena, Mohini; Aparna, Asokan; Asolekar, Shyam R; Asoletar, Shyam R

    2004-08-01

    Coal-fired power plants all over the world are cited as one of the major sources that generate huge quantities of coal combustion residues (CCRs) as solid wastes. Most frequently CCRs are collected through electrostatic precipitators, mixed with bottom ash by hydraulic systems and deposited in ash ponds. The quality of the CCRs at different locations in one of the ash ponds in Central India was evaluated to understand the variation in characteristics with a view to effective utilization. Results revealed that the presence of fine particles (electrical conductivity increased (from 0.25 to 0.65 dS m(-3)). The presence of almost all the heavy metals in CCRs exhibited an increase with distance from the ash slurry discharge zone due to the increase in surface area (from 0.1038 to 2.3076 m2 g(-1)) of CCRs particles. The present paper describes the variation of characteristics of CCRs deposited in the ash pond and their potential applications.

  8. High plant availability of phosphorus and low availability of cadmium in four biomass combustion ashes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaoxi, E-mail: Xiaoxi.Li@agro.au.dk; Rubæk, Gitte H.; Sørensen, Peter

    2016-07-01

    For biomass combustion to become a sustainable energy production system, it is crucial to minimise landfill of biomass ashes, to recycle the nutrients and to minimise the undesirable impact of hazardous substances in the ash. In order to test the plant availability of phosphorus (P) and cadmium (Cd) in four biomass ashes, we conducted two pot experiments on a P-depleted soil and one mini-plot field experiment on a soil with adequate P status. Test plants were spring barley and Italian ryegrass. Ash applications were compared to triple superphosphate (TSP) and a control without P application. Both TSP and ash significantly increased crop yields and P uptake on the P-depleted soil. In contrast, on the adequate-P soil, the barley yield showed little response to soil amendment, even at 300–500 kg P ha{sup −1} application, although the barley took up more P at higher applications. The apparent P use efficiency of the additive was 20% in ryegrass - much higher than that of barley for which P use efficiencies varied on the two soils. Generally, crop Cd concentrations were little affected by the increasing and high applications of ash, except for relatively high Cd concentrations in barley after applying 25 Mg ha{sup −1} straw ash. Contrarily, even modest increases in the TSP application markedly increased Cd uptake in plants. This might be explained by the low Cd solubility in the ash or by the reduced Cd availability due to the liming effect of ash. High concentrations of resin-extractable P (available P) in the ash-amended soil after harvest indicate that the ash may also contribute to P availability for the following crops. In conclusion, the biomass ashes in this study had P availability similar to the TSP fertiliser and did not contaminate the crop with Cd during the first year. - Highlights: • Effects of four biomass ashes vs. a P fertiliser (TSP) on two crops were studied. • Ashes increased crop yields with P availability similar to TSP on P-depleted soil

  9. An Experimental Study of High Strength-High Volume Fly Ash Concrete for Sustainable Construction Industry

    Science.gov (United States)

    Kate, Gunavant K.; Thakare, Sunil B., Dr.

    2017-08-01

    Concrete is the most widely used building material in the construction of infrastructures such as buildings, bridges, highways, dams, and many other facilities. This paper reports the development, the basic idea, the main properties of high strength-high volume fly ash with application in concrete associated with the development and implementation of Sustainable Properties of High Volume Fly Ash Concrete (HVFAC) Mixtures and Early Age Shrinkage and mechanical properties of concrete for 7,28,56 and 90days. Another alternative to make environment-friendly concrete is the development of high strength-high-volume fly ash concrete which is an synthesized from materials of geological origin or by-product materials such as fly ash which is rich in silicon and aluminum. In this paper 6 concrete mixtures were produced to evaluate the effect of key parameters on the mechanical properties of concrete and its behavior. The study key parameters are; binder material content, cement replacement ratios, and the steel fibers used to High Volume Fly Ash mixtures for increasing performance of concrete.

  10. High temperature co-treatment of bottom ash and stabilized fly ashes from waste incineration

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Mogensen, E.P.B.; Lundtorp, Kasper

    2001-01-01

    Bottom ashes from two Danish municipal solid waste incineration plants were heated at 900 degreesC with iron oxide stabilized air pollution control residues at actual mass flow ratios (9:1), simulating a treating method for the residues. The two residues were cotreated, producing one combined...

  11. The High Teperature Influence on Geopolymer Fly Ash Mixture’s Compressisive Strength with Insudtrial Waste Material Substitution

    Science.gov (United States)

    Bayuaji, R.; Wibowo, B.; Subekti, S.; Santoso, S. E.; Hardiyanto, E.; Kaelani, Y.; Mallu, L. L.

    2017-11-01

    This research aimed to figure out the influence of fly ash mixture from the industrial waste at the temperatures of 150°C, 450°C, 750°C viewed from the strength and resistance of geopolymer paste. As a result, cement will be substituted by industrial waste like fly ash. This experimental research was conducted on the mix design of geopolymer concrete which was made by dimension with 2.5 cm in diameter and 5 cm in height from four mixture composition of fly ash and industrial waste i.e. 100% fly ash, 50% fly ash+50% bottom ash, 50% fly ash+50% sandblast, and 50% fly ash+50% carbide waste. Each mixture was tested in terms of porosity and compressive strength. In conclusion, in the mixture of 50% fly ash+50% Sandblast and 50% fly ash+50% bottom ash in 12 molars, 1.5 activator comparison can be used to substitute fly ash at high temperature. Meanwhile, the mixture of 50% fly ash+50% carbide waste in 8 molars, 0.5 activator comparison has very small strength remaining if it is compared to the mixture of fly ash and other industrial waste (Bottom ash and Sandblast). The performance of mixture paste of 50% fly ash+50% carbide waste was very vulnerable after being burnt. Consequently, it cannot be used as the main structure at high temperature.

  12. The removal of reactive dyes using high-ash char

    Directory of Open Access Journals (Sweden)

    Moreira R.F.P.M.

    2001-01-01

    Full Text Available The thermodynamics and kinetics of adsorption of reactive dyes on high-ash char was studied. Equilibrium data were obtained using the static method with controlled agitation at temperatures in the range of 30 to 60ºC. The Langmuir isotherm model was used to describe the equilibrium of adsorption, and the equilibrium parameters, R L, in the range of 0 to 1 indicate favorable adsorption. The amount of dye adsorbed increased as temperature increased from 30 to 40ºC, but above 40ºC the increase in temperature resulted in a decrease in the amount of dye adsorbed. The kinetic data presented are for controlled agitation at 50 rpm and constant temperature with dye concentrations in the range of 10 ppm to50 ppm. The film mass transfer coefficient, Kf, and the effective diffusivity inside the particle, De, were fitted to the experimental data. The results indicate that internal diffusion governs the adsorption rate.

  13. Thermal stability of nano structured fly ash synthesized by high ...

    African Journals Online (AJOL)

    The size, shape and texture of the fresh as well as nano structured fly ash were studied using Scanning Electron Microscopy (SEM). The fresh ... The shape of the 30h milled particles is irregular and the surface morphology is rough. Isothermal ... Keywords: Nano materials, Particulates and Powders, XRD- analysis; Fly ash.

  14. STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hurt; Eric Suuberg; John Veranth; Xu Chen

    2002-09-10

    The overall objective of the present project is to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific research issues to be addressed include: (1) the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; (2) the effect of various low-NOx firing modes on ash properties and adsorptivity; and (3) the kinetics and mechanism of ash ozonation. This data will provide scientific and engineering support of the ongoing process development activities. During this fourth project period we completed the characterization of ozone-treated carbon surfaces and wrote a comprehensive report on the mechanism through which ozone suppresses the adsorption of concrete surfactants.

  15. Workability and strength of coarse high calcium fly ash geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    P. Chindaprasirt; T. Chareerat; V. Sirivivatnanon [Khon Kaen University, Khon Kaen (Thailand). Department of Civil Engineering

    2007-03-15

    In this paper, the basic properties viz., workability and strength of geopolymer mortar made from coarse lignite high calcium fly ash were investigated. The geopolymer was activated with sodium hydroxide (NaOH), sodium silicate and heat. The results revealed that the workable flow of geopolymer mortar was in the range of 110 {+-}5%-135 {+-}5% and was dependent on the ratio by mass of sodium silicate to NaOH and the concentration of NaOH. The obtained compressive strength was in the range of 10-65 MPa. The optimum sodium silicate to NaOH ratio to produce high strength geopolymer was 0.67-1.0. The concentration variation of NaOH between 10 M and 20 M was found to have a small effect on the strength. The geopolymer samples with high strength were obtained with the following practices: the delay time after moulding and before subjecting the sample to heat was 1 h and the optimum curing temperature in the oven was 75{sup o}C with the curing duration of not less than two days.

  16. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2015-08-01

    Full Text Available Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  17. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash.

    Science.gov (United States)

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-08-21

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  18. STRATEGIES AND TECHNOLOGY FOR MANAGING HIGH-CARBON ASH

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hurt; Eric Suuberg; John Veranth; Xu Chen; Indrek Kulaots

    2004-02-13

    The overall objective of the present project was to identify and assess strategies and solutions for the management of industry problems related to carbon in ash. Specific issues addressed included: (1) the effect of parent fuel selection on ash properties and adsorptivity, including a first ever examination of the air entrainment behavior of ashes from alternative (non-coal) fuels; (2) the effect of various low-NOx firing modes on ash properties and adsorptivity based on pilot-plant studies; and (3) the kinetics and mechanism of ash ozonation. This laboratory data has provided scientific and engineering support and underpinning for parallel process development activities. The development work on the ash ozonation process has now transitioned into a scale-up and commercialization project involving a multi-industry team and scheduled to begin in 2004. This report describes and documents the laboratory and pilot-scale work in the above three areas done at Brown University and the University of Utah during this three-year project.

  19. Fibrous Fillers to Manufacture Ultra High Ash/Performance Paper

    Energy Technology Data Exchange (ETDEWEB)

    Dr. VIjay K. Mathur

    2009-04-30

    The paper industry is one of the largest users of energy and emitters of CO2 in the US manufacturing industry. In addition to that, it is facing tremendous financial pressure due to lower cost imports. The fine paper industry has shrunk from 15 million tons per year production to 10 million tons per year in the last 5 years. This has resulted in mill closures and job loses. The AF&PA and the DOE formed a program called Agenda 2020 to help in funding to develop breakthrough technologies to provide help in meeting these challenges. The objectives of this project were to optimize and scale-up Fibrous Fillers technology, ready for commercial deployment and to develop ultra high ash/high performance paper using Fibrous Fillers. The goal was to reduce energy consumption, carbon footprint, and cost of manufacturing paper and related industries. GRI International (GRI) has been able to demonstrate the techno - economic feasibility and economic advantages of using its various products in both handsheets as well as in commercial paper mills. GRI has also been able to develop sophisticated models that demonstrate the effect of combinations of GRI's fillers at multiple filler levels. GRI has also been able to develop, optimize, and successfully scale-up new products for use in commercial paper mills.

  20. Durability Study on High Calcium Fly Ash Based Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Ganesan Lavanya

    2015-01-01

    Full Text Available This study presents an investigation into the durability of geopolymer concrete prepared using high calcium fly ash along with alkaline activators when exposed to 2% solution of sulfuric acid and 5% magnesium sulphate for up to 45 days. The durability was also assessed by measuring water absorption and sorptivity. Ordinary Portland cement concrete was also prepared as control concrete. The grades chosen for the investigation were M20, M40, and M60. The alkaline solution used for present study is the combination of sodium silicate and sodium hydroxide solution with the ratio of 2.50. The molarity of sodium hydroxide was fixed as 12. The test specimens were 150×150×150 mm cubes, 100×200 mm cylinders, and 100×50 mm discs cured at ambient temperature. Surface deterioration, density, and strength over a period of 14, 28, and 45 days were observed. The results of geopolymer and ordinary Portland cement concrete were compared and discussed. After 45 days of exposure to the magnesium sulfate solution, the reduction in strength was up to 12% for geopolymer concrete and up to 25% for ordinary Portland cement concrete. After the same period of exposure to the sulphuric acid solution, the compressive strength decrease was up to 20% for geopolymer concrete and up to 28% for ordinary Portland cement concrete.

  1. Hydrothermal Synthesis of High Crystalline Silicalite from Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    Chaiwat Kongmanklang

    2015-01-01

    Full Text Available The objective of this research work was to evaluate the hydrothermal synthesis of silicalite with high crystallinity within a small particle size. The current study focused on investigating the effects of silica sources such as rice husk ash (RHA and silica gel (SG, crystallization time, and ratios of NaOH/SiO2, H2O/NaOH, and SiO2/TPABr. The crystallinity, particle size, and morphology were characterized by FT-IR, XRD, particle size analyser, and SEM. The conclusion of the main findings indicated that the XRD patterns of these samples clearly showed a pure phase of MFI structure corresponding to FT-IR spectra with vibration mode at 550 and 1223 cm−1. The highest crystallinity was obtained at reaction time only 6 hours with the mole ratios of NaOH/SiO2, H2O/NaOH and SiO2/TPABr as 0.24, 155, and 30, respectively. When SG was used as a silica source, it was found that the particle size was smaller than that from RHA. The morphologies of all silicalite samples were coffin and cubic-like shape.

  2. A Study on the Evaluation of Field Application of High-Fluidity Concrete Containing High Volume Fly Ash

    Directory of Open Access Journals (Sweden)

    Yun-Wang Choi

    2015-01-01

    Full Text Available In the recent concrete industry, high-fluidity concrete is being widely used for the pouring of dense reinforced concrete. Normally, in the case of high-fluidity concrete, it includes high binder contents, so it is necessary to replace part of the cement through admixtures such as fly ash to procure economic feasibility and durability. This study shows the mechanical properties and field applicability of high-fluidity concrete using mass of fly ash as alternative materials of cement. The high-fluidity concrete mixed with 50% fly ash was measured to manufacture concrete that applies low water/binder ratio to measure the mechanical characteristics as compressive strength and elastic modulus. Also, in order to evaluate the field applicability, high-fluidity concrete containing high volume fly ash was evaluated for fluidity, compressive strength, heat of hydration, and drying shrinkage of concrete.

  3. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    OpenAIRE

    Solikin Mochamad; Setiawan Budi

    2017-01-01

    High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC) and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly ...

  4. High levels of particulate matter in Iceland due to direct ash emissions by the Eyjafjallajökull eruption and resuspension of deposited ash

    Science.gov (United States)

    Thorsteinsson, Throstur; Jóhannsson, Thorsteinn; Stohl, Andreas; Kristiansen, Nina I.

    2012-09-01

    The dangers to people living near a volcano due to lava and pyroclastic flows, and, on glacier- or snow-covered volcanoes, jökulhlaups, are well known. The level of risk to human health due to high concentrations of ash from direct emission and resuspension from the ground is, however, not as well known. The eruption at Eyjafjallajökull, 14 April to 20 May 2010, produced abundant particulate matter due to its explosive eruption style. Even after the volcanic activity ceased, high particulate matter (PM) concentrations were still measured on several occasions, due to resuspended ash. The 24 hour mean concentration of PM10 in the small town of Vík, 38 km SE of the volcano, reached 1230 μg m-3, which is about 25 times the health limit, on 7 May 2010, with 10 min average values over 13,000 μg m-3. Even after the eruption ceased, values as high as 8000 μg m-3 (10 min), and 900 μg m-3 (24 h), were measured because of resuspension of freshly deposited fine ash. In Reykjavík, 125 km WNW of the volcano, the PM10 concentration reached over 2000 μg m-3 (10 min) during an ash storm on 4 June 2010, which should have warranted airport closure. Summarizing, our study reveals the importance of ash resuspension compared to direct volcanic ash emissions. This likely has implications for air quality but could also have detrimental effects on the quality of ash dispersion model predictions, which so far generally do not include this secondary source of volcanic ash.

  5. Zeolite synthesis from a high Si-Al fly ash from East China

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, R.; Umana, J.C.; Querol, X.; Lopez-Soler, A.; Plana, F.; Zhuang, X. [CAS, Beijing (China). Inst. of Geology & Geophysics

    2002-07-01

    A high Al-Si Chinese fly ash from Dou He power plant (Tangshan city, Hebei Province, Eastern China) was selected as starting material of the zeolitisation process. Zeolitic material was obtained by conventional alkaline activation using NaOH and KOH solutions. The process of synthesis was optimised by applying a wide range of reaction temperature, time and activation reagent concentrations. A high solution/fly ash ratio was used in order to dissolve highly resistant Al-Si phases such as mullite. High yields were obtained with both KOH and NaOH solutions. Final products reached a cation exchange capacity (CEC) of up to 2.3 meq g{sup 3}. Major zeolites obtained with a high CEC were: NaP1, KM and F-linde zeolite. The low contents of major impurities of this fly ash enhance the potential application for the synthesis of zeolites for waste-water treatment.

  6. High ash fuels for diesel engines II; Korkean tuhkapitoisuuden omaavan polttoaineen kaeyttoe dieselvoimaloissa II

    Energy Technology Data Exchange (ETDEWEB)

    Norrmen, E.; Vestergren, R.; Svahn, P. [Wartsila Diesel International Ltd, Vaasa (Finland)

    1996-12-01

    Heavy fuel oils containing a large amount of ash, that is used in some geographically restricted areas, can cause problems with deposit formation and hot corrosion, leading to burned exhaust gas valves in some diesel engines. The Liekki 2 programs Use of high ash fuel in diesel power plants I and II have been initiated to clarify the mechanisms of deposit formation, and start and propagation of hot corrosion. The aim is to get enough knowledge to enable the development of the Waertsilae diesel engines to be able to handle heavy fuel with a very high ash content. The chemistry, sintering, melting, and corrosiveness of deposits from different part of the diesel engine and on different exhaust valve materials, as well as the chemistry in different depths of the deposit have been investigated. Theories for the mechanisms mentioned above have been developed. Additives changing the sintering/melting point and physical properties of the formed deposits have been screened. Exhaust gas particle measurements have been performed when running on high ash fuel, both without deposit modifying fuel additive and with. The results have been used to verify the ABC (Aerosol Behaviour in Combustion) model, and the particle chemistry and morphology has been examined. Several tests, also high load endurance tests have been run in diesel engines with high ash fuels. (author)

  7. Prediction of the Chloride Resistance of Concrete Modified with High Calcium Fly Ash Using Machine Learning.

    Science.gov (United States)

    Marks, Michał; Glinicki, Michał A; Gibas, Karolina

    2015-12-11

    The aim of the study was to generate rules for the prediction of the chloride resistance of concrete modified with high calcium fly ash using machine learning methods. The rapid chloride permeability test, according to the Nordtest Method Build 492, was used for determining the chloride ions' penetration in concrete containing high calcium fly ash (HCFA) for partial replacement of Portland cement. The results of the performed tests were used as the training set to generate rules describing the relation between material composition and the chloride resistance. Multiple methods for rule generation were applied and compared. The rules generated by algorithm J48 from the Weka workbench provided the means for adequate classification of plain concretes and concretes modified with high calcium fly ash as materials of good, acceptable or unacceptable resistance to chloride penetration.

  8. High plant availability of phosphorus and low availability of cadmium in four biomass combustion ashes

    DEFF Research Database (Denmark)

    Li, Xiaoxi; Rubæk, Gitte Holton; Sørensen, Peter

    2016-01-01

    of the additive was 20% in ryegrass - much higher than that of barley for which P use efficiencies varied on the two soils. Generally, crop Cd concentrations were little affected by the increasing and high applications of ash, except for relatively high Cd concentrations in barley after applying 25 Mg ha− 1 straw...

  9. Extraction and recovery of polycyclic aromatic hydrocarbons from highly sorptive matrices such as fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Griest, W. H.; Caton, J. E.; Guerin, M. R.; Yeatts, Jr., L. B.; Higgins, C. E.

    1979-01-01

    The highly sorptive nature of some potentially environmentally significant materials such as fly ash may seriously hinder quantitative extraction of their sorbed organic content. Radiolabeled tracers offer a convenient means of probing the sorptive nature of such matrices and of obtaining the corrections for extraction and handling recoveries which are necessary to quantitative analysis.

  10. Effect of adding acid solution on setting time and compressive strength of high calcium fly ash based geopolymer

    Science.gov (United States)

    Antoni, Herianto, Jason Ghorman; Anastasia, Evelin; Hardjito, Djwantoro

    2017-09-01

    Fly ash with high calcium oxide content when used as the base material in geopolymer concrete could cause flash setting or rapid hardening. However, it might increase the compressive strength of geopolymer concrete. This rapid hardening could cause problems if the geopolymer concrete is used on a large scale casting that requires a long setting time. CaO content can be indicated by pH values of the fly ash, while higher pH is correlated with the rapid setting time of fly ash-based geopolymer. This study investigates the addition of acid solution to reduce the initial pH of the fly ash and to prolong the setting time of the mixture. The acids used in this study are hydrochloric acid (HCl), sulfuric acid (H2 SO4), nitric acid (HNO3) and acetic acid (CH3 COOH). It was found that the addition of acid solution in fly ash was able to decrease the initial pH of fly ash, however, the initial setting time of geopolymer was not reduced. It was even faster than that of the control mixture. The acid type causes various influence, depending on the fly ash properties. In addition, the use of acid solution in fly ash reduces the compressive strength of geopolymer mortar. It is concluded that the addition of acid solution cannot prolong the rapid hardening of high calcium fly ash geopolymer, and it causes adverse effect on the compressive strength.

  11. Hydrophobic high surface area zeolites derived from fly ash for oil spill remediation.

    Science.gov (United States)

    Sakthivel, Tamilselvan; Reid, David L; Goldstein, Ian; Hench, Larry; Seal, Sudipta

    2013-06-04

    Fly ash, a coal combustion byproduct with a predominantly aluminosilicate composition, is modified to develop an inexpensive sorbent for oil spill remediation. The as-produced fly ash is a hydrophilic material with poor sorption capacity. A simple two-step chemical modification process is designed to improve the oil sorption capacity. First, the fly ash was transformed to a zeolitic material via an alkali treatment, which increased the specific surface area up to 404 m(2) g(-1). Then, the material was surface functionalized to form a hydrophobic material with high contact angle up to 147° that floats on the surface of an oil-water mixture. The reported oil sorption capacities of X-type zeolite sorbent with different surface functionalization (propyl-, octyl-, octadecyl-trimethoxysilane and esterification) were estimated to 1.10, 1.02, 0.86, and 1.15 g g(-1), respectively. Oil sorption was about five times higher than the as-received fly ash (0.19 g g(-1)) and also had high buoyancy critical for economic cleanup of oil over water.

  12. Fresh properties and compressive strength of high calcium alkali activated fly ash mortar

    Directory of Open Access Journals (Sweden)

    Eslam Gomaa

    2017-10-01

    Full Text Available This paper reports the fresh properties and compressive strength of high calcium alkali-activated fly ash (AAFA mortar. Two different sources of class C fly ash, with different chemical compositions were used to prepare alkali-activated mortar mixtures. Four different sodium silicate to sodium hydroxide (SS/SH ratios of 0.5, 1.0, 1.5, and 2.5 were used as alkaline activators with a constant sodium hydroxide concentration of 10 M. Two curing regimes were also applied, oven curing at 70 °C for 24 h, and ambient curing at 23 ± 2 °C. The rest time, i.e., the time between casting the mortar cubes and starting the oven curing was 2 h. The results revealed that the setting time, and workability of mortar decreased with increasing the alkali to fly ash ratio, and decreasing the water to fly ash ratio. The optimum sodium silicate to sodium hydroxide ratio was 1.0, which showed the highest compressive strength and setting time. An increase of sodium silicate to sodium hydroxide ratio to 2.5 led to a significant reduction in the setting time, and workability of mortar. The 7-day compressive strength of the mortar approached 20.80 MPa for ambient cured regime and 41.10 for oven cured regime.

  13. Mechanically activated fly ash as a high performance binder for civil engineering

    Science.gov (United States)

    Rieger, D.; Kullová, L.; Čekalová, M.; Novotný, P.; Pola, M.

    2017-01-01

    This study is aimed for investigation of fly ash binder with suitable properties for civil engineering needs. The fly ash from Czech brown coal power plant Prunerov II was used and mechanically activated to achieve suitable particle size for alkaline activation of hardening process. This process is driven by dissolution of aluminosilicate content of fly ash and by subsequent development of inorganic polymeric network called geopolymer. Hardening kinetics at 25 and 30 °C were measured by strain controlled small amplitude oscillatory rheometry with strain of 0.01 % and microstructure of hardened binder was evaluated by scanning electron microscopy. Strength development of hardened binder was investigated according to compressional and flexural strength for a period of 180 days. Our investigation finds out, that mechanically activated fly ash can be comparable to metakaolin geopolymers, according to setting time and mechanical parameters even at room temperature curing. Moreover, on the bases of long time strength development, achieved compressional strength of 134.5 after 180 days is comparable to performance of high grade Portland cement concretes.

  14. Influence of Utilization of High-Volumes of Class F Fly Ash on the Abrasion Resistance of Concrete

    Directory of Open Access Journals (Sweden)

    William PRINCE

    2007-01-01

    Full Text Available Utilization of large volumes of fly ash in various concrete applications is a becoming a more general practice in an efforts towards using large quantities of fly ash. Around the world, Class C or Class F or both as available have been used in high volumes in cement-based materials. In India, majority of fly generated is of Class F type as per ASTM C 618. Yearly fly ash generation in India is approximately 95 million tonnes. Out of which around 15-20% is utilized in cement production and cement/concrete related activities. In order to increase its percentage utilization, an investigation was carried out to use it in concrete.In this paper, abrasion resistance of high volume fly ash (HVFA concretes made with 35, 45, 55, and 65% of cement replacement was evaluated in terms of its relation with compressive strength. Comparison was made between ordinary Portland cement and fly ash concrete. Test results indicated that abrasion resistance of concrete having cement replacement up to 35 percent was comparable to the normal concrete mix with out fly ash. Beyond 35% cement replacement, fly ash concretes exhibited slightly lower resistance to abrasion relative to non-fly ash concretes. Test results further indicated that abrasion resistance of concrete is closely related with compressive strength, and had a very good correlation between abrasion resistance and compressive strength (R2 value between 0.9018 and 0.9859 depending upon age.

  15. Ash deposition and high temperature corrosion at combustion of aggressive fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hede Larsen, O. [I/S Fynsvaerket, Faelleskemikerne, Odense (Denmark); Henriksen, N. [Elsamprojekt A/S, Faelleskemikerne, Fredericia (Denmark)

    1996-12-01

    In order to reduce CO{sub 2} emission, ELSAM is investigating the possibilities of using biomass - mainly straw - for combustion in high efficiency power plants. As straw has very high contents of chlorine and potassium, a fuel with high corrosion and ash deposition propensities has been introduced. ELSAM has investigated 3 ultra supercritical boiler concepts for combustion of straw alone or together with coal: (1) PF boilers with a relatively low share of straw, (2) CFB boilers with low to high share of straw and (3) vibrating grate boilers with 100% straw. These investigations has mainly been full-scale tests with straw fed into existing boilers. Corrosion tests have been performed in these boilers using temperature regulated probes and in-plant test tubes in existing superheaters. The corrosion has been determined by detailed measurements of wall thickness reduction and light optical microscopic measurements of the material degradation due to high temperature corrosion. Corrosion mechanisms have been evaluated using SEM/EDX together with thermodynamical considerations based on measurements of the chemical environment in the flue gas. Ash deposition is problematic in CFB boilers and in straw fired boilers, especially in years with high potassium and chlorine content of the straw. This ash deposition also is related to condensation of KCl and can probably only be handled by improved cleaning devices. (EG)

  16. Radiolarian zonation and volcanic ash layers in two Quaternary sediment cores from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.

    and redistribution of Pliocene taxa by a bottom water current (probably Antarctic Bottom Water Current). Volcanic ash layers of apparently about 20,000; 30,000 - 40,000; 80,000; 340,000 and younger than 4000,000 years are also recognised, which suggest suboceanic...

  17. Optimisation of nano-silica modified self-compacting high-Volume fly ash mortar

    Science.gov (United States)

    Achara, Bitrus Emmanuel; Mohammed, Bashar S.; Fadhil Nuruddin, Muhd

    2017-05-01

    Evaluation of the effects of nano-silica amount and superplasticizer (SP) dosage on the compressive strength, porosity and slump flow on high-volume fly ash self-consolidating mortar was investigated. Multiobjective optimisation technique using Design-Expert software was applied to obtain solution based on desirability function that simultaneously optimises the variables and the responses. A desirability function of 0.811 gives the optimised solution. The experimental and predicted results showed minimal errors in all the measured responses.

  18. High spatial resolution spectral unmixing for mapping ash species across a complex urban environment

    Science.gov (United States)

    Jennifer Pontius; Ryan P. Hanavan; Richard A. Hallett; Bruce D. Cook; Lawrence A. Corp

    2017-01-01

    Ash (Fraxinus L.) species are currently threatened by the emerald ash borer (EAB; Agrilus planipennis Fairmaire) across a growing area in the eastern US. Accurate mapping of ash species is required to monitor the host resource, predict EAB spread and better understand the short- and long-term effects of EAB on the ash resource...

  19. Equilibrium and kinetic mechanism for Reactive Black 5 sorption onto high lime Soma fly ash.

    Science.gov (United States)

    Eren, Zeynep; Acar, Filiz Nuran

    2007-05-08

    Batch adsorption studies were carried out for the sorption of C.I. Reactive Black 5, a reactive dye, onto high lime fly ash, obtained from Soma Thermal Power Plant (Turkey), to be low cost adsorbent. The effect of various experimental parameters such as contact time, adsorbent dose and initial dye concentration were investigated. Determination of the adsorption equilibrium concentrations was determined by UV-vis spectrophotometry analytical method. Equilibrium data were fitted to the Freundlich and Langmuir isotherm equations and the equilibrium data were found to be well represented by the Freundlich isotherm equation. The adsorption kinetics of C.I. Reactive Black 5 onto high lime fly ash were also studied to characterize of the surface complexation reaction. A pseudo-second-order mechanism has been developed to predict the rate constant of the adsorption, the equilibrium capacity and initial adsorption rate with the effect of initial concentration. A single-stage batch adsorber design of the adsorption of C.I. Reactive Black 5 onto high lime fly ash has been studied based on the Freundlich isotherm equation.

  20. A High-Resolution Map of Emerald Ash Borer Invasion Risk for Southern Central Europe

    Directory of Open Access Journals (Sweden)

    Viktoria Valenta

    2015-08-01

    Full Text Available Ash species (Fraxinus spp. in Europe are threatened by the Emerald Ash Borer (Agrilus planipennis, EAB, an invasive wood boring beetle native to East Asia and currently spreading from European Russia westwards. Based on a high-resolution habitat distribution map (grid cell size: 25 × 25 m and data on distribution and abundance of Common Ash (Fraxinus excelsior, the most widespread and highly susceptive host species of EAB in Europe, we assess the spatial distribution of EAB invasion risks for southern Central Europe (Austria, Switzerland, Liechtenstein, southern Germany, South Tyrol. We found highest F. excelsior abundance and thus invasion risks in extensive lowland floodplain forests, medium risks in zonal lowland forests and low risks in upper montane and subalpine forests. Based on average velocities of spread in Russia (13–31 km/year and North America (2.5–80 km/year from flight and human-assisted transport, EAB is likely to cover the distance (1500 km between its current range edge in western Russia and the eastern border of the study region within few decades. However, secondary spread by infested wood products make earlier introductions likely. The high susceptibility and mortality of F. excelsior leave no doubt that this beetle will become a major forest pest once it reaches Central Europe. Therefore, developing and testing management approaches with the aim to halt or at least slow down the invasion of EAB in Europe have to be pursued with great urgency.

  1. Radiating heat transfer in the power boiler downtake gas duct when firing high-ash coal

    Energy Technology Data Exchange (ETDEWEB)

    Sudarev, A.V.; Antonovsky, V.I.; Kiselev, O.V.; Sivchikov, S.B. (VTUS-Leningrad Metal Plant-LMZ, Leningrad (USSR))

    1990-01-01

    The experimental study of radiation heat transfer in the downtake gas duct of the pulverized-coal fired steam boiler for 500 MW power unit when firing high-ash (40% ash content) coal from Ekibastuz coal field was carried out by means of the radiometer probe with rotary optical axis. The local values of the combustion product temperature were measured simultaneously in the down-take and the operation parameters for boiler gas and steam ducts were registered. The dependence of the extinction coefficient of combustion products on the radiating layer thickness was obtained. The radiating power, generated in the gas space, remote from the steam superheater and reaching the super heater boundaries, was measured. The heat release coefficients from radiation and heat transfer coefficients, were determined for definite operation conditions of the superheater working. The contribution of the gas space outside the steam superheater into the radiating heat transfer negligible.

  2. Performance at high temperature of alkali-activated slag pastes produced with silica fume and rice husk ash based activators

    National Research Council Canada - National Science Library

    Bernal, S. A; Rodríguez, E. D; Mejía de Gutiérrez, R; Provis, J. L

    2015-01-01

    This study assessed the mechanical properties, and structural changes induced by high temperature exposure, of alkali-silicate activated slag cements produced with sodium silicates derived from silica fume (SF) and rice husk ash (RHA...

  3. Sewage sludge ash (SSA in high performance concrete: characterization and application

    Directory of Open Access Journals (Sweden)

    C. M. A. Fontes

    Full Text Available ABSTRACT Sewage sludge originated from the process of treatment of wastewater has become an environmental issue for three main reasons: contains pathogens, heavy metals and organic compounds that are harmful to the environmental and human health; high volumes are daily generated; and shortage of landfill sites for proper disposal. This research deals with the viability study of sewage sludge utilization, after calcination process, as mineral admixture in the production of concrete. High-performance concretes were produced with replacement content of 5% and 10% by weight of Portland cement with sewage sludge ash (SSA. The influence of this ash was analyzed through physical and mechanical tests. Analysis showed that the mixtures containing SSA have lower values of compressive strength than the reference. The results of absorptivity, porosity and accelerated penetration of chloride ions, presents that mixtures containing ash showed reductions compared to the reference. This indicates that SSA provided refinement of the pore structure, which was confirmed by mercury intrusion porosimetry test.

  4. Statistical evaluation of the mechanical properties of high-volume class F fly ash concretes

    KAUST Repository

    Yoon, Seyoon

    2014-03-01

    High-Volume Fly Ash (HVFA) concretes are seen by many as a feasible solution for sustainable, low embodied carbon construction. At the moment, fly ash is classified as a waste by-product, primarily of thermal power stations. In this paper the authors experimentally and statistically investigated the effects of mix-design factors on the mechanical properties of high-volume class F fly ash concretes. A total of 240 and 32 samples were produced and tested in the laboratory to measure compressive strength and Young\\'s modulus respectively. Applicability of the CEB-FIP (Comite Euro-international du Béton - Fédération Internationale de la Précontrainte) and ACI (American Concrete Institute) Building Model Code (Thomas, 2010; ACI Committee 209, 1982) [1,2] to the experimentally-derived mechanical property data for HVFA concretes was established. Furthermore, using multiple linear regression analysis, Mean Squared Residuals (MSRs) were obtained to determine whether a weight- or volume-based mix proportion is better to predict the mechanical properties of HVFA concrete. The significance levels of the design factors, which indicate how significantly the factors affect the HVFA concrete\\'s mechanical properties, were determined using analysis of variance (ANOVA) tests. The results show that a weight-based mix proportion is a slightly better predictor of mechanical properties than volume-based one. The significance level of fly ash substitution rate was higher than that of w/b ratio initially but reduced over time. © 2014 Elsevier Ltd. All rights reserved.

  5. ashing, non-ashing

    African Journals Online (AJOL)

    cistvr

    Three commonly used techniques, namely atomic absorption spectrophotometry (AAS-Ashing and. AAS-Non Ashing) and titrimetry (potassium permanganate titration) have been evaluated in this study to determine the calcium content in six food samples whose calcium levels ranged from 0 to more than. 250mg/100g ...

  6. High resolution numerical weather prediction over the Indian ...

    Indian Academy of Sciences (India)

    In this study, the Florida State University Global Spectral Model (FSUGSM), in association with a high-resolution nested regional spectral model (FSUNRSM), is used for short-range weather forecasts over the Indian domain. Three-day forecasts for each day of August 1998 were performed using different versions of the ...

  7. Impact of high resolution land surface initialization in Indian summer ...

    Indian Academy of Sciences (India)

    The direct impact of high resolution land surface initialization on the forecast bias in a regional climatemodel in recent years over Indian summer monsoon region is investigated. Two sets of regional climatemodel simulations are performed, one with a coarse resolution land surface initial conditions and secondone used a ...

  8. Quartz in ash, and air in a high lung cancer incidence area in China.

    Science.gov (United States)

    Downward, George S; Hu, Wei; Rothman, Nat; Reiss, Boris; Tromp, Peter; Wu, Guoping; Wei, Fusheng; Xu, Jun; Seow, Wei Jie; Chapman, Robert S; Lan, Qing; Vermeulen, Roel

    2017-02-01

    Exposure to crystalline silica (quartz) has been implicated as a potential cause of the high lung cancer rates in the neighbouring counties of Xuanwei and Fuyuan, China, where the domestic combustion of locally sourced "smoky" coal (a bituminous coal) is responsible for some of the highest lung cancer rates in the nation, irrespective of gender or smoking status. Previous studies have shown that smoky coal contains approximately twice as much quartz when compared to alternative fuels in the area, although it is unclear how the quartz in coal relates to household air pollution. Samples of ash and fine particulate matter (PM 2.5 ) were collected from 163 households and analysed for quartz content by Fourier transformed infrared spectroscopy (FT-IR). Additionally, air samples from 12 further households, were analysed by scanning electron microscopy (SEM) to evaluate particle structure and silica content. The majority (89%) of household air samples had undetectable quartz levels (quartz in smoky coal went on to form part of the ash. These findings indicate that the quartz within smoky coal does not become adequately airborne during the combustion process to cause significant lung cancer risk, instead going on to form part of the ash. The identification of fibre-like particles in air samples is an interesting finding, although the clinical relevance of this finding remains unclear. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Review: Potential Strength of Fly Ash-Based Geopolymer Paste with Substitution of Local Waste Materials with High-Temperature Effect

    Science.gov (United States)

    Subekti, S.; Bayuaji, R.; Darmawan, M. S.; Husin, N. A.; Wibowo, B.; Anugraha, B.; Irawan, S.; Dibiantara, D.

    2017-11-01

    This research provided an overview of the potential fly ash based geopolymer paste for application in building construction. Geopolymer paste with various variations of fly ash substitution with local waste material and high-temperature influence exploited with the fresh and hardened condition. The local waste material which utilized for this study were sandblasting waste, carbide waste, shell powder, bagasse ash, rice husk and bottom ash. The findings of this study indicated that fly-based geopolymer paste with local waste material substitution which had high-temperature influence ash showed a similar nature of OPC binders potentially used in civil engineering applications.

  10. High Strength Lightweight Concrete Made with Ternary Mixtures of Cement-Fly Ash-Silica Fume and Scoria as Aggregate

    OpenAIRE

    Yaşar, Ergül; ATIŞ, Cengiz Duran; KILIÇ, Alaettin

    2004-01-01

    This paper presents part of the results of an ongoing laboratory study carried out to design a structural lightweight high strength concrete (SLWHSC) made with and without ternary mixtures of cement-fly ash-silica fume. In the mixtures, lightweight basaltic-pumice (scoria) aggregate was used. A concrete mixture made with lightweight scoria, and another lightweight scoria concrete mixture incorporating 20% fly ash and 10% silica fume as a cement replacement, were prepared. Two normal...

  11. Use of high ash fuel in diesel power plants II; Korkean tuhkapitoisuuden omaavan polttoaineen kaeyttoe dieselvoimaloissa II

    Energy Technology Data Exchange (ETDEWEB)

    Vestergren, R.; Normen, E.; Hellen, G. [Wartsila Diesel International Ltd Oy, Vaasa (Finland)] [and others

    1997-10-01

    Heavy fuel oils containing a large amount of ash are used in some geographically restricted areas. The ash components can cause problems with deposit formation and hot corrosion, leading to burned exhaust gas valves in some diesel engines. The LIEKKI 2 programs Use of high ash fuel in diesel power plants, Part I and II, have been initiated to clarify the mechanisms of deposit formation, and start and propagation of hot corrosion. The aim is to get enough knowledge to enable the development of the Waertsilae diesel engines to be able to handle heavy fuels with a very high ash content. The chemistry during combustion has been studied. The chemical and physical properties of the particles in the exhaust gas, of the deposits, and of exhaust valves have been investigated. Exhaust gas particle measurements have been performed when running on high ash fuel, both with and without deposit modifying fuel additive. Theories for the mechanisms mentioned above have been developed. On the practical side two long time field tests are going on, one with an ash/deposit modifying fuel additive (vanadium chemistry alteration), one with fuel water washing (sodium removal). Seven different reports have been written. (orig.)

  12. Understanding and integrating native knowledge to determine and identify high quality ash resources

    Science.gov (United States)

    Suzanne Greenlaw; Marla R. Emery; Robin W. Kimmerer; Michael. Bridgen

    2010-01-01

    Black ash (Fraxinus nigra) is spiritually, economically, and culturally connected to Native American tribes throughout its range. Considered a cultural keystone species, black ash can be pounded and split along its growth rings to produce exceptionally strong and pliable strips to weave into baskets. Black ash harvesters and basketmakers (...

  13. High tensile strength fly ash based geopolymer composite using copper coated micro steel fiber

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mehdi; Mehrali, Mohammad

    2016-01-01

    As a ceramic-like material, geopolymers show a high quasi-brittle behavior and relatively low fracture energy. To overcome this, the addition of fibers to a brittle matrix is a well-known method to improve the flexural strength. Moreover, the success of the reinforcements is dependent on the fiber...... of 56 days. Test results confirmed that MSF additions could significantly improve both ultimate flexural capacity and ductility of fly ash based geopolymer, especially at early ages without an adverse effect on ultimate compressive strength....

  14. A Highly Selective Photoresist Ashing Process for Silicon Nitride Films by Addition of Trifluoromethane

    Science.gov (United States)

    Saito, Makoto; Eto, Hideo; Makino, Nobuaki; Omiya, Kayoko; Homma, Tetsuya; Nagatomo, Takao

    2001-09-01

    A highly selective photoresist ashing process was developed for the fabrication of thin-film transistor liquid-crystal displays (TFT-LCDs). This ashing process utilizes downflow plasma consisting of a carbon trifluoromethane/oxygen (CHF3/O2) gas mixture at a low temperature. The etching selectivity of photoresist films to silicon nitride (SiN) film increased when using the CHF3/O2 gas mixture plasma, as compared to that when using the carbon tetrafluoride/oxygen (CF4/O2) gas mixture plasma. At the CHF3 gas flow rate of 30 sccm, a high etching selectivity ratio of about 1080 for the photoresist films to the SiN films was achieved at room temperature. On the basis of surface analysis results for SiN films and plasma analysis results for the CHF3/O2 gas mixture, a mechanism for the high etching selectivity of the photoresist films was proposed. Reaction products that were formed on SiN films by the CHF3/O2 gas mixture plasma obstructed the etching of SiN films by fluorine (F) radicals, resulting in the high selectivity. It was found that the CHF3/O2 gas mixture plasma reacted with SiN, resulting in the formation of a protective reaction product that is considered to be an ammonium salt such as (NH4)2SiF6.

  15. Properties of high calcium fly ash geopolymer pastes with Portland cement as an additive

    Science.gov (United States)

    Phoo-ngernkham, Tanakorn; Chindaprasirt, Prinya; Sata, Vanchai; Pangdaeng, Saengsuree; Sinsiri, Theerawat

    2013-02-01

    The effect of Portland cement (OPC) addition on the properties of high calcium fly ash geopolymer pastes was investigated in the paper. OPC partially replaced fly ash (FA) at the dosages of 0, 5%, 10%, and 15% by mass of binder. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions were used as the liquid portion in the mixture: NaOH 10 mol/L, Na2SiO3/NaOH with a mass ratio of 2.0, and alkaline liquid/binder (L/B) with a mass ratio of 0.6. The curing at 60°C for 24 h was used to accelerate the geopolymerization. The setting time of all fresh pastes, porosity, and compressive strength of the pastes at the stages of 1, 7, 28, and 90 d were tested. The elastic modulus and strain capacity of the pastes at the stage of 7 d were determined. It is revealed that the use of OPC as an additive to replace part of FA results in the decreases in the setting time, porosity, and strain capacity of the paste specimens, while the compressive strength and elastic modulus seem to increase.

  16. Compression Behavior of Confined Columns with High-Volume Fly Ash Concrete

    Directory of Open Access Journals (Sweden)

    Sung-Won Yoo

    2017-01-01

    Full Text Available The use of fly ash in ordinary concrete provides practical benefits to concrete structures, such as a gain in long-term strength, reduced hydration heat, improved resistance to chloride, and enhanced workability. However, few studies with high-volume fly ash (HVFA concrete have been conducted that focus on the structural applications such as a column. Thus, there is a need to promote field applications of HVFA concrete as a sustainable construction material. To this end, this study investigated the compressive behavior of reinforced concrete columns that contain HVFA with a 50 percent replacement rate. Six columns were fabricated for this study. The study variables were the HVFA replacement rate, tied steel ratio, and tie steel spacing. The computed ultimate strength by the American Concrete Institute (ACI code conservatively predicted the measured values, and, thus, the existing equation in the ACI code is feasible for confined RC columns that contain HVFA. In addition, an analysis model was calibrated based on the experimental results and is recommended for predicting the stress-strain relationship of confined reinforced concrete columns that contain HVFA.

  17. Impact of Micro Silica on the properties of High Volume Fly Ash Concrete (HVFA)

    Science.gov (United States)

    Sripragadeesh, R.; Ramakrishnan, K.; Pugazhmani, G.; Ramasundram, S.; Muthu, D.; Venkatasubramanian, C.

    2017-07-01

    In the current situation, to overcome the difficulties of feasible construction, concrete made with various mixtures of Ordinary Portland Cement (OPC) and diverse mineral admixtures, is the wise choice for engineering construction. Mineral admixtures viz. Ground Granulated Blast Furnace Slag (GGBS), Meta kaolin (MK), Fly Ash (FA) and Silica Fume (SF) etc. are used as Supplementary Cementitious Materials (SCM) in binary and ternary blend cement system to enhance the mechanical and durability properties. Investigation on the effect of different replacement levels of OPC in M25 grade with FA + SF in ternary cement blend on the strength characteristics and beam behavior was studied. The OPC was partially replaced (by weight) with different combinations of SF (5%, 10%, 15%, 20% and 25%) and FA as 50% (High Volume Fly Ash - HVFA). The amount of FA addition is kept constant at 50% for all combinations. The compressive strength and tensile strength tests on cube and cylinder specimens, at 7 and 28 days were carried out. Based on the compressive strength results, optimum mix proportion was found out and flexural behaviour was studied for the optimum mix. It was found that all the mixes (FA + SF) showed improvement in compressive strength over that of the control mix and the mix with 50% FA + 10% SF has 20% increase over the control mix. The tensile strength was also increased over the control mix. Flexural behaviour also showed a significant improvement in the mix with FA and SF over the control mix.

  18. Gasification of high ash content coals with steam in a semibatch fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schmal, M.; Monterio, J.L.F.; Toscani, M.

    1983-10-01

    This work reports a study on gasification of Brazilian mineral subbituminous coal with steam in a semibatch fluidized bed reactor. Several tests for the fluidization characteristics of mixtures of coal and ash were performed. Fluidization velocity was determined from the data of the minimum velocity, calculated at high temperatures and later tested. Experimental results show that flow conditions must be determined experimentally for high temperatures and pressures. The influence of temperature and pressure on product gases during the reaction and on the ratio CO/CO/sub 2/ were determined. The reaction rate is very sensitive to temperature variations between 850 and 1000 /sup 0/C. For pressures higher than 10 atm the effect of the pressure on reaction rate is negligible. The experimental results are well described by the unreacted core model above 850 /sup 0/C where the chemical reaction is the rate controlling step. The activation energy was found to be 39 kcal/mol.

  19. The maximum percentage of fly ash to replace part of original Portland cement (OPC) in producing high strength concrete

    Science.gov (United States)

    Mallisa, Harun; Turuallo, Gidion

    2017-11-01

    This research investigates the maximum percent of fly ash to replace part of Orginal Portland Cement (OPC) in producing high strength concrete. Many researchers have found that the incorporation of industrial by-products such as fly ash as in producing concrete can improve properties in both fresh and hardened state of concrete. The water-binder ratio was used 0.30. The used sand was medium sand with the maximum size of coarse aggregate was 20 mm. The cement was Type I, which was Bosowa Cement produced by PT Bosowa. The percentages of fly ash to the total of a binder, which were used in this research, were 0, 10, 15, 20, 25 and 30%; while the super platicizer used was typed Naptha 511P. The results showed that the replacement cement up to 25 % of the total weight of binder resulted compressive strength higher than the minimum strength at one day of high-strength concrete.

  20. High-efficiency cogeneration boiler bagasse-ash geochemistry and mineralogical change effects on the potential reuse in synthetic zeolites, geopolymers, cements, mortars, and concretes.

    Science.gov (United States)

    Clark, Malcolm W; Despland, Laure M; Lake, Neal J; Yee, Lachlan H; Anstoetz, Manuela; Arif, Elisabeth; Parr, Jeffery F; Doumit, Philip

    2017-04-01

    Sugarcane bagasse ash re-utilisation has been advocated as a silica-rich feed for zeolites, pozzolans in cements and concretes, and geopolymers. However, many papers report variable success with the incorporation of such materials in these products as the ash can be inconsistent in nature. Therefore, understanding what variables affect the ash quality in real mills and understanding the processes to characterise ashes is critical in predicting successful ash waste utilisation. This paper investigated sugarcane bagasse ash from three sugar mills (Northern NSW, Australia) where two are used for the co-generation of electricity. Data shows that the burn temperatures of the bagasse in the high-efficiency co-generation boilers are much higher than those reported at the temperature measuring points. Silica polymorph transitions indicate the high burn temperatures of ≈1550 °C, produces ash dominated α -quartz rather than expected α-cristobilite and amorphous silica; although α-cristobilite, and amorphous silica are present. Furthermore, burn temperatures must be ≤1700 °C, because of the absence of lechatelierite where silica fusing and globulisation dominates. Consequently, silica-mineralogy changes deactivate the bagasse ash by reducing silica solubility, thus making bagasse ash utilisation in synthetic zeolites, geopolymers, or a pozzolanic material in mortars and concretes more difficult. For the ashes investigated, use as a filler material in cements and concrete has the greatest potential. Reported mill boiler temperatures discrepancies and the physical characteristics of the ash, highlight the importance of accurate temperature monitoring at the combustion seat if bagasse ash quality is to be prioritised to ensure a usable final ash product.

  1. High-efficiency cogeneration boiler bagasse-ash geochemistry and mineralogical change effects on the potential reuse in synthetic zeolites, geopolymers, cements, mortars, and concretes

    Directory of Open Access Journals (Sweden)

    Malcolm W. Clark

    2017-04-01

    Full Text Available Sugarcane bagasse ash re-utilisation has been advocated as a silica-rich feed for zeolites, pozzolans in cements and concretes, and geopolymers. However, many papers report variable success with the incorporation of such materials in these products as the ash can be inconsistent in nature. Therefore, understanding what variables affect the ash quality in real mills and understanding the processes to characterise ashes is critical in predicting successful ash waste utilisation. This paper investigated sugarcane bagasse ash from three sugar mills (Northern NSW, Australia where two are used for the co-generation of electricity. Data shows that the burn temperatures of the bagasse in the high-efficiency co-generation boilers are much higher than those reported at the temperature measuring points. Silica polymorph transitions indicate the high burn temperatures of ≈1550 °C, produces ash dominated α −quartz rather than expected α-cristobilite and amorphous silica; although α-cristobilite, and amorphous silica are present. Furthermore, burn temperatures must be ≤1700 °C, because of the absence of lechatelierite where silica fusing and globulisation dominates. Consequently, silica-mineralogy changes deactivate the bagasse ash by reducing silica solubility, thus making bagasse ash utilisation in synthetic zeolites, geopolymers, or a pozzolanic material in mortars and concretes more difficult. For the ashes investigated, use as a filler material in cements and concrete has the greatest potential. Reported mill boiler temperatures discrepancies and the physical characteristics of the ash, highlight the importance of accurate temperature monitoring at the combustion seat if bagasse ash quality is to be prioritised to ensure a usable final ash product.

  2. Ultrasonic characterization of GRC with high percentage of fly ash substitution.

    Science.gov (United States)

    Genovés, V; Gosálbez, J; Miralles, R; Bonilla, M; Payá, J

    2015-07-01

    New applications of non-destructive techniques (NDT) with ultrasonic tests (attenuation and velocity by means of ultrasonic frequency sweeps) have been developed for the characterization of fibre-reinforced cementitious composites. According to new lines of research on glass-fibre reinforced cement (GRC) matrix modification, two similar GRC composites with high percentages of fly ash and different water/binder ratios will be studied. Conventional techniques have been used to confirm their low Ca(OH)(2) content (thermogravimetry), fibre integrity (Scanning Electron Microscopy), low porosity (Mercury Intrusion Porosimetry) and good mechanical properties (compression and four points bending test). Ultrasound frequency sweeps allowed the estimation of the attenuation and pulse velocity as functions of frequency. This ultrasonic characterization was correlated successfully with conventional techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Influence of portland cement replacement in high calcium fly ash geopolymer paste

    Directory of Open Access Journals (Sweden)

    Tanakorn Phoo-ngernkham

    2014-03-01

    Full Text Available This article presents the influence of ordinary Portland cement (OPC replacement in high calcium fly ash (FA geopolymer paste. FA was used to replace OPC at the rate of 5, 10 and 15% by mass of binder. Sodium silicate (Na2SiO3 and 10 molar sodium hydroxide (NaOH solutions were used as the alkaline solution in the reaction. The Na2SiO3/NaOH ratio of 2.0 and the liquid/binder (L/B ratio of 0.60 were used in all mixtures. The results of increase OPC replacement, the setting time and compressive strain capacity decreased while the compressive strength and modulus of elasticity increased. The compressive strength and modulus of elasticity at 28 days of geopolymer pastes with 15% OPC replacement were 36.7 MPa and 13,300 MPa, respectively.

  4. Gasification of high ash content coals with steam in a semibatch fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schmal, M.

    1983-10-01

    The work reports a study of gasification of a Brazilian subbituminous coal with steam in a semi-batch fluidized bed reactor. Several tests of the fluidization characteristics of mixtures of coal and ash were carried out. Experimental results show that flow conditions must be determined experimentally for high temperatures and pressures. The influences of temperature and pressure on product gases and on the CO/CO/sub 2/ ratio were determined. The reaction is very sensitive to temperature variations between 850 and 1000 C. For pressures above 10 atm, the effect of pressure on the reaction rate is negligible. The experimental results are well described by the uncreacted core model above 850 C where the chemical reaction is the rate-controlling step.

  5. Rice husk ash with high carbon content proves favourable for soil stabilization

    NARCIS (Netherlands)

    Pham, P.V.; van der Star, WRL; van Paassen, L.A.; Ye, G.

    2015-01-01

    Rice husk ash is a promising pozzolanic material produced from rice husk burning and has significant potential a sustainable replacement for cement in construction and ground improvement applications. In this study the effect of burning conditions on the ash reactivity and its potential for soil

  6. 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.

  7. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals

    Energy Technology Data Exchange (ETDEWEB)

    Boca Santa, Rozineide A. Antunes, E-mail: roosebs@gmail.com; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Highlights: • Geopolymers from bottom ash and metakaolin (BA/M). • Solidification/immobilization (S/I) waste of heavy metals. • Activators: Sodium hydroxide (NaOH), potassium hydroxide (KOH) and sodium silicate (Na{sub 2}SiO{sub 3}). - Abstract: Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1 wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30 ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12 M in the composition of Na{sub 2}SiO{sub 3} in 1:2 vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%.

  8. High stenghth concrete with high cement substitution by adding fly ash, CaCO3, silica sand, and superplasticizer

    Science.gov (United States)

    Wicaksono, Muchammad Ridho Sigit; Qoly, Amelia; Hidayah, Annisaul; Pangestuti, Endah Kanti

    2017-03-01

    Concrete is a mixture of cement, fine aggregate, coarse aggregate and water with or without additives. Concrete can be made with substitution of cement with materials like Fly Ash, CaCO3 and silica sand that can increase the binding on pasta and also increase the compressive strength of concrete. The Superplasticizer on a mixture is used to reduce the high water content, improve concrete durability, low permeability concrete by making it more resilient, and improve the quality of concrete. The combination between Fly Ash (30% of cement required), CaCO3 (10% of cement required) and silica sand (5% of cement required) with added MasterGlenium ACE 8595 as much as 1,2% from total cement will produces compressive strength of up to 1080 kN/cm2 or 73,34 Mpa when the concrete is aged at 28 day. By using this technique and innovation, it proves that the cost reduction is calculated at 27%, which is much more efficient. While the strength of the concrete is increased at 5% compared with normal mixture.

  9. High resolution 3D confocal microscope imaging of volcanic ash particles.

    Science.gov (United States)

    Wertheim, David; Gillmore, Gavin; Gill, Ian; Petford, Nick

    2017-07-15

    We present initial results from a novel high resolution confocal microscopy study of the 3D surface structure of volcanic ash particles from two recent explosive basaltic eruptions, Eyjafjallajökull (2010) and Grimsvötn (2011), in Iceland. The majority of particles imaged are less than 100μm in size and include PM10s, known to be harmful to humans if inhaled. Previous studies have mainly used 2D microscopy to examine volcanic particles. The aim of this study was to test the potential of 3D laser scanning confocal microscopy as a reliable analysis tool for these materials and if so to what degree high resolution surface and volume data could be obtained that would further aid in their classification. First results obtained using an Olympus LEXT scanning confocal microscope with a ×50 and ×100 objective lens are highly encouraging. They reveal a range of discrete particle types characterised by sharp or concave edges consistent with explosive formation and sudden rupture of magma. Initial surface area/volume ratios are given that may prove useful in subsequent modelling of damage to aircraft engines and human tissue where inhalation has occurred. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Evaluation of the Chemical and Mechanical Properties of Hardening High-Calcium Fly Ash Blended Concrete.

