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

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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.

Fly ash leachate generation and qualitative trends at Ohio test sites

Energy Technology Data Exchange (ETDEWEB)

Solc, J.; Foster, H.J.; Butler, R.D. [Energy & Environmental Research Center, Grand Forks, ND (United States)

1995-12-01

Under the sponsorship of the U.S. Department of Energy, the environmental impact and potential contamination from landfilled fly ash (coal conversion solid residues - CCSRs) have been studied at field sites in Ohio. The progressive increase of moisture content within pilot cells over depth and time facilitated intensive chemical processes and generation of highly alkaline (pH of 10 to 12) leachate. Chemistry of pore water from lysimeters and ASTM leachate from fly ash and soil cores indicate the leachate potential to migrate out of deposit and impact the pore water quality of surrounding soils. Na, SO{sub 4} and, particularly, K, Cl, pH, and EC appeared to be valuable indicator parameters for tracking potential leachate transport both within the cells and below the ash/soil interface.

Acidic Food pH Increases Palatability and Consumption and Extends Drosophila Lifespan.

Science.gov (United States)

Deshpande, Sonali A; Yamada, Ryuichi; Mak, Christine M; Hunter, Brooke; Soto Obando, Alina; Hoxha, Sany; Ja, William W

2015-12-01

Despite the prevalent use of Drosophila as a model in studies of nutrition, the effects of fundamental food properties, such as pH, on animal health and behavior are not well known. We examined the effect of food pH on adult Drosophila lifespan, feeding behavior, and microbiota composition and tested the hypothesis that pH-mediated changes in palatability and total consumption are required for modulating longevity. We measured the effect of buffered food (pH 5, 7, or 9) on male gustatory responses (proboscis extension), total food intake, and male and female lifespan. The effect of food pH on germfree male lifespan was also assessed. Changes in fly-associated microbial composition as a result of food pH were determined by 16S ribosomal RNA gene sequencing. Male gustatory responses, total consumption, and male and female longevity were additionally measured in the taste-defective Pox neuro (Poxn) mutant and its transgenic rescue control. An acidic diet increased Drosophila gustatory responses (40-230%) and food intake (5-50%) and extended survival (10-160% longer median lifespan) compared with flies on either neutral or alkaline pH food. Alkaline food pH shifted the composition of fly-associated bacteria and resulted in greater lifespan extension (260% longer median survival) after microbes were eliminated compared with flies on an acidic (50%) or neutral (130%) diet. However, germfree flies lived longer on an acidic diet (5-20% longer median lifespan) compared with those on either neutral or alkaline pH food. Gustatory responses, total consumption, and longevity were unaffected by food pH in Poxn mutant flies. Food pH can directly influence palatability and feeding behavior and affect parameters such as microbial growth to ultimately affect Drosophila lifespan. Fundamental food properties altered by dietary or drug interventions may therefore contribute to changes in animal physiology, metabolism, and survival. © 2015 American Society for Nutrition.

Electrodialytic upgrading of municipal waste incineration fly ash for reuse

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

2012-01-01

As incineration becomes a more widespread means of waste treatment, volumes of incineration residues increase and new means of handling become a demand. Municipal Solid Waste Incineration (MSWI) fly ash is hazardous material, which is presently disposed off as such; primarily due to its high......]. In order to optimize the process and reach the lowest possible leachability of target constituents (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Zn, Cl, Na and SO4) at minimum time and energy consumption, the present work gives results of 10 pilot scale (8 kg MSWI fly ash each) electrodialysis experiments at different...... to investigate the leachability of salts and toxic elements as a function of treatment time and current density. Results show that a delicate balance between pH and treatment-time exist and that continuous monitoring of pH and conductivity may be used for controlling of the process at an industrial scale...

High-Resolution Remotely Sensed Small Target Detection by Imitating Fly Visual Perception Mechanism

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Fengchen Huang

2012-01-01

Full Text Available The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

High-resolution remotely sensed small target detection by imitating fly visual perception mechanism.

Science.gov (United States)

Huang, Fengchen; Xu, Lizhong; Li, Min; Tang, Min

2012-01-01

The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

Geochemical modeling and assessment of leaching from carbonated municipal solid waste incinerator (MSWI) fly ash.

Science.gov (United States)

Wang, Lei; Chen, Qi; Jamro, Imtiaz Ali; Li, Rundong; Li, Yanlong; Li, Shaobai; Luan, Jingde

2016-06-01

Municipal solid waste incinerator (MSWI) fly ashes are characterized by high calcium oxide (CaO) content. Carbon dioxide (CO2) adsorption by MSWI fly ash was discussed based on thermogravimetry (TG)/differential thermal analysis (DTA), minerology analysis, and adapting the Stenoir equation. TG/DTA analysis showed that the weight gain of the fly ash below 440 °C was as high as 5.70 %. An adapted Stenoir equation for MSWI fly ash was discussed. The chloride in MSWI fly ash has a major impact on CO2 adsorption by MSWI fly ash or air pollution control (APC) residues. Geochemical modeling of the critical trace elements copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), and antimony (Sb) before and after carbonation was performed using a thermodynamic equilibrium model for solubility and a surface complexation model for metal sorption. Leaching of critical trace elements was generally found to be strongly dependent on the degree of carbonation attained, and their solubility appeared to be controlled by several minerals. Adsorption on ferrum (Fe) and aluminum (Al) colloids was also responsible for removal of the trace elements Cd, Pb, and Sb. We used Hakanson's potential ecological risk index (HPERI) to evaluate the risk of trace element leaching in general. The results demonstrate that the ecological risk showed a V-shaped dependency on pH; the optimum pH of the carbonated fly ash was found to be 10.3-11, resulting from the optimum carbonation (liquid-to-solid (L/S) ratio = 0.25, carbonation duration = ∼30-48 h). The dataset and modeling results presented here provide a contribution to assessing the leaching behavior of MSWI fly ash under a wide range of conditions.

Rheology and setting of high volume fly ash mixtures

Energy Technology Data Exchange (ETDEWEB)

Dale P. Bentz; Chiara F. Ferraris [National Institute of Standards and Technology, Gaithersburg, MD (United States). Building and Fire Research Laboratory

2010-04-15

While high volume fly ash (HVFA) concretes can be designed and produced to meet 28-d strength requirements and often even exceed the durability performance of conventional concretes, a persistent problem is the potentially long delay in setting time that produces concurrently long delays in finishing the concrete in the field. Previous isothermal calorimetry studies on two different powder additions, namely calcium hydroxide and a rapid set cement, have shown that these powders can mitigate excessive retardation of the hydration reactions. In this paper, rheological measurements and conventional Vicat setting time studies are conducted to verify that these powder additions do indeed reduce setting times in paste systems based on both ASTM Class C and ASTM Class F fly ashes. The reductions depend on the class of fly ash and suggest that trial mixtures would be a necessity to apply these technologies to each specific fly ash/cement/admixture combination being employed in the field. Potentially, for such screening studies, the rheological measurement of yield stress may provide a faster indication of setting (and finishability) than conventional Vicat needle penetration measurements on pastes.

Characterization of municipal solid waste incineration fly ash before and after electrodialytic treatment

DEFF Research Database (Denmark)

Pedersen, Anne Juul; Gardner, Kevin H.

2003-01-01

Municipal solid waste incineration (MSWI) fly ash, which has been treated electrodialytically for the removal of heavy metals, may have changed characteristics compared to untreated fly ash. In this study, MSWI fly ash was characterized with respect to leaching properties (pH static leaching...

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 ...

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

Directory of Open Access Journals (Sweden)

Solikin Mochamad

2017-01-01

Full Text Available 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 Ash Concrete. The experiment and data analysis were prepared using minitab, a statistic software for design of experimental. The specimens were concrete cylinder with diameter of 15 cm and height of 30 cm, tested for its compressive strength at 56 days. The result of the research demonstrates that high volume fly ash concrete can produce comparable compressive strength which meets the strength of OPC design strength especially for high strength concrete. In addition, the best mix proportion to achieve the design strength is the combination of high strength concrete and 50% content of fly ash. Moreover, the use of spraying method for curing method of concrete on site is still recommended as it would not significantly reduce the compressive strength result.

Adaptive-Repetitive Visual-Servo Control of Low-Flying Aerial Robots via Uncalibrated High-Flying Cameras

Science.gov (United States)

Guo, Dejun; Bourne, Joseph R.; Wang, Hesheng; Yim, Woosoon; Leang, Kam K.