    Science.gov (United States)

    Fan, Wei-Jie; Wang, Xiao-Yong; Park, Ki-Bong

    2015-09-07

    High-calcium fly ash (FH) is the combustion residue from electric power plants burning lignite or sub-bituminous coal. As a mineral admixture, FH can be used to produce high-strength concrete and high-performance concrete. The development of chemical and mechanical properties is a crucial factor for appropriately using FH in the concrete industry. To achieve sustainable development in the concrete industry, this paper presents a theoretical model to systematically evaluate the property developments of FH blended concrete. The proposed model analyzes the cement hydration, the reaction of free CaO in FH, and the reaction of phases in FH other than free CaO. The mutual interactions among cement hydration, the reaction of free CaO in FH, and the reaction of other phases in FH are also considered through the calcium hydroxide contents and the capillary water contents. Using the hydration degree of cement, the reaction degree of free CaO in FH, and the reaction degree of other phases in FH, the proposed model evaluates the calcium hydroxide contents, the reaction degree of FH, chemically bound water, porosity, and the compressive strength of hardening concrete with different water to binder ratios and FH replacement ratios. The evaluated results are compared to experimental results, and good consistencies are found.

  11. The high strain rate compressive response of Mg-Al alloy/fly Ash cenosphere composites

    Science.gov (United States)

    Luong, Dung D.; Gupta, Nikhil; Rohatgi, Pradeep K.

    2011-02-01

    The strain rate dependence of mechanical properties of AZ91D alloy composites filled with 5 wt.% hollow fly ash cenosphere is examined in the strain rate range of 630-1,203 s-1 using a split-Hopkinson pressure bar system. In addition, a test scheme is designed to study the intermediate strain rate response of the material. Addition of fly ash caused grain refinement and finer precipitates in the matrix alloy. Compared to the matrix alloy, the energy absorption is higher in AZ91D/fly ash cenosphere composites at comparable strain rates. In addition, the yield strength is found to be about 19-41% higher in the composites containing fly ash cenospheres.

  12. Dust separation at high temperatures a method for cleaning fly ashes? Final report; Stoftavskiljning vid hoeg temperatur en metod foer rening av flygaska? Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Zintl, Frank [TPS Termiska Processer AB, Nykoeping (Sweden)

    2002-12-01

    An experimental study of separation of fly ashes by a filter at high temperatures, 300-650 deg C, with the purpose to study: Capture of heavy metals (Cd, Hg, Pb, Zn) in the fly ash; Relation between heavy metal capture and temperature; Relation between heavy metal capture and the availability of fuel chlorine. Pelletized forestry waste fuel was doped with heavy metals in two different forms. Pelletized Salix was also used, without doping. The study shows that: There is a strong inverse relation between the capture of heavy metals and the filter temperature; There is a strong relation between the availability of chlorine and the capture of heavy metals. Separation at 300-650 deg C gives much less heavy metals in the fly ash, however the ash is not clean enough to allow disposal in ordinary landfills. Thus, high temperature filtering does not seem to be a promising solution for producing 'clean' fly ash.

  13. Evaluation of the Battelle Agglomerating Ash Burner High Btu Coal Gasification Process

    Energy Technology Data Exchange (ETDEWEB)

    Malow, M.; West, A.S.

    1978-06-01

    The economics of the Battelle Agglomerating Ash Burner Process for the production of high Btu gas (SNG) from coal has been evaluated. A conceptual process design including process flowsheets, heat and material balances and equipment specifications has been prepared. Capital costs, operating costs and gas costs have been developed using the CFBraun ''Gas Cost Guidelines''. The estimated capital and gas costs for the Battelle process have been compared to the alternative high Btu processes described in CFBraun's ''Factored Estimates for Western Coal Commercial Concepts'' and were found to be economically unattractive. Some of the reasons for the higher capital cost and gas costs for the Battelle process are: Low Gasifier and Combustor Operating Pressure, Low Methane Make and Concentration in the Gasifier Effluent, Large Volume of Combustion Gases Produced and SO/sub 2/ Content, Use of Dual CO/sub 2/ Removal Units, and the Methanation Scheme. The Battelle process shows thermal efficiencies significantly lower than the most efficient processes, i.e., HYGAS, CO/sub 2/ Acceptor and BI-GAS.

  14. High-resolution nanoprobe X-ray fluorescence characterization of heterogeneous calcium and heavy metal distributions in alkali-activated fly ash.

    Science.gov (United States)

    Provis, John L; Rose, Volker; Bernal, Susan A; van Deventer, Jannie S J

    2009-10-06

    The nanoscale distribution of elements within fly ash and the aluminosilicate gel products of its alkaline activation ("fly ash geopolymers") are analyzed by means of synchrotron X-ray fluorescence using a hard X-ray Nanoprobe instrument. The distribution of calcium within a hydroxide-activated (fly ash/KOH solution) geopolymer gel is seen to be highly heterogeneous, with these data providing for the first time direct evidence of the formation of discrete high-calcium particles within the binder structure of a geopolymer synthesized from a low-calcium (geopolymer gel binder structure surrounding the unreacted fly ash particles. This has important implications for the understanding of calcium chemistry within aluminosilicate geopolymer gel phases. Additionally, chromium and iron are seen to be very closely correlated within the structures of both fly ash and the geopolymer product and remain within the regions of the geopolymer which can be identified as unreacted fly ash particles. Given that the potential for chromium release has been one of the queries surrounding the widespread utilization of construction materials derived from fly ash, the observation that this element appears to be localized within the fly ash rather than dispersed throughout the gel binder indicates that it is unlikely to be released problematically into the environment.

  15. R&D of Novel Materials for Animal Litters Using High Carbon Fly Ash Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Boxley, Chett J. [Ceramatec, Inc., Salt Lake City, UT (United States); Kadota, Rod [Ceramatec, Inc., Salt Lake City, UT (United States)

    2012-10-29

    This research program performed by Ceramatec may significantly increase the beneficial utilization of fly ash, and improve the overall performance of high quality animal litter products. Ceramatec has developed a novel high surface area material, which is capable of ammonia adsorption. High surface area zeolites when combined with agglomerated fly ash can significantly reduce the use of naturally mined materials (i.e. clay bentonite) for animal litter manufacture. This not only preserves natural resources and the natural environment, but it also will reduce CO2 emissions, via the reduced need for heavy mining equipment. This novel animal litter is made with over 85% of recycled materials, thus preventing their disposition to landfills. The novel litter material is similar to traditional clay-like litters, and it is clumpable and has superior odor control properties.

  16. Leaching behaviour of bottom ash from RDF high-temperature gasification plants.

    Science.gov (United States)

    Gori, M; Pifferi, L; Sirini, P

    2011-07-01

    This study investigated the physical properties, the chemical composition and the leaching behaviour of two bottom ash (BA) samples from two different refuse derived fuel high-temperature gasification plants, as a function of particle size. The X-ray diffraction patterns showed that the materials contained large amounts of glass. This aspect was also confirmed by the results of availability and ANC leaching tests. Chemical composition indicated that Fe, Mn, Cu and Cr were the most abundant metals, with a slight enrichment in the finest fractions. Suitability of samples for inert waste landfilling and reuse was evaluated through the leaching test EN 12457-2. In one sample the concentration of all metals was below the limit set by law, while limits were exceeded for Cu, Cr and Ni in the other sample, where the finest fraction showed to give the main contribution to leaching of Cu and Ni. Preliminary results of physical and geotechnical characterisation indicated the suitability of vitrified BA for reuse in the field of civil engineering. The possible application of a size separation pre-treatment in order to improve the chemical characteristics of the materials was also discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Cellular lightweight concrete containing high-calcium fly ash and natural zeolite

    Science.gov (United States)

    Jitchaiyaphum, Khamphee; Sinsiri, Theerawat; Jaturapitakkul, Chai; Chindaprasirt, Prinya

    2013-05-01

    Cellular lightweight concrete (CLC) with the controlled density of approximately 800 kg/m3 was made from a preformed foam, Type-I Portland cement (OPC), fly ash (FA), or natural zeolite (NZ), and its compressive strength, setting time, water absorption, and microstructure of were tested. High-calcium FA and NZ with the median particle sizes of 14.52 and 7.72 μm, respectively, were used to partially replace OPC at 0, 10wt%, 20wt%, and 30wt% of the binder (OPC and pozzolan admixture). A water-to-binder mass ratio (W/B) of 0.5 was used for all mixes. The testing results indicated that CLC containing 10wt% NZ had the highest compressive strength. The replacement of OPC with NZ decreased the total porosity and air void size but increased the capillary porosity of the CLC. The incorporation of a suitable amount of NZ decreased the setting time, total porosity, and pore size of the paste compared with the findings with the same amount of FA. The total porosity and cumulative pore volume decreased, whereas the gel and capillary pores increased as a result of adding both pozzolans at all replacement levels. The water absorption increased as the capillary porosity increased; this effect depended on the volume of air entrained and the type or amount of pozzolan.

  18. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals.

    Science.gov (United States)

    Boca Santa, Rozineide A Antunes; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12M in the composition of Na2SiO3 in 1:2vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Impact of high resolution land surface initialization in Indian summer ...

    Indian Academy of Sciences (India)

    Case studies of heat wave and a monsoon depression simulation show that, the model biases were also improved with .... feedback process can modulate the internal vari- ability of the Indian summer monsoon. However, ..... mer monsoon; Indian J. Radio and Space Phys. (ISSN: 0367-8393), 41 488–500. Case Jonathan L ...

  20. Properties of concrete incorporating high volumes of class F fly ash and san fibers

    Energy Technology Data Exchange (ETDEWEB)

    Rafat Siddique [University of Wisconsin-Milwaukee, Milwaukee, WI (United States). Department of Civil Engineering and Mechanics, UWM Center for By-Products Utilization, College of Engineering and Applied Science

    2004-01-01

    The results of an experimental investigation to study the effects of replacement of cement (by mass) with three percentages of fly ash and the effects of addition of natural san fibers on the slump, Vebe time, compressive strength, splitting tensile strength, flexural strength and impact strength of fly ash concrete are presented. San fibers belong to the category of 'natural bast fibers.' It is also known as 'sunn hemp.' Its scientific (botanical) name is Crotalaria juncea. A control mixture of proportions 1:1.4:2.19 with W/Cm of 0.47 and superplasticizer/cementitious ratio of 0.015 was designed. Cement was replaced with three percentages (35%, 45% and 55%) of class F fly ash. Three percentages of san fibers (0.25%, 0.50% and 0.75%) having 25-mm length were used. The test results indicated that the replacement of cement with fly ash increased the workability (slump and Vebe time), decreased compressive strength, splitting tensile strength and flexural strength and had no significant effect on the impact strength of plain (control) concrete. Addition of san fibers reduced the workability, did not significantly affect the compressive strength, increased the splitting tensile strength and flexural strength and tremendously enhanced the impact strength of fly ash concrete as the percentage of fibers increased.

  1. A brief on high-volume Class F fly ash as cement replacement – A guide for Civil Engineer

    Directory of Open Access Journals (Sweden)

    Alaa M. Rashad

    2015-12-01

    Full Text Available Disposal of fly ash (FA resulting from the combustion of coal-fired electric power stations is one of the major environmental challenges. This challenge continues to increase with increasing the amount of FA and decreasing the capacity of landfill space. Therefore, studies have been carried out to re-use high-volumes of fly ash (HVFA as cement replacement in building materials. This paper presents an overview of the previous studies carried out on the use of high volume Class F FA as a partial replacement of cement in traditional paste/mortar/concrete mixtures based on Portland cement (PC. Fresh properties, mechanical properties, abrasion resistance, thermal properties, drying shrinkage, porosity, water absorption, sorptivity, chemical resistance, carbonation resistance and electrical resistivity of paste/mortar/concrete mixtures containing HVFA (⩾45% as cement replacement have been reviewed. Furthermore, additives used to improve some properties of HVFA system have been reviewed.

  2. A high unburned carbon fly ash concrete’s performance characteristics

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Valderrama

    2011-01-01

    Full Text Available Engineering today requires that structures are strong and durable; the latter concept is a decisive factor in their design and construction. The scientific community continues developing new cementitious materials and improving tra-ditional concrete’s properties, specifically reducing permeability by incorporating materials such as pozzolans. This paper analyses the effect of fly ash (FA added to concrete on mechanical strength regarding compression, capillary absorption and chloride permeability and their behaviour compared to concrete containing silica fume (SF. An optimum 10% mechanical strength was found for fly ash; however, this increased with addition, resulting in positive effects on durability. Fly ash had lower performance for all properties evaluated when compared to silica fume.

  3. Fly ash porous material using geopolymerization process for high temperature exposure.

    Science.gov (United States)

    Abdullah, Mohd Mustafa Al Bakri; Jamaludin, Liyana; Hussin, Kamarudin; Bnhussain, Mohamed; Ghazali, Che Mohd Ruzaidi; Ahmad, Mohd Izzat

    2012-01-01

    This paper presents the results of a study on the effect of temperature on geopolymers manufactured using pozzolanic materials (fly ash). In this paper, we report on our investigation of the performance of porous geopolymers made with fly ash after exposure to temperatures from 600 °C up to 1000 °C. The research methodology consisted of pozzolanic materials (fly ash) synthesized with a mixture of sodium hydroxide and sodium silicate solution as an alkaline activator. Foaming agent solution was added to geopolymer paste. The geopolymer paste samples were cured at 60 °C for one day and the geopolymers samples were sintered from 600 °C to 1000 °C to evaluate strength loss due to thermal damage. We also studied their phase formation and microstructure. The heated geopolymers samples were tested by compressive strength after three days. The results showed that the porous geopolymers exhibited strength increases after temperature exposure.

  4. Fly Ash Porous Material using Geopolymerization Process for High Temperature Exposure

    Directory of Open Access Journals (Sweden)

    Mohd Izzat Ahmad

    2012-04-01

    Full Text Available This paper presents the results of a study on the effect of temperature on geopolymers manufactured using pozzolanic materials (fly ash. In this paper, we report on our investigation of the performance of porous geopolymers made with fly ash after exposure to temperatures from 600 °C up to 1000 °C. The research methodology consisted of pozzolanic materials (fly ash synthesized with a mixture of sodium hydroxide and sodium silicate solution as an alkaline activator. Foaming agent solution was added to geopolymer paste. The geopolymer paste samples were cured at 60 °C for one day and the geopolymers samples were sintered from 600 °C to 1000 °C to evaluate strength loss due to thermal damage. We also studied their phase formation and microstructure. The heated geopolymers samples were tested by compressive strength after three days. The results showed that the porous geopolymers exhibited strength increases after temperature exposure.

  5. Characteristics and the behavior in electrostatic precipitators of high-alumina coal fly ash from the Jungar power plant, Inner Mongolia, China.

    Science.gov (United States)

    Qi, Liqiang; Yuan, Yongtao

    2011-08-15

    In China, flue gases emitted by coal-fired power plants are mainly cleaned using electrostatic precipitators (ESPs). However, based on observations, there is a decrease in the collection efficiency of ESPs in some power plants after burning Jungar coal in Inner Mongolia. In order to find the mechanism of coal fly ash escaping from ESPs, the size distribution, resistivity, and cohesive force of particulate matter samples from Jungar coal-fired power plants in China were measured using a Bahco centrifuge, a dust electrical resistivity test instrument, and a cohesive force test apparatus invented by the authors. Experiments were carried out to determine the chemical composition and current-voltage curve of fly ash under operating ESPs. The Al(2)O(3) content in fly ash was found to reach more than 50%, with the size distribution showing a higher content of PM2.5 and PM10 in high-alumina coal fly ash than in other coal fly ashes. The resistivity of high-alumina coal fly ash was recorded at over 10(12)Ω cm, but this did not result in a clear back corona. The cohesive force of high-alumina coal fly ash was very little. It was sensitive to smoke speed in the electric field, facilitating dust re-entrainment. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Ternary Blends of High Aluminate Cement, Fly ash and Blast-furnace slag for Sewerage Lining Mortar

    Science.gov (United States)

    Chao, L. C.; Kuo, C. P.

    2018-01-01

    High aluminate cement (HAC), fly ash (FA) and blast-furnace slag (BFS) have been treated sustainable materials for the use of cement products for wastewater infrastructure due to their capabilities of corrosion resistance. The purpose of this study is to optimize a ternary blend of above mentioned materials for a special type of mortar for sewerage lining. By the using of Taguchi method, four control parameters including water/cementitious material ratio, mix water content, fly ash content and blast-furnace slag content were considered in nine trial mix designs in this study. By evaluating target properties including (1) maximization of compressive strength, (2) maximization of electricity resistance and (3) minimization of water absorption rate, the best possible levels for each control parameter were determined and the optimal mix proportions were verified. Through the implementation of the study, a practical and completed idea for designing corrosion resistive mortar comprising HAC, FA and BSF is provided.

  7. Determination of rutin in cigarette tobacco, filters, mainstream smoke and burned ash of different branded cigarettes by high performance liquid chromatography

    National Research Council Canada - National Science Library

    Sun, Yinshi; Li, Wei; Wang, Jianhua; Bi, Jianjie; Su, Shudong

    2012-01-01

    ... and anti-protozoal properties. A high performance liquid chromatography method was used to analyze rutin in tobacco and filters, mainstream smoke, and burned ash of ten varieties of cigarettes made in China...

  8. Use of wood ash in the treatment of high tannin sorghum for poultry ...

    African Journals Online (AJOL)

    conniek

    There was no significant difference in feed intake between the maize based diet and the diet that contained wood ash extract treated .... 2 Provided per kg diet: Vitamin A - 12500 IU; vitamin D3 - 2500 IU; vitamin E - 20 IU; vitamin K3 - 3.0 mg; vitamin. B1 - 1.0 mg .... lysine when sorghum grain was treated with Magadi soda.

  9. High resolution numerical weather prediction over the Indian ...

    Indian Academy of Sciences (India)

    resolution physical initialization applied at the regional model level. Higher skills in wind and precipitation forecasts over the Indian summer monsoon region are achieved using this version of the regional model with physical initialization.

  10. Utilize Cementitious High Carbon Fly Ash (CHCFA) to Stabilize Cold In-Place Recycled (CIR) Asphalt Pavement as Base Coarse

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Haifang; Li, Xiaojun; Edil, Tuncer; O' Donnell, Jonathan; Danda, Swapna

    2011-02-05

    The purpose of this study was to evaluate the performance of cementitious high carbon fly ash (CHCFA) stabilized recycled asphalt pavement as a base course material in a real world setting. Three test road cells were built at MnROAD facility in Minnesota. These cells have the same asphalt surface layers, subbases, and subgrades, but three different base courses: conventional crushed aggregates, untreated recycled pavement materials (RPM), and CHCFA stabilized RPM materials. During and after the construction of the three cells, laboratory and field tests were carried out to characterize the material properties. The test results were used in the mechanistic-empirical pavement design guide (MEPDG) to predict the pavement performance. Based on the performance prediction, the life cycle analyses of cost, energy consumption, and greenhouse gasses were performed. The leaching impacts of these three types of base materials were compared. The laboratory and field tests showed that fly ash stabilized RPM had higher modulus than crushed aggregate and RPM did. Based on the MEPDG performance prediction, the service life of the Cell 79 containing fly ash stabilized RPM, is 23.5 years, which is about twice the service life (11 years) of the Cell 77 with RPM base, and about three times the service life (7.5 years) of the Cell 78 with crushed aggregate base. The life cycle analysis indicated that the usage of the fly ash stabilized RPM as the base of the flexible pavement can significantly reduce the life cycle cost, the energy consumption, the greenhouse gases emission. Concentrations of many trace elements, particularly those with relatively low water quality standards, diminish over time as water flows through the pavement profile. For many elements, concentrations below US water drinking water quality standards are attained at the bottom of the pavement profile within 2-4 pore volumes of flow.

  11. A comparative study of self-consolidating concretes incorporating high-volume natural pozzolan or high-volume fly ash

    KAUST Repository

    Celik, Kemal

    2014-09-01

    The purpose of this study is to compare the effects of Portland cement replacement on the strength and durability of self-consolidating concretes (SSC). The two replacement materials used are high-volume natural pozzolan (HVNP), a Saudi Arabian aluminum-silica rich basaltic glass and high-volume Class-F fly ash (HVFAF), from Jim Bridger Power Plant, Wyoming, US. As an extension of the study, limestone filler (LF) is also used to replace Portland cement, alongside HVNP or HVFAF, forming ternary blends. Along with compressive strength tests, non-steady state chloride migration and gas permeability tests were performed, as durability indicators, on SCC specimens. The results were compared to two reference concretes; 100% ordinary Portland cement (OPC) and 85% OPC - 15% LF by mass. The HVNP and HVFAF concrete mixes showed strength and durability results comparable to those of the reference concretes; identifying that both can effectively be used to produce low-cost and environmental friendly SCC. © 2013 Elsevier Ltd. All rights reserved.

  12. Poor early growth and high salt intake in Indian infants.

    Science.gov (United States)

    Genovesi, Simonetta; Antolini, Laura; Orlando, Antonina; Brahmochary, Sujit; De Servi, Alessandra; Capelli, Silvia; Giussani, Marco; Nava, Elisa; Agostoni, Carlo; Gallieni, Maurizio

    2017-06-01

    The influence of feeding patterns on the growth of infants and how salt is included in the diet are unknown in the area of West Bengal, India. A cross-sectional study was carried on 517 infants (median age 6.5 months). Negative Z-scores were observed for all anthropometric parameters. About 72.7% of infants aged 0-6 months received exclusive breastfeeding. In the 6-12-month-old group (n = 235), 91.5% had salt added to foods. In a regression model adjusted for age, a low salt diet resulted a significant factor in increasing weight-for-length and BMI for age z-scores, with increments equal to 0.637 SD (p = 0.037) and 0.650 SD (p = 0.036), respectively. In West Bengal infants showing poor growth, breastfeeding was associated with better anthropometric indexes, but early in life salt is added to their diet. Early life low weight coupled with high salt intake may be a risk factor for arterial hypertension in Indian children.

  13. High alpha-cellulose from fast growing Indian plants

    Energy Technology Data Exchange (ETDEWEB)

    Manavalan, R.; Anand, S.M.; Mithal, B.M.; Chawla, J.S.

    1979-01-01

    Sesbania sesban, S. paludosa, Crotalaria juncea, C. retusa, and poplarwood contained 22-25% pentosan, 20-26% lignin, 72-77% holocellulose (I), and 1-1.6% ash. Kraft cooking of prehydrolyzed wood species at 165/sup 0/ gave pulp in 21-43% yield and with 90-95% I content. Bleaching of kraft pulps by CEHED sequence gave product in 19-37% yield, with 93-96% alpha-cellulose content and 75-91% brightness.

  14. Influence of Temperature on Workability and Compressive Strength of Ordinary Concrete with High Calcium Fly Ash

    Directory of Open Access Journals (Sweden)

    Gołaszewski Jacek

    2017-06-01

    Full Text Available The rheological properties of fresh ordinary concrete are closely affected by temperature and time. The paper presents the study of consistency of fresh concrete mixtures made with Portland cement and cement with calcareous fly ash. Two types of admixtures were used. It was proven that the temperature has a clear effect on workability and compressive strength concrete. Influence on workability can be reduced by selecting the appropriate superplasticizer and cement.

  15. Synthesis of granular zeolitic materials with high cation exchange capacity from agglomerated coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Roberto Juan; Susana Hernandez; Jose Manuel Andres; Carmen Ruiz [Instituto de Carboquimica (CSIC), Zaragoza (Spain)

    2007-08-15

    Fly ash from coal combustion is a potential source of pollution and there is continuous interest in its recycling by converting it into products such as zeolitic materials for use in retaining pollutants. In this paper, production of granular zeolitic material from a commercially-unusable fine-fraction of a lightweight aggregate (LA) building material made from coal fly ash agglomerated with lime, by conventional alkaline activation is described. NaP1 zeolite, K-F zeolite, K-Phillipsite and K-Chabazite were synthesised. The process was optimised by combining four reaction parameters (temperature, alkali concentration, solution/fly ash ratio and reaction time). Zeolitic materials with the highest zeolite yields and cation exchange capacities were selected for future application in environmental processes. End-product zeolitic materials maintain its granular form and this could favour their use in some particular applications for environmental waste treatment (e.g. ionic exchange in column) without any further transformation stages. 21 refs., 6 figs., 6 tabs.

  16. The use of a non-standard high calcium fly ash in concrete and its response to accelerated curing

    Directory of Open Access Journals (Sweden)

    Atis, C. D.

    2002-09-01

    Full Text Available An experimental work was carried out to investigate the use of a non-standard high calcium fly ash in concrete. The response of the same fly ash to the accelerated curing was also explored. With three different cementitious material contents, a total of 48 concretes were produced. The water/ cement ratios were varied from 0.40 to 0.87. Compressive strengths of the moist cured cube specimens cast from the concrete mixtures made with 0%, 15%, 30% and 45% replacement of normal Portland cement with fly ash were measured at 28 days and 3 months. Accelerated compressive strengths were also measured using warmwater method and boiling-water method in accordance with the relevant ASTM and Turkish Standards. Despite the fact that the fly ash used was a non-standard, the laboratory test results showed that it could be utilized in concrete production at a replacement level between 15% and 30% by weight basis because fly ash concrete developed comparable or higher compressive strength than that of corresponding normal Portland cement concrete. The laboratory test results also indicated that the accelerated curing could be used to predict the compressive strength of fly ash concrete with 85% correlation coefficient. The amount of fly ash was found to be immaterial in the strength prediction. The relation between warm-water method and boiling-water method was of linear form with 93% correlation coefficient.

    Se llevó a cabo un trabajo experimental para investigar el uso de una ceniza volante de alto contenido en cal en el hormigón, la cual no cumple las especificaciones recogidas en norma. También, se estudió el comportamiento de la ceniza bajo un curado acelerado. Se elaboraron un total de 48 hormigones con tres proporciones diferentes de material cementante. Las relaciones agua/cemento (a/c usadas estaban comprendidas entre 0,40 y 0,87. A 28 días y 3 meses de curado, se determinaron las resistencias a compresión de probetas cúbicas de hormig

  17. 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.

  18. 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.

    2016-03-01

    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.

  19. DOLOMITE DESULFURIZATION BEHAVIOR IN A BUBBLING FLUIDIZED BED PILOT PLANT FOR HIGH ASH COAL

    Directory of Open Access Journals (Sweden)

    G. M. F. Gomes

    Full Text Available Abstract Although fluidized bed in situ desulphurization from coal combustion has been widely studied, there are aspects that remain under investigation. Additionally, few publications address Brazilian coal desulphurization via fluidized beds. This study used a 250 kWth bubbling fluidized bed pilot plant to analyze different aspects of the dolomite desulphurization of two Brazilian coals. Superficial velocities of 0.38 and 0.46 m/s, flue gas recycling, Ca/S molar ratios and elutriation were assessed. Results confirmed the influence of the Ca/S molar ratio and superficial velocity - SO2 conversion up to 60.5% was achieved for one coal type, and 70.9% was achieved for the other type. A recycling ratio of 54.6% could increase SO2 conversion up to 86.1%. Elutriation and collection of ashes and Ca-containing products did not present the same behavior because a lower wt. % of CaO was collected by the gas controlled mechanism compared to the ash.

  20. 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...... in water. The content of the selected heavy metals (i.e. Cr, Ni, Pb and Cd) complied with the Danish Statutory Order on the use of bio-ash for agricultural purposes; however, critical releases of Cr were detected in the leachate extracts, especially in the fly ash. High alkaline pHs were measured in all...

  1. Flexural toughness of steel fiber reinforced high performance concrete containing nano-SiO2 and fly ash.

    Science.gov (United States)

    Zhang, Peng; Zhao, Ya-Nan; Li, Qing-Fu; Wang, Peng; Zhang, Tian-Hang

    2014-01-01

    This paper aims to clarify the effect of steel fiber on the flexural toughness of the high performance concrete containing fly ash and nano-SiO2. The flexural toughness was evaluated by two methods, which are based on ASTM C1018 and DBV-1998, respectively. By means of three-point bending method, the flexural toughness indices, variation coefficients of bearing capacity, deformation energy, and equivalent flexural strength of the specimen were measured, respectively, and the relational curves between the vertical load and the midspan deflection (P(V)-δ) were obtained. The results indicate that steel fiber has great effect on the flexural toughness parameters and relational curves (P(V)-δ) of the three-point bending beam specimen. When the content of steel fiber increases from 0.5% to 2%, the flexural toughness parameters increase gradually and the curves are becoming plumper and plumper with the increase of steel fiber content, respectively. However these flexural toughness parameters begin to decrease and the curves become thinner and thinner after the steel fiber content exceeds 2%. It seems that the contribution of steel fiber to the improvement of flexural toughness of the high performance concrete containing fly ash and nano-SiO2 is well performed only when the steel fiber content is less than 2%.

  2. Flexural Toughness of Steel Fiber Reinforced High Performance Concrete Containing Nano-SiO2 and Fly Ash

    Science.gov (United States)

    Zhao, Ya-Nan; Li, Qing-Fu; Wang, Peng; Zhang, Tian-Hang

    2014-01-01

    This paper aims to clarify the effect of steel fiber on the flexural toughness of the high performance concrete containing fly ash and nano-SiO2. The flexural toughness was evaluated by two methods, which are based on ASTM C1018 and DBV-1998, respectively. By means of three-point bending method, the flexural toughness indices, variation coefficients of bearing capacity, deformation energy, and equivalent flexural strength of the specimen were measured, respectively, and the relational curves between the vertical load and the midspan deflection (P V-δ) were obtained. The results indicate that steel fiber has great effect on the flexural toughness parameters and relational curves (P V-δ) of the three-point bending beam specimen. When the content of steel fiber increases from 0.5% to 2%, the flexural toughness parameters increase gradually and the curves are becoming plumper and plumper with the increase of steel fiber content, respectively. However these flexural toughness parameters begin to decrease and the curves become thinner and thinner after the steel fiber content exceeds 2%. It seems that the contribution of steel fiber to the improvement of flexural toughness of the high performance concrete containing fly ash and nano-SiO2 is well performed only when the steel fiber content is less than 2%. PMID:24883395

  3. Distinctive features of high-ash bituminuos coals combution with low milling fineness in furnace chambers with bottom blowing

    Science.gov (United States)

    Zroychikov, N. A.; Kaverin, A. A.; Biryukov, Ya A.

    2017-11-01

    Nowadays the problem of improvement of pulverized coal combustion schemes is an actual one for national power engineering, especially for combustion of coals with low milling fineness with significant portion of moisture or mineral impurities. In this case a big portion of inert material in the fuel may cause impairment of its ignition and combustion. In addition there are a lot of boiler installations on which nitrogen oxides emission exceeds standard values significantly. Decreasing of milling fineness is not without interest as a way of lowering an electric energy consumption for pulverization, which can reach 30% of power plant’s auxiliary consumption of electricity. Development of a combustion scheme meeting the requirements both for effective coal burning and environmental measures (related to NOx emission) is a complex task and demands compromising between these two factors, because implementation of NOx control by combustion very often leads to rising of carbon-in-ash loss. However widespread occurrence of such modern research technique as computer modeling allows to conduct big amount of variants calculations of combustion schemes with low cost and find an optimum. This paper presents results of numerical research of combined schemes of coal combustion with high portion of inert material based on straight-flow burners and nozzles. Several distinctive features of furnace aerodynamics, heat transfer and combustion has been found. The combined scheme of high-ash bituminouos coals combustion with low milling fineness, which allows effective combustion of pointed type of fuels with nitrogen oxides emission reduction has been proposed.

  4. Assessment and comparison of three high-aluminum fly ash utilization scenarios in Inner Mongolia, China using an eco-efficiency indicator.

    Science.gov (United States)

    Yang, Shuo; Lin, Ling; Li, Shao Peng; Li, Qiang; Wang, Xiu Teng; Sun, Liang

    2017-05-01

    Utilization of fly ash is of great importance in China in the context of resource and environmental crises. Different fly ash utilization processes are proposed, and some have been practically applied. However, none of these fly ash utilization pathways has been evaluated comprehensively by integrating both environmental and economic perspectives. In this study, three high-aluminum fly ash utilization methods in Mongolia were assessed and compared based on the concept of eco-efficiency. The environmental assessment was conducted in accordance with life-cycle assessment principles, and a monetization-weighting approach was applied to obtain social willingness-to-pay as a reflection of environmental impact. The environmental assessment results revealed that the reuse of fly ash had significant advantage for saving primary resource, while solid waste, depletion of water, and global warming were the three highest environmental impacts from the life cycle perspective. The economic performance assessment showed positive net profits for fly ash utilization, but high value-added products were not necessarily indicative of better economic performance due to the relatively high operation cost. Comparison of the eco-efficiency indicators (EEIs) implied that the process of scenario 1#, which produced mullite ceramic and active calcium silicate, was the most recommended out of the three scenarios on the present scale. This judgment was consistent with the evaluation of the resource utilization rate. The present study showed that the EEI could be used to compare different fly ash utilization processes in a comprehensive and objective manner, thus providing definitive and insightful suggestions for decision-making and technical improvement.

  5. 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

  6. Experimental Study on Volume for Fly Ash of Building Block

    OpenAIRE

    Ling Wang; He Sun; Zhihui Sun; Enqing Ma

    2013-01-01

    Fly ash is a waste substance from thermal power plants, steel mills, etc. That is found in abundance in the world. It has polluted the environment, wasting the cultivated land. This study introduces an experimental research on fly ash being reused effectively, the study introduces raw materials of fly ash brick, production process and product inspection, fly ash content could be amounted to 40%~75%. High doping fly ash bricks are manufactured, which selects wet fly ash from the power plants, ...

  7. Peculiar high temperature corrosion of martensite alloy under impact of Estonian oil shale fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Tallermo, H.; Klevtsov, I. [Thermal Engineering Department of Tallinn Technical University, Tallinn (Estonia)

    1998-12-31

    The superheaters` surfaces of oil shale steam boiler made of pearlitic and austenitic alloys, are subject to intensive corrosion, mainly due to presence of chlorine in external deposits. The applicability of martensitic alloys X1OCrMoVNb91 and X20CrMoV121 for superheaters is examined here and empirical equations allowing to predict alloys` corrosion resistance in the range of operational temperatures are established. Alloy X1OCrMoVNb91 is found been most perspective for superheaters of boilers firing fossil fuel that contain alkaline metals and chlorine. The abnormal dependence of corrosion resistance of martensitic alloys on temperature is revealed, namely, corrosion at 580 deg C in presence of oil shale fly ash is more intensive than at 620 deg C. (orig.) 2 refs.

  8. Treatment of fly ash for use in concrete

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Ternary blends containing demercurated lighting phosphor and MSWI fly ash as high-performance binders for stabilizing and recycling electroplating sludge.

    Science.gov (United States)

    Huang, Wu-Jang; Wu, Chia-Teng; Wu, Chang-En; Hsieh, Lin-Huey; Li, Chang-Chien; Lain, Chi-Yuan; Chu, Wei

    2008-08-15

    This paper describes the solidification and stabilization of electroplating sludge treated with a high-performance binder made from portland type-I cement, municipal solid waste incineration fly ash, and lighting phosphor powder (called as cement-fly ash-phosphor binder, CFP). The highest 28-day unconfined compressive strength of the CFP-treated paste was 816 kg/cm(2) at a ratio of cement to fly ash to lighting phosphor powder of 90:5:5; the strength of this composition also fulfilled the requirement of a high-strength concrete (>460 kg/cm(2) at 28 days). The CFP-stabilized sludge paste samples passed the Taiwanese EPA toxicity characteristic leaching procedure test and, therefore, could be used either as a building material or as a controlled low-strength material, depending on the sludge-to-CFP binder ratio.

  10. Leaching study of trace elements from coal ashes: A case study of Bokaro Thermal Power Station "B".

    Science.gov (United States)

    Singh, Bihari; Kumar, Sanjay; Kumar, Madanjeet

    2004-07-01

    Electricity generation has been increasing at a rapid rate due to rapid industrialization and changing life styles. In our Country coal is the major source of energy since India has vast reserves of thermal power grade coal. Nearly every naturally occurring element is likely to be present in coal and these get entertained in the resultant coal ash. Indian coals contain high ash coupled with low calorific value and consequently resulting huge amount of coal ashes. This ash accumulates in on site piles and ponds thereby resulting in serious environmental problems particularly trace elements contamination of ground and surface waters. This study envisages the environmental assessment of coal ashes from Bokaro Thermal Power Station- Leaching study of coal ashes was made through analysis of leachates from open percolation leaching column experiments over a period of 300 days. Trace elements were observed within the regulatory limits. Many of the trace elements evaluated viz. Ni., Co, Se, Al, As, B, Ba, Sb, Hg, were observed at below detection limits of AAS. Na, K, Ca, Fe, Pb, Cd and other dissolved ions leached at significant concentration levels. This study suggests low cost high volume utilisation of bottom ash as fill material for reclaiming surrounding abandoned mined out areas in an environmentally acceptable manner.

  11. Freeze-Thaw Resistance of Normal and High Strength Concretes Produced with Fly Ash and Silica Fume

    Directory of Open Access Journals (Sweden)

    Cenk Karakurt

    2015-01-01

    Full Text Available This study is based on determination of the freeze-thaw resistance of air-entrained and non-air-entrained normal strength concrete (NC and high strength concrete (HSC produced with fly ash and silica fume according to surface scaling. The procedure allows us to measure the amount of scaling per unit surface area due to a number of well defined freezing and thawing cycles in the presence of deicing salt. The weight loss, surface scaling, moisture uptake, and internal damage were measured after 0 and after every 4th freeze-thaw cycle. The test results showed that the freeze-thaw resistance is influenced directly by the compressive strength property of the concrete. Silica fume significantly reduced the resistance of normal strength concrete against freeze-thaw effect without plasticizing agent. The surface scaling of silica fume concrete without admixture was 22% higher than reference normal concrete.

  12. 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

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

    Science.gov (United States)

    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 ...

  14. Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM2.5) Fraction of Coal Combustion Ash

    Energy Technology Data Exchange (ETDEWEB)

    T. L. Robl; J. G. Groppo; R. Rathbone; B. Marrs; R. Jewell

    2008-07-18

    The overall objective of this research was to determine the feasibility of recovering a very fine fraction of fly ash, that is 5 microns in diameter or less and examining the characteristics of these materials in new or at least less traditional applications. These applications included as a polymer filler or as a 'super' pozzolanic concrete additive. As part of the effort the ash from 6 power plants was investigated and characterized. This work included collection from ESP Hoppers and ponds. The ash was thoroughly characterized chemically and physically. Froth flotation was used to reduce the carbon and testing showed that flotation could effectively reduce carbon to acceptable levels (i.e. 0.5% LOI) for most of the substrates tested. in order to enable eventual use as fillers. Hydraulic classification was used in the separation of the fine ash from the coarse ash. Hydraulic classification requires the ash to be dispersed to be effective and a range of dispersants were tested for adsorption as well as sedimentation rate. A wide range of dosages were required (0.3 to 10 g/kg). In general the ponded ash required less dispersant. A model was developed for hydraulic classification. A pilot-scale hydraulic classifier was also designed and operated for the project. Product yields of up to 21% of feed solids were achieved with recoveries of <5 {micro}m particles as high as 64%. Mean particle sizes (D{sub 50}) of the ultra fine ash (UFA) products varied from 3.7 to 10 {micro}m. A patent was filed on the classifier design. A conceptual design of a Process Demonstration Unit (PDU) with a feed rate of 2 tons of raw ash feed per hour was also completed. Pozzolanic activity was determined for the UFA ashes in mortars. In general the overall strength index was excellent with values of 90% achieved in 3 days and {approx}100% in 7 days. Three types of thermoplastic polymers were evaluated with the UFA as a filler: high density polyethylene, thermoplastic elastomer and

  15. Making the most of South Africa’s low-quality coal: Converting high-ash coal to fuel gas using bubbling fluidised bed gasifiers

    CSIR Research Space (South Africa)

    Engelbrecht, AD

    2010-08-31

    Full Text Available South Africa has abundant resources of high-ash and other low-quality coals. The aim of this work is to investigate the possibility of using fluidised bed gasification technology to convert these coals into clean fuel gas. The fuel gas can be used...

  16. NUCLEOTIDE COMPARISON OF GDF9 GENE IN INDIAN YAK AND GADDI GOAT: HIGH ALTITUDE LIVESTOCK ANIMALS

    Directory of Open Access Journals (Sweden)

    Lakshya Veer Singh

    2013-06-01

    Full Text Available The present study was undertaken to characterize exon 1 and exon 2 sequence of one of fecundity genes: GDF9 (Growth differentiation factor 9, in high altitude livestock animal (Yak and Gaddi goat. Six nucleotide differences were identified between sheep (AF078545 and goats (EF446168 in exon 1 and exon 2. Sequencing revealed nine novel single nucleotide mutations in exon 1 and exon 2 of Indian yak that compared with Bos taurus (GQ922451. These results preliminarily showed that the GDF9 gene might be a major gene that influences prolificacy of Gaddi goats and Indian yak.

  17. Simultaneous determination of V, Ni and Fe in fuel fly ash using solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Cárdenas Valdivia, A; Vereda Alonso, E; López Guerrero, M M; Gonzalez-Rodriguez, J; Cano Pavón, J M; García de Torres, A

    2018-03-01

    A green and simple method has been proposed in this work for the simultaneous determination of V, Ni and Fe in fuel ash samples by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS HR CS GFAAS). The application of fast programs in combination with direct solid sampling allows eliminating pretreatment steps, involving minimal manipulation of sample. Iridium treated platforms were applied throughout the present study, enabling the use of aqueous standards for calibration. Correlation coefficients for the calibration curves were typically better than 0.9931. The concentrations found in the fuel ash samples analysed ranged from 0.66% to 4.2% for V, 0.23-0.7% for Ni and 0.10-0.60% for Fe. Precision (%RSD) were 5.2%, 10.0% and 9.8% for V, Ni and Fe, respectively, obtained as the average of the %RSD of six replicates of each fuel ash sample. The optimum conditions established were applied to the determination of the target analytes in fuel ash samples. In order to test the accuracy and applicability of the proposed method in the analysis of samples, five ash samples from the combustion of fuel in power stations, were analysed. The method accuracy was evaluated by comparing the results obtained using the proposed method with the results obtained by ICP OES previous acid digestion. The results showed good agreement between them. The goal of this work has been to develop a fast and simple methodology that permits the use of aqueous standards for straightforward calibration and the simultaneous determination of V, Ni and Fe in fuel ash samples by direct SS HR CS GFAAS. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. 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.

  19. Treatment of fly ash for use in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Boxley, Chett [Park City, UT; Akash, Akash [Salt lake City, UT; Zhao, Qiang [Natick, MA

    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.

  20. Substance Use and Sexual Risk Behaviors among American Indian and Alaska Native High School Students

    Science.gov (United States)

    de Ravello, Lori; Everett Jones, Sherry; Tulloch, Scott; Taylor, Melanie; Doshi, Sonal

    2014-01-01

    Background: We describe the prevalence of behaviors that put American Indian and Alaska Native (AI/AN) high school students at risk for teen pregnancy and sexually transmitted infections (STIs) and the relationships among race/ethnicity and these behaviors. Methods: We analyzed merged 2007 and 2009 data from the national Youth Risk Behavior…

  1. Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

    Science.gov (United States)

    Kristiawan, S. A.; Sunarmasto; Tyas, G. P.

    2016-02-01

    Concrete is susceptible to a variety of chemical attacks. In the sulfuric acid environment, concrete is subjected to a combination of sulfuric and acid attack. This research is aimed to investigate the degradation of self-compacting concrete (SCC) due to sulfuric acid attack based on measurement of compressive strength loss and diameter change. Since the proportion of SCC contains higher cement than that of normal concrete, the vulnerability of this concrete to sulfuric acid attack could be reduced by partial replacement of cement with fly ash at high volume level. The effect of high volume fly ash at 50-70% cement replacement levels on the extent of degradation owing to sulfuric acid will be assessed in this study. It can be shown that an increase in the utilization of fly ash to partially replace cement tends to reduce the degradation as confirmed by less compressive strength loss and diameter change. The effect of fly ash to reduce the degradation of SCC is more pronounced at a later age.

  2. Highly Skilled Professionals on the Move: The International Migration of South African Indians

    OpenAIRE

    Gerelene Jagganath

    2014-01-01

    This paper is about the migration behaviour of highly skilled South African Indians from the period 2006 to present. The ethnography of the highly skilled is relatively new in Anthropology and while it contributes to recent discourse on migration and diaspora, it also foregrounds the need for an array of methodological approaches to support the global mobilities of people, the nature of multi-sited research and what “highly skilled” means in different geographical contexts. The paper is arran...

  3. Morphological, mechanical and thermo-kinetic characterization of coal ash incorporated high performance PEO/PMMA thin film electrolyte composites

    Science.gov (United States)

    Sultana, Sabiha; Saleem Khan, Mohammad; Rehan, Imran; Rehan, Kamran; Amin, Noor-ul-; Humayun, Muhammad; Tabassum, Safia; Minhaz, Aaliya

    2017-11-01

    In the present work indigenous coal ash of Pakistan was used to prepare polymeric nanocomposites with Poly (ethylene oxide) (PEO)/Poly (methyl methacrylate) (PMMA)/lithium perchlorate (LiClO4). The coal ash was first characterized by various advanced spectroscopic techniques. The coal ash loading into the polymeric blend composites was considered by Thermo gravimetric/differential thermal analysis (TG/DTA), universal testing machine (UTM) and scanning electron microscopy (SEM)/energy dispersive x-rays (EDX) analysis. From TG/DTA data detailed kinetic analysis was performed. By applying various kinetic models, a range of kinetic parameters like ▵E, ▵G, ▵H, ▵S and A were successfully calculated for the first time for the studied system. Based upon aforementioned characterization it was established that coal ash incorporation into the polymeric blend composites improves its thermal and mechanical performance.

  4. Emerald Ash Borer: Invasion of the Urban Forest and the Threat to North America's Ash Resource

    Science.gov (United States)

    Therese M. Poland; Deborah G. McCullough

    2006-01-01

    The emerald ash borer (EAB), a phloem-feeding beetle native to Asia, was discovered killing ash trees in southeastern Michigan and Windsor, Ontario, in 2002. Like several other invasive forest pests, the EAB likely was introduced and became established in a highly urbanized setting, facilitated by international trade and abundant hosts. Up to 15 million ash trees in...

  5. The Role of Biocontrol of Emerald Ash Borer in Protecting Ash Regeneration after Invasion

    Science.gov (United States)

    Emerald ash borer (EAB) is an invasive Asian beetle that is destroying ash in forests over much of eastern North America because of the high susceptibility of our native ash and a lack of effective natural enemies. To increase mortality of EAB larvae and eggs, the USDA (FS, ARS and APHIS) is carryin...

  6. Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash

    Energy Technology Data Exchange (ETDEWEB)

    T.L. Robl; J.G. Groppo; Robert Rathebone

    2005-12-14

    Work on the project focused on the determination of the hydraulic classification characteristics of the Coleman and Mill Creek ashes. The work utilized the hydraulic classifier developed earlier in the project. Testing included total yield, recovery of <5 {micro}m ash diameter particles and LOI partitioning as functions of dispersant dosage and type, retention time and superficial velocity. Yields as high as 21% with recoveries of up to 2/3 of the <5 {micro}m ash fractions were achieved. Mean particle size (D{sub 50}) of varied from 3.7 to 10 {micro}m. The ashes were tested for there pozzolanic activity in mortars as measured by strength activity index using ASTM criteria. Additional testing included air entrainment reagent demand and water requirements. The classified products all performed well, demonstrating excellent early strength development in the mortars. Some increased air entrainment demand was noted. The conceptual design of a process demonstration unit PDU was also completed. A flexible, trailer-mounted field unit is envisioned.

  7. Pure, single phase, high crystalline, chamfered-edge zeolite 4A synthesized from coal fly ash for use as a builder in detergents.

    Science.gov (United States)

    Hui, K S; Chao, C Y H

    2006-09-01

    Single phase chamfered-edge zeolite 4A samples in pure form with a high crystallinity were synthesized by applying step-change of synthesis temperature during hydrothermal treatment of coal fly ash. The calcium binding capacity of these zeolite 4A samples (prepared from coal fly ash) and the commercial detergent grade zeolite 4A were tested for usage as a detergent builder. The results show that these zeolite 4A samples behaved similarly as the commercial one in removing calcium ions during the washing cycle. Moreover, from the leaching tests (evaluation of toxicological safety), the results show that these zeolite 4A samples leached the same elements (Sb, As, Se and Tl) as the commercial one with the concentrations in the same order of magnitude. This shows that the toxicological effect of the coal fly ash converted zeolite 4A was not worse than that of the commercial sample. Finally, economic and environmental aspects of converting coal fly ash to useful products were discussed.

  8. The evaluation of geopolymer properties prepared by alkali activation of black coal ashes with high content of loss on ignition

    Directory of Open Access Journals (Sweden)

    Michalíková Františka

    2010-11-01

    Full Text Available The utilization of fly ashes in Slovakia is lower than in other countries and dumping of fly ashes prevails. The dumping changeschemical and phase composition of fly ashes and so it decreases possibilities for their utilization. Fly ashes are mainly used in buildingindustry, where the content of loss on ignition (LOI is limited due to standards. Black coal fly ashes produced in Slovakia have a highcontent of loss on ignition – more than 20 % - so they straight utilization in building industry is not possible. The current possibility fortheir utilization is in geopolymer synthesis. Products with 28-day compression strength of 35.7 MPa and 180-day compression strengthof 55.0 MPa were obtained by alkali activation of fly ashes with 23.25 % LOI with 8 wt% Na2O and their next hardening in temperatureof 80 °C during 6 hours. Products have a great frost-resistance and aggressive environments resistance (NaCl a H2SO4 solutions.

  9. Ultra high performance concrete made with rice husk ash for reduced autogenous shrinkage

    NARCIS (Netherlands)

    Van Breugel, K.; Van Tuan, N.

    2014-01-01

    Ultra High Strength Concrete (UHPC) is generally made with low w/c mixtures and by adding silica fume. Low w/c mixtures, however, exhibit high autogenous shrinkage, while a high amount of silica fume increases the price of these mixtures. For designing ultra high strength mixtures with low

  10. Reusing fly ash in glass fibre reinforced cement: a new generation of high-quality GRC composites.

    Science.gov (United States)

    Payá, J; Bonilla, M; Borrachero, M V; Monzó, J; Peris-Mora, E; Lalinde, L F

    2007-01-01

    New composite materials based on an alkali-resistant glass-fibre reinforced cement (AR-GRC) system are being developed by using fly ash (FA) produced at coal thermoelectric power plants, and fluid catalytic cracking catalyst residue (FC3R) from the petrol industry as cement replacement materials. These wastes are reactive from the pozzolanic viewpoint, and modify the nature and the microstructure of the cement matrix when a part of the Portland cement is replaced in the formulation of GRC. Several microstructural and mechanical aspects are being studied for AR-GRC systems. The behaviour of composites exposed to ageing shows that the pozzolanic activity of the ground FA added in high amounts and its mixture with the FC3R increase the flexural strength and no evidences of strength decay are observed. Additionally, the fibres due to the high alkalinity of the cementing matrix can be deteriorated. Fibres in the control (only Portland cement) and FC3R containing composites were attacked, whereas composites with FA and their mixture with FC3R show that the fibres have not been attacked, due to the pozzolanic activity of replacing materials that reduce the calcium hydroxide content in the cementing matrix.

  11. Reusing fly ash in glass fibre reinforced cement: A new generation of high-quality GRC composites

    Energy Technology Data Exchange (ETDEWEB)

    Paya, J.; Bonilla, M.; Borrachero, N.; Monzo, J.; Peris-Mora, E.; Lalinde, L.F.

    2007-07-01

    New composite materials based on an alkali-resistant glass-fibre reinforced cement (AR-GRC) system are being developed by using fly ash (FA) produced at coal thermoelectric power plants, and fluid catalytic cracking catalyst residue (FC3R) from the petrol industry as cement replacement materials. These wastes are reactive from the pozzolanic viewpoint, and modify the nature and the microstructure of the cement matrix when a part of the Portland cement is replaced in the formulation of GRC. Several microstructural and mechanical aspects are being studied for AR-GRC systems. The behaviour of composites exposed to ageing shows that the pozzolanic activity of the ground FA added in high amounts and its mixture with the FOR increase the flexural strength and no evidences of strength decay are observed. Additionally, the fibres due to the high alkalinity of the cementing matrix can be deteriorated. Fibres in the control (only Portland cement) and FOR containing composites were attacked, whereas composites with FA and their mixture with FC3R show that the fibres have not been attacked, due to the pozzolanic activity of replacing materials that reduce the calcium hydroxide content in the cementing matrix.

  12. 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.

  13. 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.

  14. High Performance Work Practices In Indian Organizations- An Understanding

    OpenAIRE

    Awasthi, Shakti

    2013-01-01

    In todays global competitive era, every business aims to optimize their processes. High performance work practices are such a practice, which can lead to the optimal utilization of human resources. In the present article I have tried to bring into light different aspects related to the high performing work practices in the organizational setup and their implementation can make a difference in the organization. The high performance work practices not only can bring the change in human resource...

  15. Electrodialytic removal of Cd from biomass combustion fly ash

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

    2004-01-01

    . The initial Cd concentration in the ashes varied between 8.8 mg Cd/kg DM (co-firing ash) and 64 mg Cd/kg DM (pre-washed straw ash), and pH varied from 3.7 to 13.3. In spite of large differences in ash characteristics, the electrodialytic remediation experiments indicated a good remediation potential for all......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...

  16. Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

    Full Text Available This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA as partial replacement of cement in presence of copolymer latexes. Portland cement (PC was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA and 2-hydroxymethylacrylate (2-HEMA. Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM. The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  17. Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

    Science.gov (United States)

    Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  18. A Novel MK-based Geopolymer Composite Activated with Rice Husk Ash and KOH: Performance at High Temperature

    Directory of Open Access Journals (Sweden)

    M. A. Villaquirán-Caicedo

    2017-02-01

    Full Text Available Geopolymers were produced using an environmentally friendly alkali activator (based on Rice Husk Ash and potassium hydroxide. Aluminosilicates particles, carbon and ceramic fibres were used as reinforcement materials. The effects of reinforcement materials on the flexural strength, linear-shrinkage, thermophysical properties and microstructure of the geopolymers at room and high temperature (1200 ÅãC were studied. The results indicated that the toughness of the composites is increased 110.4% for geopolymer reinforced by ceramic fibres (G-AF at room temperature. The presence of particles improved the flexural behaviour 265% for geopolymer reinforced by carbon fibres and particles after exposure to 1200 .C. Linear-shrinkage for geopolymer reinforced by ceramic fibres and particles and the geopolymer G-AF compared with reference sample (without fibres and particles is improved by 27.88% and 7.88% respectively at 900 ÅãC. The geopolymer materials developed in this work are porous materials with low thermal conductivity and good mechanical properties with potential thermal insulation applications for building applications.

  19. Rheumatic diseases in Alaskan Indians of the southeast coast: high prevalence of rheumatoid arthritis and systemic lupus erythematosus.

    Science.gov (United States)

    Boyer, G S; Templin, D W; Lanier, A P

    1991-10-01

    A review of rheumatic diseases in the southeast coastal Indians of Alaska revealed high frequencies of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Both prevalence and incidence rates of RA were significantly higher and the peak age of incidence was younger in the southeast Alaskan Indian population than in Alaskan Eskimo groups and the United States population in general. The prevalence of SLE in the Alaskan Indian population was about twice that reported for most white populations. The frequency of seronegative spondyloarthropathic disorders was similar in the Alaskan Indian and Eskimo populations. Comparable studies of the prevalence of spondyloarthropathy in general have not been carried out in white populations. The prevalence rate of ankylosing spondylitis, one of the major types of spondyloarthropathy, did not differ significantly in the SE Indians from rates in predominantly white US populations.

  20. Quartz in ash, and air in a high lung cancer incidence area in China

    NARCIS (Netherlands)

    Downward, George S|info:eu-repo/dai/nl/412435667; Hu, Wei; Rothman, Nat; Reiss, Boris|info:eu-repo/dai/nl/314119205; Tromp, Peter; Wu, Guoping; Wei, Fusheng; Xu, Jun; Seow, Wei Jie; Chapman, Robert S.; Lan, Qing; Vermeulen, Roel|info:eu-repo/dai/nl/216532620

    Exposure to crystalline silica (quartz) has been implicated as a potential cause of the high lung cancer rates in the neighbouring counties of Xuanwei and Fuyuan, China, where the domestic combustion of locally sourced "smoky" coal (a bituminous coal) is responsible for some of the highest lung

  1. A History of Ashes: An 80 Year Comparative Portrait of Smoking Initiation in American Indians and Non-Hispanic Whites—the Strong Heart Study

    Directory of Open Access Journals (Sweden)

    Jack Goldberg

    2013-05-01

    Full Text Available The consequences of starting smoking by age 18 are significant. Early smoking initiation is associated with higher tobacco dependence, increased difficulty in smoking cessation and more negative health outcomes. The purpose of this study is to examine how closely smoking initiation in a well-defined population of American Indians (AI resembles a group of Non-Hispanic white (NHW populations born over an 80 year period. We obtained data on age of smoking initiation among 7,073 AIs who were members of 13 tribes in Arizona, Oklahoma and North and South Dakota from the 1988 Strong Heart Study (SHS and the 2001 Strong Heart Family Study (SHFS and 19,747 NHW participants in the 2003 National Health Interview Survey. The participants were born as early as 1904 and as late as 1985. We classified participants according to birth cohort by decade, sex, and for AIs, according to location. We estimated the cumulative incidence of smoking initiation by age 18 in each sex and birth cohort group in both AIs and NHWs and used Cox regression to estimate hazard ratios for the association of birth cohort, sex and region with the age at smoking initiation. We found that the cumulative incidence of smoking initiation by age 18 was higher in males than females in all SHS regions and in NHWs (p < 0.001. Our results show regional variation of age of initiation significant in the SHS (p < 0.001. Our data showed that not all AIs (in this sample showed similar trends toward increased earlier smoking. For instance, Oklahoma SHS male participants born in the 1980s initiated smoking before age 18 less often than those born before 1920 by a ratio of 0.7. The results showed significant variation in age of initiation across sex, birth cohort, and location. Our preliminary analyses suggest that AI smoking trends are not uniform across region or gender but are likely shaped by local context. If tobacco prevention and control programs depend in part on addressing the origin of AI

  2. Characterization of ash cenospheres in fly ash from Australian power stations

    Energy Technology Data Exchange (ETDEWEB)

    Ling-ngee Ngu; Hongwei Wu; Dong-ke Zhang [Curtin University of Technology, Perth, WA (Australia). Centre for Fuels and Energy and Department of Chemical Engineering

    2007-12-15

    Ash cenospheres in fly ashes from five Australian power stations have been characterized. The experimental data show that ash cenosphere yield varies across the power stations. Ash partitioning occurred in the process of ash cenosphere formation during combustion. Contradictory to conclusions from the literature, iron does not seem to be essential to ash cenosphere formation in the cases examined in the present work. Further investigation was also undertaken on a series of size-fractioned ash cenosphere samples from Tarong power station. It is found that about 70 wt% of ash cenospheres in the bulk sample have sizes between 45 and 150 {mu}m. There are two different ash cenosphere structures, that is, single-ring structure and network structure. The percentage of ash cenospheres of a network structure increases with increasing ash cenosphere size. Small ash cenospheres (in the size fractions {lt}150 {mu}m) have a high SiO{sub 2}/Al{sub 2}O{sub 3} ratio, and the majority of the ash cenospheres are spherical and of a single-ring structure. Large ash cenosphere particles (in the size fractions of 150-250 {mu}m and {gt}250 {mu}m) have a low SiO{sub 2}/Al{sub 2}O{sub 3} ratio, and a high proportion of the ash cenospheres are nonspherical and of a network structure. A novel quantitative technique has been developed to measure the diameter and wall thickness of ash cenospheres on a particle-to-particle basis. A monolayer of size-fractioned ash cenospheres was dispersed on a pellet, which was then polished carefully before being examined using a scanning electron microscope and image analysis. The ash cenosphere wall thickness broadly increases with increasing ash cenosphere size. The ratios between wall thickness and diameter of ash cenospheres are limited between an upper bound of about 10.5% and a lower bound of about 2.5%, irrespective of the ash cenosphere size. 52 refs., 9 figs., 4 tabs.

  3. Hookah use among high school children in an Indian city

    Directory of Open Access Journals (Sweden)

    Nayak Prathibha Anand

    2013-01-01

    Full Text Available Context: Use of hookah is on the rise among youngsters. A growing body of evidence suggests that these children are experimenting with this form of tobacco. Aims: The study was carried out to know prevalence estimates of hookah use and factors associated with it among high school students.Settings and Design: This study adds to the current literature by providing prevalence estimates and factors associated with hookah use among high school students of Indore - a city in central India.Materials and Methods: A cross-sectional survey of 1000 students from high schools was conducted to find hookah users and factors associated with its use. Results: Hookah users in this study population were 7.6%. Most of them first learned about hookah from friends (63.2%. They usually smoked in hookah lounges (85.5%. These children believed that hookah was safer and more socially acceptable than cigarettes.Conclusions: Misperceptions of safety and popularity of hookah among the younger generation are cause for concern. Presence of hookah lounges should be a target for further regulation. Prevention activities are necessary to prevent this rising public health concern.

  4. Hookah use among high school children in an Indian city.

    Science.gov (United States)

    Anand, Nayak Prathibha; Vishal, Khandelwal; Anand, Nayak Ullal; Sushma, Khandelwal; Nupur, Ninawe

    2013-01-01

    Use of hookah is on the rise among youngsters. A growing body of evidence suggests that these children are experimenting with this form of tobacco. The study was carried out to know prevalence estimates of hookah use and factors associated with it among high school students. This study adds to the current literature by providing prevalence estimates and factors associated with hookah use among high school students of Indore - a city in central India. A cross-sectional survey of 1000 students from high schools was conducted to find hookah users and factors associated with its use. Hookah users in this study population were 7.6%. Most of them first learned about hookah from friends (63.2%). They usually smoked in hookah lounges (85.5%). These children believed that hookah was safer and more socially acceptable than cigarettes. Misperceptions of safety and popularity of hookah among the younger generation are cause for concern. Presence of hookah lounges should be a target for further regulation. Prevention activities are necessary to prevent this rising public health concern.

  5. Mass Spectrometric Determination of Uranium and Thorium in High Radiopurity Polymers Using Ultra Low Background Electroformed Copper Crucibles for Dry Ashing

    Energy Technology Data Exchange (ETDEWEB)

    Arnquist, Isaac J.; Hoppe, Eric J.; Bliss, Mary; Grate, Jay W.

    2017-02-21

    A rapid new method for determining the U and Th mass concentrations in high radiopurity plastics is described, consisting of 1) dry ashing the plastic sample and tracers in low mass crucibles made of ultra low background electroformed copper (ULB EF-Cu) foil cut and folded into boats, 2) dissolving both the ash and the boat in acid, 3) performing a column separation to remove copper, and 4) determining the elements of interest by isotope dilution mass spectrometry. This method was demonstrated on both unfluorinated and fluorinated plastics, demonstrating high tracer recoveries and detection limits to pg/g (i.e., parts per trillion) levels or below, corresponding to μBq/kg of material. Samples of biomedical polyester (Max-Prene® 955) and a fluoropolymer (polyvinylidene fluoride, PVDF) were analyzed in powder raw material forms as well as solids in the form of pellets or injection molded parts. The polyester powder contained 6 pg/g and 2 pg/g for Th and U respectively. These levels correspond to 25 and 25 μBq/kg radioactivity, respectively. Determinations on samples of PVDF powder were typically below 1 pg/g for Th and 2 pg/g for U, corresponding to 4 and 25 μBq/kg radioactivity, respectively. The use of low mass ULB EF-Cu boats for dry ashing successfully overcame the problem of crucible-generated contaminants in the analysis; absolute detection limits, calculated as 3 × standard deviation of the process blanks, were typically 20-100 fg within a sample set. Complete dissolution of the ash and low mass boat provided high tracer recoveries, and provides a convincing method to recover both the tracer and sample isotopes when full equilibration of tracer isotopes with sample isotopes is not possible prior to beginning chemical sample processing on solids.

  6. Best Practices Guide for High-Performance Indian Office Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Reshma [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sartor, Dale [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ghatikar, Girish [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-04-01

    This document provides best practice guidance and energy- efficiency recommendations for the design, construction, and operation of high-­performance office buildings in India. Through a discussion of learnings from exemplary projects and inputs from experts, it provides recommendations that can potentially help achieve (1) enhanced working environments, (2) economic construction/faster payback, (3) reduced operating costs, and (4) reduced greenhouse gas (GHG) emissions. It also provides ambitious (but achievable) energy performance benchmarks, both as adopted targets during building modeling (design phase) and during measurement and verification (operations phase). These benchmarks have been derived from a set of representative best-in-class office buildings in India. The best practices strategies presented in this guide would ideally help in delivering high-­performance in terms of a triad—of energy efficiency, cost efficiency, and occupant comfort and well-­being. These best practices strategies and metrics should be normalized—that is, corrected to account for building characteristics, diversity of operations, weather, and materials and construction methods.

  7. Modeling of Compressive Strength for Self-Consolidating High-Strength Concrete Incorporating Palm Oil Fuel Ash

    Science.gov (United States)

    Safiuddin, Md.; Raman, Sudharshan N.; Abdus Salam, Md.; Jumaat, Mohd. Zamin

    2016-01-01

    Modeling is a very useful method for the performance prediction of concrete. Most of the models available in literature are related to the compressive strength because it is a major mechanical property used in concrete design. Many attempts were taken to develop suitable mathematical models for the prediction of compressive strength of different concretes, but not for self-consolidating high-strength concrete (SCHSC) containing palm oil fuel ash (POFA). The present study has used artificial neural networks (ANN) to predict the compressive strength of SCHSC incorporating POFA. The ANN model has been developed and validated in this research using the mix proportioning and experimental strength data of 20 different SCHSC mixes. Seventy percent (70%) of the data were used to carry out the training of the ANN model. The remaining 30% of the data were used for testing the model. The training of the ANN model was stopped when the root mean square error (RMSE) and the percentage of good patterns was 0.001 and ≈100%, respectively. The predicted compressive strength values obtained from the trained ANN model were much closer to the experimental values of compressive strength. The coefficient of determination (R2) for the relationship between the predicted and experimental compressive strengths was 0.9486, which shows the higher degree of accuracy of the network pattern. Furthermore, the predicted compressive strength was found very close to the experimental compressive strength during the testing process of the ANN model. The absolute and percentage relative errors in the testing process were significantly low with a mean value of 1.74 MPa and 3.13%, respectively, which indicated that the compressive strength of SCHSC including POFA can be efficiently predicted by the ANN. PMID:28773520

  8. Graphitization of unburned carbon from oil-fired fly ash applied for anode materials of high power lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Tzoo-Shing [Department of Material Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China); Wu, Yu-Shiang, E-mail: yswu@cc.cust.edu.tw [Department of Mechanical Engineering, China University of Science and Technology, Taipei 115, Taiwan (China); Lee, Yuan-Haun [Department of Material Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China)

    2011-10-17

    Highlights: {center_dot} From TEM observations, the graphitization treatment samples had annular microstructure. {center_dot} Sample with heat treatment at 2300 deg. C is a suitable material for the higher C-rate region. {center_dot} Sample with heat treatment at 2700 deg. C yields the first columbic efficiency of about 93.6%. - Abstract: Unburned carbon is an industrial waste product of oil-fired fly ash. From the viewpoint of waste recycling, using ground unburned carbon with an average size of 6 {mu}m heat treatment at 2700 deg. C, and both charge and discharge at 0.1 C, yields the first columbic efficiency of about 93.6%. Moreover, after 50 cycles, the discharge capacity is 325.5 mAh g{sup -1}, and the capacity retention is about 97.5%. The two conditions tested for rate capability are as follows: First, a charge at 0.2 C rate and discharge at variable C-rates in which the unburned carbon after heat treatment at higher temperature exhibits a higher capacity in the 0.2-3 C region. However, unburned carbon with heat treatment at 2300 deg. C is a suitable material for the higher C-rate region (5-10 C). Second, for both charge and discharge at the same C-rate, the unburned carbon after heat treatment at higher temperature exhibits a higher capacity in the 0.2-0.5 C region; however, unburned carbon without graphitization treatment is a suitable material for the higher C-rate region (3-10 C). Based on TEM observations, the graphitization treatment samples had annular microstructure which has many active sites, improving the intercalation/deintercalation of lithium ions. Therefore, these results show that compared to natural graphite, graphitization of unburned carbon is more suitable for the anode materials of a high power battery.

  9. Modeling of Compressive Strength for Self-Consolidating High-Strength Concrete Incorporating Palm Oil Fuel Ash

    Directory of Open Access Journals (Sweden)

    Md. Safiuddin

    2016-05-01

    Full Text Available Modeling is a very useful method for the performance prediction of concrete. Most of the models available in literature are related to the compressive strength because it is a major mechanical property used in concrete design. Many attempts were taken to develop suitable mathematical models for the prediction of compressive strength of different concretes, but not for self-consolidating high-strength concrete (SCHSC containing palm oil fuel ash (POFA. The present study has used artificial neural networks (ANN to predict the compressive strength of SCHSC incorporating POFA. The ANN model has been developed and validated in this research using the mix proportioning and experimental strength data of 20 different SCHSC mixes. Seventy percent (70% of the data were used to carry out the training of the ANN model. The remaining 30% of the data were used for testing the model. The training of the ANN model was stopped when the root mean square error (RMSE and the percentage of good patterns was 0.001 and ≈100%, respectively. The predicted compressive strength values obtained from the trained ANN model were much closer to the experimental values of compressive strength. The coefficient of determination (R2 for the relationship between the predicted and experimental compressive strengths was 0.9486, which shows the higher degree of accuracy of the network pattern. Furthermore, the predicted compressive strength was found very close to the experimental compressive strength during the testing process of the ANN model. The absolute and percentage relative errors in the testing process were significantly low with a mean value of 1.74 MPa and 3.13%, respectively, which indicated that the compressive strength of SCHSC including POFA can be efficiently predicted by the ANN.

  10. Synthesis of high-purity Na-A and Na-X zeolite from coal fly ash.

    Science.gov (United States)

    Panitchakarn, Panu; Laosiripojana, Navadol; Viriya-Umpikul, Nawin; Pavasant, Prasert

    2014-05-01

    Coal fly ash (CFA) was used as a raw material for the synthesis of zeolite molecular sieve. The synthesis began with the pretreatment of CFA to remove impurities (e.g., Fe2O3, CaO, etc.) under various acid types (HCl, H2SO4, and HNO3) and acid/CFA ratios (5-25 mL(acid)/g(CFA)). High product purity (up to 97%) was achieved with HCl (20%wt), and acid/CFA ratio of 20 mL(HCl)/g(CFA). The treated CFA was then converted to zeolite by the fusion reaction under various Si/Al molar ratios (0.54-1.84). Zeolite type A was synthesized when the Si/Al molar ratios were lower than 1, whereas sodium aluminum silicate hydrate was formed when the Si/Al molar ratio were higher than 1. The highest water adsorption performance of the zeolite product, i.e., the outlet ethanol concentration of 99.9%wt and the specific adsorption capacity of 2.31 x 10(-2) g(water)/g(zeolite), was observed with the Si/Al molar ratio of 0.82. The zeolite was tested for its water adsorption capacity repeatedly 10 times without deactivation. This work evaluated the technical feasibility in the conversion of CFA to zeolite, which would help reduce the quantity of waste needed to be landfilled. This adds value to the unwanted material by converting it into something that can be further used. The synthesized products were shown to be quite stable as water adsorbent for the dehydration of ethanol solution.

  11. SYNTHESIS AND CHARACTERIZATION OF HIGH BELITE SULFOALUMINATE CEMENT THROUGH RICH ALUMINA FLY ASH AND DESULFURIZATION GYPSUM

    Directory of Open Access Journals (Sweden)

    BING MA,

    2013-03-01

    Full Text Available The objective of this study was the preparation and characterization of high belite sulfoaluminate cement (HBSC from industrial residues. HBSC promises eco-friendly building materials with great mechanical performance at earlier ages than Ordinary Portland Cement (OPC. Preliminary results show the formation of main phase dicalcium silicate (C2S and ye’elimite (C4A3$ at 1250°C, as determined by X-ray diffraction (XRD, are promising. The formation of minerals in the clinker was analyzed by differential scanning calorimetry-thermogravimetry (DSC–TG. Likewise, Scanning electron microscope (SEM and XRD were used to carry out the analysis of the micro-structural and hydration products. The main HBSC hydration products, Ettringite and amorphous Al(OH3, were formed in the early stages; however, during the later stages, monosulfate and Strätlingite were formed. Isothermal conduction calorimetry measurements indicate that hydration properties of the cements are comparable to OPC; the total hydration heat after 3 days was 438 J/g. The optimum compressive strength values of the mortars after 1-, 3-, 7-, and 28-days were 24.9 MPa, 33.2 MPa, 35.6 MPa and 52.8 MPa which can meet the requirement of special structures.

  12. INRA, a new high-frequency antigen in the INDIAN (IN023) blood group system.

    Science.gov (United States)

    Joshi, Sanmukh R; Sheladiya, Ankita; Mendapara-Dobariya, Kinjal V

    2017-01-01

    The INDIAN blood group system comprises 4 antigens sensitive to enzymes and 2-aminoethyl isothiouronium bromide (AET). The patient's antibody was investigated for its specificity to the high-frequency antigens (HFA) of this system. Low ionic strength solution (LISS)-tube/LISS-indirect antiglobulin test (IAT) methods were used. The patient's red blood cells (RBCs) were tested with antisera to HFA. Her antibody was tested with RBCs lacking the HFA. Furthermore, it was tested with RBCs as untreated or treated with enzyme or AET. The genetic sequence was studied for mutation in CD44 gene that encodes INDIAN antigens. The patient was grouped A1B, RhD+, antibody screening test positive, direct antiglobulin test negative. A negative autocontrol test had suggested to the alloantibody being present. Antibody had agglutinated RBCs in LISS-tube at RT and by LISS-IAT at 37°C. The RBCs of the 11-cell panel, those lacking HFA and from 50 random donors, were agglutinated by her antibody indicating its specificity to the HFA, though the RBCs of Lu (a-b-)/In (Lu) type showed a weaker reaction. The patient's RBCs were agglutinated by antisera to a number of the enzyme-sensitive HFA, including those of INDIAN blood groups. The antibody showed reduced reactivity with the RBCs treated with papain, chymotrypsin, and AET but resistant to trypsin and dithiothreitol. The patient's genetic sequence revealed a novel homozygous mutation 449G>A in exon 5 of CD44. The antibody to enzyme sensitive HFA was tested for serological and molecular genetics studies and found to be directed to the novel HFA, named as INRA of the INDIAN blood group system and was assigned a numerical symbol IN: 005 by the International Society of Blood Transfusion (ISBT).

  13. CZECH FLUID SULFOCALCIC ASH AND FLY ASH

    Directory of Open Access Journals (Sweden)

    Frantisek Skvara

    2016-10-01

    Full Text Available Sulfocalcic ash is formed during the fluidized bed combustion of coal in the presence of limestone. It differs from classical fly ash by its composition and properties. Sulfocalcic ash contains free CaO, CaSO₄ and partially sintered aluminosilicates. In contact with water, it produces Ca(OH₂, expansive ettringite and a small amount of the CSH phase. There is little information about these ashes in the literature. At present, the possibility of using fluid sulfocalcic ashes is quite limited because of the formation of expansive ettringite. More research in the field of sulfocalcic ashes is a necessity because increasing quantities of this product are rejected by the energy-generation industry.

  14. Nature, source and composition of volcanic ash in sediments from a fracture zone trace of Rodriguez Triple Junction in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas-Pereira, M.B.L.; Nath, B.N.; Borole, D.V.; Gupta, S.M.

    are highly porous with varying colors like orange, straw yellow, pale brown and off white, very few exhibit waxy luster. Next in abundance are glass shards, which in general display angular to smoothened surfaces. In addition, > 63 ? m fraction also...

  15. Electrodialytic removal of Cd from biomass combustion fly ash suspensions

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor M.; Ottosen, Lisbeth M.; Damoe, Anne J.

    2013-01-01

    was investigated with the aim of enabling reuse of the ashes. The ashes originated from combustion of straw (two ashes), wood chips, and co-firing of wood pellets and fuel oil, respectively. A series of laboratory scale electrodialytic remediation experiments were conducted with each ash. The initial Cd...... the final Cd concentration was below 2.0. mg Cd/kg DM in at least one experiment done with each ash. This was obtained within 2 weeks of remediation and at liquid to solid (L/S) ratios of L/S 16 for the pre-washed straw ash and L/S 8 for the straw, co-firing and wood ash. © 2013 Elsevier B.V.......Due to relatively high concentrations of Cd, biomass combustion fly ashes often fail to meet Danish legislative requirements for recycling as fertilizer. In this study, the potential of using electrodialytic remediation for removal of Cd from four different biomass combustion fly ashes...

  16. Can vegetative ash be water repellent?

    Science.gov (United States)

    Bodí, M. B.; Cerdà, A.; Mataix-Solera, J.; Doerr, S. H.

    2012-04-01

    In most of the literature, ash is referred to as a highly wettable material (e.g. Cerdà and Doerr, 2008; Etiegni and Campbell, 1991; Woods and Balfour 2010). However, the contrary was suggested in few articles, albeit with no further quantification (Gabet and Sternberg, 2008; Khanna et al., 1996; Stark, 1977). To clarify this question, water repellency measurements on ash using the Water Drop Penetration Times (WDPT) method were performed on ash from Mediterranean ecosystems and it was found to be water repellent (Bodí et al. 2011). Water repellency on ash from different wildfires ranged from 40 to 10 % occurrence with samples being extreme repellent (lasting more than 3600 s to penetrate). Part of the ash produced in the laboratory was also water repellent. After that, other ash samples had been found water repellent in wildfires in Colorado (unpublished results), Portugal (Gonzalez-Pelayo, 2009), or in prescribed fires in Australia (Bodí et al. 2011b; Petter Nyman, personnal communication). All the samples exhibiting water repellent properties had in common that were combusted at low temperatures, yielding in general ash with dark colour and contents of organic carbon of more than 18 % (Bodí et al. 2011a), although these properties were not exactly proportional to its water repellency occurrence or persistence. In addition, the species studied in Bodí et al. (2011) had been found to produce different levels of WR repellency, being ash from Pinus halepensis more repellent than that from Quercus coccifera and Rosmarins officinalis. Ash from Eucaliptus radiata had been found also very water repellent, as Pinus halepensis (unpublished data). The reasons of the existance of water repellent ash are that the charred residue produced by fire (an also contained in the ash) can contain aromatic compounds that have a lower free energy than water and therefore behave as hydrophobic materials with reduced solubility (Almendros et al., 1992 and Knicker, 2007

  17. Possibilities of utilizing power plant fly ashes

    Directory of Open Access Journals (Sweden)

    Mezencevová Andrea

    2003-09-01

    mechanical action. It is known, that performance of fly ash in concrete improves with its increased fineness. Intensive milling of fly ash leads to the increasing fly ash fineness and to the enhancement of its hydration activity. The cement-fly ash composites with 25 wt.% of activated fly ash as cement replacement have exhibited a higher 28-day compressive strength in comparison with a reference concrete sample without fly ash. An unfavorable effect in milling process is the agglomeration of fine particles of fly ash. By high-energy milling of fly ash with addition of surfactants, the ultrafine products can be prepared. Concrete samples containing such fly ash have achieved higher compressive strengths than the reference sample without fly ash or with addition of non-milled fly ash. The considerable physical effect of ultrafine fly ash consists in superior filling of spaces between coarser cement particles and in the favorable influence of hardness of the mixtures at setting.The current research activities in mechanochemistry are oriented to the mechanical activation of poly-component systems. The knowledge in this field indicate that by high-energy milling of fly ash as a poly-component system and following heating of prepared metastable precursors, the cement minerals could be prepared.

  18. 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.

  19. 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)

  20. Characterisation of Turkish fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, O. [Cukurova University, Adana (Turkey). Mining Engineering Dept.

    1998-07-01

    The mineralogical, morphological, physical and chemical properties of 7 fly ashes from coal fields in Turkey are compared. The mineral matter in the fly ashes, determined by X-ray diffraction, is dominated by anhydride, lime, quartz and hematite + ferrite spinel. The three low-calcium ashes have the typical, relatively simple, crystalline phase Q, M, H and FS. The high-calcium fly ashes have the most complex assemblage of crystalline phases. The much higher calcium concentrations in these samples result in the formation of lime (CaO), melilite ((Ca, Na){sub 2}(Mg,Al,Fe)(Si,Al){sub 2}O{sub 7}) and merwinite. The presence of anhydride in all samples indicates that the high activity of calcium not only promotes the formation of sulfates from calcite but also the dehydration of gypsum during and after combustion, which occurs at temperatures above 400-500{degree}C. It is important to understand the interaction of high-calcium fly ashes with water occurring in Portland cement (C{sub 3}A,C{sub 2}S), Ah, which hydrates to give gypsum and lime, with the latter hydrating to give the Ca(OH){sub 2} solutions that promote pozzolonic reactions. Some of the particles comprised irregularly formed, vesicular particles with some well-formed individual spheres in Catalagzi and Tuncbilek fly ashes. About 55-80 wt% was less than 45 {mu}m in size for Yatagan, Soma, Yenikoy and Afsin-Elbistan fly ashes. The fly ashes were mainly composed of CaO, SiO{sub 2} and Al{sub 2}O{sub 3}. They have a potential use in wastewater treatment since they can be easily obtained in large quantities at low price or even free. The chemical and mineralogical compositions of the high-calcium Turkish fly ashes investigated make them a good binding agent and a possible substitute for slags, pozzolana and gypsum in the amelioration of clinker. 53 refs., 10 figs., 5 tabs.

  1. Abundances and distribution of minerals and elements in high-alumina coal fly ash from the Jungar Power Plant, Inner Mongolia, China

    Science.gov (United States)

    Dai, S.; Zhao, L.; Peng, S.; Chou, C.-L.; Wang, X.; Zhang, Y.; Li, D.; Sun, Y.

    2010-01-01

    The fly ash from the Jungar Power Plant, Inner Mongolia, China, is unique because it is highly enriched in alumina (Al2O3>50%). The fly ash mainly consists of amorphous glass and mullite and trace amounts of corundum, quartz, char, calcite, K-feldspar, clay minerals, and Fe-bearing minerals. The mullite content in fly ash is as high as 37.4% because of high boehmite and kaolinite contents in feed coal. Corundum is a characteristic mineral formed during the combustion of boehmite-rich coal.Samples from the economizer were sieved into six size fractions (500 mesh) and separated into magnetic, mullite+corundum+quartz (MCQ) and glass phases for mineralogical and chemical analysis. The corundum content increases but amorphous glass decreases with decreasing particle size. Fractions of small particle sizes are relatively high in mullite, probably because mullite was formed from fine clay mineral particles under high-temperature combustion condition. Similarly, fine corundum crystals formed in the boiler from boehmite in feed coal. The magnetic phase consists of hematite, magnetite, magnesioferrite, and MgFeAlO4 crystals. The MCQ phase is composed of 89% mullite, 6.1% corundum, 4.5% quartz, and 0.5% K-feldspar.Overall, the fly ash from the power plant is significantly enriched in Al2O3 with an average of 51.9%, but poor in SiO2, Fe2O3, CaO, MgO, Na2O, P2O5, and As. Arsenic, TiO2, Th, Al2O3, Bi, La, Ga, Ni, and V are high in mullite, and the magnetic matter is enriched in Fe2O3, CaO, MnO, TiO2, Cs, Co, As, Cd, Ba, Ni, Sb, MgO, Zn, and V. The remaining elements are high in the glass fraction. The concentration of K2O, Na2O, P2O5, Nb, Cr, Ta, U, W, Rb, and Ni do not clearly vary with particle size, while SiO2 and Hg decrease and the remaining elements clearly increase with decreasing particle size. ?? 2009 Elsevier B.V.

  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. Performance at high temperature of alkali-activated slag pastes produced with silica fume and rice husk ash based activators

    Directory of Open Access Journals (Sweden)

    Bernal, S. A.

    2015-06-01

    Full Text Available This study assessed the mechanical properties, and structural changes induced by high temperature exposure, of alkali-silicate activated slag cements produced with sodium silicates derived from silica fume (SF and rice husk ash (RHA. Similar reaction products were identified, independent of the type of silicate used, but with subtle differences in the composition of the C-S-H gels, leading to different strength losses after elevated temperature exposure. Cements produced with the alternative activators developed higher compressive strengths than those produced with commercial silicate. All samples retained strengths of more than 50 MPa after exposure to 600 °C, however, after exposure to 800 °C only the specimens produced with the RHA-based activator retained measurable strength. This study elucidated that silicate-activated slag binders, either activated with commercial silicate solutions or with sodium silicates based on SF or RHA, are stable up to 600 °C.Este estudio evaluó las propiedades mecánicas, y cambios estructurales inducidos por exposición a temperaturas elevadas, de cementos de escoria activada alcalinamente producidos con silicatos sódicos derivados de humo de sílice (SF y ceniza de cascarilla de arroz (RHA. Se identificaron productos de reacción similares, independiente del tipo de silicato utilizado, pero con diferencias menores en la composición de las geles C-S-H, lo cual indujo diferentes pérdidas de resistencia posterior a exposición a temperaturas elevadas. Los cementantes producidos con los activadores alternativos desarrollaron resistencias a la compresión más altas que aquellos producidos con silicato comercial. Todas las muestras retuvieron resistencias de más de 50 MPa posterior a la exposición a 600 °C, sin embargo, posterior a la exposición a 800 °C únicamente muestras producidas con activadores de RHA retuvieron resistencias medibles. Este estudio elucidó que cementantes de escoria activada con

  4. Highly Skilled Professionals on the Move: The International Migration of South African Indians

    Directory of Open Access Journals (Sweden)

    Gerelene Jagganath

    2014-08-01

    Full Text Available This paper is about the migration behaviour of highly skilled South African Indians from the period 2006 to present. The ethnography of the highly skilled is relatively new in Anthropology and while it contributes to recent discourse on migration and diaspora, it also foregrounds the need for an array of methodological approaches to support the global mobilities of people, the nature of multi-sited research and what “highly skilled” means in different geographical contexts. The paper is arranged in two parts: the first part contextualises the highly skilled professional in recent global migration literature and theory, and the second part presents case studies of highly skilled migrants in several international destinations, highlighting and contextualising their experiences abroad.

  5. 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)

  6. Asymmetric Ashes

    Science.gov (United States)

    2006-11-01

    , it is. "This has some impact on the use of Type Ia supernovae as standard candles," says Ferdinando Patat. "This kind of supernovae is used to measure the rate of acceleration of the expansion of the Universe, assuming these objects behave in a uniform way. But asymmetries can introduce dispersions in the quantities observed." "Our discovery puts strong constraints on any successful models of thermonuclear supernova explosions," adds Wang. Models have suggested that the clumpiness is caused by a slow-burn process, called 'deflagration', and leaves an irregular trail of ashes. The smoothness of the inner regions of the exploding star implies that at a given stage, the deflagration gives way to a more violent process, a 'detonation', which travels at supersonic speeds - so fast that it erases all the asymmetries in the ashes left behind by the slower burning of the first stage, resulting in a smoother, more homogeneous residue.

  7. 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),

  8. Wet physical separation of MSWI bottom ash

    NARCIS (Netherlands)

    Van Breugel, K.; Muchova, L.

    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),

  9. Significance of High Resolution GHRSST on prediction of Indian Summer Monsoon

    KAUST Repository

    Jangid, Buddhi Prakash

    2017-02-24

    In this study, the Weather Research and Forecasting (WRF) model was used to assess the importance of very high resolution sea surface temperature (SST) on seasonal rainfall prediction. Two different SST datasets available from the National Centers for Environmental Prediction (NCEP) global model analysis and merged satellite product from Group for High Resolution SST (GHRSST) are used as a lower boundary condition in the WRF model for the Indian Summer Monsoon (ISM) 2010. Before using NCEP SST and GHRSST for model simulation, an initial verification of NCEP SST and GHRSST are performed with buoy measurements. It is found that approximately 0.4 K root mean square difference (RMSD) in GHRSST and NCEP SST when compared with buoy observations available over the Indian Ocean during 01 May to 30 September 2010. Our analyses suggest that use of GHRSST as lower boundary conditions in the WRF model improve the low level temperature, moisture, wind speed and rainfall prediction over ISM region. Moreover, temporal evolution of surface parameters such as temperature, moisture and wind speed forecasts associated with monsoon is also improved with GHRSST forcing as a lower boundary condition. Interestingly, rainfall prediction is improved with the use of GHRSST over the Western Ghats, which mostly not simulated in the NCEP SST based experiment.

  10. Alkali ash material: a novel fly ash-based cement

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Rostami; William Brendley [Philadelphia University, Philadelphia, PA (United States)

    2003-08-01

    The United States generates 110 million t of coal ash annually. Approximately 70 million t of this coal ash is fly ash, of which 27% is recycled and the remaining 73% is landfilled. Disposal of such a huge quantity of ash poses a significant environmental problem. A new cementitious material has been developed, called alkali ash material (AAM), which is used to produce concrete for construction. AAM can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economic advantage. AAM contains 40-95% Class F fly ash and is used as cement to bind sand, stone, and fibers creating concrete. AAM concrete has been tested for strength, durability, mechanical properties, and, most importantly, economic viability. AAM concrete is economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of ultimate in 1 d), high ultimate strengths (110 MPa or 16 000 psi in 1 d), excellent acid resistance, and freeze-thaw durability. AAM's resistance to chemical attack, such as sulfuric (H{sub 2}SO{sub 4}), nitric (HNO{sub 3}), hydrochloric (HCl), and organic acids, is far better than portland cement concrete. AAM is resistant to freeze-thaw attack based on ASTM C-666 specifications. Potential immediate applications of AAM are blocks, pipe, median barriers, sound barriers, and overlaying materials. Eventual markets are high strength construction products, bridge beams, prestressed members, concrete tanks, highway appurtenances, and other concrete products. 28 refs., 7 figs., 2 tabs.

  11. High-precision /sup 40/Ar//sup 39/Ar ages of widespread Oligocene ash-flow tuff sheets near Socorro, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Kedzie, L.L.; Sutter, J.F.; Chapin, C.E.

    1985-01-01

    High-precision /sup 40/Ar//sup 39/Ar age spectrum dating on 5 ash-flow tuff sheets erupted from a group of cauldrons in the Mogollon-Datil volcanic field near Socorro, New Mexico, has produced a precise stratigraphic framework. Previous dating by K-Ar and fission-track methods was not precise enough to distinguish units erupted during a short time (1 million-2 million years), and many K-Ar analyses of cogenetic biotite and Na-sanidine yielded discordant ages. The five units and their high-precision /sup 40/Ar//sup 39/Ar ages, compared to an adopted age of 519.4 Ma for the McClure Mountain hornblende standard (MMhb-1), are listed in ascending stratigraphic order: Hells Mesa Tuff, 32.04 Ma; La Jencia Tuff, 28.76 Ma; Vicks Peak Tuff, 28.46 Ma; Lemitar Tuff, 27.95 Ma; South Canyon Tuff, 27.36 Ma. The temporal resolution for each unit is about 150,000 years. Na-sanidines yield the most concordant age spectra; however, plateau ages of cogenetic sanidine and biotite are equivalent for most samples. Preliminary investigations suggest that the approximately 3.3-million-year hiatus between the Hells Mesa and La Jencia Tuffs may represent a regional lull in volcanic activity. If so, ash-flow tuffs erupted after the hiatus are unlikely to have been derived by differentiation from magmas that produced the underlying volcanic units. Eruption of 4 major ash-flow sheets in 1 million-1.5 million years following the hiatus coincides with the onset of strong, regional extension in the Rio Grande rift and may represent a different magma genesis.

  12. Quality characteristics of Greek fly ashes and potential uses

    Energy Technology Data Exchange (ETDEWEB)

    Skodras, G.; Grammelis, P.; Kakaras, E. [Institute for Solid Fuels Technology and Applications, Ptolemais (Greece); Karangelos, D.; Anagnostakis, M.; Hinis, E. [Nuclear Engineering Section, Mechanical Engineering Department, National Technical University of Athens, Athens (Greece)

    2007-01-15

    The main characteristics of fly ash from Greek coal-fired boilers are presented in this paper in relation to its exploitation potential. Both fuel and fly ash samples were collected and analyzed according to the ASTM Standards. Apart from the typical analyses (proximate, ultimate, ash analysis and calorific value), an ICP-AES spectrometer was used for the analysis of heavy metals in the ash. Experimental measurements in order to determine the radioactivity content of raw fuel and the fly ash were carried out as well. A representative fly ash sample from Ptolemais power plant was evaluated and tested as filler in Self-Compacting Concrete (SCC). Ashes from the Greek brown coal are classified in type C, most of the fly ash being produced in Ptolemais of Northern Greece, while the rest in Megalopolis. Ptolemais fly ash is rich in calcium compounds, while Megalopolis fly ash contains more pyrite. Increased heavy metal concentrations are observed in the fly ash samples of Greek coal. Greek fly ash appears to have not only pozzolanic but also hydraulic behaviour. Furthermore, Greek fly ash, depending on its origin, may have relatively high natural radioactivity content, reaching in the case of Megalopolis fly ash 1 kBq kg{sup -1} of {sup 226}Ra. The laboratory results showed that fly ashes can be a competitive substitute to conventional limestone filler material in SCC. Fly ash is mostly used in Greece in cement industry replacing cement clinker and aiming to the production of special types of Portland cements. However, a more aggressive utilisation strategy should be developed, since low quantities of the total produced fly ash are currently further utilised. (author)

  13. AsH3 ultraviolet photochemistry.

    Science.gov (United States)

    Smith-Freeman, L A; Schroeder, W P; Wittig, C

    2009-03-12

    High-n Rydberg time-of-flight spectroscopy has been used to study the 193.3 nm photolysis of AsH(3). The center-of-mass translational energy distribution for the 1-photon process, AsH(3) + h nu --> AsH(2) + H, P(E(c.m.)), indicates that AsH(2) internal excitation accounts for approximately 64% of the available energy [i.e., h nu - D(0)(H(2)As - H)]. Secondary AsH(2) photodissociation also takes place. Analyses of superimposed structure atop the broad P(E(c.m.)) distribution suggest that AsH(2) is formed with significant a-axis rotation as well as bending excitation. Comparison of the results obtained with AsH(3) versus those of the lighter group-V hydrides (NH(3), PH(3)) lends support to the proposed mechanisms. Of the group-V hydrides, AsH(3) lies intermediate between the nonrelativistic and relativistic regimes, requiring high-level electronic structure theory.

  14. Market assessment and technical feasibility study of PFBC ash use

    Energy Technology Data Exchange (ETDEWEB)

    Smith, V.E.; Bland, A.E.; Brown, T.H. [Western Research Inst., Laramie, WY (United States); Georgiou, D.N. [Jacques, Whitford and Associates Ltd., Dartmouth, NS (Canada); Wheeldon, J. [Electric Power Research Inst., Palo Alto, CA (United States)

    1994-10-01

    The overall objectives of this study are to determine the market potential and the technical feasibility of using PFBC ash in high volume ash use applications. The information will be of direct use to the utility industry in assessing the economics of PFBC power generation in light of ash disposal avoidance through ash marketing. In addition, the research is expected to result in the generation of generic data on the use of PFBC ash that could lead to novel processing options and procedures. The specific objectives of the proposed research and demonstration effort are: Define resent and future market potential of PFBC ash for a range of applications (Phase I); assess the technical feasibility of PFBC ash use in construction, civil engineering and agricultural applications (Phase II); and demonstrate the most promising of the market and ash use options in full-scale field demonstrations (Phase III).

  15. 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. Copyright 2009 Elsevier Ltd. All rights reserved.

  16. High Connectivity of the Crocodile Shark between the Atlantic and Southwest Indian Oceans: Highlights for Conservation

    Science.gov (United States)

    da Silva Ferrette, Bruno Lopes; Mendonça, Fernando Fernandes; Coelho, Rui; de Oliveira, Paulo Guilherme Vasconcelos; Hazin, Fábio Hissa Vieira; Romanov, Evgeny V.; Oliveira, Claudio; Santos, Miguel Neves; Foresti, Fausto

    2015-01-01

    Among the various shark species that are captured as bycatch in commercial fishing operations, the group of pelagic sharks is still one of the least studied and known. Within those, the crocodile shark, Pseudocarcharias kamoharai, a small-sized lamnid shark, is occasionally caught by longline vessels in certain regions of the tropical oceans worldwide. However, the population dynamics of this species, as well as the impact of fishing mortality on its stocks, are still unknown, with the crocodile shark currently one of the least studied of all pelagic sharks. Given this, the present study aimed to assess the population structure of P. kamoharai in several regions of the Atlantic and Indian Oceans using genetic molecular markers. The nucleotide composition of the mitochondrial DNA control region of 255 individuals was analyzed, and 31 haplotypes were found, with an estimated diversity Hd = 0.627, and a nucleotide diversity π = 0.00167. An analysis of molecular variance (AMOVA) revealed a fixation index ΦST = -0.01118, representing an absence of population structure among the sampled regions of the Atlantic Ocean, and between the Atlantic and Indian Oceans. These results show a high degree of gene flow between the studied areas, with a single genetic stock and reduced population variability. In panmictic populations, conservation efforts can be concentrated in more restricted areas, being these representative of the total biodiversity of the species. When necessary, this strategy could be applied to the genetic maintenance of P. kamoharai. PMID:25689742

  17. High connectivity of the crocodile shark between the Atlantic and Southwest Indian Oceans: highlights for conservation.

    Directory of Open Access Journals (Sweden)

    Bruno Lopes da Silva Ferrette

    Full Text Available Among the various shark species that are captured as bycatch in commercial fishing operations, the group of pelagic sharks is still one of the least studied and known. Within those, the crocodile shark, Pseudocarcharias kamoharai, a small-sized lamnid shark, is occasionally caught by longline vessels in certain regions of the tropical oceans worldwide. However, the population dynamics of this species, as well as the impact of fishing mortality on its stocks, are still unknown, with the crocodile shark currently one of the least studied of all pelagic sharks. Given this, the present study aimed to assess the population structure of P. kamoharai in several regions of the Atlantic and Indian Oceans using genetic molecular markers. The nucleotide composition of the mitochondrial DNA control region of 255 individuals was analyzed, and 31 haplotypes were found, with an estimated diversity Hd = 0.627, and a nucleotide diversity π = 0.00167. An analysis of molecular variance (AMOVA revealed a fixation index ΦST = -0.01118, representing an absence of population structure among the sampled regions of the Atlantic Ocean, and between the Atlantic and Indian Oceans. These results show a high degree of gene flow between the studied areas, with a single genetic stock and reduced population variability. In panmictic populations, conservation efforts can be concentrated in more restricted areas, being these representative of the total biodiversity of the species. When necessary, this strategy could be applied to the genetic maintenance of P. kamoharai.

  18. 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.

  19. Ash in fire affected ecosystems

    Science.gov (United States)

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

    2015-04-01

    -263. Dlapa, P., Bodí, M.B., Mataix-Solera, J., Cerdà, A., Doerr, S.H., Organic matter and wettability characteristics of wildfire ash from Mediterranean conifer forests. Catena. doi:10.1016/j.catena.2014.06.018 Dorta Almenar, I., Navarro Rivero, F.J., Arbelo, C.D., Rodríguez, A., Notario del Pino, J., The temporal distribution of water-soluble nutrients from high mountain soils following a wildfire within legume scrubland of Tenerife, Canary Islands, Spain. Catena. Escuday, M., Arancibia-Miranda, N., Pizarro, C., Antilén, M., Effect of ash from forest fires on leaching in volcanic soils. Catena. doi:10.1016/j.catena.2014.08.006 León, J., Echeverría, M.T., Marti, C., Badía, D., Can ash control infiltration rate after burning? An example in burned calcareous and gypseous soils in the Ebro Basin (NE Spain). Catena. doi:10.1016/j.catena.2014.05.024 Lombao, A., Barreiro, A., Carballas, T., Fontúrbel, M.T., Martín, C., Vega, J.A., Fernández, C., Díaz-Raviña, M., 2014. Changes in soil properties after a wildfire in Fragas do Eume Natural Park (Galicia, NW Spain). Catena. doi:10.1016/j.catena.2014.08.007 Pereira, P., Jordan, A., Cerda, A., Martin, D. (2014) Editorial: The role of ash in fire-affected ecosystems, Catena (In press) doi:10.1016/j.catena.2014.11.016 Pereira, P., Úbeda, X., Martin, D., Mataix-Solera, J., Cerdà, A., Burguet, M. (2014a) Wildfire effects on extractable elements in ash from a Pinus pinaster forest in Portugal, Hydrological Processes, 28, 3681-3690. Pereira, P., Ubeda, X., Mataix-Solera, J., Oliva, M., Novara, A. (2014) Short-term spatio-temporal spring grassland fire effects on soil colour,organic matter and water repellency in Lithuania, Solid Earth, 5, 209-225. Silva, V., Pereira, J.S., Campos, I., Keizer, J.J., Gonçalves, F., Abrantes, N., Toxicity assessment of aqueous extracts of ash from forest fires. Catena doi:10.1016/j.catena.2014.06.021

  20. Effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor.

    Science.gov (United States)

    Varol, Murat; Atimtay, Aysel T

    2015-12-01

    This study aimed to investigate the effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor. The tests included co-combustion of 50-50% by wt. mixtures of Bursa-Orhaneli lignite+olive cake and Denizli-Kale lignite+olive cake, with and without limestone addition. Ash samples were subjected to XRF, XRD and SEM/EDS analyses. While MgO was high in the bottom ash for Bursa-Orhaneli lignite and olive cake mixture, Al2O3 was high for Denizli-Kale lignite and olive cake mixture. Due to high Al2O3 content, Muscovite was the dominant phase in the bottom ash of Denizli Kale. CaO in the bottom ash has increased for both fuel mixtures due to limestone addition. K was in Arcanite phase in the co-combustion test of Bursa/Orhaneli lignite and olive cake, however, it mostly appeared in Potassium Calcium Sulfate phase with limestone addition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Ash basin reclamation with forest trees

    Energy Technology Data Exchange (ETDEWEB)

    Horton, J.H.; McMinn, J.W.

    1977-09-01

    An ash basin at the Savannah River Plant, Aiken, South Carolina is growing trees as well as, and with some species better than, a local soil. The basin contains ashes from a stoker-fed boiler and was last used about 12 years before the trees were planted. The concentrations of 24 chemical elements were measured in ashes, soil and trees. The concentrations of most of the chemical elements were higher in ashes than in soil; however, with a few exceptions, these elements were less available to the trees on ashes than to the trees on soil. The trees do not show any toxicity or deficiency symptoms, but the concentration of manganese in sycamore growing on ashes indicates a possible deficiency. No concentration of an element in trees appears to be high enough to be toxic to the trees. A longer period of study will be required to determine whether the ashes can produce commercial timber, but trees can be used to stabilize ash basins and improve their appearance.

  2. Hydrothermal liquefaction of harvested high-ash low-lipid algal biomass from Dianchi Lake: effects of operational parameters and relations of products.

    Science.gov (United States)

    Tian, Chunyan; Liu, Zhidan; Zhang, Yuanhui; Li, Baoming; Cao, Wei; Lu, Haifeng; Duan, Na; Zhang, Li; Zhang, Tingting

    2015-05-01

    Hydrothermal liquefaction (HTL) allows a direct conversion of algal biomass into biocrude oil, not only solving the environmental issues caused by the over-growing algae but also producing renewable energy. This study reports HTL of algae after separation from eutrophicated Dianchi Lake in China. Conversion efficiency was studied under different operational conditions via an orthogonal design, including holding temperature (HT) (260-340 °C), retention time (RT) (30-90 min) and total solid (TS) (10-20%). A highest biocrude oil yield (18.4%, dry ash-free basis, daf) was achieved at 300 °C, 60 min, and 20% (TS), due to the low contents of lipids (1.9%, daf) and proteins (24.8%, daf), and high contents of ash (41.6%, dry basis) and carbohydrates (71.8%, daf). Operational parameters significantly affected the biocrude yields, and chemical distribution of HTL products. The biocrude production also related to other HTL products, and involved chemical reactions, such as deoxygenation and/or denitrogenation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Determination of Rutin in Cigarette Tobacco, Filters, Mainstream Smoke and Burned Ash of Different Branded Cigarettes by High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Shudong Su

    2012-03-01

    Full Text Available Tobacco consists of at least 3,800 chemical constituents. Among them, rutin is an important polyphenolic secondary metabolite in tobacco, which has positive actions such as antiallergic, anti-inflammatory and vasoactive, antitumor, antibacterial, antiviral and anti-protozoal properties. A high performance liquid chromatography method was used to analyze rutin in tobacco and filters, mainstream smoke, and burned ash of ten varieties of cigarettes made in China. The chromatographic analysis was performed on a Hypersil ODS2 column with a gradient elution of acetonitrile and water at a flow rate of 1.0 mL/min. Detection was carried out at 350 nm using a photodiode array detector. The calibration curves for the determination of analytes showed good linearity over the investigated ranges (R2 > 0.9998. Precision and reproducibility were evaluated by six replicated analyses, and the R.S.D. values were less than 0.59% and 1.53%. The recoveries were between 98.47 and 100.84%. Under the optimized conditions, namely 45 mL/g of solvent to solid ratio, 30 min of extraction time and 200 W of ultrasound power, the concentrations of rutin in tobacco and filter, mainstream smoke, burned ash of different brands cigarettes were 10.20–63.98, 0.10–0.32, 0.06–0.16 and 0 μg/per cigarette, respectively.

  4. 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...

  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. Dietary carbohydrates, glycemic load and serum high-density lipoprotein cholesterol concentrations among South Indian adults.

    Science.gov (United States)

    Radhika, G; Ganesan, A; Sathya, R M; Sudha, V; Mohan, V

    2009-03-01

    To examine the relationship between dietary carbohydrates, glycemic load and high-density lipoprotein cholesterol (HDL-C) concentrations in Asian Indians, a high-risk group for diabetes and premature coronary artery disease. The study population comprised of 2043 individuals aged >/=20 years randomly selected from Chennai Urban Rural Epidemiological Study (CURES), an ongoing population-based study on a representative population of Chennai (formerly Madras) city in southern India. Participants with self-reported history of diabetes or heart disease or on drug therapy for dyslipidemia were excluded from the study. Dietary carbohydrates, glycemic index and glycemic load were assessed using a validated interviewer administered semiquantitative Food Frequency Questionnaire (FFQ). Both dietary glycemic load (Pcarbohydrate intake (Pglycemic load, the multivariate-adjusted mean HDL-C values were 44.1 mg per 100 ml and 41.2 mg per 100 ml (6.6% difference, P for trendcarbohydrate it was less (5% difference, P for trend=0.016). The pattern of decrease in HDL-C for the lowest to highest quintile of glycemic load was more pronounced among men (1st vs 5th quintile: adjusted HDL-C: 4.3 mg per 100 ml decrease (10.3%)) than women (1st vs 5th quintile: adjusted HDL-C: 3.2 mg per 100 ml decrease (6.9%)). Our findings indicate that both total carbohydrates and dietary glycemic load intake are inversely associated with plasma HDL-C concentrations among Asian Indians, with dietary glycemic load having a stronger association.

  7. Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami

    Science.gov (United States)

    Rubin, Charles M.; Horton, Benjamin P.; Sieh, Kerry; Pilarczyk, Jessica E.; Daly, Patrick; Ismail, Nazli; Parnell, Andrew C.

    2017-07-01

    The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami.

  8. Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami.

    Science.gov (United States)

    Rubin, Charles M; Horton, Benjamin P; Sieh, Kerry; Pilarczyk, Jessica E; Daly, Patrick; Ismail, Nazli; Parnell, Andrew C

    2017-07-19

    The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami.

  9. Highly variable recurrence of tsunamis in the 7,400 years before the 2004 Indian Ocean tsunami

    Science.gov (United States)

    Rubin, Charles M.; Horton, Benjamin P.; Sieh, Kerry; Pilarczyk, Jessica E.; Daly, Patrick; Ismail, Nazli; Parnell, Andrew C.

    2017-01-01

    The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami. PMID:28722009

  10. Ash tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Hald, P.

    1995-12-01

    This report describes the ash tracer technique which has been developed, used and evaluated for description of the extent of burnout for Cerrejon coal and wheat straw converted in a pressurized entrained-flow reactor. The uncertainty in the calculated extent of burnout depends on the uncertainty in the ash percentages determined for fuel and fuel sample. The uncertainty increases with decreasing amounts of material used for the ash percent determinations, as the natural variation within the fuel and fuel sample becomes obvious. Ash percentages for the original fuels have an absolute deviation within 0.2% with a remaining ash amount of minimum 100 mg and of 2% when using thermogravimetric analysis equipment where 0.4 - 4 mg was remaining. Repeated ash percent determinations by thermogravimetric analysis equipment of 40 samples showed an average absolute deviation of 3%. A temperature of 1000 deg. C is shown to be the best choice for the ash percent determinations in order to reduce the uncertainties. collection of representative straw samples is shown to make higher demands to the sampling procedure than collection of those for coal. A representative sample collection is shown to be easier from combustion experiments that form gasification and pyrolysis experiments. The ash tracer technique is verified by elemental ash analyses. (au) 14 tabs., 6 refs.

  11. A Pilot Study of Sources of Information and Substance Use Patterns among Selected American Indian High School Seniors.

    Science.gov (United States)

    Lamarine, Roland J.

    1993-01-01

    A survey of 168 American Indian (primarily Navajo) high school seniors in New Mexico examined experiences with alcohol, tobacco, and illegal drugs; sources of information about these substances; and student attitudes, perceptions of risk, perceptions of parent attitudes, and reasons for not using. Implications for drug education are discussed. (SV)

  12. Influence of fly ash aided phytostabilisation of Pb, Cd and Zn highly contaminated soils on Lolium perenne and Trifolium repens metal transfer and physiological stress

    Energy Technology Data Exchange (ETDEWEB)

    Lopareva-Pohu, A.; Verdin, A.; Garcon, G.; Sahraoui, A.L.H.; Pourrut, B.; Debiane, D.; Waterlot, C.; Laruelle, F.; Bidar, G.; Douay, F.; Shirali, P. [University of Lille Nord France, Lille (France)

    2011-06-15

    Due to anthropogenic activities, large extends of soils are highly contaminated by Metal Trace Element (MTE). Aided phytostabilisation aims to establish a vegetation cover in order to promote in situ immobilisation of trace elements by combining the use of metal-tolerant plants and inexpensive mineral or organic soil amendments. Eight years after Coal Fly Ash (CFA) soil amendment, MTE bioavailability and uptake by two plants, Lolium perenne and Trifolium repens, were evaluated, as some biological markers reflecting physiological stress. Results showed that the two plant species under study were suitable to reduce the mobility and the availability of these elements. Moreover, the plant growth was better on CFA amended MTE-contaminated soils, and the plant sensitivity to MTE-induced physiological stress, as studied through photosynthetic pigment contents and oxidative damage was lower or similar. In conclusion, these results supported the usefulness of aided phytostabilisation of MTE-highly contaminated soils.

  13. Effect of fly ash on sorption behavior of metribuzin in agricultural soils.

    Science.gov (United States)

    Singh, Neera; Raunaq; Singh, Shashi B

    2012-01-01

    This investigation was undertaken to determine the effect of two different fly ashes [Kota and Inderprastha (IP)] amendment on the sorption behavior of metribuzin in three Indian soil types. The IP fly ash was very effective in increasing the metribuzin sorption in the soils. The sorption with IP amendment was increased by 15-92%, whereas with the Kota fly ash an increase in sorption by 13-38% was noted. The adsorption isotherms fitted very well to the Freundlich adsorption equation and, in general, slope (1/n) values less then unity were observed. Although both the fly ashes significantly decreased metribuzin desorption, the IP fly ash was comparatively more effective in retaining metribuzin in the soils. Metribuzin sorption in the IP fly ash-amended soils showed strong correlation with the fly ash content and compared to K(f)/K(d) values, K(FA) values (sorption normalized to fly ash content) showed less variation. Metribuzin sorption-desorption did not correlate to the organic carbon content of the soil-fly ash mixture. The study demonstrates that all coal fly ashes may not be effective in enhancing the sorption of metribuzin in soils to the same extent. However, among the fly ashes used in this study, the IP fly ash was observed to be significantly effective in enhancing the sorption of metribuzin in soils. This may play an important role in reducing the run off and leaching losses of the herbicide by retaining it in the soil.

  14. 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...... have been employed in a simple model for prediction of ash deposit formation, the results of which have been compared to ash deposition formation rates measured at the respective boilers.The ash fusion results were found to directly reflect the ash compositional data:a) Fly ashes and deposits from...

  15. Indian Summer

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, E. [Sho-Ban High School, Fort Hall, ID (United States)

    1997-08-01

    This paper focuses on preserving and strengthening two resources culturally and socially important to the Shoshone-Bannock Indian Tribe on the Fort Hall Reservation in Idaho; their young people and the Pacific-Northwest Salmon. After learning that salmon were not returning in significant numbers to ancestral fishing waters at headwater spawning sites, tribal youth wanted to know why. As a result, the Indian Summer project was conceived to give Shoshone-Bannock High School students the opportunity to develop hands-on, workable solutions to improve future Indian fishing and help make the river healthy again. The project goals were to increase the number of fry introduced into the streams, teach the Shoshone-Bannock students how to use scientific methodologies, and get students, parents, community members, and Indian and non-Indian mentors excited about learning. The students chose an egg incubation experiment to help increase self-sustaining, natural production of steelhead trout, and formulated and carried out a three step plan to increase the hatch-rate of steelhead trout in Idaho waters. With the help of local companies, governmental agencies, scientists, and mentors students have been able to meet their project goals, and at the same time, have learned how to use scientific methods to solve real life problems, how to return what they have used to the water and land, and how to have fun and enjoy life while learning.

  16. The climatic impact of supervolcanic ash blankets

    Science.gov (United States)

    Jones, Morgan T.; Sparks, R. Stephen J.; Valdes, Paul J.

    2007-11-01

    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 Niño 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 instigate 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.

  17. 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.)

  18. NEW TECHNOLOGY OF ASH AND SLAG CONCRETES

    Directory of Open Access Journals (Sweden)

    PAVLENKO T. M.

    2017-03-01

    Full Text Available Summary. Purpose. Development of scientific-technical bases of manufacture and application of concrete on the basis of ash and slag mixes of thermal power plants. Methods. It is proposed a new technology of preparation of ash and slag concrete mixes. First the ash and slag mix is dispersed through the sieve with meshes 5 mm in a fine-grained fraction and slag. Then, in accordance with the composition of the concrete, obtained fine-grained fraction, slag, cement and tempering water are separately dosed into the mixer. Results. It is proven the high efficiency of the proposed technology of manufacture of ash and slag concretes. It is established that this technological solution allows to increase the strength of concrete by 20...30%, and in the preparation of full-strength concrete to reduce the cement consumption by 15...20%. Scientific novelty. It is developed the new technology of ash and slag mixes application. The concrete mix on the basis of ash and slag mix has an optimal particle size distribution, which ensures the best compaction and, accordingly, the greatest strength of ash and slag concrete with the given cement consumption. Practical significance. The research results promote the mass application of ash and slag mixes of thermal power plants in construction, obtaining of products from the proposed concretes of low cost with high physical-mechanical properties. Conclusion. It is proven the high efficiency of the proposed technology of production of ash and slag concretes. It is established that this technological solution allows increasing concrete strength, and obtaining full-strength concrete to reduce cement consumption. The extensive application of such concrete in construction makes it possible to solve the problem of aggregates for concrete, promotes recycling of TPP waste and consequently the protection of the environment.