2017-08-01

This paper presents the design and implementation of an adaptive-repetitive visual-servo control system for a moving high-flying vehicle (HFV) with an uncalibrated camera to monitor, track, and precisely control the movements of a low-flying vehicle (LFV) or mobile ground robot. Applications of this control strategy include the use of high-flying unmanned aerial vehicles (UAVs) with computer vision for monitoring, controlling, and coordinating the movements of lower altitude agents in areas, for example, where GPS signals may be unreliable or nonexistent. When deployed, a remote operator of the HFV defines the desired trajectory for the LFV in the HFV's camera frame. Due to the circular motion of the HFV, the resulting motion trajectory of the LFV in the image frame can be periodic in time, thus an adaptive-repetitive control system is exploited for regulation and/or trajectory tracking. The adaptive control law is able to handle uncertainties in the camera's intrinsic and extrinsic parameters. The design and stability analysis of the closed-loop control system is presented, where Lyapunov stability is shown. Simulation and experimental results are presented to demonstrate the effectiveness of the method for controlling the movement of a low-flying quadcopter, demonstrating the capabilities of the visual-servo control system for localization (i.e.,, motion capturing) and trajectory tracking control. In fact, results show that the LFV can be commanded to hover in place as well as track a user-defined flower-shaped closed trajectory, while the HFV and camera system circulates above with constant angular velocity. On average, the proposed adaptive-repetitive visual-servo control system reduces the average RMS tracking error by over 77% in the image plane and over 71% in the world frame compared to using just the adaptive visual-servo control law.

Removal of metallic ions from aqueous solutions by fluidized bed fly ashes

Energy Technology Data Exchange (ETDEWEB)

Rio, S.; Delebarre, A.; Hequet, V. [Ecole des Mines de Nantes, 44 - Nantes (France); Blondin, J. [Cerchar 62 - Mazingarbe (France)

2001-07-01

One of the main constraints deriving from the generation of power by coal combustion is to find some use for the fly ashes instead of disposing of them. Fly ashes from two fluidized bed power plants were tested to remove Pb{sup 2+}, Cu{sup 2+}, Cr (III), Ni{sup 2+}, Zn{sup 2+} and Cr (VI) from aqueous solutions. Experimental design methodology was used to study the removal and the leaching as a function of (i) the water pollutant content, (ii) the metal concentration in water, (iii) the pH of the solution and (iv) the addition of lime to fly ashes. The results show that the percentage of adsorbed ions was more important when they were in contact with silico-aluminous fly ashes than sulfo-calcic fly ashes, except in the case of the ion Ni{sup 2+}. The removal of metallic ions increases with increasing pH. The metallic canons removal accounting for the leaching test was higher when lime was added to silico-aluminous fly ashes during the adsorption. (authors)

High precision relative position sensing system for formation flying spacecraft

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop and test an optical sensing system that provides high precision relative position sensing for formation flying spacecraft.  A high precision...

Karakteristik Fisiko-Kimiawi (Morfologi, Higroskopisitas, pH dan Toksisitas Panel Bangunan yang Dihasilkan dari Komposit Limbah Abu Terbang Batu Bara (Fly Ash, Daun-Ampas Tebu, Jerami-Sekam Padi dan Ijuk (Palm Fiber

Directory of Open Access Journals (Sweden)

Yulianto P. Prihatmaji

2015-10-01

Full Text Available Telah dilakukan penelitian tentang karakteristik fisiko-kimiawi (morfologi, higroskopisitas, ph dan toksisitas panel bangunan yang dihasilkan dari komposit limbah abu terbang batu bara (fly ash, daunampas tebu, jerami-sekam padi dan ijuk (palm fiber. Berdasarkah hasil uji dan analisis fisiko-kimiawi kaitannya dengan morfologi secara makroskopis menunjukkan bahwa komposit panel bangunan dari berbagai macam jenis bahan baku tersebut tampak menyatu secara solid dengan ikatan kimia antar bahan yang terlibat. Bahan organik yang berupa limbah ampas-daun tebu, jerami-sekam padi, dan ijuk tampak menyatu padu dengan komponen anorganiknya berupa fly ash dan semen. Kaitannya dengan higroskopisitasnya, produk panel bangunan yang dihasilkan tampaknya tidak terpengaruh oleh iklim dan kelembaban di dalam maupun di luar ruang karena kadar air panel bangunan yang diuji pada hari ke-30 dan hari ke-60 relatif stabil yakni 19,65% yang berarti normal. Kaitannya dengan tingkat keasaman (pH, panel bangunan yang dihasilkan menunjukkan kondisi yang aman/tidak menyebabkan iritasi karena pH: 7-8 yang berarti tidak mengiritasi/aman. Adapun hasil uji dan analisis toksisitas fly ash dilakukan menggunakan indikator biologis; mencit menunjukkan harga LD50: 32,915 mg/kg (bb yang berarti relatif tidak berbahaya. Kutu air menunjukkan harga LC50: 75,515 ppm (7,552% yang berarti hampir tidak toksik dan ikan mas menunjukkan harga LC50: 121,943 ppm (12,194% yang berarti tidak toksik. Oleh sebab itu produk panel bangunan yang dihasilkan dapat dipastikan aman dikonsumsi.

Recombinant Salivary Proteins of Phlebotomus orientalis are Suitable Antigens to Measure Exposure of Domestic Animals to Sand Fly Bites.

Science.gov (United States)

Sima, Michal; Ferencova, Blanka; Warburg, Alon; Rohousova, Iva; Volf, Petr

2016-03-01

Certain salivary proteins of phlebotomine sand flies injected into the host skin during blood-feeding are highly antigenic and elicit strong antibody-mediated immune responses in repeatedly-exposed hosts. These antibodies can be measured by enzyme-linked immuno sorbent assays (ELISAs) using salivary gland homogenates (SGHs) as the source of antigens and serve as a markers for exposure to biting sand flies. Large-scale screening for anti-sand fly saliva antibodies requires replacement of SGH with recombinant salivary proteins. In East Africa, Phlebotomus orientalis is the main vector of Leishmania donovani, a trypanosomatid parasite causing visceral leishmaniasis. We tested recombinant salivary proteins derived from Ph. orientalis saliva to study exposure of domestic animals to this sand fly species. Antigenic salivary proteins from Ph. orientalis were identified by immunoblot and mass spectrometry. Recombinant apyrase rPorSP15, yellow-related protein rPorSP24, ParSP25-like protein rPorSP65, D7-related protein rPorSP67, and antigen 5-related protein rPorSP76 were tested using ELISA with sera of domestic animals from L. donovani foci in Ethiopia where Ph. orientalis is present. Our results highlighted recombinant yellow-related protein rPorSP24 as the most promising antigen, displaying a high positive correlation coefficient as well as good sensitivity and specificity when compared to SGH. This recombinant protein was the most suitable one for testing sera of dogs, sheep, and goats. In addition, a different antigen, rPorSP65 was found efficacious for testing canine sera. Recombinant salivary proteins of Ph. orientalis, specifically rPorSP24, were shown to successfully substitute SGH in serological experiments to measure exposure of domestic animals to Ph. orientalis, the vector of L. donovani. The results suggest that rPorSP24 might be a suitable antigen for detecting anti-Ph. orientalis antibody-mediated reactions also in other host species.

Preparation of Fly ash Based Adsorbents for Removal Active Red X-3B from Dying Wastewater

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Li Jinping

2016-01-01

Full Text Available Fly ash with a large number of active sites can occur with the adsorbent chemical and physical adsorption, and therefore have a strong adsorption capacity. The original fly ash and raw fly ash compared to the physical and chemical properties to a significant change. On the fly ash in industrial water treatment application were outlined. The purpose is to focus on the modification methods of fly ash and comparison of raw fly ash and fly ash in the effect of dyeing wastewater. Single factor test method; select the appropriate modifier to study the dosage, pH, stirring time on the modification of adsorption properties of fly ash before and after. The results showed that the modified fly ash was better than the adsorption. Greatly improves on active red X-3B dye wastewater removal capacity, pH = 5, 6, dosage is 5g / L, the mixing time is 30min, COD removal rate reached 73.07%. This modified material can be used as adsorbent for pre-treating dying wastewater.

Disposal of low-level radioactive waste using high-calcium fly ash. Final report

International Nuclear Information System (INIS)

Cogburn, C.O.; Hodgson, L.M.; Ragland, R.C.

1986-04-01

The feasibility of using calcium-rich fly ash from coal-fired power plants in the disposal of low-level radioactive waste was examined. The proposed areas of use were: (1) fly-ash cement as a trench lining material; (2) fly ash as a backfill material; and (3) fly ash as a liquid waste solidifier. The physical properties of fly-ash cement were determined to be adequate for trench liner construction, with compressive strengths attaining greater than 3000 psi. Hydraulic conductivities were determined to be less than that for clay mineral deposits, and were on the order of 10 -7 cm/sec, with some observed values as low as 10 -9 cm/sec. Removal of radioisotopes from acidified solutions by fly ash was good for all elements tested except cesium. The removal of cesium by fly ash was similar to that of montmorillonite clay. The corrosive effects on metals in fly ash environments was determined to be slight, if not non-existent. Coatings at the fly-ash/metal interfaces were observed which appeared to inhibit or diminish corrosion. The study has indicated that high-calcium fly ash appears to offer considerable potential for improved retention of low-level radioactive wastes in shallow land disposal sites. Further tests are needed to determine optimum methods of use. 8 refs., 4 figs., 7 tabs