  19. Wood ash used as partly sand and/or cement replacement in mortar

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Hansen, Esben Østergaard; Jensen, Pernille Erland

    2016-01-01

    , and the present work reports a characterization of three different WAs. Properties of mortar samples with the WAs used as partly cement and/or sand replacement are reported. Compressive strength development and porosity are the mortar properties in focus. The overall aim of the work is to evaluate the influence...... from the differences in ash characteristics to the properties of the mortar samples. The characteristics of the ashes did vary considerably. For example, one ash had very high loss on ignition (LoI) of 14% compared to 3% for the other ashes. Ash solubility in water ranged from 18% to 28%. Two...... to a reference without ash, however, the decrease was small for two of the ashes. Using the ash with the high LoI resulted in significantly lower compressive strength compared to the other two ashes. The mortar samples with two of the ashes (with low LoI) had qualities, which were very encouraging in order...

  20. Heavy metals in MSW incineration fly ashes

    DEFF Research Database (Denmark)

    Ferreira, Celia; Ribeiro, Alexandra B.; Ottosen, Lisbeth M.

    2003-01-01

    is characterized regarding its physical-chemical properties: pH, solubility, chemical composition, and leaching, amongst others. Results indicate a high alkalinity and the presence of large amounts of calcium, chlorides, sulfates, carbonates, sodium and potassium. Metal concentrations in fly ash are: 6,2 g....../kg for zinc, 2,4 g/kg for lead, 1,7 g/kg for iron, and 7,9 g/kg for magnesium. Copper, manganese, chromium and cadmium are also present with 546, 338, 104 and 91 mg/kg of fly ash, respectively. These results are extremely important in subsequent studies on the treatment of fly ash....

  1. 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.

  2. Production and engineering application of C60 high-performance pump pebble concrete containing ultra-fine fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Y.L. [Changsha Univ. of Science and Technology, Changsha (China). College of Highway Engineering; Ma, B.G. [Wuhan Univ. of Technology, Wuhan (China). Key Laboratory for Silicate Materials Science and Engineering

    2008-08-15

    Ultra-fine fly ash (UFA) is commonly used as an additive to concrete in the place of Portland cement due to its durability, and the environmental benefits associated with recycling waste materials. This study examined the workability, mechanical properties, and durability of a 30 per cent UFA addition to pump pebble concrete with a C60 strength grade. The concrete was designed for use in the reinforced concrete short columns of an underground structure at a power plant in China. River pebbles were used as a coarse aggregate for the pump concrete. Ordinary Portland cement and class F UFA were used in the concrete mixes. Sulphonated naphthalene superplasticizers were used to reduce water demands for the materials. River sand was used as a fine aggregate. Slump and slump losses estimated for the UFA concrete were studied in a laboratory. Results showed that slump and slump losses after 1 hour with the UFA concrete were 254 and 590 mm, and 205, and 405 mm, respectively. Compressive strength tests met requirements for C60 strength grade concretes. Tests conducted to measure resistance-chloride ion penetrability showed that penetration rates for the UFA concrete were excellent due to the concrete's particle size distribution; pozzolanic reaction; changes in pore solution chemistry; and more refined capillary pores. Dry shrinkage rates were reduced with the application of UFA, and crack resistance rates were also improved. It was concluded that the use of UFA resulted in significant cost savings. 10 refs., 7 tabs., 8 figs.

  3. High calcium fly ash geopolymer stabilized lateritic soil and granulated blast furnace slag blends as a pavement base material.

    Science.gov (United States)

    Phummiphan, Itthikorn; Horpibulsuk, Suksun; Rachan, Runglawan; Arulrajah, Arul; Shen, Shui-Long; Chindaprasirt, Prinya

    2018-01-05

    Granulated Blast Furnace Slag (GBFS) was used as a replacement material in marginal lateritic soil (LS) while class C Fly Ash (FA) was used as a precursor for the geopolymerization process to develop a low-carbon pavement base material at ambient temperature. Unconfined Compression Strength (UCS) tests were performed to investigate the strength development of geopolymer stabilized LS/GBFS blends. Scanning Electron Microscopy and X-ray Diffraction analysis were undertaken to examine the role of the various influencing factors on UCS development. The influencing factors studied included GBFS content, Na2SiO3:NaOH ratio (NS:NH) and curing time. The 7-day soaked UCS of FA geopolymer stabilized LS/GBFS blends at various NS:NH ratios tested was found to satisfy the specifications of the Thailand national road authorities. The GBFS replacement was found to be insignificant for the improvement of the UCS of FA geopolymer stabilized LS/GBFS blends at low NS:NH ratio of 50:50. Microstructural analysis indicated the coexistence of Calcium Silicate Hydrate (CSH) and Sodium Alumino Silicate Hydrate products in FA geopolymer stabilized LS/GBFS blends. This research enables GBFS, which is traditionally considered as a waste material, to be used as a replacement and partially reactive material in FA geopolymer pavement applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Simultaneous removal of aqueous Zn(2+), Cu(2+), Cd(2+), and Pb(2+) by zeolites synthesized from low-calcium and high-calcium fly ash.

    Science.gov (United States)

    Ji, X D; Ma, Y Y; Peng, S H; Gong, Y Y; Zhang, F

    2017-10-01

    In this study, zeolites were synthesized from low-calcium (LCZ) and high-calcium (HCZ) fly ash, respectively. Subsequently, the zeolites were tested for their removal effectiveness for four aqueous cations, namely, Zn(2+), Cu(2+), Cd(2+), and Pb(2+), as a function of contact time, pH value, adsorbent dosage, and initial concentration of heavy metals. Both zeolites were characterized by X-ray diffraction, X-ray fluorescence spectrometry, scanning electron microscopy, specific surface area, and cation exchange capacity. The results show that HCZ mainly consists of an unnamed zeolite (Na6[AlSiO4]6·4H2O), whereas LCZ mainly consists of faujasite-type zeolite. The optimum sorption conditions were pH = 6.0; adsorbent dosage = 1.0 g·L(-1); temperature = 25 °C; contact time = 100 min; and initial heavy metal concentration = 100 mg·L(-1). The sorption kinetics of the four aqueous cations on both LCZ and HCZ followed the pseudo-second-order kinetic model, and the sorption isotherm data fitted well with the Langmuir isotherm model. For LCZ, the maximum adsorption capacities of Zn(2+), Cu(2+), Cd(2+), and Pb(2+) were 155.76, 197.86, 123.76, and 186.22 mg·g(-1), respectively. For HCZ, the values were 154.08, 183.15, 118.91, and 191.94 mg·g(-1), respectively. The zeolites were regenerated by NaCl solution (1 mol·L(-1)) and showed high removal efficiency. In conclusion, zeolites produced by fly ash are promising materials for removing Zn(2+), Cu(2+), Cd(2+), and Pb(2+) from wastewater.

  5. 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

  6. Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report E : hardened mechanical properties and durability performance of HVFA concrete.

    Science.gov (United States)

    2012-10-01

    A rising concern in todays construction industry is environmental responsibility. : The addition of fly ash is a leading innovation in sustainable design of concrete. Fly ash, : a waste by-product of coal burning power plants, can be used to repla...

  7. 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.

  8. Corrosion of high temperature resisting alloys exposed to heavy fuel ash; Corrosion de aleaciones resistentes a altas temperaturas expuestas a ceniza de combustoleo pesado

    Energy Technology Data Exchange (ETDEWEB)

    Wong Moreno, Adriana del Carmen

    1998-03-01

    The objective of the performed research was to study the degradation process by high temperature corrosion of alloys exposed to heavy fuel oil ashes through a comparative experimental evaluation of its performance that allowed to establish the mechanisms involved in the phenomenon. The experimentation carried out involved the determination of the resistance to the corrosion of 14 alloys of different type (low and medium alloy steels, ferritic and austenitic stainless steels, nickel base alloys and a FeCrAl alloy of type ODS) exposed to high temperatures (580 Celsius degrees - 900 Celsius degrees) in 15 ash deposits with different corrosive potential, which were collected in the high temperature zone of boilers of thermoelectric power stations. The later studies to the corrosion tests consisted of the analysis by sweeping electron microscopy supported by microanalysis of the corroded probes, with the purpose of determining the effect of Na, V and S on the corrosivity of the ash deposits and the effect of the main alloying elements on the corrosion resistance of the alloys. Such effects are widely documented to support the proposed mechanisms of degradation that are occurring. The global analysis of the generated results has allowed to propose a model to explain the global mechanism of corrosion of alloys exposed to the high temperatures of ash deposits. The proposed model, complements the processed one by Wilson, widely accepted for fused vanadates, as far as on one hand, it considers the effect of the sodium sulfate presence (in addition to the vanadium compounds) in the deposits, and on the other hand, it extends it to temperatures higher than the point of fusion of constituent vanadium compounds of the deposits. Both aspects involve considering the roll that the process of diffusion of species has on the degradation and the capacity of protection of the alloy. The research performed allowed to confirm what the Wilson model had established for deposits with high

  9. assessment of assessment of bagasse ash bagasse ash bagasse ...

    African Journals Online (AJOL)

    eobe

    This study was carried out to evaluate the effect of bagasse ash s carried out to evaluate the effect of bagasse ash s carried out to evaluate the effect of bagasse ash on the California bearing ratio of lateritic soil. on the California bearing ratio of lateritic soil. Laboratory tests were performed on the natural and bagasse ash ...

  10. A chimeric fusion of the hASH1 and EZH2 promoters mediates high and specific reporter and suicide gene expression and cytotoxicity in small cell lung cancer cells

    DEFF Research Database (Denmark)

    Poulsen, T.T.; Pedersen, N.; Juel, H.

    2008-01-01

    Transcriptionally targeted gene therapy is a promising experimental modality for treatment of systemic malignancies such as small cell lung cancer (SCLC). We have identified the human achaete-scute homolog 1 (hASH1) and enhancer of zeste homolog 2 (EZH2) genes as highly upregulated in SCLC compared...

  11. Influence of Indian Ocean high pressure on streamflow variability over southwestern Australia

    Directory of Open Access Journals (Sweden)

    Saqib Ur Rehman

    2014-05-01

    Full Text Available  The seasonal and interannual variability of the southwestern Australia streamflow was examined based on re-analysis dataset from the National Centers for Environmental Prediction / National Center for Atmospheric Research, plus monthly streamflow data from 17 meteorological stations obtained from the Department of Water of the Australian Water Resource Council (1976-2008. Significant findings reveal that since the middle of the last century, the early winter (May-August streamflow variability over southwestern Australia has been associated with variability in the intensity of the Indian Ocean high pressure (IOHP system, as well as the zonal movement of the high pressure system across the Indian Ocean. Of note, however, the emphasis in the previous studies has linked the ongoing winter drought in western Australia to changes in sea level pressure, both on a local basis and over larger areas. We introduce objective indices for the area-weighted pressure of the IOHP, and the IOHP area-weighted latitude (IOHLT and longitude (IOHLN positions. When the IOHP is shifted to the east, there is less streamflow in the southwestern Australian rivers that are examined in this study. The situation is reversed when the IOHP is shifted to the west, when there is more streamflow in the southwestern Australian rivers. The characteristics of the streamflow pattern are determined for the river catchment areas located around the coastal region over southwestern Australia using principal component analysis. The first principal component taken into consideration describes 84.43% of the total variance. The multiple correlation between the loading of the first principal component scores of the streamflow and the IOHP and IOHLN is 0.54, while the correlation between the southern oscillation index is 0.44. Centers of action indices explain 29% of the streamflow variability, while the southern oscillation index explains only of the 19% streamflow variability. This

  12. Detection of arecoline by simple high-performance thin-layer chromatographic method in Indian nontobacco pan masala.

    Science.gov (United States)

    Adhikari, Anjan; Hazra, Alok Kumar; Sur, Tapas Kumar

    2015-01-01

    Chewing the habit of blended pan masala containing areca nut with or without tobacco is a common practice in the Indian subcontinent. Arecoline, a pyridine alkaloid presence in areca nut alarmed for oral carcinogenesis and strictly prohibited in the western world. However, in India using blended pan masala is very popular among young and old individuals. In this context, we aimed to detect arecoline in Indian blended nontobacco pan masala sold in Kolkata using a simple densitometric high-performance thin-layer chromatographic (HPTLC) method and for alarming their use in common people. Eleven popularly Indian blended nontobacco pan masala were collected from the territory of Kolkata and isolated arecoline, following solvent extraction method derived for pyridine alkaloid. The quantitative analysis of arecoline was measured using automated software-based HPTLC instruments and validated the method according to International Conference on Harmonization guidelines. Arecoline was detected in all 11 blended nontobacco pan masala samples in a range of minimum 130 to maximum 415 μg/g dry samples. Arecoline is hazardous carcinogenic compound, so the use of Indian blended nontobacco pan masala should be restricted. Further, the method was found suitable for routine quantitative analysis of arecoline in areca nut containing substances.

  13. High levels of genetic variation in Indian field and house mice

    National Research Council Canada - National Science Library

    Singh, S; Sharma, T

    1997-01-01

    Genetic variation in the Indian pygmy field miceMus booduga and theMus terricolor complex and in the house mouseMus musculus tytleri was analysed electro phoretically at 20 enzymatic and nonenzymatic protein loci...

  14. Evaluation of nitric and acetic acid resistance of cement mortars containing high-volume black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2014-01-15

    This paper presents the performance of cement mortar containing black rice husk ash (BRHA) under nitric and acetic acid attacks. The BRHA, collected from an electrical generating power plant that uses rice husk as fuel, was ground using a grinding machine. The compressive strength loss, weight loss, and expansion of mortars under nitric and acetic acid attack were investigated. The test results of BRHA properties in accordance with the ASTM C 618 standard found that the optimal grinding time was 4 h as this achieved a Blaine fineness of 5370 cm(2)/g. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 20%, 30%, 40%, and 50% by weight of binder. The water-to-binder ratios were 0.55, 0.60, and 0.65. From test results, when the percentage replacements of BRHA in cement increased, it was observed that the strength loss and weight loss of mortars containing BRHA under acetic acid attack were higher than those of the mortars against nitric acid attack. It was found that, of the various BHRA mortars, the strength loss and weight loss due to nitric and acetic acid attacks were the lowest in the mortar with 10% BRHA replacement. For 10%, 20% and 30% BRHA replacements, the rate of expansion of the BRHA mortar decreased when compared with the control mortar. For the mortars with other percentage replacements of BRHA, the rate of expansion increased. Furthermore, the effective water-to-binder ratios of control and BRHA mortars were the primary factor for determining the durability of mortar mixed with BRHA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Effect of fly ash amendment on persistence of metribuzin in soils.

    Science.gov (United States)

    Singh, Neera; Raunaq; Singh, Shashi Bala

    2013-01-01

    This study reports the effect of fly ash amendment on persistence of metribuzin in three Indian soil types. Fly ash [Inderprastha (IP) and Kota] was amended at 1, 2 and 5% levels. Metribuzin was more persistent in the flooded soils (predominantly anaerobic) than the nonflooded (aerobic) soils. Kota fly ash amendment to nonflooded soils slightly enhanced metribuzin persistence while IP fly ash reduced the herbicide persistence in nonflooded soils. In flooded soils both types of fly ash reduced metribuzin persistence, but the extent of the effect was specific to the soil and type of fly ash. A better effect was observed in low organic matter soils and IP fly ash was more effective than the Kota fly ash. The effect of fly ash amendment on metribuzin degradation in soils was more pronounced at higher dose of fly ash. No degradation of metribuzin was observed in the sterilized soils, both without and with fly ash, suggesting that degradation of metribuzin was microbial in nature. Deaminometribuzin was recovered as the only metabolite of metribuzin degradation.

  16. Aggregation of volcanic ash in explosive eruptions

    Science.gov (United States)

    Telling, J. W.; Dufek, J.

    2009-12-01

    We present the result of a recent experimental and numerical investigation of ash aggregation in volcanic plumes. Eruption dynamics are sensitive to microphysical processes, like ash aggregation, yet are difficult to parameterize based on dynamics simulations of whole eruption columns due to the lack of sufficient resolution. Here we present the results of experiments that develop a probabilistic relationship for ash aggregation based on impact velocity and atmospheric conditions (water vapor and atmospheric pressure). The probabilistic relationship can be integrated, in conjunction with a reconstructed velocity distribution of the ash in the column, and then can be readily incorporated in large-scale simulations of eruption column behavior. We also conduct detailed Eulerian-Lagrangian simulations at the scale of our experiment as a test of the ash aggregation relationship. The physical experiment was carried out in a contained tank designed to allow for the control of ‘atmospheric’ conditions. The tank can be depressurized as needed, using the gas inlet and the attached vacuum pump, and the ambient humidity can be altered by adjusting the gas mixture at the inlet. Image data is recorded with a high speed camera and post-processed to determine the number of collisions, energy of collisions and probability of aggregation. We will present the results of aggregation probability and the effects of incorporating these results into a multiphase model of a three-dimensional eruption column, where the effects of ash aggregation are especially important in regions of high shear and high granular temperature.

  17. Geotechnical properties of ash deposits near Hilo, Hawaii

    Science.gov (United States)

    Wieczorek, G.F.; Jibson, R.W.; Wilson, R.C.; Buchanan-Banks, J. M.

    1982-01-01

    Two holes were hand augered and sampled in ash deposits near Hilo, Hawaii. Color, water content and sensitivity of the ash were measured in the field. The ash alternated between reddish brown and dark reddish brown in color and had water contents as high as 392%. A downhole vane shear device measured sensitivities as high as 6.9. A series of laboratory tests including grain size distribution, Atterberg limits, X-ray diffraction analysis, total carbon determination, vane shear, direct shear and triaxial tests were performed to determine the composition and geotechnical properties of the ash. The ash is very fine grained, highly plastic and composed mostly of gibbsite and amorphous material presumably allophane. The ash has a high angle of internal friction ranging from 40-43? and is classified as medium to very sensitive. A series of different ash layers was distinguished on the basis of plasticity and other geotechnical properties. Sensitivity may be due to a metastable fabric, cementation, leaching, high organic content, and thixotropy. The sensitivity of the volcanic ash deposits near Hilo is consistent with documented slope instability during earthquakes in Hawaii. The high angles of internal friction and cementation permit very steep slopes under static conditions. However, because of high sensitivity of the ash, these slopes are particularly susceptible to seismically-induced landsliding.

  18. Fusion characterization of biomass ash

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang

    2016-01-01

    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....

  19. High storage rates of anthropogenic CO_{2} in the Indian sector of the Southern Ocean

    Science.gov (United States)

    Murata, Akihiko; Kumamoto, Yu-ichiro; Sasaki, Ken-ichi

    2017-04-01

    Using high-quality data for CO2-system and related properties collected 17 years apart through international observation programs, we examined decadal-scale increases of anthropogenic CO2 along a zonal section at nominal 62˚ S ranging from 30˚ E to 160˚ E in the Indian sector of the Southern Ocean. In contrast to previous studies, increases of anthropogenic CO2 were largest (> 9.0 μmol kg-1) in Antarctic Bottom Water, where little storage of anthropogenic CO2 has been reported. Significant increases of anthropogenic CO2 in bottom and/or deep waters were detected through the section, although they became reduced in magnitude and depth range west of 110˚ E. Vertical distributions of anthropogenic CO2 showed significant positive correlations with decadal-scale changes in CFC-12, a proxy of circulation and ventilation, meaning that the distributions were mainly controlled by physical processes. Comparison of increases of anthropogenic CO2 between calculation methods with and without total alkalinity presented differences of increases of anthropogenic CO2west of 50˚ E. This is probably because decreases in production of particulate inorganic carbons in the Southern Ocean. The highest storage rate of anthropogenic CO2 was estimated to be 1.1 ± 0.6 mol m-2 a-1 at longitudes 130˚ -160˚ E. The results highlight storage rates higher than ever reported in the Southern Ocean, where very low storage of anthropogenic CO2 has been evidenced.

  20. Fundamental Study of Low NOx Combustion Fly Ash Utilization

    Energy Technology Data Exchange (ETDEWEB)

    E. M. Suubert; I. Kuloats; K. Smith; N. Sabanegh; R.H. Hurt; W. D. Lilly; Y. M. Gao

    1997-05-01

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over forty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives.

  1. Fundamental Study of Low-Nox Combustion Fly Ash Utilization

    Energy Technology Data Exchange (ETDEWEB)

    E. M. Suuberg; I. Kuloats; K. Smith; N. Sabanegh; R. H. Hurt; W. D. Lilly; Y. M. Gao

    1997-11-01

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over forty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives.

  2. Breastfeeding duration, age of starting solids and high BMI risk and adiposity in Indian children.

    Science.gov (United States)

    Caleyachetty, Amrit; Krishnaveni, Ghattu V; Veena, Sargoor R; Hill, Jacqui; Karat, Samuel C; Fall, Caroline H D; Wills, Andrew K

    2013-04-01

    This study utilized data from a prospective birth cohort study on 568 Indian children, to determine whether a longer duration of breastfeeding and later introduction of solid feeding were associated with a reduced higher body mass index (BMI) and less adiposity. Main outcomes were high BMI (>90th within-cohort sex-specific BMI percentile) and sum of skinfold thickness (triceps and subscapular) at age 5. Main exposures were breastfeeding (six categories from 1-4 to ≥21 months) and age of starting regular solid feeding (four categories from ≤3 to ≥6 months). Data on infant-feeding practices, socio-economic and maternal factors were collected by questionnaire. Birthweight, maternal and child anthropometry were measured. Multiple regression analysis that accounted for potential confounders demonstrated a small magnitude of effect for breastfeeding duration or introduction of solid feeds on the risk of high BMI but not for lower skinfold thickness. Breastfeeding duration was strongly negatively associated with weight gain (0-2 years) [adjusted β = -0.12 standard deviation, 95% confidence interval (CI): -0.19 to -0.05 per category change in breastfeeding duration, P = 0.001], and weight gain (0-2 years) was strongly associated with high BMI at 5 years (adjusted odds ratio = 3.8, 95% CI: 2.53-5.56, P BMI risk and a negligible effect on skinfold thickness. However, accounting for sampling variability, these findings cannot exclude the possibility of no effect at the population level. © 2011 Blackwell Publishing Ltd.

  3. 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

  4. Silica from Ash

    Indian Academy of Sciences (India)

    Chemical. Tech.) ... waste disposal but also recovers a valuable silica product, together with certain useful associate recoveries. ... (consisting of residue digested ash, sodium-silicate, water and free sodium hydroxide). In the second step of the ...

  5. Environmental impact of manganese due to its leaching from coal fly ash.

    Science.gov (United States)

    Prasad, Bably; Mondal, Kajal K R

    2009-01-01

    In India, so far not much efforts have been made to use coal ash as backfill material in underground/ open cast mines and to predict its subsequent effect on ground water quality. One of the main problems in disposing of big quantities of coal ash is the possible leaching of different pollutants, including manganese. A thorough investigation regarding leaching of manganese from different fly ashes is required to know the impact of manganese due to its leaching from fly ash to ground water as well as surface water. In the present study, short term and long term leaching studies have been carried out on fly ash, bottom ash, pond ash and weathered ash of Chandrapura thermal power plant, Bokaro, Jharkhand and Ramagundam thermal power plant, Ramagundam, Andhra Pradesh. The amount of manganese released in different experiments has been evaluated. The leachate of Chandrapura fly ash has more manganese concentration (0.2001 mg/L) than the leachate of bottom ash, pond ash and weathered ash. A field investigation at Damoda abandoned open cast mine, filled with pond ash of Chandrapura thermal power plant revealed that concentration of manganese in ground water beneath the ash filled mine has been found very high (maximum up to 6.0 mg/L). But its migration to a long distance has not been seen. Remedial measures for coal ash disposal have also been formulated.

  6. Rural Indian tribal communities: an emerging high-risk group for HIV/AIDS

    Directory of Open Access Journals (Sweden)

    Galwankar Sagar

    2005-02-01

    Full Text Available Abstract Background Rural Indian tribes are anthropologically distinct with unique cultures, traditions and practices. Over the years, displacement and rapid acculturation of this population has led to dramatic changes in their socio-cultural and value systems. Due to a poor health infrastructure, high levels of poverty and ignorance, these communities are highly vulnerable to various health problems, especially, communicable diseases including HIV/AIDS. Our study sought to assess knowledge, attitudes and practices regarding sexuality, and the risk factors associated with the spread of HIV/AIDS and STDs among these communities. Methods A nested cross sectional study was undertaken as part of the on going Reproductive and Child Health Survey. A total of 5,690 participants age 18–44 were recruited for this study. Data were obtained through home interviews, and focused on socio-demographics, knowledge, attitudes and behaviors regarding sexuality, HIV/AIDS and other STDs. Results The study revealed that only 22% of adults had even heard of AIDS, and 18 % knew how it is transmitted. In addition, only 5% knew that STDs and AIDS were related to each other. AIDS awareness among women was lower compared to men (14% vs.30 %. Regarding sexual practices, 35% of the respondents reported having had extramarital sexual encounters, with more males than females reporting extramarital affairs. Conclusion Lack of awareness, permissiveness of tribal societies for premarital or extra-marital sexual relationships, and sexual mixing patterns predispose these communities to HIV/AIDS and STD infections. There is a dire need for targeted interventions in order to curtail the increasing threat of HIV and other STDs among these vulnerable populations.

  7. Tropical cyclones over the North Indian Ocean: experiments with the high-resolution global icosahedral grid point model GME

    Science.gov (United States)

    Kumkar, Yogesh V.; Sen, P. N.; Chaudhari, Hemankumar S.; Oh, Jai-Ho

    2018-02-01

    In this paper, an attempt has been made to conduct a numerical experiment with the high-resolution global model GME to predict the tropical storms in the North Indian Ocean during the year 2007. Numerical integrations using the icosahedral hexagonal grid point global model GME were performed to study the evolution of tropical cyclones, viz., Akash, Gonu, Yemyin and Sidr over North Indian Ocean during 2007. It has been seen that the GME model forecast underestimates cyclone's intensity, but the model can capture the evolution of cyclone's intensity especially its weakening during landfall, which is primarily due to the cutoff of the water vapor supply in the boundary layer as cyclones approach the coastal region. A series of numerical simulation of tropical cyclones have been performed with GME to examine model capability in prediction of intensity and track of the cyclones. The model performance is evaluated by calculating the root mean square errors as cyclone track errors.

  8. Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products

    Directory of Open Access Journals (Sweden)

    Philip Van den Heede

    2015-12-01

    Full Text Available Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25 could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete’s water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction.

  9. Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products

    Science.gov (United States)

    Van den Heede, Philip; Ringoot, Niels; Beirnaert, Arno; Van Brecht, Andres; Van den Brande, Erwin; De Schutter, Geert; De Belie, Nele

    2015-01-01

    Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA) from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25) could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete’s water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction. PMID:28787809

  10. Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products.

    Science.gov (United States)

    Van den Heede, Philip; Ringoot, Niels; Beirnaert, Arno; Van Brecht, Andres; Van den Brande, Erwin; De Schutter, Geert; De Belie, Nele

    2015-12-25

    Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA) from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25) could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete's water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction.

  11. 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.

  12. Residual Ash Formation during Suspension-Firing of Biomass

    DEFF Research Database (Denmark)

    Damø, Anne Juul; Jappe Frandsen, Flemming; Jensen, Peter Arendt

    2014-01-01

    Through 50+ years, high quality research has been conducted in order to characterize ash and deposit formation in utility boilers fired with coal, biomass and waste fractions. The basic mechanism of fly ash formation in suspension fired coal boilers is well described, documented and may even...... distribution. Thus, there is a good flair of the chemistry of fly ash formed in plants fired with biomass or waste fractions, either alone, or in conjunction with coal. But data on dedicated studies of the physical size development of fly ash, are almost non-existing for biomasses and waste fractions...... with increasing time, due to char oxidation/pyrolysis, fragmentation, and ash formation. For straw, an increase in the concentration of large particles at 1.0 – 2.0 s, indicated melting and agglomeration of ash particles. The transient release of K was massive (> 60 wt. %) for all fuels and throughout...

  13. Chemical and Physical Characterization of Fly Ash as Geopolymer Material

    Directory of Open Access Journals (Sweden)

    Risdanareni Puput

    2017-01-01

    Full Text Available Research on finding suitable cement substitute material becomes massive due to environmental effect. Geopolymer as inorganic material is potential to be the smart solution to overcome global warming issue. Fly ash is a waste material rich in silica and alumina becomes popular raw material to produce geopolymer. The best properties ofgeopolymer paste come from the high quality of fly ash. Therefore, it is important to investigate various types of fly ash and geopolymer properties. Their chemical and physical properties characterized by XRF, pH value, XRD and SEM. The results showed that type of fly ash depended on amount of Si-based of Ca-based compound which consisted of spherical morphology. Geopolymer paste produced from the ash with different compound has bulky and irregular shape morphology. The pH value of each ash has also a correlation with the setting time of fresh paste.

  14. Development and Highly Skilled Migrants: Perspectives from the Indian Diaspora and Returnees

    Directory of Open Access Journals (Sweden)

    Gabriela Tejada

    2014-06-01

    Full Text Available The migration development nexus assumes that skilled migrants possess the potential to bring benefits to their developing countries of origin. In India in particular, this brain-gain is of great interest to study because of the significant presence of Indian skilled professionals in western countries. This paper examines the role of the factors on an individual and structural level which are responsible for skilled Indian migrants’ interests in their home country’s development. It also examines the extent to which returnees actually perceive themselves as agents of development at both a collective and an interpersonal level. The authors apply logistic regression to a primary data-based survey on skilled Indians in Europe and returnees in India. They find that both familiarity with the contemporary Indian situation as well as disadvantaged identities drive skilled migrants’ interests in home-country development. Disadvantaged identities also affect returnees’ own recognition of their role as agents of development and change. Other factors bearing this agency role include membership of cultural, religious, or political organisations, professional field, and level of education.

  15. 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 qual...... and magnesium in lignite reacts with silica so it is not available for reaction with potassium chloride. Reduction of Cl and increase of S in the deposits compared to the fly ashes could be attributed to sulphation of the deposits....

  16. Effect of Climate Change on Service Life of High Volume Fly Ash Concrete Subjected to Carbonation—A Korean Case Study

    Directory of Open Access Journals (Sweden)

    Ki-Bong Park

    2017-01-01

    Full Text Available The increase in CO2 concentrations and global warming will increase the carbonation depth of concrete. Furthermore, temperature rise will increase the rate of corrosion of steel rebar after carbonation. On the other hand, compared with normal concrete, high volume fly ash (HVFA concrete is more vulnerable to carbonation-induced corrosion. Carbonation durability design with climate change is crucial to the rational use of HVFA concrete. This study presents a probabilistic approach that predicts the service life of HVFA concrete structures subjected to carbonation-induced corrosion resulting from increasing CO2 concentrations and temperatures. First, in the corrosion initiation stage, a hydration-carbonation integration model is used to evaluate the contents of the carbonatable material, porosity, and carbonation depth of HVFA concrete. The Monte Carlo method is adopted to determine the probability of corrosion initiation. Second, in the corrosion propagation stage, an updated model is proposed to evaluate the rate of corrosion, degree of corrosion for cover cracking of concrete, and probability of corrosion cracking. Third, the whole service life is determined considering both corrosion initiation stage and corrosion propagation stage. The analysis results show that climate change creates a significant impact on the service life of durable concrete.

  17. Incorporation of treated straw and wood fly ash into clay building brick

    DEFF Research Database (Denmark)

    Chen, Wan; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2016-01-01

    in the treated ash, suggests the possibility of the ash reuse in sintered clay bricks. In this study, the straw and wood fly ash treated by washing and EDR was incorporated into yellow clay bricks at different substitution rates. The properties of the clay-ash bricks were studied in terms of shrinkage, water......High Cd content in straw and wood fly ash, generated from biomass-fired power plants, prohibits its recycling as fertilizer spreading on the landfilled. To improve and alter the current mainstream of fly ash treatment by landfilling, different approaches were tried for treatment of straw and wood...

  18. BRICKS WITH TOTAL REPLACEMENT OF CLAY BY FLY ASH MIXED WITH DIFFERENT MATERIALS

    OpenAIRE

    J.N Akhtar; Alam, J; M.N Akhtar

    2011-01-01

    Fly ash is a powdery substance obtained from the dust collectors in the Thermal power plants that use coal as fuel. From the cement point of view the mineralogy of Fly ash is important as it contains 80% - 90% of glass. The impurities in coal-mostly clays, shale’s, limestone & dolomite; they cannot be burned so they turn up as ash. The Fly ash of class C category was used as a raw material to total replacement of clay for making Fly ash bricks. In present study the effect of Fly ash with high...

  19. 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

    . Hydrological effects of a layer of vegetation ash on underlying wettable and water repellent soils. Geoderma, 191, 14-23. http://dx.doi.org/10.1016/j.geoderma.2012.01.006 Bodí, M.B., Muñoz-Santa, I., Armero, C., Doerr, S.H., Mataix-Solera, J., Cerdà, A. 2013. Spatial and temporal variations of water repellency and probability of its occurrence in calcareous Mediterranean rangeland soils affected by fires. Catena, 108, 14-24. http://dx.doi.org/10.1016/j.catena.2012.04.002 Bodí, Merche B., Martin, Deborah A., Balfour, Victoria N., Santín, Cristina, Doerr, Stefan H., Pereira, Paulo, Cerdà, Artemi, Mataix-Solera, Jorge, Wildland fire ash: Production, composition and eco-hydro-geomorphic effects, Earth Science Reviews (2014), doi: 10.1016/j.earscirev.2013.12.007 Cerdà, A. 1998. Changes in overland flow and infiltration after a rangeland fire in a Mediterranean scrubland. Hydrological Processes, 12, 1031-1042. Cerdà, A. y Doerr, S.H. 2008. The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena, 74 , 256- 263. doi:10.1016/S0341-8162(02)00027-9 Dlapa, P., Bodí, M.B., Mataix-Solera, J., Cerdà, A., &, Doerr, S.H. 2013. FT-IR spectroscopy reveals that ash water repellency is highly dependent on ash chemical composition. Catena, 108, 35-43. Doi:10.1016/j.catena.2012.02.011 Fernández, C., Vega, J. A., Jiménez, E., Vieira, D. C. S., Merino, A., Ferreiro, A., Fonturbel, T. 2012. Seeding and mulching + seeding effects on post-fire runoff, soil erosion and species diversity in Galicia (NW Spain). Land Degradation & Development, 23: 150- 156. DOI 10.1002/ldr.1064 Guénon, R., Vennetier, M., Dupuy, N., Roussos, S., Pailler, A., Gros, R. 2013. Trends in recovery of Mediterranean soil chemical properties and microbial activities after infrequent and frequent wildfires. Land Degradation & Development, 24: 115- 128. DOI 10.1002/ldr.1109 Martín, A., Díaz-Raviña, M., Carballas, T. 2012. Short- and medium-term evolution of soil

  20. Morphology of equatorial plasma bubbles during low and high solar activity years over Indian sector

    Science.gov (United States)

    Kumar, Sanjay

    2017-05-01

    In the present study, slant total electron content (STEC) data computed from ground based GPS measurements over Hyderabad (Geog. Lat. 17.41° N, geog. long. 78.55° E, mag. lat. 08.81° N) and two close stations at Bangalore (Geog. Lat. 13.02°/13.03° N, geog. long. 77.57°/77.51° E, mag. lat. 04.53°/04.55° N) in Indian region during 2007-2012, have been used to study the occurrences and characteristics of equatorial plasma bubbles (EPBs). The analysis found maximum EPB occurrences during the equinoctial months and minimum during the December solstice throughout 2007-2012 except during the solar minimum years in 2007-2009. During 2007-2009, the maximum EPB occurrences were observed in June solstice which could not be predicted by the model proposed by Tsunoda (J. Geophys. Res., 90:447-456, 1985). The equinox maximum in EPB occurrences for high solar activity years could be caused by the vertical F-layer drift due to pre-reversal electric field (PRE), and expected to be maximum when day-night terminator aligns with the magnetic meridian i.e. during the equinox months whereas maximum occurrences during the solstice months of solar minimum could be caused by the seed perturbation in plasma density induced by gravity waves from tropospheric origins. Generally EPB occurrences are found to be more prominent during nighttime hours (2000-2400 hours) than the daytime hours. Peak in EPB occurrences is in early night for high solar activity years whereas same is late night for low solar activity. The day and nighttime EPB occurrences have been analyzed and found to vary in accordance with solar activity with an annual correlation coefficient (R) of ˜0.99 with F_{10.7} cm solar Flux. Additionally, solar activity influence on EPB occurrences is seasonal dependent with a maximum influence during the equinox season (R=0.88) and a minimum during winter season (R =0.73). The solar activity influences on EPB occurrences are found in agreement with the previous works reported in

  1. High prevalence of ACE DD genotype among north Indian end stage renal disease patients

    Directory of Open Access Journals (Sweden)

    Pandirikkal Baburajan Vinod

    2006-10-01

    Full Text Available Abstract Background The Renin-Angiotensin system (RAS is a key regulator of both blood pressure and kidney functions and their interaction. In such a situation, genetic variability in the genes of different components of RAS is likely to contribute for its heterogeneous association in the renal disease patients. Angiotensin converting enzyme-1 (ACE-1 is an important component of RAS which determines the vasoactive peptide Angiotensin-II. Methods In the present study, we have investigated 127 ESRD patients and 150 normal healthy controls from north India to deduce the association between ACE gene polymorphism and ESRD. The inclusion criteria for patients included a constantly elevated serum creatinine level above normal range (ranging from 3.4 to 15.8 and further the patients were recommended for renal transplantation. A total of 150 normal healthy controls were also genotyped for ACE I/D polymorphism. The criterion of defining control sample as normal was totally based on the absence of any kidney disease determined from the serum creatinin level. Genotyping of ACE I/D were assayed by polymerase chain reaction (PCR based DNA amplification using specific flanking primers Based on the method described elsewhere. Results The difference of DD and II genotypes was found highly significant among the two groups (p = 0.025; OR = 3.524; 95%CI = 1.54-8.07. The combined genotype DD v/s ID+II comparison validated that DD genotype is a high risk genotype for ESRD (p = 0.001; OR = 5.74; 95%CI limit = 3.4-8.5. However, no correlation was obtained for different biochemical parameters of lipid profile and renal function among DD and non DD genotype. Interestingly, ~87% of the DD ESRD patients were found hypertensive in comparison to the 65% patients of non DD genotype Conclusion Based on these observations we conclude that ACE DD genotype implicate a strong possible role in the hypertensive state and in renal damage among north Indians. The study will help in

  2. Ash aggregation in explosive volcanic eruptions

    Science.gov (United States)

    Telling, J. W.; Dufek, J.

    2010-12-01

    We present the result of a recent experimental and numerical investigation of ash aggregation in volcanic plumes. Eruption dynamics are sensitive to microphysical processes, like ash aggregation, yet are difficult to parameterize based on dynamics simulations of whole eruption columns due to the lack of sufficient resolution. Here we present the results of experiments that develop a probabilistic relationship for ash aggregation based on particle size, collisional energy and atmospheric water vapor. These relationships can be integrated into large-scale simulations of eruption column behavior in conjunction with a reconstructed velocity distribution of the ash in the column. The physical experiment was carried out in a contained tank designed to allow for the control of atmospheric water vapor. Image data is recorded with a high speed camera and post-processed to determine the number of collisions, energy of collisions and probability of aggregation. We will present the results of aggregation probability and the effects of incorporating these results into a multiphase model of a three-dimensional eruption column, where the effects of ash aggregation are especially important in regions of high shear and high granular temperature.

  3. Emerald ash borer aftermath forests: the future of ash ecosystems

    Science.gov (United States)

    Kathleen S. Knight; Daniel A. Herms; John Cardina; Robert Long; Kamal J.K. Gandhi; Catharine P. Herms

    2011-01-01

    The effects of emerald ash borer (EAB) (Agrilus planipennis) on forest ecosystems are being studied through a collaborative research program between the U.S. Forest Service and The Ohio State University. We are monitoring ash demographics, understory light availability, EAB population dynamics, native and non-native plants, and effects of ash...

  4. Hygroscopic properties of volcanic ash

    National Research Council Canada - National Science Library

    T. L. Lathem; P. Kumar; A. Nenes; J. Dufek; I. N. Sokolik; M. Trail; A. Russell

    2011-01-01

      Volcanic ash is hygroscopic Water vapor adsorption is the main proceess controlling ash hygroscopicity The results can be parameterized in a simple correlation for use in models Limited observational...

  5. Rising from the ashes

    Energy Technology Data Exchange (ETDEWEB)

    Short, G. [RockTron Advanced Products (United States)

    2010-05-15

    The paper describes a new process for recovering useful minerals from the world's stockpile of waste fly ash. The technology from RockTron allows separation and recycling of minerals from fly ash so they can be used again in the rubber, plastics and coatings industries. Cenospheres, carbon, magnetite and finally alumino-silicates can be recovered. The first recycling plant in the UK has been built at Fiddler's Ferry power station in Widnes and another plant is being built at Gale Common. 2 photos.

  6. 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.

  7. Screening coal combustion fly ashes for application in geopolymers

    NARCIS (Netherlands)

    Valcke, S.L.A.; Pipilikaki, P.; Sarabér, A.J.; Fischer, H.R.; Nugteren, H.W.

    2013-01-01

    Driven by cost and sustainability, secondary resource materials such as fly ash, blast furnace slag, and bottom ash are increasingly used for alternative types of concrete binders, such as geopolymers. Because secondary resources may be highly variable from the perspective of geopolymers, it is

  8. 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.

  9. 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...

  10. High pressure liquid chromatographic analysis of the main pungent principles of solar dried West Indian ginger (Zingiber officinale Roscoe)

    Energy Technology Data Exchange (ETDEWEB)

    Balladin, D.A.; Headley, O. [University of the West Indies, Cave Hill Campus, St. Michael, Barbados (West Indies). Centre for Resource Management and Environmental Studies; Chang-Yen, I. [University of the West Indies, St. Augustine Campus, Trinidad (West Indies). Faculty of Agriculture and Natural Sciences; McGaw, D.R. [University of the West Indies, St. Augustine Campus, Trinidad (West Indies). Dept. of Chemical Engineering

    1998-12-31

    The main pungent principles of West Indian ginger (Zingiber officinale Roscoe) were quantified and qualified using High Pressure Liquid Chromatography. This procedure was used to evaluate the pungency profile of fresh, solar dried and solar dried/steam distilled ginger rhizomes. In this investigation, the total oleoresin extracted was in the ratio [20: 1: 2] for [fresh ginger: solar dried: solar dried/steam distilled ginger rhizomes] with respect to the [6]-gingerol content. This simple isocratic HPLC method can be used to investigate the pungency profile of the extracted oleoresin from the ginger rhizomes. (author)

  11. Effect of zeolitization on physico-chemico-mineralogical and geotechnical properties of lagoon ash

    Energy Technology Data Exchange (ETDEWEB)

    Kolay, P. K.; Singh, D. N. [Indian Inst. of Technology, Dept. of Civil Engineering, Bombay, (India)

    2001-10-01

    Ash from coal-fired generating stations is commonly disposed of by mixing the ash with water and placing the ash-water slurry in a pond or lagoon. This allows the alkalis present to react with the water, which leads to zeolitization of the ash and changes in its overall properties. A controlled experiment was conducted to simulate such action on Indian ash and zeolitization on the physico-chemico-mineralogical properties were studied. Results of the study showed that alkali activation caused an increase in particle size and a decrease in silica and alumina content of the ash, and increased specific gravity and specific surface area of the ash by about 18 per cent and 11 per cent respectively. Cation capacity of the ash increased two-fold. Formation of NaP1 zeolite was also noted, as well as increase in the void ratio and porosity of the ash, which resulted in significantly increased water absorption capacity and hydraulic conductivity at the optimum moisture content. 39 refs., 4 tabs., 9 figs.

  12. Optimizing use of girdled ash trees for management of low-density emerald ash borer (Coleoptera: Buprestidae) populations

    Science.gov (United States)

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

    2017-01-01

    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...

  13. Characterization of ash in algae and other materials by determination of wet acid indigestible ash and microscopic examination

    Science.gov (United States)

    Algae are known for high ash content. It is important to properly characterize their ash for value added utilization of algae as food, feed, and feedstock for biofuels. In this study, 12 algae of different sources were measured for proximate composition and mineral profile. Results showed that the r...

  14. Emerald Ash Borer

    Science.gov (United States)

    Deborah G. McCullough; Steven A. Katovich

    2004-01-01

    An exotic beetle from Asia was discovered in July 2002 feeding on ash (Fraxinus spp.) trees in southeastern Michigan. It was identified as Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Larvae feed in the cambium between the bark and wood, producing galleries that eventually girdle and kill branches and entire trees. Evidence suggests that A. planipennis has...

  15. Fly ash for defluoridation

    Energy Technology Data Exchange (ETDEWEB)

    Tzimou-Tsitouridou, R.

    1985-05-01

    The authors report a study of the use of a lignite fly ash to retain fluoride ions and remove them from their solutions, with a view to the use of this process for the defluoridation of water. Results are presented and the chemistry of the process is examined.

  16. The Eocene Thermal Maximum 2 (ETM-2) in a terrestrial section of the High Arctic: identification by U-Pb zircon ages of volcanic ashes and carbon isotope records of coal and amber (Stenkul Fiord, Ellesmere Island, Canada)

    Science.gov (United States)

    Reinhardt, Lutz; von Gosen, Werner; Piepjohn, Karsten; Lückge, Andreas; Schmitz, Mark

    2017-04-01

    The Stenkul Fiord section on southern Ellesmere Island reveals largely fluvial clastic sediments with intercalated coal seams of the Margaret Formation of Late Paleocene/Early Eocene age according to palynology and vertebrate remains. Field studies in recent years and interpretative mapping of a high-resolution satellite image of the area southeast of Stenkul Fiord revealed that the clastic deposits consist of at least four sedimentary units (Units 1 to 4) separated by unconformities. Several centimeter-thin volcanic ash layers, recognized within coal layers and preserved as crandallite group minerals (Ca-bearing goyazite), suggest an intense volcanic ash fall activity. Based on new U-Pb zircon ages (ID-TIMS) of three ash layers, the volcanic ash fall took place at 53.7 Ma in the Early Eocene, i.e. within the Eocene Thermal Maximum 2 (ETM-2) hyperthermal. The ETM-2 is bracketed further by discrete negative excursions of carbon isotope records of both bulk coal and amber droplets collected from individual coal layers of the section. The identification of the ETM-2 hyperthermal provides a stratigraphic tie-point in the terrestrial Margaret Formation sediments enabling assignment of the lowermost sedimentary Unit 1 to the Late Paleocene-earliest Eocene, Unit 2 to the Early Eocene, whereas Unit 3 and 4 might be Early to Middle Eocene in age. Thus the timing of syn-sedimentary movements of the Eurekan deformation causal for the observed unconformities in the section can be studied and the positions of further hyperthermals like the PETM or the ETM-3 in the section can be identified in the future. The integration of structural studies, new U-Pb zircon ages, and different carbon isotope records provides a new stratigraphic framework for further examination of the unique Early Eocene flora and fauna preserved in this high-latitude outcrop.

  17. Towards the Creation of Appropriate Teaching Materials for High Proficiency ESL Learners: The Case of Indian Management Students

    Science.gov (United States)

    Nickerson, Catherine

    2008-01-01

    Many of the textbooks used to teach Indian management students are South East Asian editions of U.S. publications. Although these provide a great deal of information on the business world, particularly in a North American context, outside of India, they do not always meet the needs of either the Indian ESL Learner, or of Indian business and…

  18. Transport of trace elements in runoff from unamended and pond-ash amended feedlot surfaces

    Science.gov (United States)

    The use of pond ash (fly ash that has been placed in evaporative ponds for storage and subsequently dewatered) for feedlot surfaces provides a drier environment for livestock and furnishes economic benefits. However, pond ash is known to have high concentrations of trace elements and the runoff wate...

  19. Potential use of wood ash in South African forestry: a review ...

    African Journals Online (AJOL)

    The use of landfills as a disposal method for wood ash is costly, environmentally detrimental and is pitted against increasingly stern environmental regulations. Literature has shown that wood ash has the potential to be used as a forest fertiliser and the effects tend to be highly site-specific. Wood ash contains a combination ...

  20. Effects of fly ash fineness on the mechanical properties of concrete

    Indian Academy of Sciences (India)

    1. Introduction. Fly ash is an industrial waste and a material of puzzolanic characteristic occurring due to burn- ... important factor affecting index of puzzolanic activity was fineness of the fly ash, not its chemical composition. ..... Siddique R 2003 Performance characteristics of high-volume class f fly ash concrete. Cement and ...

  1. Energy source in the developing eggs of the Indian horseshoe crab, Tachypleus gigas (Muller)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Aguiar, Q.; Saldanha, C.

    Wet weight, dry weight, water content, ash weight, soluble and insoluble proteins, carbohydrates, lipids, and glycogen were determined from 0 to 40th day after fertilization of the developing eggs of the Indian horseshoe crab, Tachypleus gigas...

  2. Wet physical separation of MSWI bottom ash

    OpenAIRE

    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), silver (10 ppm), stainless steel (0.1%) and minerals that can be converted into building products such as aggregates utilized for concrete, asphalt, etc. Since the composition of BA varies from cou...

  3. Identification of Abiotic Stress Responsive Genes from Indian High Altitude Lepidium latifolium L. (Short Communication)

    OpenAIRE

    Sanjay Mohan Gupta; Atul Grover; Zakwan Ahmed

    2012-01-01

    Abiotic stresses are major environmental factors that periodically account for significant loss in crop productivity. In order to improve the abiotic stress tolerance in vegetable crops through transgenic approaches, authors isolated and cloned six up-regulated, LlaDREB1b (JN214345), LlaGPAT (JN398166), LlaNAC (FJ423495), LlaCIPK (FJ423496), LlaPR5 (GQ853409) and LlaIPK (FJ487575) and two down-regulated LlaRan (JN214347) and LlaDRT (JN214346) abiotic stress responsive genes from Indian...

  4. Gas generation in incinerator ash; Gasbildning i aska

    Energy Technology Data Exchange (ETDEWEB)

    Arm, Maria; Lindeberg, Johanna; Rodin, Aasa; Oehrstroem, Anna; Backman, Rainer; Oehman, Marcus; Bostroem, Dan

    2006-02-15

    other reactive metals in addition to aluminium (iron, copper and led were tested), the combination of high total aluminium content of an ash material and low volume of gas generation is possible, since the total aluminium content comprises both the elemental and the non-elemental aluminium and it is only the elemental aluminium that generates gas, aluminium particles can survive incineration without melting and without substantial oxidation of the particle surface, solid aluminium oxide (Al{sub 2}O{sub 3}) is the stable form of aluminium in a boiler. Based on the results in this project the following recommendations for handling the ash can be given to decrease the gas generation and to prevent the risk for explosion: The content of elemental aluminium or the potential of gas generation should be analysed regularly for ash materials from municipal waste incineration plants; Metal separation - including non-magnetic metals - of the fuel for waste incineration plants is necessary; Good ventilation of the ash after wetting, together with storage in oxygen rich environment is desirable.

  5. Microstructural and compositional change of NaOH-activated high calcium fly ash by incorporating Na-aluminate and co-existence of geopolymeric gel and C–S–H(I)

    KAUST Repository

    Oh, Jae Eun

    2012-05-01

    This study explores the reaction products of alkali-activated Class C fly ash-based aluminosilicate samples by means of high-resolution synchrotron X-ray diffraction (HSXRD), scanning electron microscope (SEM), and compressive strength tests to investigate how the readily available aluminum affects the reaction. Class C fly ash-based aluminosilicate raw materials were prepared by incorporating Na-aluminate into the original fly ashes, then alkali-activated by 10 M NaOH solution. Incorporating Na-aluminate reduced the compressive strength of samples, with the reduction magnitude relatively constant regardless of length of curing period. The HSXRD provides evidence of the co-existence of C-S-H with geopolymeric gels and strongly suggests that the C-S-H formed in the current system is C-S-H(I). The back-scattered electron images suggest that the C-S-H(I) phase exists as small grains in a finely intermixed form with geopolymeric gels. Despite providing extra source of aluminum, adding Na-aluminate to the mixes did not decrease the Si/Al ratio of the geopolymeric gel. © 2012 Elsevier Ltd.

  6. National volcanic ash operations plan for aviation

    Science.gov (United States)

    ,; ,

    2007-01-01

    The National Aviation Weather Program Strategic Plan (1997) and the National Aviation Weather Initiatives (1999) both identified volcanic ash as a high-priority informational need to aviation services. The risk to aviation from airborne volcanic ash is known and includes degraded engine performance (including flameout), loss of visibility, failure of critical navigational and operational instruments, and, in the worse case, loss of life. The immediate costs for aircraft encountering a dense plume are potentially major—damages up to $80 million have occurred to a single aircraft. Aircraft encountering less dense volcanic ash clouds can incur longer-term costs due to increased maintenance of engines and external surfaces. The overall goal, as stated in the Initiatives, is to eliminate encounters with ash that could degrade the in-flight safety of aircrews and passengers and cause damage to the aircraft. This goal can be accomplished by improving the ability to detect, track, and forecast hazardous ash clouds and to provide adequate warnings to the aviation community on the present and future location of the cloud. To reach this goal, the National Aviation Weather Program established three objectives: (1) prevention of accidental encounters with hazardous clouds; (2) reduction of air traffic delays, diversions, or evasive actions when hazardous clouds are present; and (3) the development of a single, worldwide standard for exchange of information on airborne hazardous materials. To that end, over the last several years, based on numerous documents (including an OFCMsponsored comprehensive study on aviation training and an update of Aviation Weather Programs/Projects), user forums, and two International Conferences on Volcanic Ash and Aviation Safety (1992 and 2004), the Working Group for Volcanic Ash (WG/VA), under the OFCM-sponsored Committee for Aviation Services and Research, developed the National Volcanic Ash Operations Plan for Aviation and Support of the

  7. 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.

  8. Analysis of Content of Selected Critical Elements in Fly Ash

    Directory of Open Access Journals (Sweden)

    Makowska Dorota

    2016-03-01

    Full Text Available Pursuant to the new mineral policy of the European Union, searching for new sources of raw materials is required. Coal fly ash has long been considered as a potential source of a number of critical elements. Therefore, it is important to monitor the contents of the critical elements in fly ash from coal combustion. The paper presents the results of examinations of the contents of selected elements, i.e. beryllium, cobalt, chromium and germanium in fly ash from Polish power plants. The results of the conducted investigations indicate that the examined ash samples from bituminous coal combustion cannot be treated as a potential source of the analysed critical elements. The content of these elements in ash, though slightly higher than their average content in the sedimentary rocks, is, however, not high enough to make their recovery technologically and economically justified at this moment.

  9. Thaumasite formation in concrete and mortars containing fly ash

    Energy Technology Data Exchange (ETDEWEB)

    D.M. Mulenga; J. Stark; P. Nobst [Bauhaus-University, Weimar (Germany). F.A. Finger-Institute of Material Sciences

    2003-12-01

    Due to recent reports on deterioration of concrete structures, the thaumasite form of sulfate attack has become a subject of study and close investigation. This paper investigates the formation of thaumasite in concrete and mortars containing fly ash. The results show that thaumasite formation can occur within 84 days of exposure to sulfate solutions. High volumes of fly ash can limit or promote thaumasite formation depending on the type of cement used. Thaumasite and ettringite were found among the deterioration products. However, the thaumasite formation in the specimen prepared from sulfate resisting Portland cement was not accompanied by deterioration, except by 50% fly ash addition. The mixtures of Portland limestone cement with 40% fly ash exhibited a very limited thaumasite formation while the mixtures with 50% had no thaumasite at all. It is concluded that thaumasite can also be formed in mixtures incorporating fly ash.

  10. Surface treated fly ash filled modified epoxy composites

    Directory of Open Access Journals (Sweden)

    Uma Dharmalingam

    2015-01-01

    Full Text Available Abstract Fly ash, an inorganic alumino silicate has been used as filler in epoxy matrix, but it reduces the mechanical properties due to its poor dispersion and interfacial bonding with the epoxy matrix. To improve its interfacial bonding with epoxy matrix, surface treatment of fly ash was done using surfactant sodium lauryl sulfate and silane coupling agent glycidoxy propyl trimethoxy silane. An attempt is also made to reduce the particle size of fly ash using high pressure pulverizer. To improve fly ash dispersion in epoxy matrix, the epoxy was modified by mixing with amine containing liquid silicone rubber (ACS. The effect of surface treated fly ash with varying filler loadings from 10 to 40% weight on the mechanical, morphological and thermal properties of modified epoxy composites was investigated. The surface treated fly ash was characterized by particle size analyzer and FTIR spectra. Morphological studies of surface treated fly ash filled modified epoxy composites indicate good dispersion of fillers in the modified epoxy matrix and improves its mechanical properties. Impact strength of the surface treated fly ash filled modified epoxy composites show more improvement than unmodified composites.

  11. Sulfur-bearing coatings on fly ash from a coal-fired power plant: Composition, origin, and influence on ash alteration

    Science.gov (United States)

    Fishman, N.S.; Rice, C.A.; Breit, G.N.; Johnson, R.D.

    1999-01-01

    Fly ash samples collected from two locations in the exhaust stream of a coal-fired power plant differ markedly with respect to the abundance of thin (???0.1 ??m) sulfur-rich surface coatings that are observable by scanning electron microscopy. The coatings, tentatively identified as an aluminum-potassium-sulfate phase, probably form upon reaction between condensed sulfuric acid aerosols and glass surfaces, and are preferentially concentrated on ash exposed to exhaust stream gases for longer. The coatings are highly soluble and if sufficiently abundant, can impart an acidic pH to solutions initially in contact with ash. These observations suggest that proposals for ash use and predictions of ash behavior during disposal should consider the transient, acid-generating potential of some ash fractions and the possible effects on initial ash leachability and alteration. ?? 1998 Elsevier Science Ltd.

  12. Ashes for organic farming

    OpenAIRE

    Kousa, T.; Heinonen, M; Suoniitty, T.; Peltonen, K

    2013-01-01

    Nowadays only eight percent of the cultivated field area is used for organic farming. The Ministry of Agriculture and Forestry has published the guidelines for the program of organic farming to diversify the supply and the consumption of organic food. The aim is to increase organically arable land to 20% by the year 2020.The demand of organic fertilizer products is strongly increasing. Interest in forestry by-products (ash, bark, zero fiber, etc.) for use in organic production has recently be...

  13. Circle of Ashes

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Circle of Ashes This plot tells astronomers that a pulsar, the remnant of a stellar explosion, is surrounded by a disk of its own ashes. The disk, revealed by the two data points at the far right from NASA's Spitzer Space Telescope, is the first ever found around a pulsar. Astronomers believe planets might rise up out of these stellar ashes. The data in this plot, or spectrum, were taken by ground-based telescopes and Spitzer. They show that light from around the pulsar can be divided into two categories: direct light from the pulsar, and light from the dusty disk swirling around the pulsar. This excess light was detected by Spitzer's infrared array camera. Dust gives off more infrared light than the pulsar because it's cooler. The pulsar, called 4U 0142+61, was once a massive star, until about 100,000 years ago, when it blew up in a supernova explosion and scattered dusty debris into space. Some of that debris was captured into what astronomers refer to as a 'fallback disk,' now circling the leftover stellar core, or pulsar. The disk resembles protoplanetary disks around young stars, out of which planets are thought to be born. The data have been corrected to remove the effects of light scattering from dust that lies between Earth and the pulsar. The ground-based data is from the Keck I telescope atop Mauna Kea, Hawaii.

  14. Nested high resolution models for the coastal areas of the North Indian Ocean

    Science.gov (United States)

    Wobus, Fred; Shapiro, Georgy

    2017-04-01

    . Due to the lack of effective detiding methods and the prevailing view that harmonics-derived SSH provide a cleaner tidal signal over the SSH taken from a tidal parent model it has traditionally only been the last model in a nesting chain that is tidal. But to our knowledge these assumptions haven't been sufficiently tested and need to be re-visited. Furthermore, the lack of tides in the larger-scale regional models limits their capability and we would like to push for a nesting chain where all regional models (including the intermediate ones) are tidal. In this study we have conducted a number of numerical experiments where we have tested whether a tidal regional model can effectively force a tidal nested model without resorting to detiding techniques and the use of a dedicated tidal model such as TPXO. We have tested whether it's possible to use a tidal parent model and use the total SSH (combined geostrophic SSH and tidal component) to force the child model at the boundary. We call this strategy "tidal nesting" as opposed to TPXO tidal forcing which is used in "traditional nesting". For our experiments we have developed 2 models based on the same NEMO 3.6 codebase. The medium resolution AS20 model covers the Arabian Sea at 1/20 ̊ with 50 layers using a hybrid s-on-top-of-z vertical discretisation scheme (Shapiro et al., 2013); and the high resolution AG60 model covers the Arabian/Persian Gulf at 1/60 ̊ with 50 layers. The AS20 model is "traditionally" nested within the UK Met Office non-tidal large-scale Indian Ocean model at 1/12 ̊ resolution and tidal constituents at the boundary are taken from the TPXO7.2 Global Tidal Solution. Our "tidal nesting" experiments use different forcing frequencies at which the tidal SSH is fed from the larger-scale AS20 into the smaller-scale AG60 model. These strategies are compared with "traditional nesting" where the inner AG60 uses boundary conditions from a non-tidal AS20 parent model and tides are computed from TPXO harmonics

  15. High Rates of All-cause and Gastroenteritis-related Hospitalization Morbidity and Mortality among HIV-exposed Indian Infants

    Directory of Open Access Journals (Sweden)

    Tripathy Srikanth

    2011-07-01

    Full Text Available Abstract Background HIV-infected and HIV-exposed, uninfected infants experience a high burden of infectious morbidity and mortality. Hospitalization is an important metric for morbidity and is associated with high mortality, yet, little is known about rates and causes of hospitalization among these infants in the first 12 months of life. Methods Using data from a prevention of mother-to-child transmission (PMTCT trial (India SWEN, where HIV-exposed breastfed infants were given extended nevirapine, we measured 12-month infant all-cause and cause-specific hospitalization rates and hospitalization risk factors. Results Among 737 HIV-exposed Indian infants, 93 (13% were HIV-infected, 15 (16% were on HAART, and 260 (35% were hospitalized 381 times by 12 months of life. Fifty-six percent of the hospitalizations were attributed to infections; gastroenteritis was most common accounting for 31% of infectious hospitalizations. Gastrointestinal-related hospitalizations steadily increased over time, peaking around 9 months. The 12-month all-cause hospitalization, gastroenteritis-related hospitalization, and in-hospital mortality rates were 906/1000 PY, 229/1000 PY, and 35/1000 PY respectively among HIV-infected infants and 497/1000 PY, 107/1000 PY, and 3/1000 PY respectively among HIV-exposed, uninfected infants. Advanced maternal age, infant HIV infection, gestational age, and male sex were associated with higher all-cause hospitalization risk while shorter duration of breastfeeding and abrupt weaning were associated with gastroenteritis-related hospitalization. Conclusions HIV-exposed Indian infants experience high rates of all-cause and infectious hospitalization (particularly gastroenteritis and in-hospital mortality. HIV-infected infants are nearly 2-fold more likely to experience hospitalization and 10-fold more likely to die compared to HIV-exposed, uninfected infants. The combination of scaling up HIV PMTCT programs and implementing proven health

  16. Fugitive particulate emission factors for dry fly ash disposal.

    Science.gov (United States)

    Mueller, Stephen F; Mallard, Jonathan W; Mao, Qi; Shaw, Stephanie L

    2013-07-01

    Dry fly ash disposal involves dropping ash from a truck and the movement of a heavy grader or similar vehicle across the ash surface. These operations are known to produce fugitive particulate emissions that are not readily quantifiable using standard emission measurement techniques. However there are numerous situations--such as applying for a source air permit--that require these emissions be quantified. Engineers traditionally use emission factors (EFs) derived from measurements of related processes to estimate fly ash disposal emissions. This study near a dry fly ash disposal site using state-of-the-art particulate monitoring equipment examines for the first time fugitive emissions specific to fly ash handling at an active disposal site. The study measured hourly airborne mass concentrations for particles smaller than 2.5 microm (PM2.5) and 10 microm (PM10) along with meteorological conditions and atmospheric turbidity at high temporal resolution to characterize and quantify fugitive fly ash emissions. Fugitive fly ash transport and dispersion were computed using the on-site meteorological data and a regulatory air pollutant dispersion model (AERMOD). Model outputs coupled with ambient measurements yielded fugitive fly ash EFs that averaged 96 g Mg(-1) (of ash processed) for the PM(c) fraction (= PM10 - PM2.5) and 18 g Mg(-1) for PM2.5. Median EFs were much lower due to the strongly skewed shape of the derived EF distributions. Fugitive EFs from nearby unpaved roads were also characterized. Our primary finding is that EFs for dry fly ash disposal are considerably less than EFs derived using US Environmental Protection Agency AP-42 Emissions Handbook formulations for generic aggregate materials. This appears to be due to a large difference (a factor of 10+) between fugitive vehicular EFs estimated using the AP-42 formulation for vehicles driving on industrial roads (in this case, heavy slow-moving grading equipment) and EFs derived by the current study. Fugitive

  17. DNA-A of a highly pathogenic Indian cassava mosaic virus isolated from Jatropha curcas causes symptoms in Nicotiana benthamiana.

    Science.gov (United States)

    Wang, Gang; Sun, Yanwei; Xu, Ruirui; Qu, Jing; Tee, Chuansia; Jiang, Xiyuan; Ye, Jian

    2014-04-01

    Jatropha curcas mosaic disease (JcMD) is a newly emerging disease that has been reported in Africa and India. Here, we report the complete nucleotide sequence of a new Indian cassava mosaic virus isolate (ICMV-SG) from Singapore. Infection of ICMV-SG showed more severe JcMD in Jatropha curcas and Nicotiana benthamiana than the other ICMV isolates reported previously, though ICMV-SG shares high sequence identity with the other ICMV isolates. Agroinfectious DNA-A alone sufficiently induced systemic symptoms in N. benthamiana, but not in J. curcas. Results from agroinfection assays showed that systemic infection of ICMV-SG in J. curcas required both DNA-A and DNA-B components.

  18. Electroremediation of straw and co-combustion ash under acidic conditions

    DEFF Research Database (Denmark)

    Lima, Ana T.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

    2009-01-01

    under acidic conditions.Straw ashes presented high removal rates for Ca, Cu, Cr and particularly for Cd, which has been reduced to a level bellow the established by Danish regulations. Acidification also induced a high dissolution and a lower pH of the ash. Fly ash from co-combustion of wood presents...... be addressed before biomass combustion is considered a truly sustainable technology. The electrodialytic process is a remediation technique able to assist the management of fly ash. For this work, straw and co-combustion of wood ash are briefly characterized and their electrodialytic treatment is carried out...... similarities with wood ash alone. However, further characterization should be carried out before any comparison regarding applicable legislation. Under acidic conditions, the electrodialytic treatment was not effective for the co-combustion wood ash. The heavy metals appeared in the least soluble fraction...

  19. Characteristics of biomass ashes from different materials and their ameliorative effects on acid soils.

    Science.gov (United States)

    Shi, Renyong; Li, Jiuyu; Jiang, Jun; Mehmood, Khalid; Liu, Yuan; Xu, Renkou; Qian, Wei

    2017-05-01

    The chemical characteristics, element contents, mineral compositions, and the ameliorative effects on acid soils of five biomass ashes from different materials were analyzed. The chemical properties of the ashes varied depending on the source biomass material. An increase in the concrete shuttering contents in the biomass materials led to higher alkalinity, and higher Ca and Mg levels in biomass ashes, which made them particularly good at ameliorating effects on soil acidity. However, heavy metal contents, such as Cr, Cu, and Zn in the ashes, were relatively high. The incorporation of all ashes increased soil pH, exchangeable base cations, and available phosphorus, but decreased soil exchangeable acidity. The application of the ashes from biomass materials with a high concrete shuttering content increased the soil available heavy metal contents. Therefore, the biomass ashes from wood and crop residues with low concrete contents were the better acid soil amendments. Copyright © 2016. Published by Elsevier B.V.

  20. High prevalence of Arginine to Glutamine Substitution at 98, 141 and 162 positions in Troponin I (TNNI3 associated with hypertrophic cardiomyopathy among Indians

    Directory of Open Access Journals (Sweden)

    Rani Deepa

    2012-08-01

    Full Text Available Abstract Background Troponin I (TNNI3 is the inhibitory subunit of the thin filament regulatory complex Troponin, which confers calcium-sensitivity to striated muscle actomyosin ATPase activity. Mutations (2-7% in this gene had been reported in hypertrophic cardiomyopathy patients (HCM. However, the frequencies of mutations and associated clinical presentation have not been established in cardiomyopathy patients of Indian origin, hence we have undertaken this study. Methods We have sequenced all the exons, including the exon-intron boundaries of TNNI3 gene in 101 hypertrophic cardiomyopathy patients (HCM, along with 160 healthy controls, inhabited in the same geographical region of southern India. Results Our study revealed a total of 16 mutations. Interestingly, we have observed Arginine to Glutamine (R to Q mutation at 3 positions 98, 141 and 162, exclusively in HCM patients with family history of sudden cardiac death. The novel R98Q was observed in a severe hypertrophic obstructive cardiomyopathy patient (HOCM. The R141Q mutation was observed in two familial cases of severe asymmetric septal hypertrophy (ASH++. The R162Q mutation was observed in a ASH++ patient with mean septal thickness of 29 mm, and have also consists of allelic heterogeneity by means of having one more synonymous (E179E mutation at g.4797: G → A: in the same exon 7, which replaces a very frequent codon (GAG: 85% with a rare codon (GAA: 14%. Screening for R162Q mutation in all the available family members revealed its presence in 9 individuals, including 7 with allelic heterogeneity (R162Q and E179E of which 4 were severely affected. We also found 2 novel SNPs, (g.2653; G → A and g.4003 C → T exclusively in HCM, and in silico analysis of these SNPs have predicted to cause defect in recognition/binding sites for proteins responsible for proper splicing. Conclusion Our study has provided valuable information regarding the prevalence of TNNI3 mutations in

  1. High prevalence of organ specific autoantibodies in Indian type 1 diabetic patients.

    Science.gov (United States)

    Shivaprasad, Channabasappa; Kolly, Anish; Pulikkal, Annie; Kumar, K M Prasanna

    2017-07-26

    Type 1 diabetes (T1D) is frequently associated with other autoimmune conditions such as autoimmune thyroiditis, coeliac disease (CD) and Addison's disease. There are sparse data on the prevalence of antibodies against these conditions in Indian patients with T1D. This study aims to evaluate prevalence of these T1D associated autoantibodies in Indian patients. Two hundred and fifty-eight patients with T1D were recruited from the Bangalore Diabetes Hospital and the Vydehi Institute of Medical Sciences and Research Centre (VIMS) for the study. Participants diagnosed with diabetes before the age of 18 years, as per the American Diabetes Association (ADA) criteria, and who were classified as T1D based on clinical grounds were recruited for the study. Anti-thyroid peroxidase antibody (TPO) and IgA tissue transglutaminase antibody (tTG) were estimated in all the patients. 21-Hydroxylase antibody (21-OHAb) were estimated in 170 patients. All assays were done by commercial immunoassay. Eighty-eight unrelated age-matched healthy controls were chosen for comparison. The mean age of T1D patients was 14.33 years. The mean duration of diabetes was 4.88 years. Anti-TPO was positive in 43 (16.7%) patients with T1D as compared to 3 (3.4%) in controls. IgA tTG was positive in 12 (4.65%) patients with T1D and was absent in controls. 21-OHAb was positive in two (1.1%) patients with T1D and was absent in controls. Both patients who had positive 21-OHab had the other two antibodies. Five patients had positive anti-TPO and IgA-tTG antibodies. Anti-TPO antibody was the most prevalent antibody in patients with T1D. Anti-TPO and IgA-tTG antibodies were significantly higher than in the control population. Further studies will be required to assess the clinical significance of these positive antibodies.

  2. Pharmacokinetics and pharmacogenetics of 13-cis retinoic acid in Indian high-risk neuroblastoma patients.

    Science.gov (United States)

    Gota, Vikram; Chinnaswamy, Girish; Vora, Tushar; Rath, Sanhita; Yadav, Akanksha; Gurjar, Murari; Veal, Gareth; Kurkure, Purna

    2016-10-01

    To compare the pharmacokinetics of 13-cis retinoic acid (13-cisRA) between Indian and UK neuroblastoma patients receiving comparable treatment, alongside measures of toxicity and response. 13-cisRA (160 mg/m(2)/day) was administered to 36 patients ≤16 years in two divided doses. Plasma 13-cisRA concentrations were determined on days 1 and 14 of cycles 1 and 4 of treatment. Area under the plasma concentration-time curve (AUC0-6h) was estimated using non-compartment modelling. Patients were genotyped for UGT2B7, CYP3A5*3, CYP3A7*2 and *2, *3 and *4 variants of CYP2C8. Marked inter-patient variability in 13-cisRA pharmacokinetics was observed. There was a trend towards a higher AUC0-6h on day 1 versus day 14 for both treatment cycles studied. Children who swallowed 13-cisRA capsules (n = 18) achieved higher AUC0-6h values compared to those who could not (n = 16) (Mean AUC 21.53 vs. 9.35 µM h, P < 0.05). Patients who were event free at 1 year tended to have higher AUC0-6h on C1D1 compared to those patients who progressed, although this did not reach significance with the number of patients studied (P = 0.08). Similarly, patients who achieved a 13-cisRA C max of ≥2 µM on C1D1 tended to have higher median EFS compared to those who did not (17.0 vs. 8.1 months). UGT2B7, CYP2C8*2/*3/*4 or CYP3A5*3 genotype did not have any effect on 13-cisRA pharmacokinetics. Method of administration markedly affects 13-cisRA pharmacokinetics in Indian neuroblastoma patients, supporting similar findings in UK patients. An appropriate oral liquid formulation of 13-cisRA that can be administered to all children with neuroblastoma is urgently needed on an international level.

  3. pozzolanicity and some engineering properties of rice husk ash

    African Journals Online (AJOL)

    HON

    (Neville, 1996). Rice Husks have been found to contain very high silica content, slow firing at a room temperature of 500 to 700 degrees Celsius. (Roy, 1987). The resulting ash is amorphous with a porous structure (Massazza, 1979). The ash has a specific surface as high as 50,000m2/kg and a specific gravity of 1.9 to 2.4 ...

  4. 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.

  5. The impacts of coal refuse/fly ash bulk bends on water quality and plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Stewar, B.R.; Daniels, W.L. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States)

    1995-09-01

    There is considerable interest in the beneficial reuse of coal fly ash as a soil amendment on coal refuse piles. One method of application would be to blend the coal refuse and the fly ash before deposition in a refuse pile. A field experiment was initiated to measure the effects of bulk blending fly ash with coal refuse on water quality and plant growth parameters. Fly ash (class F) from three sources were used in the experiment. Two of the fly ashes were acidic and the third was alkaline. Trenches were excavated in a coal refuse pile to a depth of 2 m and the refuse was blended with fly ash and then returned to the trench. In other plots the ash was applied as a surface amendment. A treatment of a bulk blend of 5% (w/w) rock phosphate was also included in the experiment. Large volume lysimeters were installed in some trenches to collect the leachates. The fly ash treatments appear to improve the quality of the leachates when compared to the leachates from the untreated plots. The fly ash amended treatments have lower leachate concentrations of Fe and Al. Initially the fly ash treatments showed high levels of leachate B, however those levels have decreased with time. Millet (Setaria italica) yields from the first year of the experiment were highest n the alkaline fly ash and rock phosphate blended plots. In the second growing season, the two bulk blends with alkaline fly ash had the highest yields. In the third growing season all treatments had higher yield levels than the untreated control plots. The positive effects of the fly ash on leachate quality were attributed to the alkalinity of the ash, and the increase in yield was attributed to the increases in water holding capacity due to fly ash treatments.

  6. Causes of Variability in the Effects of Vegetative Ash on Post-Fire Runoff and Erosion

    Science.gov (United States)

    Balfour, V.; Woods, S.

    2008-12-01

    Vegetative ash formed during forest wildfires has varying effects on post-fire runoff and erosion. In some cases the ash layer reduces runoff and erosion by storing rainfall and by protecting the soil surface from surface sealing and rainsplash detachment. In other cases, the ash layer increases runoff and erosion by forming a surface crust, clogging soil pores, and providing a ready source of highly erodible fine material. Since only a handful of studies have measured the hydrogeomorphic effect of ash, it is unclear whether the observed variability in its effect reflects initial spatial variability in the ash properties due to factors such as fuel type and fire severity, or differences that develop over time due to compaction and erosion or exposure of the ash to rainfall and air. The goal of our research was to determine if the observed differences in the effect of ash on runoff and erosion are due to: 1) variability in initial ash hydrologic properties due to differences in combustion temperature and fuel type, or 2) variability in ash hydrologic properties caused by mineralogical phase changes that develop after the ash is exposed to water. We created ash in the laboratory using wood and needles of Lodgepole pine (Pinus contorta), Ponderosa pine (Pinus Ponderosa) and Douglas fir (Pseudotsuga menziesii) and at 100° C temperature increments from 300 to 900° C. A subsample of ash from each fuel type / temperature combination was saturated, left undisturbed for 24 hours and then oven dried at 104° C. Dry and wetted ash samples were characterized in terms of: structure (using a scanning electron microscope), carbon content, mineralogy (using X-ray diffraction), porosity, water retention properties and hydraulic conductivity. Ash produced at the higher combustion temperatures from all three fuel types contained lime (CaO), which on wetting was transformed to portlandite (Ca(OH)2) and calcite (CaCO3). This mineralogical transformation resulted in irreversible

  7. FEATURES OF ASH OF THERMAL POWER PLANTS AS AGGREGATE FOR CONCRETES

    Directory of Open Access Journals (Sweden)

    M. A. Storozhuk

    2017-10-01

    are presented. The advantages of ash over traditional aggregate are shown. The research results contribute to the mass application of TPP ash in construction and obtaining the products from the proposed concrete of low cost with high physical-mechanical properties. Ash as an aggregate has a particularly high efficiency in vibrovacuumized concrete.

  8. 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...

  9. Dielectric properties of fly ash

    Indian Academy of Sciences (India)

    Unknown

    Abstract. 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.

  10. Common Ash (Fraxinus excelsior L.)

    NARCIS (Netherlands)

    Douglas, G.C.; Pliura, A.; Dufour, J.; Mertens, P.; Jacques, D.; Buiteveld, J.

    2013-01-01

    Common ash (Fraxinus excelsior L.) has an extensive natural distribution across Europe and extends as far east as the Volga river and south into northern Iran. Country statistics and national programmes show that common ash has major economic and ecological importance in many countries. Genetic

  11. Emerald ash borer life cycle

    Science.gov (United States)

    Leah S. Bauer; Robert A. Haack; Deborah L. Miller; Toby R. Petrice; Houping Liu

    2004-01-01

    The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), native to several Asian countries, was discovered in southeastern Michigan and nearby Ontario in June of 2002. EAB was identified as the cause of extensive ash (Fraxinus spp.) mortality in approximately 2,500 mi2, and...

  12. Construction of a Dry Ash Dam with Soilbags and Slope Stability Analysis

    Science.gov (United States)

    Li, Hui; Song, Yingjun; Gao, Jiaorong; Li, Longhua; Zhou, Yuqi; Qi, Hui

    2017-12-01

    In thermal power plants, it is necessary to build ash dams to store fly ash, which is the by-product after the combustion of coals. To solve the problem of lacking rockfill materials in Africa, A new technology of constructing ash dams using solibags filled with local sands is proposed and the method of analyzing its slope stability is suggested. The design of the ash dam using soilbags in Lamb Thermal Power Plant of Kenya is introduced in detail. The slope stability of the soilbags-constructed ash dam was analyzed by adopting the suggested method. The results show that the soilbags filled with ash or sands have high compressive strength, and the primary dam constructed with soilbags can effectively retain the backfill ash and the stacking dam reinforced with soilbags can stand stable even with the slope of 1:1.5.

  13. Influence of wheat ash on the MCPA immobilization in agricultural soils.

    Science.gov (United States)

    Hiller, E; Fargasová, A; Zemanová, L; Bartal, M

    2008-09-01

    Burning of crop residues in the fields is a routine post-harvest practice and results in accumulation of ashes in soils. Recent studies have shown that the ashes may significantly contribute to the herbicide sorption in soils. This study was conducted to evaluate the potential role of wheat ash in immobilization of anionic herbicide MCPA in soils. The results showed that wheat ash is highly effective sorbent for herbicide MCPA. Amendment of Fluvi-Gleyic Phaeozem and Eutric Regosol with 1% wheat ash caused a 8-fold and 16-fold increase in MCPA sorption, respectively. Desorption of MCPA was also influenced by wheat ash in soils. The addition of wheat ash to both soils increased the resistant fraction to desorption up to 80%. Generally, the field burning of crop residues appears to increase the sorption of pesticides in agricultural soils and decrease their leaching.

  14. Electrodialytic removal of cadmium from biomass combustion fly ash in larger scale

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Simonsen, Peter

    2005-01-01

    Due to a high concentration of the toxic heavy metal cadmium (Cd), biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. It has previously been shown that it is possible to reduce the concentration of Cd in different bio ashes......). The experimental ash was a straw combustion fly ash suspended in water. Within 4 days of remediation, Cd concentrations below the limiting concentration of 5.0 mg Cd/kg DM for straw ash were reached. On the basis of these results, the energy costs for remediation of ash in industrial scale have been estimated...... significantly by using electrodialytic remediation, an electrochemically assisted extraction method. In this work the potential of the method was demonstrated in larger scale. Three different experimental set-ups were used, ranging from bench-scale (25 L ash suspension) to pilot scale (0.3 - 3 m3...

  15. Development of Classified Fly Ash as a Pozzolanic Material

    Science.gov (United States)

    Rukzon, Sumrerng; Chindaprasirt, Prinya

    This research studies the potential for using classified fly ash from Mae Moh power plant in Thailand as a pozzolanic material. Three different fly ash finenesses viz., coarse Original Fly Ash (OFA), Medium Fly Ash (MFA) and Fine Fly Ash (FFA) were used for the study. Ordinary Portland Cement (OPC) was partially replaced with fly ash at 20 and 40% by weight of binder. The water to binder ratio was kept constant at 0.5 and the flow of mortar was maintained at 110±5% with the aid of superplasticizer (SP). Compressive strength, carbonation depth and porosity test of mortars were determined. FFA has a high potential to be used as a good pozzolanic material. The use of FFA produces mortars with good strength and low porosity. The resistance to carbonation of mortar improves with partial replacement of FFA in comparison with the normal coarse fly ash. The use of FFA results in a strong and dense mortar which is due to better dispersion and filling effect as well as an increase in the pozzolanic reaction.

  16. Pure zeolite synthesis from silica extracted from coal fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, N.; Querol, X.; Plana, F.; Andres, J.M.; Janssen, M.; Nugteren, H. [CSIC, Barcelona (Spain). Inst. Earth Science ' Jaume Almera'

    2002-07-01

    Pure zeolites can be synthesised from silica extracted from fly ash by alkaline leaching. If the process is optimised the solid residue arising from this extraction may also contain a relatively high content of zeolitic material mixed with residual fly ash components. Both the pure and the impure zeolitic material have a high potential for application in waste-water and flue gas-cleaning technologies. The silica extraction potential of 23 European coal fly ashes covering most of the possible fly ash types is investigated in this study. Optimisation of leaching processes, by varying temperature, time and alkali/fly ash rates, permitted extraction yields up to 140 g of SiO{sub 2} per kg using a single step process, but the extraction yields may reach up to 210 g kg{sup -1} by applying thermal pre-treatments prior to the extraction. The solid residue arising from the silica extraction experiments shows a high NaP1 zeolite content. A high Si/Al ratio of the glass matrix, the occurrence of easily soluble silica phases in the original fly ash and a high reactive surface area were found to be the major parameters influencing silica extraction. High purity 4A and X zeolitic material was obtained by combining the silica extracts from the Meirama fly ash and a waste solution from the Al-anodising industry. The results allowed conversion of the silica extraction yields to an equivalent 630 g of pure 4A-X zeolite per kg of fly ash with a cation exchange capacity of 4.7 meq g{sup -1}.

  17. Adiponectin, Interleukin-6 and High-sensitivity C-reactive Protein Levels in Overweight/Obese Indian children.

    Science.gov (United States)

    Jain, Vandana; Kumar, Ajay; Agarwala, Anuja; Vikram, Naval; Ramakrishnan, Lakshmy

    2017-10-15

    The aim of our study was to assess serum Adiponectin, Interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) levels and their correlation with conventional risk factors for cardiovascular disease and diabetes in overweight/obese Indian children. Body mass index (BMI), waist circumference, blood pressure, fasting serum adiponectin, IL-6, hsCRP, blood glucose, triglycerides, and total and high density lipoprotein cholesterol were measured in children aged 7-15 years with BMI >85th centile. 84 overweight/obese children (48 boys) with mean (SD) age 10.2 (1.9) years were enrolled. Mean (SD) adiponectin, hsCRP and median (IQR) IL-6 levels were 6.0 (3.1) µg/mL, 3.4 (2.4) mg/L and 12.7 (5.0-90.0) pg/mL, respectively. Low adiponectin, high hsCRP and high IL-6 were noted in 16.5%, 49.4% and 54.4% participants, respectively. Adiponectin was inversely correlated with waist circumference, and IL-6 positively with BMI and blood glucose. Inflammatory mediators, hsCRP and IL-6 were elevated in half of the overweight children. Adiponectin and IL-6 correlated well with traditional risk markers.

  18. Human retroviruses in Amerindians of Colombia: high prevalence of human T cell lymphotropic virus type II infection among the Tunebo Indians.

    Science.gov (United States)

    Duenas-Barajas, E; Bernal, J E; Vaught, D R; Nerurkar, V R; Sarmiento, P; Yanagihara, R; Gajdusek, D C

    1993-12-01

    The coexistence of infection with human T lymphotropic virus types I and II (HTLV-I and HTLV-II) has been demonstrated recently among the Wayuu Indians from the Guajira region of Colombia. To ascertain if other Indian groups in Colombia are similarly infected, we tested 1,250 sera, collected between 1990 and 1992 from 18 culturally distinct Amerindian tribes living in widely separated regions, for IgG antibodies against HTLV-I/II using enzyme-linked immunosorbent assay (ELISA) and Western blot. Sera were also tested for antibodies against human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) to investigate the overall burden of retrovirus infection in these semi-isolated indigenous groups. A total of 33 of the 1,250 samples were repeatedly reactive to HTLV-I/II antigens by ELISA, and of these, three sera from Waunana/Noanama Indians from the Choco area and two sera from Tunebo Indians from the Santander region were found to be infected with HTLV-I and HTLV-II, respectively, as verified by Western blot and differential ELISA. Thus, despite the small sample size, the overall seroprevalences for HTLV-I and HTLV-II infection among the Waunana/Noanama and Tunebo Indians were 2.1% and 5.0%, respectively. In contrast, none of the 29 Indians who exhibited reactivity to HIV-1/2 by ELISA were seropositive by Western blot. This study adds the Tunebo to the expanding list of Amerindian groups with high prevalences of HTLV-II infection. Further intensive investigations of such indigenous populations will clarify the natural history and disease potential of HTLV-II infection.

  19. Testing the efficacy of a brief sexual risk reduction intervention among high-risk American Indian adults: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Rachel Chambers

    2016-04-01

    Full Text Available Abstract Background American Indian adults are more likely to experience co-occurring mental health and substance use disorders than adults of other racial/ethnic groups and are disproportionately burdened by the most common sexually transmitted infections, namely chlamydia and gonorrhea. Several behavioral interventions are proven efficacious in lowering risk for sexually transmitted infection in various populations and, if adapted to address barriers experienced by American Indian adults who suffer from mental health and substance use problems, may be useful for dissemination in American Indian communities. The proposed study aims to examine the efficacy of an adapted evidence-based intervention to increase condom use and decrease sexual risk-taking and substance use among American Indian adults living in a reservation-based community in the Southwestern United States. Methods/Design The proposed study is a randomized controlled trial to test the efficacy of an adapted evidence-based intervention compared to a control condition. Participants will be American Indian adults ages 18–49 years old who had a recent episode of binge substance use and/or suicide ideation. Participants will be randomized to the intervention, a two-session risk-reduction counseling intervention or the control condition, optimized standard care. All participants will be offered a self-administered sexually transmitted infection test. Participants will complete assessments at baseline, 3 and 6 months follow-up. The primary outcome measure is condom use at last sex. Discussion This is one of the first randomized controlled trials to assess the efficacy of an adapted evidence-based intervention for reducing sexual risk behaviors among AI adults with substance use and mental health problems. If proven successful, there will be an efficacious program for reducing risk behaviors among high-risk adults that can be disseminated in American Indian communities as well as other

  20. Organic pollutants profiling of wood ashes from biomass power plants linked to the ash characteristics.

    Science.gov (United States)

    Rey-Salgueiro, Ledicia; Omil, Beatriz; Merino, Agustín; Martínez-Carballo, Elena; Simal-Gándara, Jesús

    2016-02-15

    Wood ash, characterized by high content of certain nutrients and charcoal, can be applied to soils as a means of managing this waste product improving the soil quality. The associated environmental risk must be assessed. The objective of this study was to characterize the bottom and fly ash collected from 15 biomass power plants in Spain by determining the benzene, toluene, ethylbenzene, xylene and styrene (BTEX+S), PAHs and aliphatic hydrocarbon contents of both types of ash. Biochar was also used for comparison purposes. Gas chromatography-mass spectrometric methods were used for the identification and determination of both BTEX+S and aliphatic hydrocarbon contents in bottom and fly ashes, as well as biochar. High performance liquid chromatography with fluorescence detection was used for PAHs measurements. Multivariate correlation analysis was used to determine the relationship between sample characteristics and pollutants identified by partial least squares regression analysis. In general, the degree to which organic matter in the sample is burned increases with T50 or the "50% burn off" temperature (possibly due to the addition of fuel), and the BTEX+S also tended to increase. However, as the Q/MO (the heat of combustion divided by organic matter mass) increased, the combustion decreased or proceeded with less oxygen, which appears to be related to an increased presence of PAHs. The results confirm that the amounts of organic pollutants (PAHs and BTEX+S, together with total aliphatic hydrocarbons) in the wood ash do not exceed limits established for different soil or industrial uses. Both types of ash, together with biochar, may therefore be suitable for application to soil as a fertilizer and an organic amendment, taking into account the target organic pollutants. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Evaluasi karakteristik abu sekam padi dengan kitosan molekul tinggi nanopartikel sebagai bahan dentinogenesis (Characteristic evaluation of rice husk ash with chitosan high molecule nanoparticle as dentinogenesis material

    Directory of Open Access Journals (Sweden)

    Pretty Farida Sinta Silalahi

    2014-06-01

    Full Text Available Background: Mineral trioxide aggregate (MTA and resin modified glass ionomer cement (RMGIC are the material used for indirect and direct pulp capping due to biocompatibility, but these materials have many shortcomings. Mineral trioxide aggregate contains a little amount of arsenic and has long setting time, while HEMA containing RMGIC are cytotoxic. Rice husk ash nanoparticles (RHAn is a potential source of silica. High molecular chitosan nanoparticles (HMCn can stimulate the formation of reparative dentin. Combination of these two materials is biocompatible and have good sealing ability. Purpose: This study was aimed to study RHAn + HMCn used as biomaterials for prevention of pulpodentinal complex by examined at the microstructure of dentin surfaces applied with RHAn + HMCn. Methods: Twenty-four mandibular premolar teeth extracted for orthodontic purposes, were made cavity class I preparation with 3 mm depth above the cemento-enamel junction (CEJ. Then each tooth was cut in bucco-lingual direction and each part was cut using a cervical disc bur. Samples were divided into 3 groups, group I the teeth were applied with MTA; group II the teeth were applied RMGIC; group III the teeth were apllied with RHAn + HMCn. Characterization was done by using Scanning Electron Microscopy (SEM on the interface between test material and dentin adjacent to the pulp to see surface microstructure. Results: Material microstructure of RHAn + HMCn applied to the dentine showed tags like structure which was more significant than MTA. RHAn + HMCn showed to have better sealing ability than MTA. Porosity of ASPn + HMCn was less than MTA and RMGIC. Conclusion: The study suggested that the combined RHAn + HMCn biomaterials could be used as an active biomaterial that can maintain the integrity of pulp dentinal complex.Latar belakang: Mineral trioksida agregat (MTA dan semen ionomer kaca modifikasi resin (SIKMR adalah bahan yang digunakan untuk pulp capping langsung dan tidak

  2. Ash contents of Costa Rican peat deposits

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, R. Jr.; Cohen, A.D.; Bish, D.L.

    1985-01-01

    Fourteen sites within 6 Costa Rican peat localities were sampled using MacCaulay samplers and soil augers. Sample localities included high mountain (>2500 meters), river floodplain, and Gulf coastal plain. Peat deposits ranged from as thin as 20 cm to greater than 460 cm. Within the peat deposits, ash (that material which will remain following combustion) occurs both dispersed within the peat layers and as layers containing nearly 100% inorganic material interstratified with the peat layers. Ash in Costa Rican peats includes material derived from both organic and inorganic origins. The predominant inorganically derived material is volcanic and may result from direct volcanic ashfall into the peat environment or as detritus transported into the peat areas. Volcanic ash is rapidly altered within the peats, leaving little if any relict structures. Alteration products are pedominantly kaolin and smectite clays and gibbsite. Unaltered minerals identified by x-ray diffraction include quartz, cristobalite, plagiolase feldspar, and anatase. Hematite and bassanite (identified by x-ray diffraction) are present but result from the alteration of iron-bearing minerals and organic sulfur or gypsum during sample preparation. Pyrite is present as a very minor component of some Costa Rican peats. Organically-derived ash constituents in Costa Rican peats include siliceous diatoms, siliceous sponge spicules, and silica phytoliths. The type and abundance of ash constituents within Costa Rican peats can be evaluated based on geographic location of the peat deposits, the geologic conditions affecting their deposition, and the plant communities existing during deposition. 6 refs., 11 figs., 3 tabs.

  3. Particles from combustion of fuel with high content of ash - Experimental study of reed canary grass and straw; Partiklar fraan foerbraenning av askrika braenslen - Experimentell studie paa roerflen och halm

    Energy Technology Data Exchange (ETDEWEB)

    Baefver, Linda; Ryde, Daniel

    2010-07-01

    Domestic combustion of solid fuels is, besides traffic and industry, a major source to particles in the air. Increased biomass combustion means a risk of contributing to high concentrations of particles with respect to the environmental goals. Particles are a health risk. The number of ultrafines and the content of the particles are considered crucial for the effects. Gradually, new solid biofuels with high ash content and different ash composition are used. This means an enhanced risk of high particle emission and a change in the formation of particles. The aim of the project is to contribute to the description of the mechanisms for formation of particles at combustion of biomass with high content of ash. The possibility to decrease the particle emission by the use of additives will be especially investigated. Thereby, problems with particle emissions, as well as formation of deposits may be minimized. The project contains two parts. The first one is about combustion of oat grain, and has already been reported. In this report the second part of the project is presented. Reed canary grass and straw were studied. To decrease the particle emission from combustion of straw, tests with straw and the additive kaolin (clay mineral) were also carried out. The fuels were pelletized and contained 4-5 % ash (dry fuel). Reed canary grass (perennial grass) was chosen because it is has potential and it has also been much studied in Sweden. Straw was chosen because it has high accessibility, and is already fired to a certain degree. Straw contained 2.6 times more chlorine than reed canary grass. Reed canary grass had Si as dominating ash element (79 %), and thereafter it contained K (6 %), Ca (6 %) and P (3 %). A good half of the straw ash contained Si and thereafter K (23 %) and Ca (15 %) were most abundant. The fuels were continuously fired in a multi-stoker from Sonnys Maskiner, connected to a boiler from Centrometal. The particles mass concentration was measured by sampling

  4. Root penetration of sealing layers made of fly ash and sewage sludge.

    Science.gov (United States)

    Neuschütz, Clara; Stoltz, Eva; Greger, Maria

    2006-01-01

    Fly ash and sewage sludge are suggested materials for constructing sealing layers covering mine tailings impoundments. Little is known, however, of their effect on vegetation or resistance to root penetration. We investigate: (i) the ability of different plant species to grow in sealing layers comprising fly ash and sewage sludge, (ii) the impact on plant growth of freshly hardened fly ash compared to aged and leached ash, and (iii) the plant stress response to fly ashes of different properties. A 6-mo greenhouse study using birch (Betula pendula Roth.), Scots pine (Pinus sylvestris L.), Kentucky bluegrass (Poa pratensis L.), and willow (Salix viminalis L.) demonstrated that no roots could grow into a compacted layer consisting only of ash, while a 6:4, ash-sludge mixture admitted roots into the upper part and a 1:9, ash-sludge mixture was totally penetrated (to 15 cm in depth) by roots of willow and Scots pine. Freshly hardened ash prevented root growth more effectively than aged ash did, as was observed in tests using reed canarygrass (Phalaris arundinacea L.) and pea (Pisum sativum L.). Furthermore, extracts of highly alkaline ash were more toxic to pea in a 48-h toxicity test than less alkaline ash was. However, stress responses to diluted ash extracts of lower pH, measured as enzyme capacities in dwarf bean (Phaseolus vulgaris L.), were more related to the metal and ion contents. Root penetration of sealing layers is most effectively prevented if little sewage sludge is added, and if ash of high alkalinity is chosen.

  5. The relation between pre-eruptive bubble size distribution, ash particle morphology, and their internal density: Implications to volcanic ash transport and dispersion models

    Science.gov (United States)

    Proussevitch, Alexander

    2014-05-01

    Parameterization of volcanic ash transport and dispersion (VATD) models strongly depends on particle morphology and their internal properties. Shape of ash particles affects terminal fall velocities (TFV) and, mostly, dispersion. Internal density combined with particle size has a very strong impact on TFV and ultimately on the rate of ash cloud thinning and particle sedimentation on the ground. Unlike other parameters, internal particle density cannot be measured directly because of the micron scale sizes of fine ash particles, but we demonstrate that it varies greatly depending on the particle size. Small simple type ash particles (fragments of bubble walls, 5-20 micron size) do not contain whole large magmatic bubbles inside and their internal density is almost the same as that of volcanic glass matrix. On the other side, the larger compound type ash particles (>40 microns for silicic fine ashes) always contain some bubbles or the whole spectra of bubble size distribution (BSD), i.e. bubbles of all sizes, bringing their internal density down as compared to simple ash. So, density of the larger ash particles is a function of the void fraction inside them (magmatic bubbles) which, in turn, is controlled by BSD. Volcanic ash is a product of the fragmentation of magmatic foam formed by pre-eruptive bubble population and characterized by BSD. The latter can now be measured from bubble imprints on ash particle surfaces using stereo-scanning electron microscopy (SSEM) and BubbleMaker software developed at UNH, or using traditional high-resolution X-Ray tomography. In this work we present the mathematical and statistical formulation for this problem connecting internal ash density with particle size and BSD, and demonstrate how the TFV of the ash population is affected by variation of particle density.

  6. Magmatic and fragmentation controls on volcanic ash surface chemistry

    Science.gov (United States)

    Ayris, Paul M.; Diplas, Spyros; Damby, David E.; Hornby, Adrian J.; Cimarelli, Corrado; Delmelle, Pierre; Scheu, Bettina; Dingwell, Donald B.

    2016-04-01

    partitioning effect, but crucially, disparities between surface and bulk chemistry remain evident. Simple glass-plagioclase mixing calculations suggest that this feature may indicate differences in bulk and surface mineral distributions; future QEMSCAN analysis will investigate this possibility further. Additionally, surface iron enrichments observed in our high temperature experiments suggest that hot oxidation effects can have a near-instantaneous, measurable effect on ash surface chemistry at the nanometre scale. Our preliminary results suggest that the chemical and mineral properties of the source magma, coupled with high temperature fragmentation processes, may have a significant influence on ash surface chemistry and mineralogy, and subsequently, on the post-eruptive alteration of ash particles and their reactivity within biotic and abiotic systems.

  7. Ash dispersal dynamics: state of the art and perspectives

    Science.gov (United States)

    Sulpizio, R.

    2013-05-01

    Volcanic ash, during dispersal and deposition, is among the major hazards from explosive eruptions. Volcanic ash fallout can disrupt communities downwind, interrupt surface transportation networks and lead to closure of airports. Airborne ash seriously threatens modern jet aircraft in flight. In several documented cases, encounters between aircraft and volcanic clouds have resulted in engine flameout and near crashes, so there is a need to accurately predict the trajectory of volcanic ash clouds in order to improve aviation safety and reduce economic losses. The ash clouds affect aviation even in distal regions, as demonstrated by several eruptions with far-range dispersal. Recent examples include Crater Peak 1992, Tungurahua 1999-2001, Mount Cleveland 2001, Chaitén 2008, Eyjafjallajökull 2010, Grimsvötn 2011, and Cordón-Caulle 2011. Amongst these, the April-May 2010 eruption of Eyjafjallajökull in Iceland provoked the largest civil aviation breakdown. Accumulation of tephra can produce roof collapse, interruption of lifelines (roads, railways, etc.), disruption to airport operations, and damage to communications and electrical power lines. Deposition of ash decreases soil permeability, increases surface runoff, and promotes floods. Ash leaching can result in the pollution of water resources, damage to agriculture, pastures, and livestock, impinge on aquatic ecosystems, and alteration of the geochemical environment on the seafloor. Despite the potential big impact, the dispersal dynamics of volcanic ash is still an unsolved problem for volcanologists, which claims for fiture high level research. Here, a critical overview about models (field, experimental and numerical) for inversion of field data to gain insights on physics of dispersal of volcanic ash is proposed. A special focus is devoted to some physical parameters that are far from a satisfactory inversion (e.g. reconstruction of total grain size distribution), and clues for future research are suggested.

  8. Mapping ash properties using principal components analysis

    Science.gov (United States)

    Pereira, Paulo; Brevik, Eric; Cerda, Artemi; Ubeda, Xavier; Novara, Agata; Francos, Marcos; Rodrigo-Comino, Jesus; Bogunovic, Igor; Khaledian, Yones

    2017-04-01

    In post-fire environments ash has important benefits for soils, such as protection and source of nutrients, crucial for vegetation recuperation (Jordan et al., 2016; Pereira et al., 2015a; 2016a,b). The thickness and distribution of ash are fundamental aspects for soil protection (Cerdà and Doerr, 2008; Pereira et al., 2015b) and the severity at which was produced is important for the type and amount of elements that is released in soil solution (Bodi et al., 2014). Ash is very mobile material, and it is important were it will be deposited. Until the first rainfalls are is very mobile. After it, bind in the soil surface and is harder to erode. Mapping ash properties in the immediate period after fire is complex, since it is constantly moving (Pereira et al., 2015b). However, is an important task, since according the amount and type of ash produced we can identify the degree of soil protection and the nutrients that will be dissolved. The objective of this work is to apply to map ash properties (CaCO3, pH, and select extractable elements) using a principal component analysis (PCA) in the immediate period after the fire. Four days after the fire we established a grid in a 9x27 m area and took ash samples every 3 meters for a total of 40 sampling points (Pereira et al., 2017). The PCA identified 5 different factors. Factor 1 identified high loadings in electrical conductivity, calcium, and magnesium and negative with aluminum and iron, while Factor 3 had high positive loadings in total phosphorous and silica. Factor 3 showed high positive loadings in sodium and potassium, factor 4 high negative loadings in CaCO3 and pH, and factor 5 high loadings in sodium and potassium. The experimental variograms of the extracted factors showed that the Gaussian model was the most precise to model factor 1, the linear to model factor 2 and the wave hole effect to model factor 3, 4 and 5. The maps produced confirm the patternd observed in the experimental variograms. Factor 1 and 2

  9. High resolution modeling of tropical cyclones-ocean interactions in the South-West Indian Ocean.

    Science.gov (United States)

    Chanut, J.; Samson, G.; Giordani, H.; Barbary, D.; Drillet, Y.

    2016-02-01

    The ocean surface can cool by several degrees during the passage of a tropical cyclone (TC) due to the extreme winds associated with. This cooling decreases the ocean-to-atmosphere heat and moisture supply which can modulate the TC intensity. Hence, atmospheric models need an accurate description of the sea surface temperature (SST) under TCs to correctly predict their intensities. This SST evolution and its feedback on the TC evolution can only be captured by ocean-atmosphere coupled models. In order to evaluate this potential benefit on TC forecasts in the South West Indian Ocean, Mercator-Ocean has developed a new coupled regional model based on the Meteo-France operational atmospheric model AROME and the NEMO ocean model. Exchanges between the two models are handled by the OASIS3 coupler. AROME is initialized and forced at its lateral boundaries with ALADIN 10km-resolution 6-hourly analysis and is integrated during 96 hours at 2.5km convective-resolving resolution. NEMO is initialized and forced with global 1/4° oceanic analyses performed weekly at Mercator-Ocean and is integrated at 1/12° eddy-resolving resolution. An ensemble of 25 coupled simulations and 25 atmospheric-only (forced) simulations based on 5 different TCs over the 2008-2013 seasons are then computed to explore the sensitivity of the TC hindcast to the SST. The ensemble is generated by varying the initial simulation time with a 6-hours step. A clear improvement of the SST evolution under the TCs is observed in the coupled simulations when compared to satellite data. This SST difference directly impacts turbulent latent and sensible heat fluxes spatial distribution and intensities, which lead to different intensification rates in the coupled and the forced simulations. The intensity hindcast mean error is significantly reduced in the coupled ensemble for hindcast ranges extending from 36h up to 96h. A statistical analysis confirms the robustness of this intensity hindcast improvement achieved

  10. Recirculation of biomass ashes onto forest soils: ash composition, mineralogy and leaching properties.

    Science.gov (United States)

    Maresca, A; Hyks, J; Astrup, T F

    2017-12-01

    In Denmark, increasing amounts of wood ashes are generated from biomass combustion for energy production. The utilisation of ashes on top of forest soil for liming purposes has been proposed asan alternative to landfilling. Danish wood ash samples were collected and characterised with respect to chemical composition, mineralogy and leaching properties (batch leaching at L/S 2 and 10L/kg, and pH-dependent leaching at 10L/kg). Large variations in the ash liming properties were observed (ANC7.5: 1.8-6.4meqH+/g), indicating that similar soil application dosages may result in different liming effects. High contents of Ca, Si, P, K and Mg were observed in all samples, while the highest contents of S and N were found in fly ashes and mixed ashes (combination of fly and bottom ashes). Similarly, the highest contents of some trace metals, e.g. Cd, Mo and Se, were observed for fly ash. Releases of major, minor and trace elements were affected significantly by pH: high releases of PO43-, Mg, Zn, Cu and Cd were found for acidic conditions relevant to forest soils, while the highest releases of Mo and Cr were observed in alkaline conditions. Mineral phases were selected based on XRD analyses and the existing literature, and they were applied as inputs for the geochemical modelling of pH-dependent leaching. Mineral dissolution was found adequate for a wide range of major elements and nutrients, while the description of trace elements could be done only for parts of the pH-range. Content and leaching of PAHs were observed below detection limits. The source-term release of Ca, K, Mg, Mn, and P in acidic conditions relevant to forest soils was higher than ten years of atmospheric deposition, in contrast to the relatively low release of Al, Fe and Na. The potential release of Cd was found to be the most critical element compared with soil quality criteria, whereas the maximum theoretical loads of Ba, Cd, Cr, Sr, Mo, Ni, Pb, Sb, Se, Sn and V were relatively low. Copyright © 2017

  11. Producing a synthetic zeolite from secondary coal fly ash.

    Science.gov (United States)

    Zhou, Chunyu; Yan, Chunjie; Zhou, Qi; Wang, Hongquan; Luo, Wenjun

    2016-11-01

    Secondary coal fly ash is known as a by-product produced by the extracting alumina industry from high-alumina fly ash, which is always considered to be solid waste. Zeolitization of secondary coal fly ash offers an opportunity to create value-added products from this industrial solid waste. The influence of synthesis parameters on zeolite NaA such as alkalinity, the molar ratio of SiO2/Al2O3, crystallization time and temperature was investigated in this paper. It was found that the types of synthetic zeolites produced were to be highly dependent on the conditions of the crystallization process. Calcium ion exchange capacity and whiteness measurements revealed that the synthesized product meets the standard for being used as detergent, indicating a promising use as a builder in detergent, ion-exchangers or selective adsorbents. Yield of up to a maximum of 1.54 g/g of ash was produced for zeolite NaA from the secondary coal fly ash residue. This result presents a potential use of the secondary coal fly ash to obtain a high value-added product by a cheap and alternative zeolitization procedure.

  12. Large-scale reintroduction of ash

    Science.gov (United States)

    Ronald. Overton

    2010-01-01

    No strategies currently exist for reintroducing ash; progression of emerald ash borer (EAB) through the eastern United States is likely to be a decades-long process, and extirpation of ash from this area is likely to take even longer. Reintroduction of ash into areas where it has been extirpated by EAB will require addressing technical issues as well as social and...

  13. 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)

  14. High temperatures influence sexual development differentially in male and female tadpoles of the Indian skipper frog, Euphlyctis cyanophlyctis.

    Science.gov (United States)

    Phuge, Samadhan Krushna

    2017-09-01

    Although sex determination in amphibians is believed to be a genetic process, environmental factors such as temperature are known to influence the sex differentiation and development. Extremely low and high temperatures influence gonadal development and sex ratio in amphibians but the mechanism of action is not known. In the present study, effect of different temperatures on gonadal development, sex ratio and metamorphosis was studied in the Indian skipper frog, Euphlyctis cyanophlyctis. The embryos of Gosner stage 7 were exposed to 20, 22, 24, 26, 28, 30 and 32 degrees C up to tadpole stage 42. The embryos (stage 7) were also exposed to 20 and 32 degrees C up to tadpole stage 25 (non-feeding stages). Tadpoles of stage 25 were reared at 20 and 32 degrees C up to stage 42 (feeding stages). The results show that exposure to higher temperatures (28, 30 and 32 degrees C) during stages 7-42 produced male-biased sex ratio. Rearing of tadpoles at 32 degrees C during stages 25-42 produced malebiased sex ratio, while exposure during stages 7-25 did not affect sex ratio. Embryos and tadpoles exposed to lower temperatures (20 and 22 degrees C) died during the early stages. High temperatures stimulated testis development, and disturbed ovary development. Exposure to high temperatures resulted in the early metamorphosis of tadpoles with reduced body size. These results demonstrated that high temperatures influence gonadal development differently in male and female tadpoles, leading to male-biased sex ratio. These results suggest that high temperature probably acts through stress hormones and favours the small-sized sex.

  15. Breast-feeding Duration, Age of Starting Solids, and High BMI Risk and Adiposity in Indian Children

    Science.gov (United States)

    2011-01-01

    This study utilized data from a prospective birth cohort study on 568 Indian children, to determine whether a longer duration of breast-feeding and later introduction of solid feeding was associated with a reduced higher body mass index (BMI) and less adiposity. Main outcomes were high BMI (>90th within-cohort sex-specific BMI percentile) and sum of skinfold thickness (triceps and subscapular) at age 5. Main exposures were breast-feeding (6 categories from 1-4 to ≥21 months) and age of starting regular solid feeding (4 categories from ≤3 to ≥6 months). Data on infant feeding practices, socioeconomic and maternal factors were collected by questionnaire. Birthweight, maternal and child anthropometry were measured. Multiple regression analysis which accounted for potential confounders, demonstrated a small magnitude of effect for breast-feeding duration or introduction of solid feeds on the risk of high BMI but not for lower skinfold thickness. Breast-feeding duration was strongly negatively associated with weight gain (0-2 years) (adjusted β= −0.12 SD 95% CI: −0.19 to −0.05 per category change in breast-feeding duration, p=0.001) and weight gain (0-2 years) was strongly associated with high BMI at 5 years (adjusted OR = 3.8, 95 % CI: 2.53 to 5.56, pbreast-feeding duration and later introduction of solids has a small reduction on later high BMI risk and a negligible effect on skinfold thickness. However, accounting for sampling variability, these findings cannot exclude the possibility of no effect at the population-level. PMID:21978208

  16. Final base case community analysis: Indian Springs, Nevada for the Clark County socioeconomic impact assessment of the proposed high- level nuclear waste repository at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-06-18

    This document provides a base case description of the rural Clark County community of Indian Springs in anticipation of change associated with the proposed high-level nuclear waste repository at Yucca Mountain. As the community closest to the proposed site, Indian Springs may be seen by site characterization workers, as well as workers associated with later repository phases, as a logical place to live. This report develops and updates information relating to a broad spectrum of socioeconomic variables, thereby providing a `snapshot` or `base case` look at Indian Springs in early 1992. With this as a background, future repository-related developments may be analytically separated from changes brought about by other factors, thus allowing for the assessment of the magnitude of local changes associated with the proposed repository. Given the size of the community, changes that may be considered small in an absolute sense may have relatively large impacts at the local level. Indian Springs is, in many respects, a unique community and a community of contrasts. An unincorporated town, it is a small yet important enclave of workers on large federal projects and home to employees of small- scale businesses and services. It is a rural community, but it is also close to the urbanized Las Vega Valley. It is a desert community, but has good water resources. It is on flat terrain, but it is located within 20 miles of the tallest mountains in Nevada. It is a town in which various interest groups diverge on issues of local importance, but in a sense of community remains an important feature of life. Finally, it has a sociodemographic history of both surface transience and underlying stability. If local land becomes available, Indian Springs has some room for growth but must first consider the historical effects of growth on the town and its desired direction for the future.

  17. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

    for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition......The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...

  18. 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...

  19. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

    of the ashes complied with Danish ash quality criteria, indicating that they may be applied onto forest soil. However, according to EU landfill waste acceptance criteria, the leachates corresponded to “non-hazardous” or “hazardous” waste, thereby suggesting that recirculation of the same ashes to forestry land...... to fewer than two years on the field scale). While an overall increase in the leached amounts of As and Cu from the organic soil horizon were observed in the case of ash application (from 2.2 to 5.0-5.8 mg/m2 for As and from 2.0 to 4.9-7.6 mg/m2 for Cu), their concentration levels in the percolating soil...

  20. Utilization of power plant bottom ash as aggregates in fiber-reinforced cellular concrete.

    Science.gov (United States)

    Lee, H K; Kim, H K; Hwang, E A

    2010-02-01

    Recently, millions tons of bottom ash wastes from thermoelectric power plants have been disposed of in landfills and coastal areas, regardless of its recycling possibility in construction fields. Fiber-reinforced cellular concrete (FRCC) of low density and of high strength may be attainable through the addition of bottom ash due to its relatively high strength. This paper focuses on evaluating the feasibility of utilizing bottom ash of thermoelectric power plant wastes as aggregates in FRCC. The flow characteristics of cement mortar with bottom ash aggregates and the effect of aggregate type and size on concrete density and compressive strength were investigated. In addition, the effects of adding steel and polypropylene fibers for improving the strength of concrete were also investigated. The results from this study suggest that bottom ash can be applied as a construction material which may not only improve the compressive strength of FRCC significantly but also reduce problems related to bottom ash waste.

  1. 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.)