Stabilisation of clayey soils with high calcium fly ash and cement

Energy Technology Data Exchange (ETDEWEB)

S. Kolias; V. Kasselouri-Rigopoulou; A. Karahalios [National Technical University of Athens, Athens (Greece)

2005-02-01

The effectiveness of using high calcium fly ash and cement in stabilising fine-grained clayey soils (CL,CH) was investigated in the laboratory. Strength tests in uniaxial compression, in indirect (splitting) tension and flexure were carried out on samples to which various percentages of fly ash and cement had been added. Modulus of elasticity was determined at 90 days with different types of load application and 90-day soaked CBR values are also reported. Pavement structures incorporating subgrades improved by in situ stabilisation with fly ash and cement were analyzed for construction traffic and for operating traffic. These pavements are compared with conventional flexible pavements without improved subgrades and the results clearly show the technical benefits of stabilising clayey soils with fly ash and cement. In addition TG-SDTA and XRD tests were carried out on certain samples in order to study the hydraulic compounds, which were formed.

Influence of ammonia on leaching behaviors of incineration fly ash and its geochemical modeling

DEFF Research Database (Denmark)

Astrup, Thomas Fruergaard; Guan, Zhen Zhen; Chen, De Zhen

2013-01-01

Incineration fly ash could be contaminated with NH3 that was slipped from the ammonia-based selective non-catalytic reduction(SNCR) process and from evaporation of municipal solid wastes' leachate involved in the wastes. This research was conducted to investigate the impacts of ammonia on leaching....... It was proved that at pH>9, the leaching of DOC increased significantly in the presence of high concentrations of ammonia (≥1357 mg·L-1), but there was little effect when the ammonia level in eluates was not higher than 537 mg·L-1. At pH12, for Cd, Cu, Ni and Zn, their leaching species were predominantly...... by precipitation/dissolution and surface complexation/precipitation processes; Visual MINTEQ modeling could well describe the leaching behaviors of Al, Cu, Pb and Zn from incineration fly ash....

The Study of Sand Fly Fauna in an Endemic Focus for Cutaneous Leishmaniasis in Fasa from April to October in the year 2013

Directory of Open Access Journals (Sweden)

Mehdi Sharafi

2015-02-01

Full Text Available Background & Objectives: Leishmaniasis as a zoonosis disease seen in three forms including Cutaneous, mucocutaneous, and visceral (kala- azar. The Leishmania transferred by sand flies is the causative agent of this disease. Considering that leishmaniasis is an endemic disease in Fasa, this study was performed to determine the sand fly species of Fasa, Materials & Methods: In this cross- sectional study from April to September 2014, the fauna of sand flies was investigated. Sampling was done in villages with above, medium, and low incidence by using sticky traps every 15 days. Then, captured specimens were mounted and identified by specific key. Results: 3842 sand flies were captured for ecological studies. 2305 of them (60% were males and the rest of them were females. 1152 specimens (30% of them were from indoors and the rest were from outdoors. Totally, 10 species were identified including Phlebotomus. Papatasi, Ph. Alexandri, Ph. Sergenti, Ph. Mongolensis, Ph. Bergeroti, Ph. Caucasicus, Sergentomyia theodori, S. Baghdadis, S. sintuni, and S. antennata. Among captured specimens Phlebotomus Papatasi, Ph. Sergenti had the first and the second places, respectively. Conclusion: Sandflies in Fasa are very active with high prevalence and species diversity. Phlebotomus Papatasi as the predominant species transfers Leishmania from rodents to humans. This subject is related to the prevalence of rural leishmaniasis in this area. According to the semi-domestic vector, spraying is not helpful in a rural foci of cutaneous leishmaniasis. But the control of reservoir and educating the residents about prevention ways of bite are effective in disease control and prevention.

Formation Design Strategy for SCOPE High-Elliptic Formation Flying Mission

Science.gov (United States)

Tsuda, Yuichi

2007-01-01

The new formation design strategy using simulated annealing (SA) optimization is presented. The SA algorithm is useful to survey a whole solution space of optimum formation, taking into account realistic constraints composed of continuous and discrete functions. It is revealed that this method is not only applicable for circular orbit, but also for high-elliptic orbit formation flying. The developed algorithm is first tested with a simple cart-wheel motion example, and then applied to the formation design for SCOPE. SCOPE is the next generation geomagnetotail observation mission planned in JAXA, utilizing a formation flying techonology in a high elliptic orbit. A distinctive and useful heuristics is found by investigating SA results, showing the effectiveness of the proposed design process.

Leishmania attachment in permissive vectors and the role of sand fly midgut proteins in parasite-vector interaction

OpenAIRE

Dostálová, Anna

2012-01-01

of PhD. thesis named "Leishmania attachment in permissive vectors and the role of sand fly midgut proteins in parasite-vector interaction", Anna Dostálová, 2011 This thesis focuses on the development of protozoan parasites of the genus Leishmania in their insect vectors, sand flies. It sums up results of three projects I was involved in during my PhD studies. Main emphasis was put on permissive sand fly species that support development of various species of Leishmania. Using a novel method of...

Porosity of Self-Compacting Concrete (SCC) incorporating high volume fly ash

Science.gov (United States)

Kristiawan, S. A.; Sunarmasto; Murti, G. Y.

2017-02-01

Degradation of concrete could be triggered by the presence of aggressive agents from the environment into the body of concrete. The penetration of these agents is influenced by the pore characteristics of the concrete. Incorporating a pozzolanic material such as fly ash could modify the pore characteristic of the concrete. This research aims to investigate the influence of incorporating fly ash at high volume level on the porosity of Self-Compacting Concrete (SCC). Laboratory investigations were carried out following the ASTM C642 for measuring density and volume of permeable pores (voids) of the SCC with varying fly ash contents (50-70% by weight of total binder). In addition, a measurement of permeable voids by saturation method was carried out to obtain an additional volume of voids that could not be measured by the immersion and boiling method of ASTM C642. The results show that the influence of fly ash content on the porosity appears to be dependent on age of SCC. At age less than 56 d, fly ash tends to cause an increase of voids but at 90 d of age it reduces the pores. The additional pores that can be penetrated by vacuum saturation method counts about 50% of the total voids.

Vector soup: high-throughput identification of Neotropical phlebotomine sand flies using metabarcoding.

Science.gov (United States)

Kocher, Arthur; Gantier, Jean-Charles; Gaborit, Pascal; Zinger, Lucie; Holota, Helene; Valiere, Sophie; Dusfour, Isabelle; Girod, Romain; Bañuls, Anne-Laure; Murienne, Jerome

2017-03-01

Phlebotomine sand flies are haematophagous dipterans of primary medical importance. They represent the only proven vectors of leishmaniasis worldwide and are involved in the transmission of various other pathogens. Studying the ecology of sand flies is crucial to understand the epidemiology of leishmaniasis and further control this disease. A major limitation in this regard is that traditional morphological-based methods for sand fly species identifications are time-consuming and require taxonomic expertise. DNA metabarcoding holds great promise in overcoming this issue by allowing the identification of multiple species from a single bulk sample. Here, we assessed the reliability of a short insect metabarcode located in the mitochondrial 16S rRNA for the identification of Neotropical sand flies, and constructed a reference database for 40 species found in French Guiana. Then, we conducted a metabarcoding experiment on sand flies mixtures of known content and showed that the method allows an accurate identification of specimens in pools. Finally, we applied metabarcoding to field samples caught in a 1-ha forest plot in French Guiana. Besides providing reliable molecular data for species-level assignations of phlebotomine sand flies, our study proves the efficiency of metabarcoding based on the mitochondrial 16S rRNA for studying sand fly diversity from bulk samples. The application of this high-throughput identification procedure to field samples can provide great opportunities for vector monitoring and eco-epidemiological studies. © 2016 John Wiley & Sons Ltd.

Inorganic contaminants attenuation in acid mine drainage by fly ash and fly ash-ordinary Portland cement (OPC) blends : column experiments

International Nuclear Information System (INIS)

Gitari, W.M.; Petrik, L.F.; Etchebers, O.; Key, D.L.; Okujeni, C.