  2. Spreading dynamic of viscous volcanic ash in stimulated jet engine conditions

    Science.gov (United States)

    song, wenjia; Lavallée, Yan; Hess, Kai-Uwe; Kueppers, Ulrich; Cimarelli, Corrado

    2016-04-01

    The ingestion of volcanic ash is widely recognised as a potentially fatal hazard for aircraft operation. The volcanic ash deposition process in a jet turbine is potentially complex. Volcanic ash in the air stream enters the inner liners of the combustors and partially or completely melts under the flames up to 2000 °C, at which point part of the ash deposits in the combustor fuel nozzle. Molten volcanic particles within high energy airflow escape the combustor to enter the turbine and impact the stationary (e.g., inlet nozzle guide vanes) and rotating airfoils (e.g., first stage high-pressure turbine blades) at high speed (up to Mach 1.25) in different directions, with the result that ash may stick, flow and remain liquid or solidify. Thus, the wetting behaviour of molten volcanic ash particle is fundamental to investigate impingement phenomena of ash droplet on the surface of real jet engine operation. The topic of wetting has received tremendous interest from both fundamental and applied points of view. However, due to the interdisciplinary gap between jet engine engineering and geology science, explicit investigation of wetting behaviour of volcanic ash at high temperature is in its infancy. We have taken a big step towards meeting this challenge. Here, we experimentally and theoretically investigate the wetting behaviour of viscous volcanic ash over a wide temperature range from 1100 to 1550 °C using an improved sessile-drop method. The results of our experiment demonstrate that temperature and viscosity play a critical role in determining the wetting possibility and governing the spreading kinetics of volcanic ash at high temperatures. Our systemic analysis of spreading of molten volcanic ash systems allows us to report on the fundamental differences between the mechanisms controlling spreading of organic liquids at room temperature and molten volcanic ash droplets.

  3. Suspension-firing of wood with coal ash addition: Probe measurements of ash deposit build-up at Avedøre Power Plant (AVV2)

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Jappe Frandsen, Flemming

    This report is about full-scale probe measurements of deposit build-up and removal conducted at the Avedøreværket Unit 2, a 800 MWth suspension boiler, firing wood and natural gas with the addition of coal ash. Coal ash was used as an additive to capture potassium (K) from wood-firing. Investigat......This report is about full-scale probe measurements of deposit build-up and removal conducted at the Avedøreværket Unit 2, a 800 MWth suspension boiler, firing wood and natural gas with the addition of coal ash. Coal ash was used as an additive to capture potassium (K) from wood......-firing. Investigations of deposit formation rate were made by use of an advanced online ash deposition/shedding probe. Quantification of ash deposition and shedding was made via deposit mass uptake signals obtained from the deposit probe. The influence of coal ash, flue gas temperature, probe surface temperature...... and boiler load on ash deposition propensity was investigated. Results of ash deposition propensity showed increasing trend with increasing flue gas temperature. Video monitoring revealed that the deposits formed were not sticky and could be easily removed, and even at very high flue gas temperatures (> 1350...

  4. Stabilize ash using Clemson`s sintering process (Part 1 -- Phase 1 results): Mixed waste fly ash stabilization. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    1998-12-01

    Incineration of applicable Department of Energy (DOE) mixed wastes has produced a secondary waste stream of radioactive and Resource Conservation and Recovery Act (RCRA) hazardous fly ash that also requires treatment before land disposal. Unlike bottom ash, fly ash usually contains constituents making efficient stabilization difficult. For example, fly ash from the DOE Waste Experimental Reduction Facility (WERF) incinerator at the Idaho National Engineering and Environmental Laboratory (INEEL) contains volatile metals, metal salts, high concentrations of zinc, and unburned organic residues. All of these constituents can effect the stabilization process. The Department of Energy, and in particular the Mixed Waste Focus Area (MWFA) of EM-50, has stated the need for improved stabilization methods would accept a higher ash waste loading while meeting waste form disposal criteria. These alternative stabilization technologies should include delivery systems to minimize worker exposure and minimize secondary waste generation, while maximizing operational flexibility and radionuclide containment. Currently, the standard practice for stabilizing ash is mixing with Portland cement at room temperature. This standard practice produces a significant increase of waste material volume or has difficulty in adequately stabilizing the components in the fly ash to ensure regulatory requirements are consistently satisfied. To address these fly ash stabilization shortcomings, the MWFA, a DOE/EM-50 program, invested in the development of several fly ash stabilization alternatives, including the Clemson University sintering method.

  5. Evaluation of the Biotoxicity of Tree Wood Ashes in Zebrafish Embryos.

    Science.gov (United States)

    Consigli, Veronica; Guarienti, Michela; Bilo, Fabjola; Benassi, Laura; Depero, Laura E; Bontempi, Elza; Presta, Marco

    2016-10-01

    Ashes derived from biomass combustion and used as soil fertilizers can generate negative environmental and human health risks, related to leaching of heavy metals and other putative toxic elements. Tree wood ash composition may vary depending on geographical location and surrounding industrial processes. In this study, we evaluated the biotoxicity of lixiviated tree wood ash samples from trees of the Ash (Fraxinus), Cherry (Pronus), Hazel (Corylus), and Black locust (Robinia) genus collected in an industrialized region in Northern Italy. Elemental chemical analysis of the samples was performed by total reflection X-ray fluorescence technique and their biotoxicity was assessed in zebrafish (Danio rerio) embryos. Ashes from Ash, Cherry, and Hazel trees, but not Black locust trees, had a high concentration of heavy metals and other putative toxic elements. Accordingly, a dose-dependent increase in mortality rate and morphological and teratogenic defects was observed in zebrafish embryos treated with lixiviated Ash, Cherry, and Hazel tree wood samples, whereas the toxicity of Black locust tree wood ashes was negligible. In conclusion, lixiviated wood ashes from different plants show a different content of toxic elements that correlate with their biotoxic effects on zebrafish embryos. Tree wood ashes derived from biomass combustion may represent a potential risk for the environment and human health.

  6. Can pore-clogging by ash explain post-fire runoff?

    Science.gov (United States)

    Stoof, Cathelijne R.; Gevaert, Anouk I.; Baver, Christine; Hassanpour, Bahareh; Morales, Veronica L.; Zhang, Wei; Martin, Deborah; Giri, Shree K.; Steenhuis, Tammo S.

    2016-01-01

    Ash plays an important role in controlling runoff and erosion processes after wildfire and has frequently been hypothesised to clog soil pores and reduce infiltration. Yet evidence for clogging is incomplete, as research has focussed on identifying the presence of ash in soil; the actual flow processes remain unknown. We conducted laboratory infiltration experiments coupled with microscope observations in pure sands, saturated hydraulic conductivity analysis, and interaction energy calculations, to test whether ash can clog pores (i.e. block pores such that infiltration is hampered and ponding occurs). Although results confirmed previous observations of ash washing into pores, clogging was not observed in the pure sands tested, nor were conditions found for which this does occur. Clogging by means of strong attachment of ash to sand was deemed unlikely given the negative surface charge of the two materials. Ponding due to washing in of ash was also considered improbable given the high saturated conductivity of pure ash and ash–sand mixtures. This first mechanistic step towards analysing ash transport and attachment processes in field soils therefore suggests that pore clogging by ash is unlikely to occur in sands. Discussion is provided on other mechanisms by which ash can affect post-fire hydrology.

  7. Differences in perceptions and fast food eating behaviours between Indians living in high- and low-income neighbourhoods of Chandigarh, India

    OpenAIRE

    Aloia Christopher Robert; Gasevic Danijela; Yusuf Salim; Teo Koon; Chockalingam Arun; Patro Binod Kumar; Kumar Rajesh; Lear Scott Alexander

    2013-01-01

    Abstract Background Increased density of fast food restaurants is associated with increased prevalence of obesity in developed countries. However, less is known about this relationship in developing countries undergoing rapid urbanization and how differences in neighbourhood income affect the patronage of fast food outlets. The purpose of the study is to explore the differences in fast food preferences, perceptions, and patronage between Indians living in high- and low-income neighbourhoods. ...

  8. Phenolic acids as bioindicators of fly ash deposit revegetation.

    Science.gov (United States)

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

    2006-05-01

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

  9. Concentration of heavy metals in ash produced from Lithuanian forests

    Science.gov (United States)

    Baltrenaite, Edita; Pereira, Paulo; Butkus, Donatas; Úbeda, Xavier

    2010-05-01

    Wood ash contains important amounts of heavy metals. This quantity depends on burned specie, temperature of exposition and heat duration time. Due the high mineralization imposed by the temperatures, ash is used as lime product in agriculture and forests. Also, after a forest fire large quantities of ash are produced and distributed in soil surface. This mineralized organic matter can induce important environmental problems, including soil toxicity provoked by heavy metals leachates from ash. There is an extensive literature about heavy metals contents on ash in different species. However, it recently highlighted that the same species placed in different environments can respond diversely to same temperatures. This question is of major importance because temperature effects on severity can be a function of the plant communities instead of specie characteristics. These findings add a higher degree of complexity in the understanding of temperature effects on ash composition and consequent availability of heavy metals. The aim of this study is to compare the ash chemical heavy metal composition, Cobalt (Co), Chromium (Cr), Cooper (Cu), Silver (Ag), Lead (Pb), Nickel (Ni), Manganese (Mn) and Zinc (Zn), from Pinus sylvestris and Betula pendula, collected in key and representative areas of Lithuanian forests, located in southern, coastal and central part. Samples were collected from alive trees, taken to laboratory and air dried. Subsequently were crushed and submitted to muffle furnace at temperature of 550°C during two hours. The ash samples were digested and in a HNO3-HCl solution and then analysed with AAS. Comparisons between species and sites were performed with a Non-parametric one-way ANOVA‘s on rank transformed data followed by Tukey‘s HSD, significant at a pcommunication.

  10. KINETICS OF FLY ASH BENEFICIATION BY CARBON BURNOUT

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Joseph N.D. Dodoo; Dr. Joseph M. Okoh

    2000-11-01

    Surface area analyses performed on fly ash samples reveal that the surface area is controlled by carbon content. The higher surface areas found in large particles are due to the presence of highly porous carbonaceous particles. Adsorption-desorption isotherms and t-plots of fly ash samples indicate that fly ash is porous. BJH Adsorption/Desorption pore size analysis reveal that pore diameters are independent of sieve size. They appear to be dependent only on the nature of the material which confers porosity. Based on the results of Brown and Dykstra (41) it is reasonable to assume that calculations of reaction rates at temperatures above 550 C were confounded by weight losses from processes other than carbon oxidation and, therefore, are not useful in determination of the temperature dependence of carbon oxidation in fly ash. The results of the present study indicate that temperatures below 550 C should be used for future studies in order to satisfactorily assess the temperature dependence of carbon oxidation in fly ash. Furthermore, it is also advisable that percent carbon determinations be performed on fly ash samples after the oxidation reactions to determine whether all carbon present in fly ash is oxidized. This will ensure that reaction rates are representative of the complete oxidation of carbon. An inverse relationship was determined between reaction rates and oxygen concentration for this study. As discussed, this may be due to volatilization of volatiles from fly ash and ease of transport of products away from the reaction sites by the action of the vacuum applied to the samples. A more accurate determination of oxygen dependence of carbon oxidation can be accomplished by the use of specialty gases containing different concentrations of oxygen which could eliminate the need to apply vacuum to the samples.

  11. Illinois basin coal fly ashes. 2. Equilibria relationships and qualitative modeling of ash-water reactions

    Science.gov (United States)

    Roy, W.R.; Griffin, R.A.

    1984-01-01

    Alkaline and acidic Illinois Basin coal fly ash samples were each mixed with deionized water and equilibrated for about 140 days to simulate ash ponding environments. Common to both equilibrated solutions, anhydrite solubility dominated Ca2+ activities, and Al3+ activities were in equilibrium with both matrix mullite and insoluble aluminum hydroxide phases. Aqueous silica activities were controlled by both mullite and matrix silicates. The pH of the extract of the acidic fly ash was 4.1 after 24 h but increased to a pH value of 6.4 as the H2SO4, assumed to be adsorbed to the particle surfaces, was exhausted by the dissolution of matrix iron oxides and aluminosilicates. The activities of aqueous Al3+ and iron, initially at high levels during the early stages of equilibration, decreased to below analytical detection limits as the result of the formation of insoluble Fe and Al hydroxide phases. The pH of the extract of the alkaline fly ash remained above a pH value of 10 during the entire equilibration interval as a result of the hydrolysis of matrix oxides. As with the acidic system, Al3+ activities were controlled by amorphous aluminum hydroxide phases that began to form after about 7 days of equilibration. The proposed mechanisms and their interrelations are discussed in addition to the solubility diagrams used to deduce these relationships. ?? 1984 American Chemical Society.

  12. ZEOLITIZATION OF SEWAGE SLUDGE ASH WITH A FUSION METHOD

    Directory of Open Access Journals (Sweden)

    Jolanta Latosińska

    2016-11-01

    Full Text Available The study shows the results of zeolitization of municipal sewage sludge ash with the indirect fusion method followed by a hydrothermal method. The zeolitization of sewage sludge ash was conducted at the melting temperature of 550°C and the melting time of 60 minutes, crystallization temperatures of 60°C and 90°C, crystallization time of 6 hours and the SSA:NaOH ratio of 1:1.8; 1:1.4. The research of modified sewage sludge ashes included the observation of changes of ash particles surface and the identification of crystalized phases. The zeolitization of sewage sludge ash at the ratio of SSA:NaOH 1.0:1.4 did not cause the formation of zeolite phases. On the other hand, the zeolitization at the ratio of SSA:NaOH 1.0:1.8 resulted in the formation of desired zeolite phases such as zeolite Y (faujasite and hydroxysodalite. The presented method of sewage sludge ash zeolitization allows to obtain highly usable material. Synthesized zeolites may be used as adsorbents and ion exchangers. They can be potentially used to remove heavy metals as well as ammonia from water and wastewater.

  13. Study on solidification for municipal solid waste incineration fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Lu, C.; Liu, Q.; Yang, J.; Xi, W. [Chongqing Univ., Chongqing (China); Huang, B. [Southwest Petroleum Univ., Chengdu (China)

    2008-07-01

    The appropriate management of municipal solid waste (MSW) is a major environmental issues, despite the significant efforts to prevent, reduce, reuse and recycle waste. Two primary options can be used for managing MSW incineration fly ash. These are landfill disposal or incineration. Incineration is effective in toxic substance destruction, waste volume reduction and energy recovery, as compared with landfill. MSW fly ash generally contains higher content of easily leachable heavy metals such as lead, cadmium, and zinc. In China, source separation of municipal solid wastes is not well practiced and has resulted in high concentrations of heavy metals being detected in the MSW fly ash. This paper presented a preliminary study to examine the properties of MSW fly ash and the fixing abilities of ordinary Portland cement and hydrated time on heavy metals. The paper discussed the effects of experimental parameters on the properties of solidified fly ash and the optimal technology conditions. The fly ash used in the study was collected from solid waste incineration plants in Shenzhen, Shanghai, and Chongqing, China. It was concluded that the effect on solidification got better and the leaching quantities of heavy metals such as zinc, lead, cadmium, or chromium decreased with the addition of cement used as adhesive. The optimal proportion of cement was 8 per cent. 14 refs., 5 tabs., 2 figs.

  14. Ash Reduction of Corn Stover by Mild Hydrothermal Preprocessing

    Energy Technology Data Exchange (ETDEWEB)

    M. Toufiq Reza; Rachel Emerson; M. Helal Uddin; Garold Gresham; Charles J. Coronella

    2014-04-22

    Lignocellulosic biomass such as corn stover can contain high ash content, which may act as an inhibitor in downstream conversion processes. Most of the structural ash in biomass is located in the cross-linked structure of lignin, which is mildly reactive in basic solutions. Four organic acids (formic, oxalic, tartaric, and citric) were evaluated for effectiveness in ash reduction, with limited success. Because of sodium citrate’s chelating and basic characteristics, it is effective in ash removal. More than 75 % of structural and 85 % of whole ash was removed from the biomass by treatment with 0.1 g of sodium citrate per gram of biomass at 130 °C and 2.7 bar. FTIR, fiber analysis, and chemical analyses show that cellulose and hemicellulose were unaffected by the treatment. ICP–AES showed that all inorganics measured were reduced within the biomass feedstock, except sodium due to the addition of Na through the treatment. Sodium citrate addition to the preconversion process of corn stover is an effective way to reduced physiological ash content of the feedstock without negatively impacting carbohydrate and lignin content.

  15. Seeding effect on cocomposting wastewater biosolids with coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Fang, M.; Wong, J.W.C. [Hong Kong Baptist University, Hong Kong (China). Dept. of Biology

    2001-10-01

    The seeding effect on fly ash-amended biosolids composting was evaluated by inoculating a mixture of ash and biosolids with seeding materials before composting. These inocula included thermophilic bacteria (Bacillus. brevis, B. coagulans, and B. licheniformis) isolated from the ash-biosolids compost, a commercial decomposter, and recycled biosolids compost. Although the addition of these microbial additives to the ash-biosolids compost improved the population of thermophilic bacteria at the early stage of composting, the improvement was negligible after 4 days of composting. Inoculation with isolated bacterial culture, milk powder, or the decomposter, only, did not effectively improve the decomposition of organic matter compared with those receiving inoculation of both microbial additives and milk powder together. The isolated Bacillus species was as efficient as the commercial decomposter in accelerating the decomposition rate during ash-amended biosolids composting as indicated by the high amounts of carbon dioxide evolved and cumulative weight loss. Taking into consideration the lower operating cost and acceptable decomposition efficiency, recycled biosolids compost seemed to be a promising additive to ash-amended biosolids compost to improve composting efficiency.

  16. Unraveling the complex magma dynamics during the Eyjafjallajökull 2010 eruption by high-resolution geochemistry of volcanic ash

    Science.gov (United States)

    Laeger, K.; Petrelli, M.; Andronico, D.; Misiti, V.; Scarlato, P.; Cimarelli, C.; Taddeucci, J.; Perugini, D.

    2016-12-01

    The April-May 2010 eruption of Eyjafjallajökull (Iceland) volcano was characterized by a change in eruptive style and a large compositional variability of erupted products. Lava deposits of the initial phase consist of evolved Fe-Ti-basalt ( 47 wt% SiO2), whereas fallout deposits of the explosive phases are characterized by a wider compositional spread. We present new EMPA and LA-ICP-MS analyses on groundmass glasses of ash particles erupted between May 18th and 22nd in 2010, i.e. the last days of the eruption. The glasses define two well-separated groups; a basalt composition ranging from 49.98 to 51.76wt% SiO2 and a second group of trachyandesitic and rhyolitic compositions between 57.13 and 70.38 wt% SiO2. Introduction of basalt to a resident silicic melt increased that compositional diversity in the chamber. The ash particles contain plagioclase (An81-10), clinopyroxene (Mg#=0.44-0.71), olivine (Fo83-42) and magnetite. Several plagioclase and clinopyroxene crystals exhibit resorbed cores and rims suggesting disequilibrium caused by recharge of a hotter magma. Additionally, certain clinopyroxene reveals reverse zoning (core: Mg# = 0.53-0.60, rim: Mg# = 0.59-0.71) what can be taken as evidence for mixing between a younger, less evolved magma, and one with a more evolved composition. Here, we unravel the genesis of the compositional variance using petrological, mineralogical and geochemical implications. Magma mixing modeling and element concentration frequency diagrams indicate that incomplete magma mixing between a trachyandesite magma and a trachyte-rhyolite component is the probable main process forming the great compositional variability observed in the erupted products. The rhyolite composition probably represents the residual melt of the AD 1821-23 eruption of Eyjafjallajökull. We suggest that different magmas generated and emplaced separately prior to the eruption have been mobilized by a new intrusion in 2010, and have mingled and mixed with each other

  17. On the visibility of airborne volcanic ash and mineral dust

    Science.gov (United States)

    Weinzierl, B.; Sauer, D. N.; Minikin, A.; Reitebuch, O.; Dahlkötter, F.; Mayer, B. C.; Emde, C.; Tegen, I.; Gasteiger, J.; Petzold, A.; Veira, A.; Kueppers, U.; Schumann, U.

    2012-12-01

    aerosol layer and the background, the illumination, the particle size distribution and mass concentration, the wavelength-dependent light scattering and absorption by the aerosol layer, the human perception, etc. In addition, the optical depth along the line of sight through an aerosol layer is more important than just the (vertical) optical depth, which is measured, for example, by sun photometers or satellites. The results of our study are in particular interesting for the question on the visibility of volcanic ash. Our analyses of "visible ash" demonstrate that under clear sky conditions volcanic ash is visible already at concentrations far below what is currently considered as the upper limit for safe operation of an aircraft engine (2 mg m-3). The presence of a grayish-brown layer in the atmosphere does not unambiguously indicate the presence of volcanic ash. An uninformed observer is unlikely to identify an aged volcanic ash layer in his field of view without further information. The presence of clouds would make it even more complicated to visually detect volcanic ash. In regions with high background aerosol loading in the atmosphere from natural or anthropogenic influences, such as seen in large parts of Asia, the visual detection of volcanic ash as an additional contaminant will be substantially more difficult.

  18. Life courses of highly skilled Indian migrants in the Netherlands and the United Kingdom

    NARCIS (Netherlands)

    Kou, Anu

    2016-01-01

    Many developed countries have adopted policies that facilitate and regulate the immigration of highly skilled migrants as a partial remedy against short-term frictions on the labour market caused by an ageing population. Migration regulations, however, often lack the recognition that migration is a

  19. The American Indian High School Dropout Rate: A Matter of Style?

    Science.gov (United States)

    Backes, John S.

    1993-01-01

    The Gregorc Style Delineator was administered to 358 graduates and dropouts from 2 matched, racially homogeneous white and Chippewa high schools in Minnesota. Dominant learning styles were abstract random for all Chippewa subjects and concrete sequential for all whites. No significant differences were found between Chippewa graduates and dropouts.…

  20. Ash storms: impacts of wind-remobilised volcanic ash on rural communities and agriculture following the 1991 Hudson eruption, southern Patagonia, Chile

    Science.gov (United States)

    Wilson, T. M.; Cole, J. W.; Stewart, C.; Cronin, S. J.; Johnston, D. M.

    2011-04-01

    Tephra fall from the August 1991 eruption of Volcán Hudson affected some 100,000 km2 of Patagonia and was almost immediately reworked by strong winds, creating billowing clouds of remobilised ash, or `ash storms'. The immediate impacts on agriculture and rural communities were severe, but were then greatly exacerbated by continuing ash storms. This paper describes the findings of a 3-week study tour of the diverse environments of southern Patagonia affected by ash storms, with an emphasis on determining the impacts of repeated ash storms on agriculture and local practices that were developed in an attempt to mitigate these impacts. Ash storms produce similar effects to initial tephra eruptions, prolonged for considerable periods. These have included the burial of farmland under dune deposits, abrasion of vegetation and contamination of feed supplies with fine ash. These impacts can then cause problems for grazing animals such as starvation, severe tooth abrasion, gastrointestinal problems, corneal abrasion and blindness, and exhaustion if sheep fleeces become laden with ash. In addition, ash storms have led to exacerbated soil erosion, human health impacts, increased cleanup requirements, sedimentation in irrigation canals, and disruption of aviation and land transport. Ash deposits were naturally stabilised most rapidly in areas with high rainfall (>1,500 mm/year) through compaction and enhanced vegetation growth. Stabilisation was slowest in windy, semi-arid regions. Destruction of vegetation and suppression of regrowth by heavy tephra fall (>100 mm) hindered the stabilisation of deposits for years, and reduced the surface friction which increased wind erosivity. Stabilisation of tephra deposits was improved by intensive tillage, use of windbreaks and where there was dense and taller vegetative cover. Long-term drought and the impracticality of mixing ash deposits with soil by tillage on large farms was a barrier to stabilising deposits and, in turn

  1. Engineering Behavior and Characteristics of Wood Ash and Sugarcane Bagasse Ash

    National Research Council Canada - National Science Library

    Francisco Grau; Hyunwook Choo; Jong Wan Hu; Jongwon Jung

    2015-01-01

    .... Plenty of biomasses are produced nationwide. Biomasses are mostly combusted and usually discarded or disposed of without treatment as biomass ashes, which include wood and sugarcane bagasse ashes...

  2. Preliminary safety and efficacy results with robotic high-intensity focused ultrasound : A single center Indian experience

    Directory of Open Access Journals (Sweden)

    Shashikant Mishra

    2011-01-01

    Full Text Available Background : There are no Indian data of high-intensity focused ultrasound (HIFU. Being an alternative, still experimental modality, reporting short-term safety outcome is paramount. Aims : This study was aimed at to assess the safety and short-term outcome in patients with prostate cancer treated by HIFU. Settings and Design : A retrospective study of case records of 30 patients undergoing HIFU between January 2008 to September 2010 was designed and conducted. Materials and Methods : The procedural safety was analyzed at 3 months. Follow-up consisted of 3 monthly prostate-specific antigen (PSA levels and transrectal biopsy if indicated. All the patients had a minimum follow-up of 6 months. Results : A mean prostate volume of 26.9 ± 8.5 cm 3 was treated in a mean time of 115 ± 37.4 min. There was no intraoperative complication. The postoperative pain visual analogue score at day 0 was 2.1 ± 1.9 and at day 1 was 0.4 ± 0.8 on a scale of 1-10. Mean duration of perurethral catheter removal was 3.9 days. The complications after treatment were: LUTS in seven patients, stress incontinence in two, stricture in two, and symptomatic urinary tract infection in five. Average follow-up duration was 10.4 months (range, 6-20 months. Mean time to obtain PSA nadir was 6 ± 3 months with a median PSA nadir value of 0.3 ng/ml. Two patients had positive prostatic biopsy in the localized (high risk group. Conclusions : HIFU was safe in carcinoma prostate patients. The short-term results were efficacious in localized disease. The low complication rates and favorable functional outcome support the planning of further larger studies.

  3. Study on the valorization routes of ashes from thermoelectric power plants working under mono-and co-combustion regimes

    Science.gov (United States)

    Barbosa, Rui Pedro Fernandes

    The main objective of this thesis was to study new valorization routes of ashes produced in combustion and co-combustion processes. Three main valorization pathways were analyzed: (i)production of cement mortars, (ii) production of concretes, and (iii) use as chemical agents to remove contaminants from wastewaters. Firstly, the ashes produced during the mono-combustion of coal, co-combustion of coal and meat and bone meal (MBM), and mono-combustion of MBM were characterized. The aim of this study was to understand the ashes properties in extreme levels of substitution of coal by a residue with a high contamination of specific metals. The substitution of coal by MBM produced ashes with higher content of heavy metals. Secondly, the ashes coming from an industrial power plant working under mono-combustion(coal) and co-combustion conditions (coal+sewage sludge+MBM) were studied. The use of cofuels did not promote significant changes in the chemical and ecotoxicological properties of ashes. Fly ashes were successfully stabilized/solidified in cement mortar, and bottom and circulating ashes were successfully used as raw materials in concrete. The third step involved the characterization and valorization of biomass ashes resulting from the combustion of forestry residues. The highest concentrations of metals/metalloids were found in the lowest particle size fractions of ashes. Biomass ashes successfully substituted cement and natural aggregates in concretes, without compromising their mechanical, chemical, and ecotoxicological properties. Finally, the biomass ashes were tested as chemical agents to remove contaminants from wastewaters. The removal of P, mainly phosphates, and Pb from wastewaters was assayed. Biomass ashes presented a high capacity to remove phosphates. As fly ashes were more efficient in removing phosphates, they were further used to remove Pb from wastewaters. Again, they presented a high efficiency in Pb removal. New potential valorization routes for

  4. Assessing the potential of coal ash and bagasse ash as inorganic amendments during composting of municipal solid wastes.

    Science.gov (United States)

    Mohee, Romeela; Boojhawon, Anuksha; Sewhoo, Babita; Rungasamy, Selven; Somaroo, Geeta D; Mudhoo, Ackmez

    2015-08-15

    This study investigates the potential of incorporating inorganic amendments such as coal and bagasse ashes in different composting mixes. 10 different composting mixes were assessed as follows: A-20% bagasse ash (BA) with unsorted municipal solid wastes (UMSW); B-40% BA with UMSW; C-UMSW; D-20% BA with sorted municipal solid wastes (SMSW); E-40% BA with SMSW; F-SMSW; G-20% coal ash (CA) with UMSW; H-40% CA with UMSW; I-20% CA with SMSW and J-40% CA with SMSW. The composting processes were carried out in rotary drum composters. Composting mixes D, F, G and I achieved a temperature above 55 °C for at least 3 days, with the following peak temperatures: D-62 °C, F-57 °C, G-62 °C and I-58 °C. D resulted in the highest average net Volatile solids (VS) degradation of 68.6% and yielded the highest average volume reduction of 66.0%. The final compost from D, G, I, C and F were within range for electrical conductivities (EC) (794-1770 μS/cm) and pH (6.69-7.12). The ashes also helped in maintaining high average water holding capacities within the range of 183-217%. The C/N ratio of sorted wastes was improved by the addition of 20% coal ash and bagasse ash. Higher germination indices, above 0.8 were obtained for the ash-amended compost (D, G, I), indicating the feasibility and enhancement of using bagasse and coal ash as inorganic amendment in the composting process. Regarding heavy metals content, the chromium concentration for the composting mix G was found to be the highest whereas mixes D and I showed compliance with the MS (Mauritian Standards) 164 standards. Copyright © 2015. Published by Elsevier Ltd.

  5. Indian high-school students dive into particle physics at CERN

    CERN Multimedia

    CERN Bulletin

    2014-01-01

    CERN hosted its first group of high-school students from India in a week-long programme in June, with lectures, visits and hands-on activities that brought them a little closer to the world of particle physics. Abhishek Anand, whose internship with CMS coincided with this programme, documented his experience for the CMS blog (see here).   The students with CERN Director-General Rolf Heuer and Head of International Relations Rüdiger Voss.

  6. Pilot Demonstration of Technology fo the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash

    Energy Technology Data Exchange (ETDEWEB)

    T.L. Robl; J.G. Groppo; K.R. Henke

    2005-06-27

    Work on the project primarily focused on the design and testing of different hydraulic classifier configurations. A four cell, open channel, cross flow classifier with and without weirs separating the cells was evaluated. Drawbacks to this configuration included thick sediment compression zones and relatively low throughput. The configuration was redesigned with inclined lamellae plates, to increase sedimentation area and decreased sediment compression zone thickness. This configuration resulted in greater throughput for any given product grade and enhanced product recovery. A digital model of a hydraulic classifier was also constructed based upon Stokes law and the configurations of the tests units. When calibrated with the size of the ash used in the tests, it produced a reasonable approximation of the size, yield and recovery of the actual product. The digital model will be useful to generate test data, at least on a relative basis, of conditions that are hard to generate in the laboratory or at larger scale. Test work on the dispersant adsorption capacity, settling tests and leaching test were also conducted on materials collected from the Coleman power station pond.

  7. AVAL - The ASTER Volcanic Ash Library

    Science.gov (United States)

    Williams, D.; Ramsey, M. S.

    2016-12-01

    Volcanic ash is a rich data source for understanding the causal mechanisms behind volcanic eruptions. Petrologic and morphometric information can provide direct information on the characteristics of the parent magma. Understanding how erupted ash interacts with the atmosphere can help quantify the effect that explosive volcanism has on the local to regional climate, whereas a measure of the particle size distribution enables more accurate modeling of plume propagation. Remote sensing is regularly employed to monitor volcanic plumes using a suite of high temporal/low spatial resolution sensors. These methods employ radiative transfer modeling with assumptions of the transmissive properties of infrared energy through the plume to determine ash density, particle size and sulfur dioxide content. However, such approaches are limited to the optically-transparent regions, and the low spatial resolution data are only useful for large-scale trends. In a new approach, we are treating the infrared-opaque regions of the plume in a similar way to a solid emitting surface. This allows high spatial resolution orbital thermal infrared data from the dense proximal plume to be modeled using a linear deconvolution approach coupled with a spectral library to extract the particle size and petrology. The newly created ASTER Volcanic Ash Library (AVAL) provides the end member spectral suite, and is comprised of laboratory emission measurements of volcanic ash taken from a variety of different volcanic settings, to obtain a wide range of petrologies. These samples have been further subdivided into particle size fractions to account for spectral changes due to diffraction effects. Once mapped to the ASTER sensor's spectral resolution, this library is applied to image data and the plume deconvolved to estimate composition and particle size. We have analyzed eruptions at the Soufrière Hills Volcano, Montserrat, Chaitén and Puyehue-Cordón Caulle, both Chile, and Eyjafjallajökull, Iceland

  8. Physical characteristics, chemical composition and water contamination potential from Canadian wildfire ash

    Science.gov (United States)

    Santin, Cristina; Doerr, Stefan; Arcenegui, Vicky; Otero, Xose Luis

    2017-04-01

    Wildland fires leave a powdery residue on the ground: wildfire ash, which consists of mineral materials and charred organic components. Its quantities and characteristics depend mainly on the total amount and type of fuel burnt and the fire characteristics. Up to several tens of tons of ash per hectare have been quantified in different post-fire environments. As a new material present after a wildland fire, ash can have profound effects on ecosystems. It affects biogeochemical cycles, including the carbon cycle, stimulates microbial activity and helps the recovery of vegetation. Ash incorporated into the soil increases soil pH and nutrient pools temporarily and changes soil physical properties such as albedo, soil texture and hydraulic properties. Ash also modifies soil and landscape-scale hydrological behaviour. Its high porosity makes it very effective at absorbing rainfall, but it can also contribute to catastrophic debris flows when ash is mobilised by large storm events. Its 'fragile' nature makes ash very susceptible to wind and water erosion, facilitating its transfer to the hydrological system. Runoff containing ash from burnt areas carries soluble nutrients and pollutants, which can have detrimental impacts on aquatic ecosystems and the supply of potable water. In this presentation we will report for the first time on the physical characteristics, chemical composition and associated water pollution risk from ash produced in four typical Canadian boreal forest fires: two high-intensity fires in jack pine stands, and one high-intensity and one smouldering fire in black spruce stands.

  9. Pre-study - Straw ash in a nutrient loop; Foerstudie - Halmaska i ett kretslopp

    Energy Technology Data Exchange (ETDEWEB)

    Ottosson, Peter; Bjurstroem, Henrik; Johansson, Christina; Svensson, Sven-Erik; Mattsson, Jan Erik

    2009-03-15

    straw from soils with higher cadmium content. To avoid that a farm with a low cadmium concentration in the straw receives ash with a high content, one could combust area-wise and recycle area-wise, or choose not to fetch straw from farms with high cadmium contents in soils, or spread only bottom ash. However, if fly ash is not utilised, a large part of the potassium is lost. The conclusion is that recycling of straw ash to fields is feasible and development work should continue after this pre-study. The pre-study need to be developed in the following areas: Means to spread a small quantity of ash to fields, with as small a negative effect as possible. Machines for spreading straw ash have been studied in some Swedish investigations, and before proceeding further one should gather additional information, a.o. on foreign machinery for spreading straw ash Test lime spreading techniques, pipe model, for agglomerated ash (wet, cured, crushed and sieved straw ash) As ash is a fertiliser, a method to calculate doses should be developed. This implies a.o. an analysis of potassium and phosphorus available to plants The availability of cadmium to plants should be studied in order to determine in which phase of a crop rotation ash should be returned in order to minimize the risk that plants take up cadmium If one chooses to recycle only bottom ash, one should continue to investigate means to extract potassium from fly ash, as ca 50 % of the potassium content is in the fly ash

  10. Geochemical and Petrographic Characterization of Ash in the Cretaceous Eagle Ford Formation

    Science.gov (United States)

    Ronay, E.; Lee, C. T.

    2015-12-01

    The Eagle Ford Formation is composed of highly laminated, organic rich shales and marls interbedded with volcanic ash. Discrete ash beds are easy to identify in outcrop as recessed layers between more resistant rock. In the finely laminated shales, the ash cannot be identified visually, which fosters the questions of whether ash is present in these shales and how that can be determined. The ash is thought to come from volcanic activity in western North America during the Cenomanian and Turonian, depositing in the Western Interior Seaway in what is now South Texas. Samples of known ash-rich beds from the Eagle Ford were analyzed using micro-XRF and thin section petrography in conjunction with ICP-MS laser ablation to determine the geochemical composition of the samples. The high CaCO3 content of the marls diluted the ash in each sample so elemental data were used to separate the two components. The amount of Ca in the ash from the total measured Ca was unknown. Carbonate takes Sr but not Al, therefore the y-intercept of a Ca/Al vs. Sr/Al graph gave the concentration of Ca in the non-carbonate components. This method was used for every cation to gather a generalized overall composition of the present day ash. The ash was found to have been altered to clays, resulting in a substantial loss of Si and thereby making the original composition of the ash indeterminable. However, certain elements like Ti and Zr are not as significantly affected by weathering. Using an empirical relationship between Ti/Zr and SiO2 in magmatic rocks from the Cretaceous Peninsular Ranges batholith, the likely source of ash, our measured Ti/Zr was used to determine the original SiO2 percentage in the ash, giving a range of 60-75 wt%. This was also checked by a Ti/Al regression analysis from the same Peninsular Ranges data, which gave a range of 67-72 wt% SiO2. These results suggest that the ash came from andesitic to rhyolitic eruptions. The discrepancy in Ti/Al and Ti/Zr calculated SiO2

  11. Validity of Some Anthropometric Indicators in the Prediction of High Systolic Blood Pressure among Indian Adolescents

    Directory of Open Access Journals (Sweden)

    Shobha Rao

    2008-01-01

    Full Text Available Background In view of the increasing prevalence of obesity in children, it is necessary to investigate the relative performance of different indicators used for its assessment and health consequences. Objectives To examine concordance between various indicators used for assessing obesity among adolescents and to examine their ability to predict risk of high systolic blood pressure. Design Cross-sectional study, from two schools catering to affluent class. Subjects Children in age 9–16 yr (n = 1146 boys and 1036 girls. Measurements Body weight, height, skinfold thickness at triceps (TSFT and body fat percent by trained investigators and blood pressure measurement by a pediatrician using sphygmomanometer. Results Prevalence of overweight was lowest with criterion of TSFT (11.7% in boys; 7.6% in girls and was highest using criterion of body fat percent (53.7% in boys and 28.4% in girls. Body mass index (BMI had high significant correlation with each of the indicator and with systolic blood pressure (SBP as well, in both sexes. All the indicators with conventional cut offs showed poor sensitivity for predicting high SBP. However, receiver operating characteristics (ROC cut-offs improved sensitivity considerably, but the values were much lower compared to conventional cut-offs. Conclusions There is considerable disparity in the estimates of overweight children obtained by different indicators. Lower values of ROC cut-offs highlights the need for population specific customized classification systems for assessing obesity in view of the probable population differences in relative risks of non-communicable adult diseases.

  12. Controlled release from bio ash spread on forest soils; Styrd utlakning ur bioaska som sprids i skogsmark

    Energy Technology Data Exchange (ETDEWEB)

    Fjaellberg, Leif; Lagerblad, Bjoern; Moosberg Bustnes, Helena [Swedish Cement and Concrete Research Inst., Stockholm (Sweden); Bjurstroem, Henrik [AaF-Process AB, Stockholm (Sweden)

    2005-10-01

    In order to minimize the costs for forestry, recycling ashes from biofuels should be done on freshly logged locations. A condition is that the ash that is spread on forest soils is well stabilized, with a negligible leakage of nutrients during a few years. However, these nutrients should be released when vegetation can take them up, about 15 years after replanting. In this report are presented the results of a prestudy on the possibilities to stabilize ash and to coat ash pellets with a protective layer that provides the desired delay in leaching. The chemistry of ashes is complex and similar to that of cement. In this prestudy, we tried to utilize the ash chemistry and investigated the balance between calcium oxide and silicon dioxide as well as its effect on cementing properties. The hypothesis is that by combining different ashes and/or by adding components a more stable product that is less prone to leaching may be obtained. Alkali such as potassium salts could be immobilized in silicates. Samples of ca 10 ashes were collected from plants in order to create a variety of compositions. The ashes have been characterized with regard to chemical and mineralogical composition, particle size distribution. Their binding properties have been investigated. Ashes from fluidized bed combusters bonded best and fastest. The results would have been clearer if most ashes had not been slaked when they reached the laboratory, although they were taken out dry from the plants. Some weakly bonding ashes were mixed with strongly bonding ashes, and with silica fume in one experiment. The weak ashes could be stabilized to a product with a satisfactory compressive strength. The mineralogy of the hydrated ashes was studied. Several leaching tests were performed: by mixing an ash yielding high concentration of salts in the leachate with an ash yielding low concentrations a halving of the concentration could be obtained. Silica fume yielded similar results. Attempts to coat ash pellets

  13. In vitro antibacterial activity of seven Indian spices against high level gentamicin resistant strains of enterococci

    Science.gov (United States)

    Bipin, Chapagain; Chitra, Pai (Bhat); Minakshi, Bhattacharjee

    2015-01-01

    Introduction The aim of the study was to explore the in vitro antibacterial activity of seven ethanolic extracts of spices against high level gentamicin resistant (HLGR) enterococci isolated from human clinical samples. Material and methods Two hundred and fifteen enterococcal strains were isolated from clinical samples. High level gentamicin resistance in ethanolic extracts of cumin (Cuminum cyminum), cinnamon (Cinnamomum zeylanicum), ginger (Zingiber officinale), fenugreek (Trigonella foenum-graecum), cloves (Syzygium aromaticum), cardamom (Elettaria cardamomum Maton) and black pepper (Piper nigrum) were prepared using Soxhlet apparatus. The antibacterial effect of the extracts was studied using the well diffusion method. Statistical analysis was carried out by χ2 test using SPSS 17 software. Results Only cinnamon and ginger were found to have activity against all the isolates, whereas cumin and cloves had a variable effect on the strains. Fenugreek, black pepper and cardamom did not show any effect on the isolates. The zone diameter of inhibition obtained for cinnamon, ginger, cloves and cumin was in the range 31–34 mm, 27–30 mm, 25–26 mm and 19–20 mm respectively. Conclusions Cinnamomum zeylanicum and Z. officinale showed the maximum antibacterial activity against the enterococcal isolates followed by S. aromaticum and C. cyminum. The findings of the study show that spices used in the study can contribute to the development of potential antimicrobial agents for inclusion in the anti-enterococcal treatment regimen. PMID:26322099

  14. Impact of fly ash composition upon shaker baghouse efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Sears, R.; Miller, S.J.

    1984-03-01

    Many parameters can have major effects on fabric filter performance. The most extensively published research in fabric filtration has concentrated on baghouse related parameters such as fabric type, cleaning mode, cleaning cycle, and air-to-cloth ratio. To a lesser extent studies have considered ash characteristics such as particle size distribution and specific filter resistance coefficient, K/sub 2/. Little research has been reported relating coal or ash properties to fabric filter performance. This paper deals with penetration from a shaker chamber with one specific fabric. The independent variable is major element concentration in fly ash. Air-to-cloth ratios varied only because combustion conditions control flue gas volumes. Results indicate that first, fabric filter performance is indeed coal specific with large differences in removal efficiency with different ashes. Second, the results reveal a definite inverse correlation between penetration and sodium concentration in the fly ash for the fabric and cleaning configuration considered. For the ashes that demonstrate poor performance in tests, careful selection of the correct fabric together with a conservative air-to-cloth ratio and the optimum cleaning cycle may all be necessary in order to maintain an adequate residual dust cake and bring the efficiency up to an acceptable level. Heavy dust cake formation may be necessary to achieve high efficiencies with these coals. Residual dust cake for the coals that showed high efficiencies in these tests may not be important, since North Dakota lignites give excellent efficiencies immediately after starting with new bags. Apparently the latter ashes build up on the woven fabric layer in such a way that openings in the weave and pinholes are immediately bridged over. These coals may then be candidates for high ratio filtration with conventional, economical woven fabric. 28 references, 10 figures, 4 tables.

  15. Effects of Alcohol Use and Anti-American Indian Attitudes on Domestic-Violence Culpability Decisions for American Indian and Euro-American Actors

    Science.gov (United States)

    Esqueda, Cynthia Willis; Hack, Lori; Tehee, Melissa

    2010-01-01

    Few studies have focused on the unique issues surrounding American Indian violence. Yet American Indian women are at high risk for domestic abuse, and domestic violence has been identified as the most important issue for American Indians now and in the future by the National Congress of American Indians. American Indian women suffer from domestic…

  16. Wood ash application increases pH but does not harm the soil mesofauna.

    Science.gov (United States)

    Qin, Jiayi; Hovmand, Mads Frederik; Ekelund, Flemming; Rønn, Regin; Christensen, Søren; Groot, Gerard Arjen de; Mortensen, Louise Hindborg; Skov, Simon; Krogh, Paul Henning

    2017-05-01

    Application of bioash from biofuel combustion to soil supports nutrient recycling, but may have unwanted and detrimental ecotoxicological side-effects, as the ash is a complex mixture of compounds that could affect soil invertebrates directly or through changes in their food or habitat conditions. To examine this, we performed laboratory toxicity studies of the effects of wood-ash added to an agricultural soil and the organic horizon of a coniferous plantation soil with the detrivore soil collembolans Folsomia candida and Onychiurus yodai, the gamasid predaceous mite Hypoaspis aculeifer, and the enchytraeid worm Enchytraeus crypticus. We used ash concentrations spanning 0-75 g kg-1 soil. As ash increases pH we compared bioash effects with effects of calcium hydroxide, Ca(OH)2, the main liming component of ash. Only high ash concentrations above 15 g kg-1 agricultural soil or 17 t ha-1 had significant effects on the collembolans. The wood ash neither affected H. aculeifer nor E. crypticus. The estimated osmolalities of Ca(OH)2 and the wood ash were similar at the LC50 concentration level. We conclude that short-term chronic effects of wood ash differ among different soil types, and osmotic stress is the likely cause of effects while high pH and heavy metals is of minor importance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Investigations on desulphurisation of some high-sulphur indian coals by gamma-ray-induced chlorinolysis.

    Science.gov (United States)

    Tripathi, Prem S M; Mishra, Kamlesh K; Roy, Rajiv R P; Tewary, Dina N

    2002-06-01

    Results of investigations on desulphurisation of high-sulphur (2-8 wt%) coals of Meghalaya by radiation chlorinolysis, effected in different media of chlorination (CCl4, CCl4/H2O, and CCl4/CH3OH) via radiolysis of CCl4, for the removal of both the inorganic (pyritic and sulphate) and the organic forms of sulphur as well as mineral matter are reported. In general, maximum removal of total sulphur (up to 37%) and mineral matter (up to 10%) takes place in CCl4/CH3OH medium, which is attributed to the CH3OH acting as a better wetting agent for coal. It is found that while pyritic and sulphate sulphur are removed almost quantitatively, there is variation in the removal of organic sulphur from the coals. Furthermore, the coal matrix is not affected/degraded to any appreciable extent and the caking property of the coals is either improved or slightly degraded after desulphurisation. Mechanism of desulphurisation of coal via radiation chlorination is proposed.

  18. Compact electrostatic filter at small-scale combustion of fuels with high ash content; Kompakt elektrostatiskt filter vid smaaskalig foerbraenning av askrika braenslen

    Energy Technology Data Exchange (ETDEWEB)

    Baefver, Linda; Yngvesson, Johan

    2009-07-01

    To facilitate combustion of these fuels in small combustion devices (50 kW - a few MW), there is a need of inexpensive dust cleaning devices. Electrostatic filters for dust cleaning at heat and power plants are well established. However, the cost of these filters is often expensive to bear for a small plant. A few electrostatic filters for residential applications are available, but the experience is limited. In the capacity-area in between, i.e. small district heating plants, it is of special importance to find new cheap alternatives for an improved dust cleaning. The Norwegian company Applied Plasma Physics (APP) have products for dust- and odour-cleaning. APP also has the electrostatic filter called RESP (Residential Electrostatic Precipitator) for combustion of wood close to commercially available. The purpose of this report is to evaluate the electrostatic filter RESP at combustion of biofuels rich in ash, and by this contribute to increased knowledge about electrostatic precipitation at small-scale applications. A sub-goal is to separate 85 % of the particles in the flue gas. Experimental tests were performed at SPs Energy laboratory. RESP was mounted downstream of a chimney, which was mounted on a multi-stoker/boiler. The multi-stoker has a nominal heat output of 65 kW at combustion of wood pellets. In this project pellets of bark or reed canary grass were fired. Dust separation efficiency over the RESP with respect to number concentration and size distribution was tested for several powers of the filter, during combustion of the two fuels. Combustion of bark was selected for a longer time test with respect to separation efficiency by particle mass. Number concentration and size distribution were measured in real time using an electrical low pressure impactor (ELPI) and mass concentration was measured by filter sampling. The combustion conditions were favourable, with low concentrations of hydrocarbons and carbon monoxide. The number concentration of

  19. Ash phloem reduction models vary among species and growing conditions

    Science.gov (United States)

    Tara L. Bal; Andrew J. Storer; Linda M. Nagel

    2011-01-01

    The exotic insect, emerald ash borer (Agrilus planipennis), is responsible for the death of millions of ash trees. Removal of ash from areas in close proximity to outlier populations will reduce the potential population density of emerald ash borer (EAB).

  20. Educational Approach to Seismic Risk Mitigation in Indian Himalayas -Hazard Map Making Workshops at High Schools-

    Science.gov (United States)

    Koketsu, K.; Oki, S.; Kimura, M.; Chadha, R. K.; Davuluri, S.

    2014-12-01

    How can we encourage people to take preventive measures against damage risks and empower them to take the right actions in emergencies to save their lives? The conventional approach taken by scientists had been disseminating intelligible information on up-to-date seismological knowledge. However, it has been proven that knowledge alone does not have enough impact to modify people's behaviors in emergencies (Oki and Nakayachi, 2012). On the other hand, the conventional approach taken by practitioners had been to conduct emergency drills at schools or workplaces. The loss of many lives from the 2011 Tohoku earthquake has proven that these emergency drills were not enough to save people's lives, unless they were empowered to assess the given situation on their own and react flexibly. Our challenge is to bridge the gap between knowledge and practice. With reference to best practices observed in Tohoku, such as The Miracles of Kamaishi, our endeavor is to design an effective Disaster Preparedness Education Program that is applicable to other disaster-prone regions in the world, even with different geological, socio-economical and cultural backgrounds. The key concepts for this new approach are 1) empowering individuals to take preventive actions to save their lives, 2) granting community-based understanding of disaster risks and 3) building a sense of reality and relevancy to disasters. With these in mind, we held workshops at some high schools in the Lesser Himalayan Region, combining lectures with an activity called "Hazard Map Making" where students proactively identify and assess the hazards around their living areas and learn practical strategies on how to manage risks. We observed the change of awareness of the students by conducting a preliminary questionnaire survey and interviews after each session. Results strongly implied that the significant change of students' attitudes towards disaster preparedness occurred not by the lectures of scientific knowledge, but

  1. The paradox of low body mass index and high body fat percentage among Chinese, Malays and Indians in Singapore

    NARCIS (Netherlands)

    Deurenberg-Yap, M.; Schmidt, G.; Staveren, van W.A.; Deurenberg, P.

    2000-01-01

    To study the relationship between body fat percentage and body mass index (BMI) in three different ethnic groups in Singapore (Chinese, Malays and Indians) in order to evaluate the validity of the BMI cut-off points for obesity. DESIGN: Cross-sectional study. SUBJECTS: Two-hundred and ninety-one

  2. ‘For the sake of the family and future’: the linked lives of highly skilled Indian migrants

    NARCIS (Netherlands)

    Kõu, Anu; Mulder, Clara H.; Bailey, Ajay

    2017-01-01

    © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group While in Western literature, migration is generally considered an individual or (nuclear) household phenomenon, Indian context adds the strong presence of parents and extended family to the constellation. This

  3. Development of novel ash hybrids to introgress resistance to emerald ash borer into north American ash species

    Science.gov (United States)

    Jennifer L. Koch; David W. Carey; Mary E. Mason

    2008-01-01

    Currently, there is no evidence that any of the native North American ash species have any resistance to the emerald ash borer (EAB). This means that the entire ash resource of the eastern United States and Canada is at risk of loss due to EAB. In contrast, outbreaks of EAB in Asian ash species are rare and appear to be isolated responses to stress (Bauer et al. 2005,...

  4. Washing of fly ash from combustion of municipal solid waste using water as leachant; Vattentvaett av flygaska fraan avfallsfoerbraenning

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Zhao, Dongmei

    2010-03-15

    Ashes from combustion of municipal solid waste contain a large amount of minerals, salts and other metal compounds that are more or less soluble in water. The metal salts are often enriched in the fly ash which leads to a classification of the ash as hazardous waste. This makes ash management complicated and costly. Many stabilisation methods for Municipal Solid Waste Incineration (MSWI) fly ash have been developed and most of them are based on a removal of chloride and sulfate in addition to a binding of metals in less soluble forms. The aim is to avoid the common situation that the ash does not comply to leaching limit values due to release of harmless salts. The aim of this project was to investigate if a simple washing with water can remove enough of the fly ash content of chloride and sulphate so that the ash can be landfilled in a simpler and less costly way than today. The project was focused on fly ashes from the MSWI units owned by Boraas Energi och Miljoe AB and Renova AB Goeteborg, i.e. a electro filter ash from grate fired boilers at Renova and a cyclone ash from a fluid bed boiler at Boraas. The results show that the main part of the chloride content of the ashes can be removed easily, but the washing with water is less effective in the removal of sulphate. A water-to-ash ratio of 1-2 l/kg removes about 100% of chloride but only 8-16% of the sulphate content. In many cases, the leachability of sulphate increases after the washing step. This is due to the rather complex sulphate chemistry with several possible reactions taking place in the ash-water system. For both the tested ashes the high level of chloride leaching is an important factor that prevents admittance on a landfill for hazardous waste without treatment.. The leaching of certain metals, such as Pb, is also high from both ashes but in the case of the Renova fly ash this is dealt with by treatment of the ash according to the Bamberg method. After a water washing with L/S 1-2 (L/kg dry ash

  5. 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...

  6. 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.

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

    Science.gov (United States)

    Gray, T. M.; Bennartz, R.

    2015-12-01

    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.

  8. Experimental studies on pulp and paper mill sludge ash behavior in fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Latva-Somppi, J. [VTT Chemical Technology, Espoo (Finland). Process Technology

    1998-11-01

    Ash formation during the fluidized bed combustion (FBC) of pulp and paper mill sludges has been experimentally studied on an industrial and bench scale. The methods included aerosol measurements, chemical and crystalline composition analyses, thermogravimetry and electron microscopy. Fly ash mass and number size distributions and elemental enrichment in submicron particles and bottom ash were measured. Fly ash, bottom ash and ash deposits were characterized and their formation mechanisms are discussed. During combustion the fine paper-making additives in sludge, clay minerals and calcite, sintered fanning porous agglomerates. The fly ash mass mean size was 7.5 - 15 lam and the supermicron particles included 93.6 - 97.3 % of the fly ash. Condensation of the volatilized inorganic species formed spherical submicron particles in the fly ash. Their mass concentration was almost negligible when co-firing paper mill sludges and wood. This suggests that the fraction of the volatilized inorganic species in the paper mill sludges was low. Results from pulp mill sludge and bark co-firing were different. A clear mass mode below 0.3 pm, presenting 2.2 - 5.0 weight-% of the fly ash was detected. The condensed species included K, Na, S and Cl. Their mass fraction was higher in the pulp mill sludge than in the paper mill sludge. Evidently this resulted in increased volatilization and formation of condensed particles. The following trace elements were enriched in the submicron ash during pulp mill sludge and wood co-firing: As, Cd, Rb and Pb. The main part of the volatile species was, however, captured in the bulk ash. Presumably, this was due to the high surface area concentration in the bulk ash. Sludge moisture was observed to reduce the inorganic species volatilization. Probably steam vaporization from the wet sludge through the burning layer decreased combustion temperatures on char surface and less char was produced. Hence, the volatilization of ash forming species was

  9. Exploring the molecular and biochemical basis of ash resistance to emerald ash borer

    Science.gov (United States)

    Justin G.A. Whitehill; Daniel A. Herms; Pierluigi. Bonello

    2010-01-01

    Larvae of the emerald ash borer (EAB) (Agrilus planipennis) feed on phloem of ash (Fraxinus spp.) trees. It is hypothesized that the resistance of Asian species of ash (e.g., Manchurian ash, F. mandshurica) to EAB is due to endogenous defenses present in phloem tissues in the form of defensive proteins and/or...

  10. Quantifying the mass loading of particles in an ash cloud remobilized from tephra deposits on Iceland

    Science.gov (United States)

    Beckett, Frances; Kylling, Arve; Sigurðardóttir, Guðmunda; von Löwis, Sibylle; Witham, Claire

    2017-04-01

    On 16-17 September 2013 strong surface winds over tephra deposits in southern Iceland led to the resuspension and subsequent advection of significant quantities of volcanic ash. The resulting resuspended ash cloud was transported to the south-east over the North Atlantic Ocean and, due to clear skies at the time, was exceptionally well observed in satellite imagery. We use satellite-based measurements in combination with radiative transfer and dispersion modelling to quantify the total mass of ash resuspended during this event. Typically ash clouds from explosive eruptions are identified in satellite measurements from a negative brightness temperature difference (BTD) signal; however this technique assumes that the ash resides at high levels in the atmosphere. Due to a temperature inversion in the troposphere over southern Iceland during 16 September 2013, the resuspended ash cloud was constrained to altitudes of dispersion model NAME (Numerical Atmospheric-dispersion Modelling Environment). Total column mass loadings are determined from the VIIRS data using an optimal estimation technique which accounts for the low altitude of the resuspended ash cloud and are used to calibrate the emission rate in the resuspended ash scheme in NAME. Considering the tephra deposits from the recent eruptions of Eyjafjallajökull and Grímsvötn as the potential source area for resuspension for this event, we estimate that ˜ 0.2 Tg of ash was remobilized during 16-17 September 2013.

  11. INVESTIGATION OF AMMONIA ADSORPTION ON FLY ASH DUE TO INSTALLATION OF SELECTIVE CATALYTIC REDUCTION SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    G.F. Brendel; J.E. Bonetti; R.F. Rathbone; R.N. Frey Jr.