2010-01-01

The infiltration of acid mine drainage (AMD) material into mine voids is one of the environmental impacts of underground coal mining. In this study, the mitigation of AMD in a mine void was simulated in laboratory conditions. Various mixtures of fly ash, solid residues, and Portland cement were added to packed columns over a 6-month period. The fly ash additions generated near-neutral to alkaline pH levels, which in turn induced precipitation, co-precipitation, and adsorption contaminant attenuation mechanisms. A modelling study demonstrated that the precipitation of ferrihydrite, Al-hydroxides, Al-oxyhydroxysulphates, gypsum, ettringite, manganite, and rhodochrosite lowered contaminant levels. Results of the study indicated that the pH regime and acidity level of the AMD strongly influenced both the leaching of the toxic trace elements as well as the attenuation of the AMD. 3 refs., 2 figs.

High filler concrete using fly ash. Chloride penetration and microstructure

NARCIS (Netherlands)

Valcke, S.L.A.; Polder, R.B.; Nijland, T.G.; Leegwater, G.A.; Visser, J.H.M.; Bigaj-van Vliet, A.J.

2012-01-01

Most high filler concrete studies are based on relatively high contents of powder (cement + filler) (>400 kg m-3). This paper aims to increase the total fly ash content relative to the clinker content, while simultaneously minimizing the total powder content in the concrete to values lower than 300

High filler concrete using fly ash : Chloride penetration and microstructure

NARCIS (Netherlands)

Valcke, S.L.A.; Polder, R.B.; Nijland, T.G.; Leegwater, G.A.; Visser, J.H.M.; Bigaj-van Vliet, A.J.

2012-01-01

Most high filler concrete studies are based on relatively high contents of powder (cement + filler) (>400 kg m-3). This paper aims to increase the total fly ash content relative to the clinker content, while simultaneously minimizing the total powder content in the concrete to values lower than 300

Laboratory Investigations on Mechanical Properties of High Volume Fly Ash Concrete and Composite Sections

OpenAIRE

Aravindkumar B. Harwalkar; S. S. Awanti

2013-01-01

Use of fly ash as a supplementary cementing material in large volumes can bring both technological and economic benefits for concrete industry. In this investigation mix proportions for high volume fly ash concrete were determined at cement replacement levels of 50%, 55%, 60% and 65% with low calcium fly ash. Flexural and compressive strengths of different mixes were measured at ages of 7, 28 and 90 days. Flexural strength of composite section prepared from pavement quali...

Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

Science.gov (United States)

Robert, C. G.; Ayob, A.; Zaki, M. F. Muhammad; Razali, M. E.; Lew, E. V.; Hong, P. Y.

2018-03-01

Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA) and bottom ash (BA) mixtures with difference component percentage treated with sodium lauryl sulphate (SLS) and polyvinyl alcohol (PVA) at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

Directory of Open Access Journals (Sweden)

Robert C.G.

2018-01-01

Full Text Available Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA and bottom ash (BA mixtures with difference component percentage treated with sodium lauryl sulphate (SLS and polyvinyl alcohol (PVA at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

Energy Technology Data Exchange (ETDEWEB)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Tian, Shulei [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering; Wang, Qi [Chinese Research Academy of Environmental Science, Beijing (China); Wu, Ziyu [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Univ. of Science and Technology of China, Hefei (China). National Synchrotron Radiation Lab.; Chinese Academy of Sciences, Beijing (China). Theoretical Physics Center for Science Facilities

2009-07-15

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

International Nuclear Information System (INIS)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang; Wu, Ziyu; Univ. of Science and Technology of China, Hefei; Chinese Academy of Sciences, Beijing

2009-01-01

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

Sorption behaviour of some radioactive isotopes on treated fly ash. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

Abdel Raouf, M W; El-Dessouky, M I; Aly, H F [Hot Laboratories Center, Atomic Energy Authority, Cairo, (Egypt)

1996-03-01

Fly ash is obtained as a by-product from burning mazoute (high molecular weight hydrocarbon) at Northern Cairo Electric Power Generator, was ordinarily disposed in land fill. The carbonaceous material of fly ash was investigated as a possible sorbent for some fission products radionuclides: Cs{sup 134}, Co{sup 60}, and Eu{sup 142+154} at room temperature. The original fly ash was prepared for adsorption studies by sieving to different particle sizes (fractions), and repeated washing by tap water to neutral PH. Some fractions were further treated (after neutralization) by dilute HCl or ethyl alcohol and other fractions were heated at 200, 500, and 800 degree C. The results obtained from sorption on treated fly ash revealed that the percentage uptake (%U) was in accordance with the valency of the cation used: Eu{sup 3+}>Co{sup 2+}>>Cs{sup +} at medium hydrogen ion concentrations. The heated samples at different temperatures showed that % U obeyed the order: 800 degree C >200 degree C. Comparative studies were conducted with pyrolysis residue of domestic waste showed analogous trend in sorption studies. The feasibility of fly ash as a very cheap material in the removal of different fission products from liquid radioactive waste was assessed.