    2000-11-01

    This report summarizes an investigation of the potential impacts associated with the utilization of selective catalytic reduction (SCR) systems at coal-fired power plants. The study was sponsored by the U.S. Department of Energy Emission Control By-Products Consortium, Dominion Generation, the University of Kentucky Center for Applied Energy Research and GAI Consultants, Inc. SCR systems are effective in reducing nitrogen oxides (NOx) emissions as required by the Clean Air Act (CAA) Amendments. However, there may be potential consequences associated with ammonia contamination of stack emissions and combustion by-products from these systems. Costs for air quality, landfill and pond environmental compliance may increase significantly and the marketability of ash may be seriously reduced, which, in turn, may also lead to increased disposal costs. The potential impacts to air, surface water, groundwater, ash disposal, ash utilization, health and safety, and environmental compliance can not be easily quantified based on the information presently available. The investigation included: (1) a review of information and data available from published and unpublished sources; (2) baseline ash characterization testing of ash samples produced from several central Appalachian high-volatile bituminous coals from plants that do not currently employ SCR systems in order to characterize the ash prior to ammonia exposure; (3) an investigation of ammonia release from fly ash, including leaching and thermal studies; and (4) an evaluation of the potential impacts on plant equipment, air quality, water quality, ash disposal operations, and ash marketing.

  12. DETERMINING THE ROLE OF INDIVIDUAL FLY ASH PARTICLES IN INFLUENCING THE VARIATION IN THE OVERALL PHYSICAL, MORPHOLOGICAL, AND CHEMICAL PROPERTIES OF FLY ASH

    Directory of Open Access Journals (Sweden)

    Usman Haider

    2016-08-01

    Full Text Available The properties of fly ashes vary because of the differences in the properties of their individual particles, and the determination of variation in these properties is of interest to the industries which use pulverized raw fly ash in applications, such as in cementitious materials and in the recovery of certain rare elements from raw fly ash. To investigate the differences in individual particles, four pulverized raw fly ashes from thermal power plants of the Czech Republic were used in this research. It was observed from FE-SEM that all four fly ashes consist of glassy hollow spherical, solid spherical, porous spherical, bright spherical, porous slaggy and compact slaggy particles. Box and whisker diagrams were plotted from the data of EDX individual particle analyses, which showed that the data of percentages for the Si, Al, and Fe elements is more scattered as compared to other elements. It was further observed from ternary phase diagrams and pseudo coloured images, that nature of fly ash particles changes from alumino silicate glassy to alumino silicate calcite metallic to pure ferro-metallic,where glassy particles showed high percentages and pure calcite particles were absent in fly ashes. Furthermore, a comparison between the XRF, the EDX total area analyses, showed that the EDX individual particle analysis gives more realistic and reliable data with median, mean, and the standard deviation for percentages of each element present in the fly ashes.

  13. Hierarchical zeolites from class F coal fly ash

    Science.gov (United States)

    Chitta, Pallavi

    Fly ash, a coal combustion byproduct is classified as types class C and class F. Class C fly ash is traditionally recycled for concrete applications and Class F fly ash often disposed in landfills. Class F poses an environmental hazard due to disposal and leaching of heavy metals into ground water and is important to be recycled in order to mitigate the environmental challenges. A major recycling option is to reuse the fly ash as a low-cost raw material for the production of crystalline zeolites, which serve as catalysts, detergents and adsorbents in the chemical industry. Most of the prior literature of fly ash conversion to zeolites does not focus on creating high zeolite surface area zeolites specifically with hierarchical pore structure, which are very important properties in developing a heterogeneous catalyst for catalysis applications. This research work aids in the development of an economical process for the synthesis of high surface area hierarchical zeolites from class F coal fly ash. In this work, synthesis of zeolites from fly ash using classic hydrothermal treatment approach and fusion pretreatment approach were examined. The fusion pretreatment method led to higher extent of dissolution of silica from quartz and mullite phases, which in turn led to higher surface area and pore size of the zeolite. A qualitative kinetic model developed here attributes the difference in silica content to Si/Al ratio of the beginning fraction of fly ash. At near ambient crystallization temperatures and longer crystallization times, the zeolite formed is a hierarchical faujasite with high surface area of at least 360 m2/g. This work enables the large scale recycling of class F coal fly ash to produce zeolites and mitigate environmental concerns. Design of experiments was used to predict surface area and pore sizes of zeolites - thus obviating the need for intense experimentation. The hierarchical zeolite catalyst supports tested for CO2 conversion, yielded hydrocarbons

  14. assessment of assessment of bagasse ash bagasse ash bagasse ...

    African Journals Online (AJOL)

    eobe

    Clay material of Group A-6 using AASHTO classification and inorganic clay material. 6 using AASHTO ... Construction Industry Research and Information .... The chemical composition of the Bagasse ash (BA) was determined at the Center for Energy Research and Training. (CERT), A. B. U. Zaria using the method of Energy.

  15. Cost of potential emerald ash borer damage in U.S

    Science.gov (United States)

    Kent F. Kovacs; Robert G. Haight; Andrew M. Liebhold; Deborah G. McCullough; Rodrigo J. Mercader; Nathan W. Siegert

    2010-01-01

    Emerald ash borer (EAB; Agrilus planipennis Fairmaire), a phloem-feeding beetle native to Asia, was discovered near Detroit, MI, and Windsor, ON, in 2002. As of March 2009, isolated populations of EAB have been detected in nine additional states and Quebec. EAB is a highly invasive forest pest that has the potential to spread and kill native ash...

  16. Why is Coal Ash of Concern and How to Assess Potential Impacts?

    Science.gov (United States)

    EPA's new test methods - the leaching environmental assessment framework (LEAF) are discussed including how they have been used to evaluate fly ash and scrubber residues. Work to evaluate high-volume encapsulated use of fly ash in cementitious material is also described.

  17. Evaluation of fly ash quality control tools.

    Science.gov (United States)

    2010-06-30

    Many entities currently use fly ash in portland cement concrete (PCC) pavements and structures. Although the body of knowledge is : great concerning the use of fly ash, several projects per year are subject to poor performance where fly ash is named ...

  18. Survival of emerald ash borer in chips

    Science.gov (United States)

    Deborah G. McCullough; Therese M. Poland; David L. Cappaert

    2005-01-01

    The ability of emerald ash borer (EAB), Agrilus planipennis Fairmaire, to survive following chipping or grinding of infested ash trees remains a critical question for regulatory officials. In October 2002, we felled eight infested ash trees and sampled sections of the trunk and large branches from each tree to estimate EAB density.

  19. Mineral matter and ash in coal

    Energy Technology Data Exchange (ETDEWEB)

    Vorres, K.S. (ed.)

    1986-01-01

    The ACS Division of Fuel Chemistry was responsible for the symposium, held in Philadelphia in 1984, that gave rise to the 38 typescript papers in this volume. They are concerned with the chemistry of coal mineral matter, coal ash properties and their prediction, coal ash deposition in boilers, and catalysis by ash and mineral matter in coal utilization.

  20. Mercury capture by selected Bulgarian fly ashes: Influence of coal rank and fly ash carbon pore structure on capture efficiency

    Science.gov (United States)

    Kostova, I.J.; Hower, J.C.; Mastalerz, Maria; Vassilev, S.V.

    2011-01-01

    Mercury capture by fly ash C was investigated at five lignite- and subbituminous-coal-burning Bulgarian power plants (Republika, Bobov Dol, Maritza East 2, Maritza East 3, and Sliven). Although the C content of the ashes is low, never exceeding 1.6%, the Hg capture on a unit C basis demonstrates that the low-rank-coal-derived fly ash carbons are more efficient in capturing Hg than fly ash carbons from bituminous-fired power plants. While some low-C and low-Hg fly ashes do not reveal any trends of Hg versus C, the 2nd and, in particular, the 3rd electrostatic precipitator (ESP) rows at the Republika power plant do have sufficient fly ash C range and experience flue gas sufficiently cool to capture measurable amounts of Hg. The Republika 3rd ESP row exhibits an increase in Hg with increasing C, as observed in other power plants, for example, in Kentucky power plants burning Appalachian-sourced bituminous coals. Mercury/C decreases with an increase in fly ash C, suggesting that some of the C is isolated from the flue gas stream and does not contribute to Hg capture. Mercury capture increases with an increase in Brunauer-Emmett-Teller (BET) surface area and micropore surface area. The differences in Hg capture between the Bulgarian plants burning low-rank coal and high volatile bituminous-fed Kentucky power plants suggests that the variations in C forms resulting from the combustion of the different ranks also influence the efficiency of Hg capture. ?? 2010 Elsevier Ltd.

  1. Evaluation of Greek type Portland cement based on Megalopolis fly ash addition

    Energy Technology Data Exchange (ETDEWEB)

    Stivanakis, V.; Papamantellos, D. [University of Patras (Greece). Department of Chemical Engineering, Laboratory of Metallurgy; Galanoulis, E. [Titan Cement Company S.A., Drepano, Achaias (Greece)

    2003-04-01

    Fly-ash is considered as a fine material which is produced during firing of powdered solid fuels in steam generating plants. It is contained in the output exhaust gases and collected in the electrostatic filters. In the lignite fired power plants of Public Power Corporation in the regions of Ptolemais-Amynteon and Megalopolis 65 . 10 t/a of lignite are consumed nowadays with a corresponding fly ash production of about 13 . 10{sup 6} t/a. The utilisation of fly ash generated in Megalopolis plant ({proportional_to} 3.5 . 106 t/a) in cement industry has been investigated by the Laboratory of Metallurgy (METLAB) in collaboration with the cement company Titan and the Greek P.P.C. since 1979. The primary target of this research and development work, was to investigate the addition of Megalopolis fly ash in the manufacturing process of cement, in quantities around 10%, replacing the so-called Volcanic Rock (Santorini's earth), which was used as a pozzolanic material. Megalopolis fly ash was considered to be unsuitable for use as hydraulic powder due to its high SiO{sub 2} content ({proportional_to}50%), in contrast to Ptolemais-Amynteon fly ash, which contains high percentages of CaO (30 - 40%). The first results were very encouraging as they proved that addition of blended fly ash could be added up to 50% without considerable reduction in the compressive strength of cement. Consequently, exploitation of Megalopolis fly ash by Titan cement industry began in 1982, with the production of Greek type Portland cement that contains 15 - 20% of Megalopolis fly ash. The annual consumption of Megalopolis fly ash since 1982 is in the range of 300.000 - 500.000 t/a. In the years following 1983, a systematic investigation of the influence of Megalopolis fly ash addition, up to a content of 80% upon the technological properties of cement and concrete was carried out. The workability, compressive strength (2, 7, 28 days), long-term compressive strength (up to 180 days) and the

  2. 1998 report on development of high-efficiency waste power generation technology. 2. Development of waste gasification and ash melting power generation technology; 1998 nendo kokoritsu haikibutsu hatsuden gijutsu kaihatsu seika hokokusho. Haikibutsu gas ka yoyu hatsuden gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    In regard to waste gasification and ash melting power generation, a basic test and examination were conducted in fiscal 1998, with a full-scale development test made ready to start. In the development of technology for raising steam temperature, evaluation of high temperature corrosivity of SH materials and development of high-temperature dust removal system were carried out for example, as were development of dechlorination technology for thermal decomposition process and development of ceramic high-temperature air heater. In the development of technology to prevent exhaust gas reheating, preliminary examination was made on denitrification technologies using a catalyst with superior low-temperature activity. In the development of technology to reduce self-heat melting critical calorific value, investigation and basic test were carried out concerning a stable waste feed system, with a pilot test device experimentally manufactured and tested based on the findings. In the development of technology for reducing external fuel input, examination and analysis were performed on pretreatment techniques for waste plastics, with basic data obtained for a waste blowing system project. In addition, the thermal decomposition and combustion characteristics of waste plastics were clarified by the basic test. (NEDO)

  3. Wildland fire ash: Production, composition and eco-hydro-geomorphic effects

    Science.gov (United States)

    Bodi, Merche B.; Martin, Deborah; Balfour, Victoria N.; Santin, Cristina; Doerr, Stefan H.; Pereira, Paulo; Cerda, Artemi; Mataix-Solera, Jorge

    2014-01-01

    Fire transforms fuels (i.e. biomass, necromass, soil organic matter) into materials with different chemical and physical properties. One of these materials is ash, which is the particulate residue remaining or deposited on the ground that consists of mineral materials and charred organic components. The quantity and characteristics of ash produced during a wildland fire depend mainly on (1) the total burned fuel (i.e. fuel load), (2) fuel type and (3) its combustion completeness. For a given fuel load and type, a higher combustion completeness will reduce the ash organic carbon content, increasing the relative mineral content, and hence reducing total mass of ash produced. The homogeneity and thickness of the ash layer can vary substantially in space and time and reported average thicknesses range from close to 0 to 50 mm. Ash is a highly mobile material that, after its deposition, may be incorporated into the soil profile, redistributed or removed from a burned site within days or weeks by wind and water erosion to surface depressions, footslopes, streams, lakes, reservoirs and, potentially, into marine deposits.Research on the composition, properties and effects of ash on the burned ecosystem has been conducted on material collected in the field after wildland and prescribed fires as well as on material produced in the laboratory. At low combustion completeness (typically T  450 °C), most organic carbon is volatized and the remaining mineral ash has elevated pH when in solution. It is composed mainly of calcium, magnesium, sodium, potassium, silicon and phosphorous in the form of inorganic carbonates, whereas at T > 580 °C the most common forms are oxides. Ash produced under lower combustion completeness is usually darker, coarser, and less dense and has a higher saturated hydraulic conductivity than ash with higher combustion completeness, although physical reactions with CO2 and when moistened produce further changes in ash characteristics.As a new

  4. Wildfire Ash: Chemical Composition, Ash-Soil Interactions and Environmental Impacts

    Science.gov (United States)

    Brook, Anna; Hamzi, Seham; Wittenberg, Lea

    2015-04-01

    produced ash has significant and not always constructive pedological, ecological, hydrological and geomorphological effects and impacts (Shakesby, 2011). Abundant scientific information is assembled either from control fires by collecting samples before and after wildfire event, or conducting laboratory experiments exanimating data under truly isolated conditions (Lugassi et al., 2013). However, an integration and synthesis of the knowledge about ash including deeper understanding of inter-correlation between chemical, physical and morphological compounds in open post-burn environment and its possible interactions in soil formation or impact on soil composition are highly needed. The main aim of the presented study was to advance the science of soil-fire relationship by recognizing the remains ash as a new soil-forming factor, on par with the traditionally recognized factors: parent material, topography, time, climate, organisms, and recently recognized human activity as the sixth factor. This research was conducted to develop new methods to assess impacts and quantify the contributions/influences of post-fire products, mainly ash, on soil composition and soil properties in post-burned environment. We conducted several controlled experiments using 40 soil samples (typical Mediterranean Rendzina soil, pH 6.84, a grayish-brown, humus- and free calcium carbonate- rich, intra-zonal). The samples include bare soils and different types and loads of forest litter, were exposed to different temperatures (200° C, 400° C and 600° C) in a muffle furnace for 2 hours (Pereira et al. 2011) as fire temperature plays a key role in determining ash properties. The ash produced at a low temperatures (50% carbon and retains many of the structural characteristics of the parent material. At higher temperatures, the residue ash is greyish, consisted of very fine particles that preserve almost none of the original structural characteristics of the fuel (Woods and Balfour, 2008) creating

  5. Utilization of Coal Fly Ash

    Science.gov (United States)

    1992-01-01

    sample. Harrison et al. (1985) found that most of the aliphatic hydrocarbons were paraffins and terpenoids . Roy et al. (1984) found the majority of their...P. Rombout, "Effects of Acute Inhalation of Respirable Coal Fly Ash on Metabolic Defense Capability of the Rat Lung," Inhalation Toxicology, v.2: 361

  6. Coal ash removal in Schkopau

    Energy Technology Data Exchange (ETDEWEB)

    Geisler

    1945-05-22

    This short paper outlined an ash removal process as revealed by a conversation with a Mr. Boerner. Boerner worked with Dr. Strohfeldt in February and March of 1945 on an ash removal process performed at the Schkopau Works. A mill supplied 3 tons/hr of crushed coal, which was mixed with a dilute HCl solution. The acid suspension was immediately supplied to the first concentrator. The thickened paste was transferred by means of a diaphragm pump to the second concentator where a small amount of HCl solution was added. After concentrating in the second apparatus, the paste went to a tank car where the suspension was maintained by air bubbling. Difficulty in filtration was avoided by introduction of a rotating filter cake remover and equally-sized coal granules. The filter yield was estimated at 150 kg of wet cake per m/sup 2/ per hr. The water content of the cake was approximately 50% to 55%, and it was thought that a decrease in water content would result by slowing down the throughput rate. Ash and water analyses of the processed coal were set up, but were not run. No other specific values were given such as ash content, acid concentation, or amounts of reagents added.

  7. Bacterial Treatment and Metal Characterization of Biomedical Waste Ash

    Directory of Open Access Journals (Sweden)

    Shelly Heera

    2014-01-01

    Full Text Available Biomedical waste ash generated due to the incineration of biomedical waste contains large amounts of heavy metals and polycyclic aromatic hydrocarbons (PAHs, which is disposed of in regular landfills, and results in unfavorable amounts of hazardous materials seeping into the ground and may pollute surface water and groundwater. Therefore, it is essential to remove the toxicity of ash before disposal into landfills or reutilization. Environmental characteristic analysis of BMW ash showed increased hardness (1320 mg/L and chloride (8500 mg/L content in leachate compared to World Health Organization (WHO and Environment Protection Agency (EPA guidelines for drinking water (hardness, 300 mg/L; chloride, 250 mg/L. The alkalinity and pH of the ash leachate were 400 mg/L and 8.35, respectively. In this paper, study was carried out to investigate the metal tolerance level of bacterial isolates isolated from soil. The isolate Bacillus sp. KGMDI can tolerate up to 75 mg/L of metal concentration (Mn, Mo, Cr, Fe, Cu, and Zn in enriched growth medium. This shows that the isolated culture is capable of growing in presence of high concentration of heavy metals and acts as potential biological tool to reduce the negative impact of BMW ash on the environment during landfilling.

  8. The utilisation of fly ash in CO2 mineral carbonation

    Directory of Open Access Journals (Sweden)

    Jaschik Jolanta

    2016-03-01

    Full Text Available The fixation of CO2 in the form of inorganic carbonates, also known as mineral carbonation, is an interesting option for the removal of carbon dioxide from various gas streams. The captured CO2 is reacted with metal-oxide bearing materials, usually naturally occurring minerals. The alkaline industrial waste, such as fly ash can also be considered as a source of calcium or magnesium. In the present study the solubility of fly ash from conventional pulverised hard coal fired boilers, with and without desulphurisation products, and fly ash from lignite fluidised bed combustion, generated by Polish power stations was analysed. The principal objective was to assess the potential of fly ash used as a reactant in the process of mineral carbonation. Experiments were done in a 1 dm3 reactor equipped with a heating jacket and a stirrer. The rate of dissolution in water and in acid solutions was measured at various temperatures (20 - 80ºC, waste-to-solvent ratios (1:100 - 1:4 and stirrer speeds (300 - 1100 min-1. Results clearly show that fluidised lignite fly ash has the highest potential for carbonation due to its high content of free CaO and fast kinetics of dissolution, and can be employed in mineral carbonation of CO2.

  9. Optimising Ambient Setting Bayer Derived Fly Ash Geopolymers

    Directory of Open Access Journals (Sweden)

    Evan Jamieson

    2016-05-01

    Full Text Available The Bayer process utilises high concentrations of caustic and elevated temperature to liberate alumina from bauxite, for the production of aluminium and other chemicals. Within Australia, this process results in 40 million tonnes of mineral residues (Red mud each year. Over the same period, the energy production sector will produce 14 million tonnes of coal combustion products (Fly ash. Both industrial residues require impoundment storage, yet combining some of these components can produce geopolymers, an alternative to cement. Geopolymers derived from Bayer liquor and fly ash have been made successfully with a compressive strength in excess of 40 MPa after oven curing. However, any product from these industries would require large volume applications with robust operational conditions to maximise utilisation. To facilitate potential unconfined large-scale production, Bayer derived fly ash geopolymers have been optimised to achieve ambient curing. Fly ash from two different power stations have been successfully trialled showing the versatility of the Bayer liquor-ash combination for making geopolymers.

  10. Workability and strength of lignite bottom ash geopolymer mortar.

    Science.gov (United States)

    Sathonsaowaphak, Apha; Chindaprasirt, Prinya; Pimraksa, Kedsarin

    2009-08-30

    In this paper, the waste lignite bottom ash from power station was used as a source material for making geopolymer. Sodium silicate and sodium hydroxide (NaOH) were used as liquid for the mixture and heat curing was used to activate the geopolymerization. The fineness of bottom ash, the liquid alkaline/ash ratio, the sodium silicate/NaOH ratio and the NaOH concentration were studied. The effects of the additions of water, NaOH and napthalene-based superplasticizer on the workability and strength of the geopolymer mortar were also studied. Relatively high strength geopolymer mortars of 24.0-58.0 MPa were obtained with the use of ground bottom ash with 3% retained on sieve no. 325 and mean particle size of 15.7 microm, using liquid alkaline/ash ratios of 0.429-0.709, the sodium silicate/NaOH ratios of 0.67-1.5 and 7.5-12.5M NaOH. The incorporation of water improved the workability of geopolymer mortar more effectively than the use of napthalene-based superplasticizer with similar slight reduction in strengths. The addition of NaOH solution slightly improves the workability of the mix while maintaining the strength of the geopolymer mortars.

  11. Optimising Ambient Setting Bayer Derived Fly Ash Geopolymers

    Science.gov (United States)

    Jamieson, Evan; Kealley, Catherine S.; van Riessen, Arie; Hart, Robert D.

    2016-01-01

    The Bayer process utilises high concentrations of caustic and elevated temperature to liberate alumina from bauxite, for the production of aluminium and other chemicals. Within Australia, this process results in 40 million tonnes of mineral residues (Red mud) each year. Over the same period, the energy production sector will produce 14 million tonnes of coal combustion products (Fly ash). Both industrial residues require impoundment storage, yet combining some of these components can produce geopolymers, an alternative to cement. Geopolymers derived from Bayer liquor and fly ash have been made successfully with a compressive strength in excess of 40 MPa after oven curing. However, any product from these industries would require large volume applications with robust operational conditions to maximise utilisation. To facilitate potential unconfined large-scale production, Bayer derived fly ash geopolymers have been optimised to achieve ambient curing. Fly ash from two different power stations have been successfully trialled showing the versatility of the Bayer liquor-ash combination for making geopolymers. PMID:28773513

  12. Effects of wood-ash addition on nitrogen turnover in a highly nitrogen loaded spruce site. Final project report; Effekter av askaaterfoering paa kvaeveomsaettningen i ett kvaeverikt granbestaand i Halland. Slutrapport foer projektet

    Energy Technology Data Exchange (ETDEWEB)

    Nohrstedt, H.Oe.; Hoegbom, Lars; Nordlund, Sten [Forestry Research Inst. of Sweden, Uppsala (Sweden)

    2000-04-01

    During two consecutive years, it was studied how a fertilization with 4.2 tonnes pelleted bark ash per ha, made six-seven years earlier, affected soil chemistry, nitrogen turnover and soil-water chemistry on a Norway spruce site in SW Sweden. The actual site has a very acidic soil. At the same time, the supply of inorganic N is rich. Measures against soil acidification, e. g. addition of ash or lime, may significantly influence the turnover of N with a subsequent risk for increased leaching. Thus, there is a potential conflict between two urgent environmental goals, i. e. to decrease acidification and to decrease the N load on aquatic ecosystems. In the humus layer and the upper 5 cm of the mineral soil, pH(H{sub 2}O) had increased with at the most 0.2 units because of the ash addition. The easily extractable amounts of Mg, P and nitrate were slightly increased. The potential nitrification in the humus layer was generally higher in the ash treatment, but the difference. was not statistically significant. The soil water at 50 cm depth was 0.1-0.2 pH-units more acidic where ash had been applied. Simultaneously, there were tendencies for higher concentrations of nitrate, Al and K. This is the first time in Sweden that ash fertilization of a closed forest has given clear indications of an increased N leaching. As expected, the ash fertilization decreased the acidity of the top soil. On the contrary, the runoff became more acidic and more rich in Al. Thus, the ash fertilization has counteracted one of its primary goals, i. e. to produce a runoff less toxic to aquatic life. The acidification of the runoff may partially be because of acid production during nitrification.

  13. A simple Indian diabetes risk score could help identify nondiabetic individuals at high risk of non-alcoholic fatty liver disease (CURES-117).

    Science.gov (United States)

    Anbalagan, Viknesh Prabu; Venkataraman, Vijayachandrika; Vamsi, Mamilla; Deepa, Mohan; Mohan, Viswanathan

    2012-11-01

    We aim to determine whether a simple Indian diabetes risk score (IDRS) is associated with individuals with non-alcoholic fatty liver disease (NAFLD) among nondiabetic Asian Indians. Nondiabetic participants (n = 409) were selected from the Chennai Urban Rural Epidemiology Study. Mean age was 40 ± 11.9 years, mean body mass index was 23.2 ± 3.9 kg/m(2), and 224 (54.8%) were women. The IDRS was classified as high (≥60), medium (30-50), and low (<30) risk. Non-alcoholic fatty liver disease was assessed by high-resolution β mode ultrasonography. To determine the factors associated with NAFLD, a univariate analysis was first done and a stepwise logistic regression analysis was done based on the factors associated with NAFLD. Biochemical and anthropometric measurements were obtained using standardized procedures. The overall prevalence of NAFLD was 24.7% (101/409 participants), and it was significantly higher among those with a high (30.4%) and medium IDRS (21%) compared with the low IDRS group (15.8%; trend chi square; p = .022). In stepwise logistic regression, IDRS was associated with NAFLD with an adjusted odds ratio of 1.78 (95% confidence interval 1.04-3.06), even after adjusting for potential confounders. The IDRS can be used as the initial step to screen individuals at high risk of NAFLD in the community. © 2012 Diabetes Technology Society.

  14. Engineering Behavior and Characteristics of Wood Ash and Sugarcane Bagasse Ash

    Science.gov (United States)

    Grau, Francisco; Choo, Hyunwook; Hu, Jong Wan; Jung, Jongwon

    2015-01-01

    Biomasses are organic materials that are derived from any living or recently-living structure. Plenty of biomasses are produced nationwide. Biomasses are mostly combusted and usually discarded or disposed of without treatment as biomass ashes, which include wood and sugarcane bagasse ashes. Thus, recycling or treatment of biomass ashes leads to utilizing the natural materials as an economical and environmental alternative. This study is intended to provide an environmental solution for uncontrolled disposal of biomass ashes by way of recycling the biomass ash and replacing the soils in geotechnical engineering projects. Therefore, in this study, characteristic tests of wood and sugarcane bagasse ashes that are considered the most common biomass ashes are conducted. The test of chemical compositions of biomass ashes is conducted using energy dispersive X-ray spectroscopy (EDS), and Scanning Electron Microscope (SEM), and heavy metal analysis is also conducted. Engineering behaviors including hydraulic conductivity, constrained modulus and shear modulus are examined. Also, coal fly ash Class C is used in this study for comparison with biomass ashes, and Ottawa 20/30 sands containing biomass ashes are examined to identify the soil replacement effect of biomass ashes. The results show that the particle sizes of biomass ashes are halfway between coal fly ash Class C and Ottawa 20/30 sand, and biomass ashes consist of a heterogeneous mixture of different particle sizes and shapes. Also, all heavy metal concentrations were found to be below the US Environmental Protection Agency (EPA) maximum limit. Hydraulic conductivity values of Ottawa 20/30 sand decrease significantly when replacing them with only 1%–2% of biomass ashes. While both the constrained modulus and shear modulus of biomass ashes are lower than Ottawa 20/30 sand, those of mixtures containing up to 10% biomass ashes are little affected by replacing the soils with biomass ashes. PMID:28793611

  15. Characterization and electrodialytic treatment of wood combustion fly ash for removal of cadmium

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul

    2003-01-01

    -for the aim of recycling-was described. Initial characterisation of the experimental ash showed that the Cd content exceeded the limiting values for agricultural use and therefore needed treatment before being recycled. The pH in the ash was very high (13.3), and the Cd was not soluble at these alkaline......Due to a high content of macronutrients and a potential liming capacity, recycling of ashes from biomass combustion to agricultural fields as fertilisers and/or for soil improvement is considered in Denmark and other countries utilising biomass as an energy source. However, the fly ash fractions...... especially contain amounts of the toxic heavy metal cadmium that may exceed the limiting values for agricultural utilisation given by the Danish Environmental Protection Agency.In this work the advances of using an electrodialytic remediation method to reduce the Cd content in wood combustion fly ash...

  16. Stability and leaching of cobalt smelter fly ash

    DEFF Research Database (Denmark)

    Vítková, Martina; Hyks, Jiri; Ettler, Vojtěch

    2013-01-01

    The leaching behaviour of fly ash from a Co smelter situated in the Zambian Copperbelt was studied as a function of pH (5–12) using the pH-static leaching test (CEN/TS 14997). Various experimental time intervals (48h and 168h) were evaluated. The leaching results were combined with the ORCHESTRA...... elements, the released concentrations were very similar after 48h and 168h, indicating near-equilibrium conditions in the system. Calcite, clinopyroxenes, quartz and amorphous phases predominated in the fly ash. Various metallic sulfides, alloys and the presence of Cu, Co and Zn in silicates and glass were...... and Cu. However, there is a high risk of Co, Cu, Pb and Zn mobility in the acidic soils around the smelter facility. Therefore, potential local options for “stabilisation” of the fly ash were evaluated on the basis of the modelling results using the PHREEQC code....

  17. Strength Properties of Processed Fly Ash Concrete

    Directory of Open Access Journals (Sweden)

    Sivakumar Anandan

    2015-07-01

    Full Text Available The present paper reports on the mechanical treatment of fly ash for improving the delayed reactivity of fly ash with the hydration product of cement. Grinding of fly ash was carried out in a ball mill for different time durations and processing time was optimized for maximum fineness. Concrete mixes were prepared using various proportions of processed and unprocessed fly ash replacement in cement (25% and 50%. The influence of steel fiber addition on the mechanical properties of the concrete was studied for different curing periods. The test results on pozzolanic activity and lime reactivity indicate that the processed fly ash exhibited a higher strength gain than the unprocessed fly ash, with a maximum increase in compressive strength of up to 12%. Improved pozzolanic properties were noticed due to the increase in fineness of the fly ash particles.

  18. A geotechnical classification system for coal ashes

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, K.; Sridharan, A. [S.J. College of Engineering, Mysore (India). Dept. of Civil Engineering

    2006-04-15

    Most of the existing soil classification systems make use of the plasticity chart for classifying fine-grained soils and some coarse-grained soils as well. They cannot classify those granular materials that are non-plastic through appropriate group symbols indicative of their non-plastic nature without any ambiguity. Coal ashes, consisting of fly ash (known as pulverised fuel ash in the UK), bottom ash and pond ash, are produced in large quantities and are occasionally used in geotechnical applications. As they are non-plastic materials, the existing classification systems fail to classify them appropriately. This paper discusses this issue in detail. A classification system for coal ashes that are essentially non-plastic is formulated and proposed in this paper. It is shown through illustrative examples that the coal ashes can be classified easily and without any ambiguity using the proposed system.

  19. Market Assessment and Technical Feasibility Study of Pressurized Fluidized Bed Combustion Ash Use

    Energy Technology Data Exchange (ETDEWEB)

    Bland, A.E.; Brown, T.H. [Western Research Inst., Laramie, WY (United States)

    1996-12-31

    Western Research Institute in conjunction with the Electric Power Research Institute, Foster Wheeler Energy International, Inc. and the U.S. Department of Energy Technology Center (METC), has undertaken a research and demonstration program designed to examine the market potential and the technical feasibility of ash use options for pressurized fluidized bed combustion (PFBC) ashes. The assessment is designed to address six applications, including: (1) structural fill, (2) road base construction, (3) supplementary cementing materials in portland cement, (4) synthetic aggregate, and (5) agricultural/soil amendment applications. Ash from low-sulfur subbituminous coal-fired Foster Wheeler Energia Oy pilot circulating PFBC tests in Karhula, Finland, and ash from the high-sulfur bituminous coal-fired American Electric Power (AEP) bubbling PFBC in Brilliant, Ohio, were evaluated in laboratory and pilot-scale ash use testing. This paper addresses the technical feasibility of ash use options for PFBC unit using low- sulfur coal and limestone sorbent (karhula ash) and high-sulfur coal and dolomite sorbents (AEP Tidd ash).

  20. The rare earth elements in municipal solid waste incinerators ash and promising tools for their prospecting

    Energy Technology Data Exchange (ETDEWEB)

    Funari, Valerio, E-mail: valerio.funari@unibo.it [Dipartimento di Scienze Biologiche, Geologiche e Ambientali (BiGeA)—University of Bologna, Piazza di Porta San Donato 1, Bologna (Italy); Bokhari, Syed Nadeem Hussain [General and Analytical Chemistry—Montanuniversität Leoben, Franz-Josef-Str. 18, Leoben (Austria); Vigliotti, Luigi [Istituto di Scienze Marine (ISMAR-CNR)—National Research Council, Via Piero Gobetti 101, Bologna (Italy); Meisel, Thomas [General and Analytical Chemistry—Montanuniversität Leoben, Franz-Josef-Str. 18, Leoben (Austria); Braga, Roberto [Dipartimento di Scienze Biologiche, Geologiche e Ambientali (BiGeA)—University of Bologna, Piazza di Porta San Donato 1, Bologna (Italy)

    2016-01-15

    Highlights: • The REE concentrations of bottom and fly ashes from municipal incinerators are investigated. • First attempt toward discriminating the magnetic signature (susceptibility) of ashes from incinerators. • New methods and parameters for REE prospecting, which can be determined quickly and with limited costs, are provided. - Abstract: Bottom and fly ashes from Municipal Solid Waste Incinerators (MSWI) are hazardous products that present concern for their safe management. An attractive option to reduce their impact both on the environment and the financial commitment is turning MSWI ashes into secondary raw materials. In this study we present the REE content and distribution of bottom and fly ashes from MSWI after a highly effective digestion method and samples analysis by ICP–MS. The chondrite-normalised REE patterns of MSWI bottom and fly ash are comparable with that of crustal averages, suggesting a main geogenic source. Deviations from typical crustal pattern (e.g., Eu, Tb) disclose a contribution of likely anthropogenic provenance. The correlation with major elements indicates possible sources for REE and facilitates a preliminary resource assessment. Moreover, magnetic susceptibility measurements can be a useful prospecting method in urban ores made of MSWI ashes. The relationship between REE and some influencing parameters (e.g., Pricing Influence Factor) emphasises the importance of MSWI ash as alternative source of REE and the need of further efforts for REE recovery and purification from low concentrations but high flows waste.

  1. Removal of iron from groundwater by ash: a systematic study of a traditional method.

    Science.gov (United States)

    Das, B; Hazarika, P; Saikia, G; Kalita, H; Goswami, D C; Das, H B; Dube, S N; Dutta, R K

    2007-03-22

    A traditional method for removal of iron from ground water by using ash has been systematically investigated. Ashes from five different sources, viz., banana rind, banana pseudostem, banana leaf, rice husk and bamboo has been studied. The principle applied is enhanced precipitation of iron at high pH caused by ash. The study included laboratory analysis of some relevant chemical parameters of the ashes and the efficiency of the ashes in removing iron from prefabricated water with respect to quantity of ash and corresponding increase in pH of water. The ash of banana pseudostem has been found to be most suitable for removal of iron. A low-cost and easily made iron removal system for household use has been designed and tested in the laboratory. The ash of banana pseudostem has been found to remove iron to below 0.3ppm without increasing the pH above the acceptable limit. The optimum values of the different parameters for removal of iron are 200-300mgl(-1) ash, 1.0lh(-1) flow rate and 1h of contact time with ash for groundwater having [Fe] of about 2.20ppm. The amount of ash can be increased for groundwater having higher [Fe] and can be decreased gradually during continuous use of the system. Acceptability of the method has been examined based on chemical analysis of the treated water. Increase in the essential minerals such as Ca, K has been observed in the water after treatment. The designed iron removing system is expected to be suitable for household use.

  2. Molecular genetic analysis of the Drosophila melanogaster gene absent, small or homeotic discs1 (ash1).

    Science.gov (United States)

    Tripoulas, N A; Hersperger, E; La Jeunesse, D; Shearn, A

    1994-08-01

    The absent, small or homeotic discs1 gene (ash1) is one of the trithorax set of genes. Recessive loss of function mutations in ash1 cause homeotic transformations of imaginal disc derived tissue which resemble phenotypes caused by partial loss or gain of function mutations in genes of the Antennapedia Complex and bithorax Complex. F2 screens were used to isolate P element insertion alleles and EMS-induced alleles of ash1, including one temperature-sensitive allele, and an F1 screen was used to isolate gamma-ray-induced alleles. Analysis of ash1 mutant flies that survive until the adult stage indicates that not only imaginal disc- and histoblast-derived tissues are affected but also that oogenesis requires ash1 function. Mutations in the gene brahma (brm) which also is one of the trithorax set of genes interact with mutations in ash1 such that non-lethal ash1 +/+ brm double heterozygotes have a high penetrance of homeotic transformations in specific imaginal disc- and histoblast-derived tissues. The cytogenetic location of ash1 was determined to be 76B6-11 by the breakpoint of a translocation recovered in the F1 screen. The gene Shal, which is located cytogenetically nearby ash1, was used to initiate an 84-kb genomic walk within which the ash1 gene was identified. The ash1 gene encodes a 7.5-kb transcript that is expressed throughout development but is present at higher levels during the embryonic and pupal stages than during the larval stages. During the larval stages the transcript accumulates primarily in imaginal discs. During oogenesis the transcript accumulates in the nurse cells of developing egg chambers.

  3. Volcanic ash detection and retrievals using MODIS data by means of neural networks

    Directory of Open Access Journals (Sweden)

    M. Picchiani

    2011-12-01

    Full Text Available Volcanic ash clouds detection and retrieval represent a key issue for aviation safety due to the harming effects on aircraft. A lesson learned from the recent Eyjafjallajokull eruption is the need to obtain accurate and reliable retrievals on a real time basis.

    In this work we have developed a fast and accurate Neural Network (NN approach to detect and retrieve volcanic ash cloud properties from the Moderate Resolution Imaging Spectroradiometer (MODIS data in the Thermal InfraRed (TIR spectral range. Some measurements collected during the 2001, 2002 and 2006 Mt. Etna volcano eruptions have been considered as test cases.

    The ash detection and retrievals obtained from the Brightness Temperature Difference (BTD algorithm are used as training for the NN procedure that consists in two separate steps: ash detection and ash mass retrieval. The ash detection is reduced to a classification problem by identifying two classes: "ashy" and "non-ashy" pixels in the MODIS images. Then the ash mass is estimated by means of the NN, replicating the BTD-based model performances. A segmentation procedure has also been tested to remove the false ash pixels detection induced by the presence of high meteorological clouds. The segmentation procedure shows a clear advantage in terms of classification accuracy: the main drawback is the loss of information on ash clouds distal part.

    The results obtained are very encouraging; indeed the ash detection accuracy is greater than 90%, while a mean RMSE equal to 0.365 t km−2 has been obtained for the ash mass retrieval. Moreover, the NN quickness in results delivering makes the procedure extremely attractive in all the cases when the rapid response time of the system is a mandatory requirement.

  4. Particulate hot gas stream cleanup technical issues: Task 1.0, Assessment of ash characteristics. Quarterly report, January--March 1995

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1995-05-01

    Analyses of Hot Gas Stream Cleanup (HGSC) ashes and descriptions of filter performance were made to address the problems with filter operation that are apparently linked to the collected ash. This task is designed to generate data base of the key properties of ashes collected from operating advanced particle filters and to relate these ash proeprties to the operation and performance of these filters. Activities including initial formatting of the data base and entry, modification of the permeability model, and initial design of a high-temperature test device for measuring uncompacted bulk porosity of ashe aggregates (indicator of relative cohesivity of the ash, filter cake porosity/permeability). Chemical analyses of hopper and filter cake ashes from Tidd showed that the consolidation degree could not be accounted for by condensation/adsorption from the flue gas; the mechanism is likely physical rearrangement of the ash particles.

  5. Utilization of ash fractions from alternative biofuels used in power plants

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaisen, L.; Hinge, J.; Christensen, I. (Danish Technological Inst., Aarhus (Denmark)); Dahl, J. (Force Technology, Broendby (Denmark)); Arendt Jensen, P. (DTU-CHEC, Kgs. Lyngby (Denmark)); Soendergaard Birkmose, T. (Dansk Landbrugsraadgivning, Landscentret, Aarhus (Denmark)); Sander, B. (DONG Energy, Fredericia (Denmark)); Kristensen, O. (Kommunekemi A/S, Nyborg (Denmark))

    2008-07-15

    phosphor content and the content of the stated micro elements are equally sized in the three fractions. Provided that the ash observes the quality demands as to i.e. heavy metals, ash may be a good fertilizer choice as regards phosphate and potassium, among others. On the contrary, ash contains no nitrogen. Many field trials have shown that the availability and the utilization of phosphate are often almost on artificial fertilizer level. The higher the combustion temperature, the lower is the phosphate availability. Bottom ash would be more suitable for fertilizer purposes than fly ash. Partly the heavy metal content in bottom ash is lower, and partly the P solubility is higher. However, the trials only show the short term P and K availability. The availability of especially phosphate must be seen on a longer term, as phosphate only must replace the P and K that is used by the crop. Normally, Danish arable areas are in a fertilizer condition so fine that an optimum yield can be obtained if P and K are available during a longer period. Therefore, further studies are needed for examining the P and K availability for a longer term than one year. The nutrient composition and concentration in the examined ash products are in level with fertilizers. However, the variation between the products is so high that the utilization range of the ash products will be very wide. Five of the products are mostly characterised as K fertilizer, two are primarily P fertilizers, while one can be characterised as PK fertilizer. (LN)

  6. Ordovician ash geochemistry and the establishment of land plants

    Directory of Open Access Journals (Sweden)

    Parnell John

    2012-08-01

    Full Text Available Abstract The colonization of the terrestrial environment by land plants transformed the planetary surface and its biota, and shifted the balance of Earth’s biomass from the subsurface towards the surface. However there was a long delay between the formation of palaeosols (soils on the land surface and the key stage of plant colonization. The record of palaeosols, and their colonization by fungi and lichens extends well back into the Precambrian. While these early soils provided a potential substrate, they were generally leached of nutrients as part of the weathering process. In contrast, volcanic ash falls provide a geochemically favourable substrate that is both nutrient-rich and has high water retention, making them good hosts to land plants. An anomalously extensive system of volcanic arcs generated unprecedented volumes of lava and volcanic ash (tuff during the Ordovician. The earliest, mid-Ordovician, records of plant spores coincide with these widespread volcanic deposits, suggesting the possibility of a genetic relationship. The ash constituted a global environment of nutrient-laden, water-saturated soil that could be exploited to maximum advantage by the evolving anchoring systems of land plants. The rapid and pervasive inoculation of modern volcanic ash by plant spores, and symbiotic nitrogen-fixing fungi, suggests that the Ordovician ash must have received a substantial load of the earliest spores and their chemistry favoured plant development. In particular, high phosphorus levels in ash were favourable to plant growth. This may have allowed photosynthesizers to diversify and enlarge, and transform the surface of the planet.

  7. Current Methods to Detoxify Fly Ash from Waste Incineration

    Energy Technology Data Exchange (ETDEWEB)

    Hallgren, Christine; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2004-07-01

    Fly ash from waste incineration contains large amounts of heavy metals and dioxins, which will cause a significant disposal problem within the coming years. The amount of fly ash produced in Sweden is currently approximately 60,000 tons/y. New technological options for the decontamination and/or inertization of incinerator fly ash are being developed with the objective of rendering a product that can be reused or, at least, be deposited at standard landfill sites with no risk. Many of these technologies have been tested at industrial scale or in pilot projects. The proposed alternatives include: Thermal treatments; Immobilization/stabilization by cement based techniques; Wet chemical treatments (extractions, immobilizations); Microbiological treatments. Of these, thermal treatments are the most promising solution. Depending on the temperature thermal treatments are classified in two main types: 1) low temperature (below 600 deg C) thermal treatments and 2) high temperature (above 1200 deg C) thermal treatments (vitrification). Most dioxins can be successfully destroyed at temperatures up to 400 deg C under oxygen deficient conditions and at temperatures up to 600 deg C under oxidising conditions. However most heavy metals remain in the fly ash after low temperature treatment. At a temperature of 900 deg C most heavy metals can also be removed in a 10% HCl atmosphere by forming volatile metal chlorides (CT-Fluapur process). During vitrification processes the fly ash melts and forms an inert glassy slag. The product does not leach any significant amount of heavy metals and is free from dioxin. The volume of the fly ash is significantly reduced. The product can be land filled at low costs or used as construction material. The properties of the product depend on the cooling process and on additives such as sand, limestone or waste glass. A series of vitrification methods at industrial size or in pilot scale using different furnaces are studied. Among these, plasma

  8. High fat diet modifies the association of lipoprotein lipase gene polymorphism with high density lipoprotein cholesterol in an Asian Indian population.

    Science.gov (United States)

    Ayyappa, K A; Shatwan, I; Bodhini, D; Bramwell, L R; Ramya, K; Sudha, V; Anjana, R M; Lovegrove, J A; Mohan, V; Radha, V; Vimaleswaran, K S

    2017-01-01

    Single nucleotide polymorphisms (SNPs) in lipoprotein lipase gene (LPL) have been shown to influence metabolism related to lipid phenotypes. Dietary factors have been shown to modify the association between LPL SNPs and lipids; however, to date, there are no studies in South Asians. Hence, we tested for the association of four common LPL SNPs with plasma lipids and examined the interactions between the SNPs and dietary factors on lipids in 1,845 Asian Indians. The analysis was performed in 788 Type 2 diabetes cases and 1,057 controls randomly chosen from the cross-sectional Chennai Urban Rural Epidemiological Study. Serum triacylglycerol (TAG), serum total cholesterol, and high-density lipoprotein cholesterol (HDL-C) were measured using a Hitachi-912 autoanalyzer (Roche Diagnostics GmbH, Mannheim, Germany). Dietary intake was assessed using a semi-quantitative food frequency questionnaire. The SNPs (rs1121923, rs328, rs4922115 and rs285) were genotyped by polymerase chain reaction followed by restriction enzyme digestion and 20% of samples were sequenced to validate the genotypes obtained. Statistical Package for Social Sciences for Windows version 22.0 (SPSS, Chicago, IL) was used for statistical analysis. After correction for multiple testing and adjusting for potential confounders, SNPs rs328 and rs285 showed association with HDL-C (P = 0.0004) and serum TAG (P = 1×10(-5)), respectively. The interaction between SNP rs1121923 and fat intake (energy %) on HDL-C (P = 0.003) was also significant, where, among those who consumed a high fat diet (28.4 ± 2.5%), the T allele carriers (TT + XT) had significantly higher HDL-C concentrations (P = 0.0002) and 30% reduced risk of low HDL-C levels compared to the CC homozygotes. None of the interactions on other lipid traits were statistically significant. Our findings suggest that individuals carrying T allele of the SNP rs1121923 have increased HDL-C levels when consuming a high fat diet compared

  9. Performance evaluation of cement stabilized fly ash-GBFS mixes as a highway construction material.

    Science.gov (United States)

    Singh, S P; Tripathy, D P; Ranjith, P G

    2008-01-01

    Fly ash and granulated blast furnace slag (GBFS) are major by-products of thermal and steel plants, respectively. These materials often cause disposal problems and environmental pollution. Detailed laboratory investigations were carried out on cement stabilized fly ash-(GBFS) mixes in order to find out its suitability for road embankments, and for base and sub-base courses of highway pavements. Proctor compaction test, unconfined compressive strength (UCS) test and California Bearing Ratio (CBR) test were conducted on cement stabilized fly ash-GBFS mixes as per the Indian Standard Code of Practice. Cement content in the mix was varied from 0% to 8% at 2% intervals, whereas the slag content was varied as 0%, 10%, 20%, 30% and 40%. Test results show that an increase of either cement or GBFS content in the mixture, results in increase of maximum dry density (MDD) and decrease of optimum moisture content (OMC) of the compacted mixture. The MDD of the cement stabilized fly ash-GBFS mixture is comparably lower than that of similarly graded natural inorganic soil of sand to silt size. This is advantageous in constructing lightweight embankments over soft, compressible soils. An increase in percentage of cement in the fly ash-GBFS mix increases enormously the CBR value. Also an increase of the amount of GBFS in the fly ash sample with fixed cement content improves the CBR value of the stabilized mix. In the present study, the maximum CBR value of compacted fly ash-GBFS-cement (52:40:8) mixture obtained was 105%, indicating its suitability for use in base and sub-base courses in highway pavements with proper combinations of raw materials.

  10. Wood ash. A potential forest fertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Kuokkanen, M.; Kuokkanen, T. (Univ. of Oulu, Dept. of Chemistry (Finland)). email: toivo,kuokkanen@oulu.fi; Poeykioe, R. (City of Kemi (Finland)); Nurmesniemi, H. (Stora Enso Oyj, Veitsiluoto Mill, Kemi (Finland))

    2009-07-01

    The enhancement of wood-derived energy plays an important role in the Finnish energy and climate strategies. The use of new and upgraded biomass fuels, e.g. pellets and briquettes, has become more common in recent years, especially fuel pellets which are well suited for home heating applications. Although electrical and district heating are still the most popular heating systems in news detached and row houses in Finland, stoves and fireplaces which burn biomass fuels, e.g. logs, pellets and briquettes, are commonly used as a secondary heating system. It has been estimated that about 100 000 wood fired heating systems are currently in operation in Finland. Thousands of small-scale boilers are sold annually, and about 30% of the wood heating systems are fuelled by wood chips or pellets. Compared to traditional firewood, pellets provide possibilities for automation and optimization in the same way as for oil, with high combustion efficiency and small combustion residues. In addition, wood pellets can be stored and traded at the regional, national and international level. These features, combined with the other advantages such as environmental benefits (i.e. CO{sub 2} neutral fuel), low moisture content and bulk density (i.e. 0.28 bulk-m3 of wood pellets is equivalent to 1 bulk-m3 of wood chips), as well as a relatively high heating (i.e. calorific) value (about 17 MJ/kg), which allows long-distance transport without affecting the energy balance make wood pellets attractive in many countries from both the demand and the supply side of the market. Wood ash usually contains mineral plant nutrients, especially base cations (e.g. Ca, Mg, K), and has a strongly alkaline pH. For this reason, it would be ecologically beneficial if the ash that contains plant nutrients could be returned back to the forest ecosystem. This would save primary resources and can be seen as an example of the sustainable use of biomass. The purpose of this study was to determine the physical and

  11. Studies of the Constitution of Fly Ash Using Selective Dissolution.

    Science.gov (United States)

    1983-05-01

    crystalline phase based on its single strongest XRD peak. Fly ash collected at plants where anthracite or bituminous coal is burned tends to contain small...may be graphite . (e) One or two short crystals of prismatic habit were found in this residue. They had parallel extinction, high birefringency, and

  12. Magnetic properties of nanoparticles of cenospheres from energetic ashes

    Science.gov (United States)

    Balaev, A. D.; Rabchevskii, E. V.; Anshits, A. G.; Petrov, M. I.

    2006-12-01

    The application of magnetic cenospheres including ferrospinel nanoparticles as a “transport container” in medicine and biology is quite attractive. Their nanoscale size, high porosity, and well pronounced magnetic properties provide good consumer choice. In this contribution, we report on the magnetic properties of microspheres from energetic ashes of Ekibastuz coals.

  13. Magnetic properties of nanoparticles of cenospheres from energetic ashes

    Energy Technology Data Exchange (ETDEWEB)

    Balaev, A.D.; Rabchevskii, E.V.; Anshits, A.G.; Petrov, M.I. [Russian Academy of Sciences, Krasnoyarsk (Russian Federation)

    2006-12-15

    The application of magnetic cenospheres including ferrospinel nanoparticles as a 'transport container' in medicine and biology is quite attractive. Their nanoscale size, high porosity, and well pronounced magnetic properties provide good consumer choice. In this contribution, we report on the magnetic properties of microspheres from energetic ashes of Ekibastuz coals.

  14. Mechanical properties of millet husk ash bitumen stabilized soil block

    African Journals Online (AJOL)

    This study presents an investigation into the improvement of strength and durability properties of lateritic soil blocks using Millet Husk Ash (MHA) and Bitumen as additives so as to reduce its high cost and find alternative disposal method for agricultural waste. The lateritic soil samples were selected and treated with 0%, ...

  15. influence of addition of rice husk ash on porcelain composition

    African Journals Online (AJOL)

    ABSTRACT. Rice husk ash (RHA) has long been known to possess high silica content. The abundance of rice husk as agricultural waste makes it the most promising to be used as a supplementary cementations and ceramic material. In this study RHA was used as an additive material on porcelain body. The rice husk was ...

  16. Influence of Addition of Rice Husk Ash on Porcelain Composition ...

    African Journals Online (AJOL)

    Rice husk ash (RHA) has long been known to possess high silica content. The abundance of rice husk as agricultural waste makes it the most promising to be used as a supplementary cementations and ceramic material. In this study RHA was used as an additive material on porcelain body. The rice husk was subjected to ...

  17. Phosphorus recovery from sewage sludge ash through an electrodialytic process

    DEFF Research Database (Denmark)

    Guedes, Paula; Couto, Nazare; Ottosen, Lisbeth M.

    2014-01-01

    The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB...

  18. Leaching studies of inorganic and organic compounds from fly ash

    NARCIS (Netherlands)

    Ariese, F.; Swart, K.; Morabito, R.; Brunori, C.; Balzamo, S.; Slobodnik, J.; Korenkova, E.; Janos, P.; Wildnerova, M.; Hlavay, J.; Polyak, K.; Fodor, P.; Muntau, H.

    2002-01-01

    Fly ash is produced in massive quantities by fossil fuel based power plants and waste incinerators, and contains high levels of potentially toxic chemicals. Various leaching tests exist to determine the available fractions, but the outcome is strongly dependent on the experimental conditions, and

  19. The Effects of Bottom Ash on Setting Time and Compressive Strength of Fly Ash Geopolymer Paste

    Science.gov (United States)

    Affandhie, B. A.; Kurniasari, P. T.; Darmawan, M. S.; Subekti, S.; Wibowo, B.; Husin, N. A.; Bayuaji, R.; Irawan, S.

    2017-11-01

    This research is to find out the contribution of waste energy utilization of fly ash and bottom ash coal as binding agent of geopolymer concrete. This research methodology uses experimental approach in laboratory by making cylinder paste test object with dimension diameter of 2.5 cm x height 5 cm with some combination of fly ash and bottom ash mix with time setting test (ASTM C 191-04a) and compressive strength (ASTM C 39-04a). The research concludes that the effect of bottom ash on fly ash-based geopolymer paste shows good results in setting time and compressive strength.

  20. Formation and maintenance of high-nitrate, low pH layers in the eastern Indian Ocean and the role of nitrogen fixation

    Directory of Open Access Journals (Sweden)

    A. M. Waite

    2013-08-01

    Full Text Available We investigated the biogeochemistry of low dissolved oxygen high-nitrate (LDOHN layers forming against the backdrop of several interleaving regional water masses in the eastern Indian Ocean, off northwest Australia adjacent to Ningaloo Reef. These water masses, including the forming Leeuwin Current, have been shown directly to impact the ecological function of Ningaloo Reef and other iconic coastal habitats downstream. Our results indicate that LDOHN layers are formed from multiple subduction events of the Eastern Gyral Current beneath the Leeuwin Current (LC; the LC originates from both the Indonesian Throughflow and tropical Indian Ocean. Density differences of up to 0.025 kg m−3 between the Eastern Gyral Current and the Leeuwin Current produce sharp gradients that can trap high concentrations of particles (measured as low transmission along the density interfaces. The oxidation of the trapped particulate matter results in local depletion of dissolved oxygen and regeneration of dissolved nitrate (nitrification. We document an associated increase in total dissolved carbon dioxide, which lowers the seawater pH by 0.04 units. Based on isotopic measurements (δ15N and δ18O of dissolved nitrate, we determine that ~ 40–100% of the nitrate found in LDOHN layers is likely to originate from nitrogen fixation, and that, regionally, the importance of N-fixation in contributing to LDOHN layers is likely to be highest at the surface and offshore.

  1. Electrodialytic extraction of phosphorus from ash of low-temperature gasification of sewage sludge

    DEFF Research Database (Denmark)

    Parés Viader, Raimon; Jensen, Pernille Erland; Ottosen, Lisbeth M.

    2015-01-01

    Low-temperature gasification allows the production of energy from biomass with high contents of low melting point compounds, like sewage sludge, and the recycling of the nutrients as P from the resulting ashes as renewable fertiliser. Major drawbacks are, however, the presence of heavy metals...... and the low plant-availability of Al- and Fe- phosphate compounds in the gasification ashes. In the present research, the feasibility of a 2-compartment electrodialytic (ED) setup for P separation from Al, Fe and heavy metals in two different low-temperature gasification ashes was investigated. One ash...... was from gasification of sewage sludge where P was precipitated with Fe and Al salts, from which it was possible to extract up to 26% of the P. The other ash was from co-gasification of a mixture of biologically precipitated sewage sludge and wheat straw pellets. More promising results were obtained...

  2. Influence of ash on the fiber composition of dried dairy manures.

    Science.gov (United States)

    Reeves, James B; Van Kessel, Jo Ann S

    2002-01-01

    The objective of this work was to examine the role of ash in the compositional analysis of dried dairy manures. Ninety-nine dairy manures obtained from Connecticut, Maryland, New York, Pennsylvania and Virginia were dried at 60 degrees C, and ground to 20 mesh. Samples were analyzed for neutral and acid detergent fiber, acid detergent lignin, total carbon, total nitrogen, and ash. In addition, cellulose and hemicellulose were computed by difference. Results indicated that high ash contents (8-52% of dry matter) can dramatically and unpredictably alter various measures of fiber composition and are a significant source of error in the determination of manure composition and how it relates to mineralization or other compositional influenced factors. Also, while the ash content of the dried intact manure can easily be determined, it is difficult to estimate the ash contribution to the individual fiber determinations, especially if sequential assays are performed.

  3. High-Resolution Soil Moisture Retrieval using SMAP-L Band Radiometer and RISAT-C band Radar Data for the Indian Subcontinent

    Science.gov (United States)

    Singh, G.; Das, N. N.; Panda, R. K.; Mohanty, B.; Entekhabi, D.; Bhattacharya, B. K.

    2016-12-01

    Soil moisture status at high resolution (1-10 km) is vital for hydrological, agricultural and hydro-metrological applications. The NASA Soil Moisture Active Passive (SMAP) mission had potential to provide reliable soil moisture estimate at finer spatial resolutions (3 km and 9 km) at the global extent, but suffered a malfunction of its radar, consequently making the SMAP mission observations only from radiometer that are of coarse spatial resolution. At present, the availability of high-resolution soil moisture product is limited, especially in developing countries like India, which greatly depends on agriculture for sustaining a huge population. Therefore, an attempt has been made in the reported study to combine the C-band synthetic aperture radar (SAR) data from Radar Imaging Satellite (RISAT) of the Indian Space Research Organization (ISRO) with the SMAP mission L-band radiometer data to obtain high-resolution (1 km and 3 km) soil moisture estimates. In this study, a downscaling approach (Active-Passive Algorithm) implemented for the SMAP mission was used to disaggregate the SMAP radiometer brightness temperature (Tb) using the fine resolution SAR backscatter (σ0) from RISAT. The downscaled high-resolution Tb was then subjected to tau-omega model in conjunction with high-resolution ancillary data to retrieve soil moisture at 1 and 3 km scale. The retrieved high-resolution soil moisture estimates were then validated with ground based soil moisture measurement under different hydro-climatic regions of India. Initial results show tremendous potential and reasonable accuracy for the retrieved soil moisture at 1 km and 3 km. It is expected that ISRO will implement this approach to produce high-resolution soil moisture estimates for the Indian subcontinent.

  4. Influence of fly ash fineness on water requirement and shrinkage of blended cement mortars

    Directory of Open Access Journals (Sweden)

    Vanissorn Vimonsatit

    2015-12-01

    Full Text Available In this paper, the influence of fly ash fineness on water requirement and shrinkage of blended cement mortar was studied. The results indicate that the water requirement and shrinkage characteristic of the blended cement mortar are dependent on fly ash fineness and replacement level. The use of coarse fly ash slightly reduces the water requirement but greatly reduced the drying and the autogenous shrinkage of the blended cement mortars and the reduction is more with an increase in the fly ash replacement level. The finer fly ashes further reduce the water requirement, but increase the drying and the autogenous shrinkages as compared with coarser fly ash. The incorporation of superplasticizer drastically reduces the water requirement, but the effect on the drying and autogenous shrinkages of the normal Portland cement mortar is small. However, for the fly ash mortar, the use of superplasticizer results in a decrease in drying shrinkage and in a substantial increase in the autogenous shrinkage particularly for the fine fly ash at a high replacement level.

  5. SO2 as a possible proxy for volcanic ash in aviation hazard avoidance

    Science.gov (United States)

    Sears, T. M.; Thomas, G. E.; Carboni, E.; Smith, A. J. A.; Grainger, R. G.

    2013-06-01

    Airborne volcanic ash poses a significant danger to aircraft, but is difficult to quantify accurately using satellite data, while sulphur dioxide is much easier to detect accurately, but is much less of a direct hazard to aviation. This paper investigates the reliability of using SO2 as a proxy for the location of volcanic ash, using an SO2 retrieval from the Infrared Atmospheric Sounding Interferometer (IASI) and ash detections from IASI and the Advanced Along Track Scanning Radiometer (AATSR). Using a numerical "missed ash fraction" applied to the eruptions of Eyjafjallajökull in 2010 and Puyehue-Cordón Caulle in 2011 reveals that the SO2 flag typically misses ˜30% of the detectable ash. Furthermore, the missed ash fraction is found to be highly variable, both between the two eruptions and over the course of each eruption, with values of over 80% found on some days. The detection threshold of the AATSR ash flag is also investigated using radiative transfer calculations, allowing the threshold of the IASI flag to be inferred, and these are related to the ash contamination levels.

  6. MORPHOLOGICAL AND MECHANICAL PROPERTIES OF MT. KELUD VOLCANIC ASH REINFORCED POLYESTER AND EPOXY COMPOSITES

    Directory of Open Access Journals (Sweden)

    Henny Pratiwi

    2017-03-01

    Full Text Available The use of suitable waste products as raw materials has become an interesting matter in composite industry nowadays due to the environmental issues. Volcanic ash is one of the waste materials containing a high number of silica. The aim of this study is to examine the morphological and mechanical properties of Mt. Kelud volcanic ash reinforced polyester and epoxy composites. The volcano ash was dried and sieved into 50 mesh then mixed with polyester or epoxy manually for 10 minutes. The ash added into the matrix was varied by 0%, 10%, 20%, 30% and 40% from matrix volume content. For epoxy matrix, the composite with 40 vol. % particles has the highest tensile strength. However, for the polyester/ash composites, the tensile strength continues to decrease with the addition of particles. There is a significant increasing of 47.04 % for polyester and 5.62 % for epoxy in impact strength when 40 vol. % of volcanic ash added into both polymers. The Scanning Electron Microscopy result shows that there is void and agglomeration contained in epoxy/ash composites and crack propagation along the surface of polyester/ash composites that could be the cause of the failure.

  7. Characteristics and heavy metal leaching of ash generated from incineration of automobile shredder residue.

    Science.gov (United States)

    Lee, Hwa Young

    2007-08-17

    Bottom and fly ash collected from automobile shredder residue (ASR) incinerator have been characterized in terms of particle size, compositions, and heavy metal leaching by the standard TCLP method. Two alternative methods were also examined for the treatment of heavy metals in ASR incinerator ash from the aspect of recycling into construction or lightweight aggregate material. It was remarkable that the concentration of Cu was very high compared to common MSWI bottom and fly ash, which was probably originated from copper wires contained in ASR. As a whole, the results of characterization of ASR fly ash were in good agreement with common MSWI fly ash in terms of particle size, pH, and water-soluble compounds. It was clearly found that heavy metals could be removed thoroughly or partly from ASR fly ash through acid washing with dilute HCl solution so that the remaining fly ash could be landfilled or used as construction material. It was also found that the amount of heavy metal leachability of lightweight aggregate pellet prepared with ASR incineration ash could be significantly decreased so that the application of it to lightweight aggregate would be possible without pre-treatment for the removal of heavy metals.

  8. Experimental investigation of clay fly ash bricks for gamma-ray shielding

    Energy Technology Data Exchange (ETDEWEB)

    Mann Harjinder Singh; Mudahar, Gumel Singh [Dept. of Physics, Punjabi University, Patiala (India); Brar, Gurdarshan Singh [Dept. of Higher Education, Additional Project Director, Chandigarh (India); Mann, Kulwinder Singh [Dept. of Applied Sciences, I.K. Gujral Punjab Technical University, Jalandhar (India)

    2016-10-15

    This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

  9. 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.

  10. 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.

  11. Electrodialytic extraction of Cu, Pb and Cl from municipal solid waste incineration fly ash suspended in water

    DEFF Research Database (Denmark)

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

    2006-01-01

    The possibility of using fly ash from municipal solid waste incineration (MSWI) in, for example, concrete is considered. MSWI fly ash, however, has too high a concentration of heavy metals, which may cause leaching problems during use or problems with waste handling at the end of the lifetime...... of the concrete. The Cl content in MSWI fly ash is also too high and will cause corrosion problems in reinforced concrete. The possibility of removing some of the unwanted heavy metals (Cu and Pb) together with Cl from an MSWI fly ash suspended in water using an electrodialytic separation method was investigated...

  12. Effects of kaolin-additions in combustion of wood fuels on hardening and leaching properties of ash; Paaverkan av kaolintillsats vid foerbraenning av biobraensle paa askans haerdnings- och lakningsegenskaper

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Karlfeldt, Karin (Dept. of Chemical And Biological Engineering, Chalmers Univ. of Technology, SE-412 96 Goeteborg (Sweden)). e-mail: bms@chalmers.se

    2007-06-15

    In several investigations it has been shown that kaolin works well as an anti-agglomerating and anti-ash sintering agent in combustion of bio-fuels with a potassium rich ash in fluidised bed boilers. Combustion tests have shown that the kaolin addition may result in an ash melting temperature that is a couple of hundred degrees centigrade higher than for the original ash. This way the kaolin hinders the fouling of super heater surfaces by sticky ash. Many boiler owners treat their wood fuel ash with the aim to recycle it to forest soil as a nutrient source and acid neutralising agent. Therefore it was considered important to investigate if an addition of kaolin in the boiler would have a negative influence on the ash leaching properties. Thus, the aim of the project was to investigate the hardening reactions and leaching properties of normal wood ash and wood ash produced with addition of kaolin. The ash samples were produced in the same boiler and in similar combustion conditions. It was especially interesting to study if the ash would contain soluble aluminium due to the kaolin addition since aluminium in solution may have negative effects on the eco system. The results showed that an important difference between the normal fly ash and the fly ash with kaolin was that the release of potassium i leaching was decreased due to the kaolin addition, especially at high pH levels. This is positive, since potassium normally is released very fast in the forest. In addition, the kaolin containing ash has a faster initial setting/hardening process than the normal ash. The structure of the hardened ash particles is also more durable than that of the normal ash. This is also a positive effect since it indicates that it could be possible to handle the hardened ash after a shorter storage period. However, it has not been investigated if this effect remains in large scale operation and in a longer time perspective. The acid neutralising capacity of fly ash with kaolin is

  13. Wood pellet fly ash and bottom ash as an effective liming agent and nutrient source for rye grass (Lolium perenne L.) and oats (Avena sativa).

    Science.gov (United States)

    Park, Nathan D; Michael Rutherford, P; Thring, Ronald W; Helle, Steve S

    2012-01-01

    Fly ash (FA) and bottom ash (BA) from a softwood pellet boiler were characterized and evaluated as soil amendments. In a greenhouse study, two plant species (rye grass, Lolium perenne L. and oats, Avena sativa) were grown in three different treatments (1% FA, 1% BA, non-amended control) of a silty loam soil. Total concentrations of plant nutrients Ca, K, Mg, P and Zn in both ashes were elevated compared to conventional wood ash. Concentrations of Cd, Cr, Pb, Se and Zn were found to be elevated in the FA relative to BA and the non-amended soil. At 28 d, oat above-ground biomass was found to be significantly greater in soil amended with FA. Potassium and Mo plant tissue concentrations were significantly increased by addition of either ash, and FA significantly increased Zn tissue concentrations. Cadmium and Hg tissue concentrations were elevated in some cases. As soil amendments, either pellet ash is an effective liming agent and nutrient source, but high concentrations of Cd and Zn in FA may preclude its use as an agricultural soil amendment in some jurisdictions. Lower ash application rates than those used in this study (i.e. <1%) may still provide sufficient nutrients and effective neutralization of soil acidity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  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. Postglacial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.

    uopics and the Vlgorous exchange between rhe Indian and Atlantic oceans at the end of Dasr flvc elacial Deriods. hrature 430. 661-665. continent. summer is characterized high Ruhlemann, C., Guller, P. i, and ichnelder, R. R. (199$). Organic solar... is characterized by tow solar radiation, cold temperature, and northeasterly winds, which flow from the cold Asian continent toward the Arabian Sea. These continental winter monsoon winds carry little moisture and have Rum 1 Atm-ric dilation Wing thg summer...

  16. Radioactive wastes dispersed in stabilized ash cements

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Taylor, C.M.V.; Sivils, L.D.; Carey, J.W.

    1997-12-31

    One of the most widely-used methods for the solidification/stabilization of low-level radwaste is by incorporation into Type-I/II ordinary portland cement (OPC). Treating of OPC with supercritical fluid carbon dioxide (SCCO{sub 2}) has been shown to significantly increase the density, while simultaneously decreasing porosity. In addition, the process significantly reduces the hydrogenous content, reducing the likelihood of radiolytic decomposition reactions. This, in turn, permits increased actinide loadings with a concomitant reduction in disposable waste volume. In this article, the authors discuss the combined use of fly-ash-modified OPC and its treatment with SCCO{sub 2} to further enhance immobilization properties. They begin with a brief summary of current cement immobilization technology in order to delineate the areas of concern. Next, supercritical fluids are described, as they relate to these areas of concern. In the subsequent section, they present an outline of results on the application of SCCO{sub 2} to OPC, and its effectiveness in addressing these problem areas. Lastly, in the final section, they proffer their thoughts on why they believe, based on the OPC results, that the incorporation of fly ash into OPC, followed by supercritical fluid treatment, can produce highly efficient wasteforms.

  17. Superior photocatalytic, electrocatalytic, and self-cleaning applications of Fly ash supported ZnO nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Thirumalai, Kuppulingam; Balachandran, Subramanian [Department of Chemistry, Annamalai University, Annamalainagar, 608 002, Tamil Nadu (India); Swaminathan, Meenakshisundaram, E-mail: chemres50@gmail.com [Department of Chemistry, Annamalai University, Annamalainagar, 608 002, Tamil Nadu (India); Nanomaterials Laboratory, International Research Centre, Kalasalingam Universty, Krihnankoil, 626126 (India)

    2016-11-01

    Ever growing research on modified semiconductor oxides made a significant progress in catalytic functional materials. In this article, we report the modification of ZnO photocatalyst by a simple hydrothermal decomposition method utilizing the cheaply available industrial waste fly ash. This modified Fly ash-ZnO photocatalyst was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HR-TEM), Atomic force microscopy (AFM), photoluminescence spectroscopy (PL) and diffuse reflectance spectroscopy (DRS). The XRD pattern indicates the presence of fly ash components and the hexagonal wurtzite structured ZnO. TEM images reveal well defined nanorod like structure. Reduction of photoluminescence intensity of Fly ash-ZnO at 418 nm, when compared to, prepared ZnO, indicates the suppression of recombination of the photogenerated electron–hole pair by loaded Fly ash on ZnO. Fly ash-ZnO exhibits enhanced photocatalytic activity for the degradation of azo dyes Reactive Orange 4, Rhodamine-B and Trypan Blue. This catalyst shows higher electrocatalytic activity than ZnO in the oxidation of methanol. Significant hydrophobicity of Fly ash-ZnO reveals its self cleaning property. - Highlights: • The degradation efficiency of Fly ash-ZnO under UV and Solar irradiation is greater than prepared ZnO and TiO{sub 2}‒P25. • Electrocatalytic activity of Fly ash-ZnO exhibits enhanced current production by methanol oxidation. • Fly ash-ZnO shows the high hydrophobicity than ZnO, it can be used as a self cleaning material for industrial applications.

  18. Effect of Fly-ash on The Performance of Asphalt Concrete Mixes

    Directory of Open Access Journals (Sweden)

    Aliaa Faleh Al.ani

    2017-08-01

    Full Text Available At last year, effectively fly ash has been used in producing high performance concrete mixes with limited used in asphalt pavements. This is possibly due to the performance advantage that fly ash equipped to asphalt mixes in now days. A bituminous paving mixture is a mix of coarse aggregate, fine aggregate and bitumen mixed in suitable proportion to result strong and durable mix to bear traffic load. In this paving mix, normally limestone and fly ash are used as filler material. In this research , the performance of asphalt concrete mixes modified with fly ash as a partial replacement of limestone dust mineral filler were evaluated. Four replacement rates were used; 0, 1, 2, and 3 percent by weight of aggregate. Asphalt concrete mixes were prepared at their optimum asphalt content and then tested to evaluate their engineering properties which include moisture damage, resilient modulus, permanent deformation and fatigue characteristics. These properties have been evaluated using indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. Mixes modified with fly ash were found to have improved fatigue and permanent deformation characteristics, also showed lower moisture susceptibility and high resilient modulus. the result showed that a rate changed from 1 to 3 percent has shown an increase in resilient modulus for addition of fly ash as a filler substitute and the resilient modulus for mixes with 3 percent fly ash was 1.31 times that for mixes with 0 percent fly ash. The altering of fly ash as a filler substitute from a range (1-3 percent has modified the fatigue property of the asphalt concrete mixes as determined by flexural test, Significantly, to modify the asphalt concrete manner taken the percent of fly ash 2, and to produce the mixes more durable , higher resistance to distresses by adding the local knowledge.

  19. Evaluation of leachates from coal refuse blended with fly ash at different rates.

    Science.gov (United States)

    Stewart, B R; Daniels, W L; Zelazny, L W; Jackson, M L

    2001-01-01

    There is great interest in returning coal combustion products to mining sites for beneficial reuse as liming agents. A column study examined the effects of blending two coal fly ashes with an acid-forming coal refuse (4% pyritic S). Both fly ashes were net alkaline, but had relatively low neutralizing capacities. One ash with moderate alkalinity (CRF) was bulk blended with coal refuse at 0, 20, and 33% (w/w), while another lower alkalinity ash (WVF) was blended at 0, 5, 10, 20, and 33% (w/w). The columns were leached (unsaturated) weekly with 2.5 cm of simulated precipitation for >150 wk. Where high amounts of ash alkalinity (>20% w/w) were mixed with the coal refuse, pyrite oxidation was controlled and leachate pH was >7.0 with low metal levels throughout the study. At lower rates of alkalinity loading, trace metals were sequentially released from the WVF ash as the 5, 10, and 20% treatments acidified due to pyrite oxidation. Lechate metals increased in proportion to the total amounts applied in the ash. In this strongly acidic environment, metals such as Mn, Fe, and Cu were dissolved and leached from the ash matrix in large quantities. If ash is to be beneficially reused in the reclamation of acid-producing coal refuse, the alkalinity and potential acidity of the materials must be balanced through the appropriate addition of lime or other alkaline materials to the blend. Highly potentially acidic refuse material, such as that used here, may not be suitable for ash/refuse codisposal scenarios.

  20. Effect of additives in reducing ash sintering and slagging in biomass combustion applications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liang

    2012-07-01

    The objective of this study was to investigate sintering and slagging behaviors of biofuels during combustion processes. Biofuels tested are derived from the agricultural sector, wood and furniture industry as well as from municipal sewage sludge. It was also the aim to test and evaluate additives that can prevent and abate biomass ash sintering by conducting laboratory and industrial scale tests. Sintering characteristics of sewage sludge ashes at elevated temperatures were investigated by means of different laboratory methods. Utilizing of phosphorus participation agents Al2(SO4)3 or Fe2(SO4)3 caused substantially high contents of aluminum or iron in the studied sewage sludge ashes, respectively. High initial melting temperatures over 1100 degrees C and low sintering tendencies were observed from the sewage sludge ashes rich in aluminum. It was related to presence and formation of the inert mineral phases such as aluminum oxide, quartz and calcium aluminum silicates in the aluminum rich sewage sludge ashes at elevated temperatures. A low melting temperature, about 994 degree C, was detected from the iron rich sewage sludge ash. Severe sintering of this sewage sludge ash was mainly due to generation of low temperature melting iron silicates, as results of interaction and re-assemblage of hematite (Fe2O3), quartz (SiO2) and alkali feldspars under heating. Fusion behaviors of corn cob ashes under rising temperatures were characterized. The work revealed that chemical compositions of corn cob ashes are dominated by potassium, silicon, chlorine and phosphorus. However, the relative concentrations of these principal elements are considerably different for three studied corn cob ashes, which have major influence on ash transformation reactions and sintering tendencies. Compared with the other two, the chemical composition of the Waimanalo corn cob (WCob) was characterized with the highest K/Cl, Si/(Ca+Mg) and (Si+P+K)/(Ca+Mg) molar ratios, which was favorable for

  1. 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

  2. Gravel road stabilisation of Ehnsjoevaegen, Hallstavik[Using fly ash]; Skogsbilvaegsrenovering av Ehnsjoevaegen, Hallstavik

    Energy Technology Data Exchange (ETDEWEB)

    Macsik, Josef; Svedberg, Bo [Ecoloop, Stockholm (Sweden)

    2006-03-15

    Fly ash in geotechnical applications has stabilising, isolating, low permeability and hardening effect. Fly ash can be used in road constructions with low bearing capacity, as well as on top cover material on landfills. The aim of the project was to build a road section with fly ash stabilised gravel, based on laboratory studies, and follow up technical and environmental aspect during the first year after stabilisation. The overall aim of this project was to evaluate fly ash from Holmen Paper, Hallstavik, from technical and environmental point of view in a gravel road construction. A gravel road, Ehnsjoevaegen, was stabilised with fly ash during autumn 2004. This road was a low priority road. The fly ash stabilised road section was 1300 m long. Gravel from the road Ehnsjoevaegen was stabilised and investigated in a laboratory study. Leachability of metals and geotechnical aspects were investigated. The laboratory study showed that fly ash stabilised gravel has high shear strength, however its thawing resistance is not fully acceptable. Additives of cement or merit are needed in order to increase its thawing resistance. The actual road section is not going to be used during thawing period and no additives were used. The test road is divided into different sections including a reference section. The road stabilisation work was conducted with gravel transported to Ehnsjoevaegen from off site and not with gravel from the site. Fly ash was tipped off on a levelled road, followed by tipping of gravel. Mixing fly ash and gravel was done on site by a road scraper. After the mixing the road was gravelled with 0,1 m graded gravel. In this project the fly ash had low water content. In order to get optimal compaction water was added from a tanker supplying water before compacted with a compactor. Results from the pilot test shows that fly ash stabilised gravel can be tipped, mixed and compacted effectively. Tipping can be optimised if fly ash and gravel is mixed in a mixer

  3. Copper speciation in municipal solid waste incinerator bottom ash leachates; Kopparformer i lakvatten fraan energiaskor

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Susanna; Gustafsson, Jon Petter [Royal Inst. of Tech., Stockholm (Sweden); Schaik, Joris van; Berggren Kleja, Dan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden); Hees, Patrick van [Oerebro Univ. (Sweden)

    2006-03-15

    The formation of copper (Cu) complexes with dissolved organic carbon (DOC) in bottom ash from municipal solid waste incineration (MSWI) may increase the total amount of Cu released but at the same time reduce its toxicity. In this study, DOC in a MSWI bottom ash leachate was characterized and the Cu-binding properties of different DOC fractions in the ash leachate and in a soil solution were studied. This knowledge may be used for improved environmental assessment of MSWI bottom ash in engineering applications. The Cu{sup 2+} activity at different pH values was measured potentiometrically using a Cu-ion selective electrode (Cu-ISE). Experimental copper complexation results were compared to speciation calculations made in Visual MINTEQ with the NICA-Donnan model and the Stockholm Humic Model (SHM). The MSWI bottom ash leachate contained a larger proportion of hydrophilic organic carbon than the investigated soil solution and other natural waters. The hydrophilic fraction of both samples showed Cu{sup 2+} binding properties similar to that of the bulk, cation-exchanged, leachate. For the ash leachate, the pH dependence of the Cu activity was not correctly captured by neither the SHM nor the NICA-Donnan model, but for the soil solution the model predictions of Cu speciation were in good agreement with the obtained results. The complex formation properties of the ash DOC appears to be less pH-dependent than what is assumed for DOC in natural waters. Hence, models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate. A Biotic Ligand Model for Daphnia Magna was used to provide an estimate of the copper concentrations at LC50 for a simulated bottom ash leachate. It was concluded that the Cu concentrations in certain bottom ash leachates are high enough to pose an ecotoxicological risk; however, after dilution and soil sorption, the risks for neighboring water bodies are most likely negligible. Three processes were

  4. On the Electrical and Magnetic Properties of some Indian Spices

    CERN Document Server

    Baby, Samson K

    2010-01-01

    We have made experimental measurements of electrical conductivity, pH and relative magnetic susceptibility of the aqueous solutions of 24 indian spices. The measured values of electrical conductance of these spices are found to be linearly related to their ash content and bulk calorific values reported in literature. The physiological relevance of the pH and diamagnetic susceptibility of spices when consumed as food or medicine will be also discussed.

  5. Separation of ultrafine particles from class F fly ashes

    Directory of Open Access Journals (Sweden)

    Acar Ilker

    2016-01-01

    Full Text Available In this study, ultrafine particles were recovered from Çatalağzı (CFA and Sugözü (SFA thermal power plant fly ashes using a specific hydraulic classification technology. Since fly ashes have a high tendency to be flocculated in water, settling experiments were first designed to determine the more effective dispersant and the optimum dosage. Two different types of the superplasticizers (SP polymers based on sulphonate (NSF, Disal and carboxylate (Glenium 7500 were used as the dispersing agents in these settling experiments. Hydraulic classification experiments were then conducted to separate ultrafine fractions from the fly ash samples on the basis of the settling experiments. According to the settling experiments, better results were achieved with the use of Disal for both CFA and SFA. The classification experiments showed that the overflow products with average particle sizes of 5.2 μm for CFA and 4.4 μm for SFA were separated from the respective as-received samples with acceptable yields and high enough recoveries of -5 μm (ultrafine particles. Overall results pointed out that the hydraulic classification technology used provided promising results in the ultrafine particle separations from the fly ash samples.

  6. Leaching characteristics of ash from the May 18, 1980, eruption of Mount St. Helens volcano, Washington

    Science.gov (United States)

    Smith, D. B.; Zielinski, R. A.; Taylor, H. E.; Sawyer, M. B.

    1983-06-01

    Leaching of freshly erupted air-fall ash, unaffected by rain, from the May 18, 1980, eruption of Mount St. Helens volcano, Washington, shows that Ca2+, Na+, Mg2+, SO{4/2-}, and Cl- are the predominant chemical species released on first exposure of the ash to water. Extremely high correlation of Ca with SO4 and Na with Cl in water leachates suggests the presence of CaSO4 and NaCl salts on the ash. The amount of water soluble material on ash increases with distance from source and with the weight fraction of small (less than 63 micrometers) ash particles of high-surface area. This suggests that surface reactions such as adsorption are responsible for concentrating the soluble material. CaSO4, NaCl, and other salts are probably formed as microscopic crystals in the high-temperature core of the eruption column and are then adsorbed by silicate ash particles. The environmentally important elements Zn, Cu, Cd, F. Pb, and Ba are released by a water leach in concentrations which could pose short-term hazards to some forms of aquatic life. However, calculated concentrations are based on a water-to-ash ratio of 4:1 or less, which is probably an underestimation of the regionally operative ratio. A subsequent leach of ash by warm alkaline solution shows dramatic increases, in the amount of dissolved SiO2, U, and V, which are probably caused by increased dissolution of the glassy component of ash. Glass dissolution by alkaline ground water is a mechanism for providing these three elements to sedimentary traps where they may coaccumulate as uraniferous silica or U-V minerals. Leaching characteristics of ash from Mount St. Helens are comparable to characteristics of ash of similar composition from volcanoes in Guatemala. Ashes from each locality show similar ions predominating for a given leachate and similar fractions of a particular element in the ash removed on contact with the leach solution.

  7. Particle dispersion at road building using fly ash - model review, investigation of influence of humidity content for dust emission and fly ash particle characterisation; Partikelspriding vid byggnation av vaeg med aska - modelloeversikt, undersoekning av fuktighetsgradens betydelse foer damning och karaktaerisering av partiklar fraan flygaska

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Mats; Wik, Ola; Frogner-Kockum, Paul

    2009-03-15

    Ashes from incineration may have very good properties, such as building materials in roads. This use assumes that the ashes do not have serious environmental and health effects. Since ash might generate large amounts of dust in handling the issue on the extent of dusting and dust properties has proved to be important to assess the risks of environmental impacts during use. Inhalable particles in the ambient air are a problem that has attracted much attention and is regarded as one of the most serious health related air pollutants. The present project has aimed to: describe appropriate models for calculating the emission and dispersion of dust in the air during the construction of ash containing roads, evaluate a new method to examine the importance of moisture for dusting from fly ash and investigate the properties of fly ash, making it possible to identify ash in samples of airborne particles. The target audience is ash manufacturers, contractors and consultants with a need for knowledge of ash dusting. Project modules have included: a literature review to identify appropriate modelling tools to describe the emission and dispersion of dust from road building with ash a method study in which a piece of equipment called Duster, have been evaluated for assessing the significance of the ash humidity to dusting, and an electron microscope study where morphology and composition of some ashes, cement and Merit have been studied to find ways to identify ash particles in dust samples. The results show that there is a lack of overall model tools that can describe the emissions from all the management operations of ashes at road building and that existing models sometimes lack key variables. Also, because of high silt content of ashes, some models are deemed inferior compared to when used for ordinary mineral material. Furthermore, attempts with the Duster shows that the method works, but with limited precision, and that dusting from the ash samples was reduced significantly

  8. Indian Ledger Art.

    Science.gov (United States)

    Chilcoat, George W.

    1990-01-01

    Offers an innovative way to teach mid-nineteenth century North American Indian history by having students create their own Indian Ledger art. Purposes of the project are: to understand the role played by American Indians, to reveal American Indian stereotypes, and to identify relationships between cultures and environments. Background and…

  9. Leading Indian Business-Groups

    Directory of Open Access Journals (Sweden)

    Maria Alexandrovna Vorobyeva

    2016-01-01

    Full Text Available The goal of this paper is to investigate the evolution of the leading Indian business-groups under the conditions of economical liberalization. It is shown that the role of modern business-groups in the Indian economy is determined by their high rate in the gross domestic product (GDP, huge overall actives, substantial pert in the e[port of goods and services, as well as by their activities in modern branch structure formatting, and developing labor-intensive and high-tech branches. They strongly influence upon economical national strategies, they became a locomotive of internationalization and of transnationalization of India, the basis of the external economy factor system, the promoters of Indian "economical miracle" on the world scene, and the dynamical segment of economical and social development of modern India. The tendencies of the development of the leading Indian business groups are: gradual concentration of production in few clue sectors, "horizontal" structure, incorporation of the enterprises into joint-stock structure, attraction of hired top-managers and transnationaliziation. But against this background the leading Indian business-groups keep main traditional peculiarities: they mostly still belong to the families of their founders, even today they observe caste or communal relations which are the basis of their non-formal backbone tides, they still remain highly diversificated structures with weak interrelations. Specific national ambivalence and combination of traditions and innovations of the leading Indian business-groups provide their high vitality and stability in the controversial, multiform, overloaded with caste and confessional remains Indian reality. We conclude that in contrast to the dominant opinion transformation of these groups into multisectoral corporations of the western type is far from completion, and in the nearest perspective they will still possess all their peculiarities and incident social and economical

  10. Minor and trace elemental determination in the Indian herbal and other medicinal preparations.

    Science.gov (United States)

    Samudralwar, D L; Garg, A N

    1996-08-01

    Medicinal plants described in the Indian "Ayurvedic" literature viz. Tulsi (Ocimum sanctum), Gulvel (Tinospora cardifolia), bitter Neem (Azadirachta indica), Kanher (Nerium Andicum), Vekhand (Acorus calamus), and Peacock's feather (ash) were analyzed for minor and trace elements by instrumental neutron activation analysis. The samples and the standards from the National Institute of Standards and Technology, USA and IAEA, Vienna were irradiated for 5 min, 1 h, 5 h, and 10 h with thermal neutrons at a flux of 10(12)-10(13) n cm-2 s-1 in APSARA and CIRUS reactor at BARC, Bombay. High resolution gamma ray spectrometry was performed using a 45 cm3 HPGe detector and a 4096 MCA system. Concentrations of 13 elements were determined. Zinc, manganese, and sodium were significantly higher in Tulsi leaves while zinc is higher in Neem leaves. Peacock's feathers were found to be rich in manganese, iron, copper, and zinc. A high concentration of mercury was also found in the peacock's feather ash. The therapeutic significance in restoring ionic balance is discussed.

  11. Esophageal Cancer Epigenomics and Integrome Analysis of Genome-Wide Methylation and Expression in High Risk Northeast Indian Population.

    Science.gov (United States)

    Singh, Virendra; Singh, Laishram Chandreshwor; Vasudevan, Madavan; Chattopadhyay, Indranil; Borthakar, Bibhuti Bhusan; Rai, Avdhesh Kumar; Phukan, Rup Kumar; Sharma, Jagannath; Mahanta, Jagadish; Kataki, Amal Chandra; Kapur, Sujala; Saxena, Sunita

    2015-11-01

    Esophageal cancer is a major global health burden with a strong host-environment interaction component and epigenomics underpinnings that remain to be elucidated further. Certain populations such as the Northeast Indians suffer at a disproportionately higher rate from this devastating disease. Promoter methylation is correlated with transcriptional silencing of various genes in esophageal cancer. Very few studies on genome-wide methylation for esophageal cancer exist and yet, no one has carried out an integromics analysis of methylation and gene expression. In the present study, genome-wide methylation was measured in samples collected from the Northeast Indian population by Infinium 450k array, and integration of the methylation data was performed. To prepare a network of genes displaying enriched pathways, together with the list of genes exhibiting promoter hypermethylation or hypomethylation with inversely correlated expression, we performed an integrome analysis. We identified 23 Integrome network enriched genes with relevance to tumor progression and associated with the processes involved in metastasis such as cell adhesion, integrin signaling, cytoskeleton, and extracellular matrix organizations. These included four genes (PTK2, RND1, RND3, and UBL3) with promoter hypermethylation and downregulation, and 19 genes (SEMG2, CD97, CTNND2, CADM3, OMD, NEFM, FBN2, CTNNB1, DLX6, UGT2B4, CCDC80, PZP, SERPINA4, TNFSF13B, NPC1, COL1A1, TAC3, BMP8A, and IL22RA2) with promoter hypomethylation and upregulation. A Methylation Efficiency Index was further calculated for these genes; the top five gene with the highest index were COL1A1, TAC3, SERPINA4, TNFSF13B, and IL22RA2. In conclusion, we recommend that the circulatory proteins IL22RA2, TNFSF13B, SERPINA4, and TAC3 in serum of patients and disease-free healthy controls can be examined in the future as putative noninvasive biomarkers.

  12. Use of unwounded ash trees for the detection of emerald ash borer adults: EAB landing behavior

    Science.gov (United States)

    Jordan M. Marshall; Melissa J. Porter; Andrew J. Storer

    2011-01-01

    Incorporation of multiple trapping techniques and sites within a survey program is essential to adequately identify the range of emerald ash borer (EAB) (Agrilus planipennis Fairmaire) infestation. Within natural forests, EAB lands on stick band traps wrapped around girdled ash trees at a rate similar to that on unwounded ash trees. The objective of...

  13. Factors affecting the survival of ash (Fraxinus spp.) trees infested by emerald ash borer (Agrilus planipennis)

    Science.gov (United States)

    Kathleen S. Knight; John P. Brown; Robert P. Long

    2013-01-01

    Emerald ash borer (Agrilus planipennis) (EAB), an Asian woodboring beetle accidentally introduced in North America, has killed millions of ash (Fraxinus spp.) trees and is spreading rapidly. This study examined the effects of tree- and site-level factors on the mortality of ash trees in stands infested by EAB in OH, USA. Our data...

  14. Attraction of the emerald ash borer to ash trees stressed by girdling, herbicide treatment, or wounding

    Science.gov (United States)

    Deborah McCullough; Therese Poland; David. Cappaert

    2009-01-01

    New infestations of emerald ash borer, Agrilus planipennis Fairmaire, an invasive pest native to Asia, are difficult to detect until densities build and symptoms appear on affected ash (Fraxinus spp). We compared the attraction of A. planipennis to ash trees stressed by girdling (bark and phloem removed...

  15. Electrodialytic extraction of heavy metals from Greenlandic MSWI fly ash as a function of remediation time and L/S ratio

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Jensen, Pernille Erland; Ottosen, Lisbeth M.

    2013-01-01

    was characterized before and after the electrodialytic remediation experiments for heavy metals content, amount of soluble heavy metals and pH. Before the electrodialytic experiments the water solubility of Ba, Cr and Pb was high from the alkaline fly ash. Six electrodialytic remediation experiments were made......, where the fly ash was suspended in distilled water in different liquid to solid (L/S) ratios. Remediation times of 7 and 14 days were tested and the current strength was 50 mA in all experiments. The highest removal was seen when an acidic pH in the fly ash suspension was obtained. In an experiment......The management of Greenlandic municipal solid waste incineration (MSWI) fly ash could be improved. Presently, the fly ash is disposed of in Norway as the fly ash is classified as hazardous waste. Fly ash contains high amounts of leachable heavy metals, but also resources that could be beneficial...

  16. Ash removal by hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Rank, V.; von Hartmann, G.B.

    1942-10-17

    This method for the production of high-quality electrode coke involved the hydrogenation of coal to a filterable bitumen product. The hydrogenation and splitting processes were carried out to end at high-molecular-weight bitumens with some lighter oils produced. Variations in temperature, pressure, and throughput determined the type and amount of bitumens. Proper conditions allowed sufficient middle oil for recirculation as pasting oil as well as for increasing filterability by dilution. This partial hydrogenation could be performed without the addition of hydrogen, if hydrogen-producing aromatic compounds, such as tetraline or cresol, were used as pasting oils. For 700-atm hydrogenation, it was found that the Upper Silesian coal was the best with respect to yield, filterability, and recovery of the recycle oils. The lower pressures gave a better filterability while sacrificing yield and recycle oil. The more severe the hydrogenating conditions, the lighter the bitumens and the lower the melting point. For the range of 300 to 600 atm, it was found that filterability improved with increased temperature and decreased with a pressure gain. Larger throughputs caused relatively moderate decreases in filterability. The use of iron catalysts decreased filterability while changing gas and pasting-oil content had little effect. The optimum conditions established a pasting-oil equilibrium with the best filterability. Greater degrees of hydrogenation or splitting produced more recycle middle oils but decreased filterability, thus only the necessary paste oil was produced. By selecting proper conditions, an ashfree bituminous binder could be produced, as used in the production of the Soederberg electrode. 2 tables, 2 graphs

  17. Identification of potential concerns associated with FDOT use of ammoniated coal fly ash.

    Science.gov (United States)

    2012-12-01

    The objectives of this project include a careful examination of the issues surrounding high ammonia content in cement due to the use of ammoniated fly ash. The researchers will gather information from published material and consider policies and prac...

  18. Filling the Gaps: The Synergistic Application of Satellite Data for the Volcanic Ash Threat to Aviation

    Science.gov (United States)

    Murray, John; Vernier, Jean-Paul; Fairlie, T. Duncan; Pavolonis, Michael; Krotkov, Nickolay A.; Lindsay, Francis; Haynes, John

    2013-01-01

    Although significant progress has been made in recent years, estimating volcanic ash concentration for the full extent of the airspace affected by volcanic ash remains a challenge. No single satellite, airborne or ground observing system currently exists which can sufficiently inform dispersion models to provide the degree of accuracy required to use them with a high degree of confidence for routing aircraft in and near volcanic ash. Toward this end, the detection and characterization of volcanic ash in the atmosphere may be substantially improved by integrating a wider array of observing systems and advancements in trajectory and dispersion modeling to help solve this problem. The qualitative aspect of this effort has advanced significantly in the past decade due to the increase of highly complementary observational and model data currently available. Satellite observations, especially when coupled with trajectory and dispersion models can provide a very accurate picture of the 3-dimensional location of ash clouds. The accurate estimate of the mass loading at various locations throughout the entire plume, however improving, remains elusive. This paper examines the capabilities of various satellite observation systems and postulates that model-based volcanic ash concentration maps and forecasts might be significantly improved if the various extant satellite capabilities are used together with independent, accurate mass loading data from other observing systems available to calibrate (tune) ash concentration retrievals from the satellite systems.

  19. The American Indian Summer Institute in Earth System Science (AISESS) at UC Irvine: A Two-Week Residential Summer Program for High School Students

    Science.gov (United States)

    Johnson, K. R.; Polequaptewa, N.; Leon, Y.

    2012-12-01

    Native Americans remain severely underrepresented in the geosciences, despite a clear need for qualified geoscience professionals within Tribal communities to address critical issues such as natural resource and land management, water and air pollution, and climate change. In addition to the need for geoscience professionals within Tribal communities, increased participation of Native Americans in the geosciences would enhance the overall diversity of perspectives represented within the Earth science community and lead to improved Earth science literacy within Native communities. To address this need, the Department of Earth System Science and the American Indian Resource Program at the University California have organized a two-week residential American Indian Summer Institute in Earth System Science (AISESS) for high-school students (grades 9-12) from throughout the nation. The format of the AISESS program is based on the highly-successful framework of a previous NSF Funded American Indian Summer Institute in Computer Science (AISICS) at UC Irvine and involves key senior personnel from the AISICS program. The AISESS program, however, incorporates a week of camping on the La Jolla Band of Luiseño Indians reservation in Northern San Diego County, California. Following the week of camping and field projects, the students spend a week on the campus of UC Irvine participating in Earth System Science lectures, laboratory activities, and tours. The science curriculum is closely woven together with cultural activities, native studies, and communication skills programs The program culminates with a closing ceremony during which students present poster projects on environmental issues relevant to their tribal communities. The inaugural AISESS program took place from July 15th-28th, 2012. We received over 100 applications from Native American high school students from across the nation. We accepted 40 students for the first year, of which 34 attended the program. The

  20. 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...

  1. Ash from a pulp mill boiler--characterisation and vitrification.

    Science.gov (United States)

    Ribeiro, Ana S M; Monteiro, Regina C C; Davim, Erika J R; Fernandes, M Helena V

    2010-07-15

    The physical, chemical and mineralogical characterisation of the ash resulting from a pulp mill boiler was performed in order to investigate the valorisation of this waste material through the production of added-value glassy materials. The ash had a particle size distribution in the range 0.06-53 microm, and a high amount of SiO(2) (approximately 82 wt%), which was present as quartz. To favour the vitrification of the ash and to obtain a melt with an adequate viscosity to cast into a mould, different amounts of Na(2)O were added to act as fluxing agent. A batch with 80 wt% waste load melted at 1350 degrees C resulting in a homogeneous transparent green-coloured glass with good workability. The characterisation of the produced glass by differential thermal analysis and dilatometry showed that this glass presents a stable thermal behaviour. Standard leaching tests revealed that the concentration of heavy metals in the leaching solution was lower than those allowed by the Normative. As a conclusion, by vitrification of batch compositions with adequate waste load and additive content it is possible to produce an ash-based glass that may be used in similar applications as a conventional silicate glass inclusively as a building ecomaterial. 2010 Elsevier B.V. All rights reserved.

  2. Compressive strength and hydrolytic stability of fly ash based geopolymers

    Directory of Open Access Journals (Sweden)

    Nikolić Irena

    2013-01-01

    Full Text Available The process of geopolymerization involves the reaction of solid aluminosilicate materials with highly alkaline silicate solution yielding an aluminosilicate inorganic polymer named geopolymer, which may be successfully applied in civil engineering as a replacement for cement. In this paper we have investigated the influence of synthesis parameters: solid to liquid ratio, NaOH concentration and the ratio of Na2SiO3/NaOH, on the mechanical properties and hydrolytic stability of fly ash based geopolymers in distilled water, sea water and simulated acid rain. The highest value of compressive strength was obtained using 10 mol dm-3 NaOH and at the Na2SiO3/NaOH ratio of 1.5. Moreover, the results have shown that mechanical properties of fly ash based geopolymers are in correlation with their hydrolytic stability. Factors that increase the compressive strength also increase the hydrolytic stability of fly ash based geopolymers. The best hydrolytic stability of fly ash based geopolymers was shown in sea water while the lowest stability was recorded in simulated acid rain. [Projekat Ministarstva nauke Republike Srbije, br. 172054 i Nanotechnology and Functional Materials Center, funded by the European FP7 project No. 245916

  3. Treatment and recycling of incinerated ash using thermal plasma technology.

    Science.gov (United States)

    Cheng, T W; Chu, J P; Tzeng, C C; Chen, Y S

    2002-01-01

    To treat incinerated ash is an important issue in Taiwan. Incinerated ashes contain a considerable amount of hazardous materials such as dioxins and heavy metals. If these hazardous materials are improperly treated or disposed of, they shall cause detrimental secondary contamination. Thermal plasma vitrification is a robust technology to treat and recycle the ash residues. Under the high temperature plasma environment, incinerated ashes are vitrified into benign slag with large volume reduction and extreme detoxification. Several one-step heat treatment processes are carried out at four temperatures (i.e. 850, 950, 1,050 and 1,150 degrees C) to obtain various "microstructure materials". The major phase to form these materials is a solid solution of gehlenite (Ca2Al2SiO7) and åkermanite (Ca2MgSi2O7) belonging to the melilite group. The physical and mechanical properties of the microstructure materials are improved by using one-step post-heat treatment process after plasma vitrification. These microstructure materials with good quality have great potential to serve as a viable alternative for construction applications.

  4. 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.

  5. Removal of trivalent chromium from aqueous solution by zeolite synthesized from coal fly ash.

    Science.gov (United States)

    Wu, Deyi; Sui, Yanming; He, Shengbing; Wang, Xinze; Li, Chunjie; Kong, Hainan

    2008-07-15

    The capability of 14 zeolites synthesized from different fly ashes (ZFAs) to sequestrate Cr(III) from aqueous solutions was investigated in a batch mode. The influence of pH on the sorption of Cr(III) was examined. ZFAs had a much greater ability than fly ash to remove Cr(III), due to the high cation exchange capacity (CEC) and the high acid neutralizing capacity (ANC) of ZFAs. The mechanism of Cr(III) removal by ZFAs involved ion exchange and precipitation. A high-calcium content in both the fly ashes and ZFAs resulted in a high ANC value and, as a result, a high immobilization capacity for Cr(III). The pH strongly influenced Cr(III) removal by ZFAs. Inside the solubility range, removal of chromium increased with increasing pH. Hydroxysodalite made from a high-calcium fly ash had a higher sorptive capacity for Cr(III) than the NaP1 zeolite from medium- and low-calcium fly ashes. On the other hand, at pH values above the solubility range, the efficiency of chromium removal by the ZFAs approached 100% due to the precipitation of Cr(OH)3 on the sorbent surfaces. It is concluded that ZFAs and high-calcium fly ashes may be promising materials for the purification of Cr(III) from water/wastewater.

  6. 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....

  7. ASH structure alignment package: Sensitivity and selectivity in domain classification

    Directory of Open Access Journals (Sweden)

    Toh Hiroyuki

    2007-04-01

    Full Text Available Abstract Background Structure alignment methods offer the possibility of measuring distant evolutionary relationships between proteins that are not visible by sequence-based analysis. However, the question of how structural differences and similarities ought to be quantified in this regard remains open. In this study we construct a training set of sequence-unique CATH and SCOP domains, from which we develop a scoring function that can reliably identify domains with the same CATH topology and SCOP fold classification. The score is implemented in the ASH structure alignment package, for which the source code and a web service are freely available from the PDBj website http://www.pdbj.org/ASH/. Results The new ASH score shows increased selectivity and sensitivity compared with values reported for several popular programs using the same test set of 4,298,905 structure pairs, yielding an area of .96 under the receiver operating characteristic (ROC curve. In addition, weak sequence homologies between similar domains are revealed that could not be detected by BLAST sequence alignment. Also, a subset of domain pairs is identified that exhibit high similarity, even though their CATH and SCOP classification differs. Finally, we show that the ranking of alignment programs based solely on geometric measures depends on the choice of the quality measure. Conclusion ASH shows high selectivity and sensitivity with regard to domain classification, an important step in defining distantly related protein sequence families. Moreover, the CPU cost per alignment is competitive with the fastest programs, making ASH a practical option for large-scale structure classification studies.

  8. Treatment and toxicity evaluation of methylene blue using electrochemical oxidation, fly ash adsorption and combined electrochemical oxidation-fly ash adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Kai-sung Wang; Ming-Chi Wei; Tzu-Huan Peng; Heng-Ching Li; Shu-Ju Chao; Tzu-Fang Hsu; Hong-Shen Lee; Shih-Hsien Chang [Chung-Shan Medical University, Taichung (Taiwan)

    2010-08-15

    Treatment of a basic dye, methylene blue, by electrochemical oxidation, fly ash adsorption, and combined electrochemical oxidation-fly ash adsorption was compared. Methylene blue at 100 mg L{sup -1} was used in this study. The toxicity was also monitored by the Vibrio fischeri light inhibition test. When electrochemical oxidation was used, 99% color and 84% COD were removed from the methylene blue solution in 20 min at a current density of 428 A m{sup -2}, NaCl of 1000 mg L{sup -1}, and pH{sub 0} of 7. However, the decolorized solution showed high toxicity (100% light inhibition). For fly ash adsorption, a high dose of fly ash (>20,000 mg L{sup -1}) was needed to remove methylene blue, and the Freundlich isotherm described the adsorption behavior well. In the combined electrochemical oxidation-fly ash adsorption treatment, the addition of 4000 mg L{sup -1} fly ash effectively reduced intermediate toxicity and decreased the COD of the electrochemical oxidation-treated methylene blue solution. The results indicated that the combined process effectively removed color, COD, and intermediate toxicity of the methylene blue solution.

  9. Western Indian Ocean Journal of Marine Science

    African Journals Online (AJOL)

    The Western Indian Ocean Journal of Marine Science (WIOJMS) provides an avenue for the wide dissemination of high quality research generated in the Western Indian Ocean (WIO) region, in particular on the sustainable use of coastal and marine resources. Topics include, but are not limited to: theoretical studies, ...

  10. Ash behavior and de-fluidization in low temperature circulating fluidized bed biomass gasifier

    DEFF Research Database (Denmark)

    Narayan, Vikas

    ensures that high-alkali biomass fuels can be used without risks of bed de-fluidization. This thesis aims to understand the behavior of alkali metals and ash in the LTCFB system. The thesis work involved measurements made on bed material and product gas dust samples on a 100kW LTCFB gasifier placed....... It was observed that of the total fuel ash entering the system, a large fraction (40-50%) of the ash was retained in the secondary cyclone bottoms and a lower amount (8-10%) was released as dust in the exit gas; the residual ash was accumulated within the fluidized bed system. A dominant fraction of alkali......Biomass is increasingly used as a fuel for power generation. Herbaceous fuels however, contain high amounts of alkali metals which get volatilized at high temperatures and forms salts with low melting points and thus condense on pipelines, reactor surfaces and may cause de-fluidization. A Low...

  11. Electrochemical treatment of wood combustion fly ash for the removal of cadmium

    DEFF Research Database (Denmark)

    Damø, Anne Juul

    2002-01-01

    Due to a high content of macronutrients and a potential liming capacity, recycling of ashes from biomass combustion to agricultural fields as fertilisers and/or for soil improvement is considered in Denmark and other countries utilising biomass as an energy source. However, especially the fly ash...... fractions contain amounts of the toxic heavy metal Cd that may exceed the limiting values for agricultural utilisation given by the Danish EPA. In this work the advances of using an electrochemical remediation method to reduce the Cd content in wood combustion fly ash - for the aim of recycling...

  12. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

    The properties of the ash from co-firing of coal and straw have a large influence on boiler operation, flue gas cleaning equipment and appropriate utilization of the fly ash. A study on the fuel composition and local conditions influence on fly ash properties has been done by making entrained flow...... and bituminous coal. The laboratory experiments indicated which mineral types and local conditions that provide the most efficient binding of potassium to species with a high melting point, and where a simultaneous release of chlorine as gaseous HCl takes place....

  13. Synthesis of hydroxy sodalite from coal fly ash using waste industrial brine solution.

    Science.gov (United States)

    Musyoka, Nicholas M; Petrik, Leslie F; Balfour, Gillian; Gitari, Wilson M; Hums, Eric

    2011-01-01

    The effect of using industrial waste brine solution instead of ultra pure water was investigated during the synthesis of zeolites using three South African coal fly ashes as Si feedstock. The high halide brine was obtained from the retentate effluent of a reverse osmosis mine water treatment plant. Synthesis conditions applied were; ageing of fly ash was at 47 ° C for 48 hours, and while the hydrothermal treatment temperature was set at 140 ° C for 48 hours. The use of brine as a solvent resulted in the formation of hydroxy sodalite zeolite although unconverted mullite and hematite from the fly ash feedstock was also found in the synthesis product.

  14. A daytime climatological distribution of high opaque ice cloud classes over the Indian summer monsoon region observed from 25-year AVHRR data

    Directory of Open Access Journals (Sweden)

    A. Devasthale

    2009-06-01

    Full Text Available A daytime climatological spatio-temporal distribution of high opaque ice cloud (HOIC classes over the Indian subcontinent (0–40° N, 60° E–100° E is presented using 25-year data from the Advanced Very High Resolution Radiometers (AVHRRs for the summer monsoon months. The HOICs are important for regional radiative balance, precipitation and troposphere-stratosphere exchange. In this study, HOICs are sub-divided into three classes based on their cloud top brightness temperatures (BT. Class I represents very deep convection (BT<220 K. Class II represents deep convection (220 K<=BT<233 K and Class III background convection (233 K<=BT<253 K. Apart from presenting finest spatial resolution (0.1×0.1 degrees and long-term climatology of such cloud classes from AVHRRs to date, this study for the first time illustrates on (1 how these three cloud classes are climatologically distributed during monsoon months, and (2 how their distribution changes during active and break monsoon conditions. It is also investigated that how many deep convective clouds reach the tropopause layer during individual monsoon months. It is seen that Class I and Class II clouds dominate the Indian subcontinent during monsoon. The movement of monsoon over continent is very well reflected in these cloud classes. During monsoon breaks strong suppression of convective activity is observed over the Arabian Sea and the western coast of India. On the other hand, the presence of such convective activity is crucial for active monsoon conditions and all-India rainfall. It is found that a significant fraction of HOICs (3–5% reach the tropopause layer over the Bay of Bengal during June and over the north and northeast India during July and August. Many cases are observed when clouds penetrate the tropopause layer and reach the lower stratosphere. Such cases mostly occur during June compared to the other months.

  15. Testing hypotheses for the use of Icelandic volcanic ashes as low cost, natural fertilizers

    Science.gov (United States)

    Seward, W.; Edwards, B.

    2012-04-01

    Andisols are soils derived from tephra/volcanic bedrock and are generally considered to be fertile for plant growth (cf. University of Hawaii at Manoa, CTAHR). However, few studies have been published examining the immediate effects of the addition of volcanic ash to soils immediately after an eruption. Our research is motivated by unpublished accounts from Icelandic farmers that the growing season following the 2010 Eyjafjallajökull eruption ended with unusually high yields in areas that were covered by ash from the eruption early in the spring. To test the hypothesis that addition of volcanic ash to soil would have no immediate effect on plant growth, we conducted a ~6 week growth experiment in at controlled environment at the Dickinson College Farm. The experiment used relatively fast growing grain seeds as a test crop, controlled watering, known quantities of peat as an organic base, and the following general experimental design: peat was mixed in known but systematically differing proportions with 1) commercial quartz sand, 2) basaltic ash from the 2004 Grimsvötn eruption, and 3) trachyandesite ash from the 2010 Eyjafjallajökull eruption. For all experiments, the seeds growing in the simulated soil created with the two different composition volcanic ash had higher germination rates, higher growth rates, and produced plants that were healthier in appearance than the soil made from peat mixed with quartz sand. Some differences were also noted between the germination and grow rates between the basaltic and trachyandesitic ash experiments as well. Working hypotheses to explain these results include (1) shard shapes and vesicles from volcanic ash provide better water retention than quartz, allowing water to be stored longer and increasing average soil moisture, and (2) chemical nutrients from the ash facilitate germination and growth of plants. Documenting the potential benefits of fresh volcanic ash as a fertilizer is important as use of fresh ash fertlizer

  16. Volcanic Ash Impacts on Air Traffic from the 2009 Mt. Redoubt Eruption

    Science.gov (United States)

    Murray, J. J.; Matus, A. V.; Hudnall, L. A.; Krueger, A. J.; Haynes, J. A.; Pippin, M. R.

    2009-12-01

    The dispersion of volcanic ash during the March 2009 eruption of Mt. Redoubt created the potential for major problems for aviation. Mt. Redoubt is located 110 km west-southwest of Alaska Airlines hub in Anchorage. It last erupted in 1990 and caused an estimated $101 million cost to the aviation industry (Waythomas, 1998). This study was conducted to assist in improving warning systems, policy and procedures for addressing the impact of volcanic ash on aviation. The study had two primary components. First, the altitude and extent of SO2 dispersion was determined through analysis of synoptic meteorological conditions and satellite imagery. Second, impacts on aviation from the volcanic ash dispersion were investigated. OMI SO2 column measurements were employed to assess the altitude and extent of SO2 dispersion of volcanic ash. To accomplish this, OMI data were assimilated with CALIPSO backscatter profiles, geopotential height plots, and HYSPLIT forward model trajectories. Volcanic Ash Advisories were compared to airport and pilot reports to assess aviation impacts. The eruption produced a complex dispersion of volcanic ash. Volcanic ash altitudes estimated for 23 March 2009 indicate that the majority of the plume remained at approximately 8 km, although reports indicate that the initial plume may have reached as high as18 km (60,000 ft). A low pressure system which passed over the eruption area appears to have entrained most of the ash at approximately 8 km, however the CALIPSO satellite indicates that dispersion also extended to 10 km and 16 km. Atmospheric patterns suggest dispersion at approximately 3 km near Hudson Bay. Analysis of 25 March 2009 indicates that much of the ash plume was dispersed at higher altitudes, where CALIPSO data locates the stratospheric ash plume at approximately 14 km above mean sea level. By the time the eruptions had subsided in April, Alaska Airlines had cancelled 295 flights and disrupted the flights of over 20,000 passengers. This

  17. 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...

  18. 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)....

  19. Flight potential of the emerald ash borer

    Science.gov (United States)

    Leah S. Bauer; Deborah L. Miller; Robin A.J. Taylor; Robert A. Haack