Resistance to Corrosion of Reinforcement of High Volume Fly Ash Concrete

International Nuclear Information System (INIS)

Kwon, S. O.; Bae, S. H.; Lee, H. J.; Lee, K. M.; Jung, S. H.

2014-01-01

Due to the increasing of interest about the eco-friendly concrete, it is increased to use concretes containing by-products of industry such as fly ash(FA), ground granulated blast furnace slag(GGBFS), silica fume(SF), and etc. Especially, these are well known for improving the resistances to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance against corrosion of reinforcement of high volume fly ash(HVFA) concrete which is replaced with high volume fly ash for cement volume. For this purpose, the concrete test specimens were made for various strength level and replacement ratio of FA, and then the compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91, and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that the compressive strength of HVFA concrete was decreased with increasing replacement ratio of FA but long-term resistances against reinforcement corrosion and chloride ion penetration of that were increased

Microprofiles of oxygen, redox potential, and pH, and microbial fermentation products in the highly alkaline gut of the saprophagous larva of Penthetria holosericea (Diptera: Bibionidae)

KAUST Repository

Šustr, Vladimír

2014-08-01

The saprophagous larvae of bibionid flies harbor bacteria in their alkaline intestinal tracts, but little is known about the contribution of the gut microbiota to the digestion of their recalcitrant diet. In this study, we measured oxygen and hydrogen partial pressure, redox potential and pH in the midgut, gastric caeca and hindgut of larvae of the bibionid fly Penthetria holosericea with Clark-type O2 and H2 microsensors, platinum redox microelectrodes, and LIX-type pH microelectrodes. The center of the midgut lumen was anoxic, whereas gastric caeca and hindgut were hypoxic. However, redox potential profiles indicated oxidizing conditions throughout the gut, with lowest values in the midgut (+20 to +60mV). Hydrogen production was not detected. The midgut was extremely alkaline (pH around 11), whereas hindgut and gastric caeca were neutral to slightly alkaline. While HPLC analysis showed high concentrations of glucose in the midgut (15mM) and gastric caeca (27mM), the concentrations of microbial fermentation products such as lactate (2-4mM), acetate (<1mM) and succinate (<0.5mM) were low in all gut regions, suggesting that the contribution of microorganisms to the digestive process, particularly in the alkaline midgut, is only of minor importance. We conclude that the digestive strategy of the saprophytic larva of P. holosericea, which feeds selectively on decomposed leaves and its own microbe-rich faeces, differs fundamentally from those of detritivorous and humivorous insects, which host a highly active, fermentative microbiota in their alkaline midgut or hindgut compartments. © 2014 Elsevier Ltd.

Evaluating high pH for control of dreissenid mussels

Directory of Open Access Journals (Sweden)

Dave Evans

2013-04-01

Full Text Available Two field experiments were carried out using a custom built flow-through laboratory to test the effect of elevated pH on dreissenid musselsas a potential control method. Both experiments tested the ability of dreissenid pediveligers to settle under conditions of elevated pH and thelong-term survival of adult dreissenids under the same conditions. The two experimental sites had different water quality and differentspecies of dreissenids present. The settlement of quagga mussel pediveligers at the lower Colorado River was inhibited with increasing pH.At the maximum achieved pH of 9.1, there was approximately 90% reduction compared to the maximum settlement observed in the controls.Since the settlement was almost as low in pH 8.9 as at pH 9.1, the inhibition in settlement may have been due to the presence of a precipitateformed under high pH conditions rather than the increase in background pH. No mortality of quagga mussel adults was observed in theexperimental pH levels at the lower Colorado River. At San Justo Reservoir, zebra mussel settlement decreased with increasing pH. Newsettlement was almost entirely absent at the highest pH tested (pH 9.6. The observed mortality of adult zebra mussels was low, but did tendto increase with increasing pH. We also tested the response of adult zebra mussels to short-term exposure to very high pH levels (i.e. pH 10,11, and 12. Adult mussels in poor physical condition experienced 90% mortality after 12 hours at pH 12. For unstressed adult zebra mussels,90% mortality was reached after 120 hours at pH 12. Significant mortalities were also observed both at pH 10 and pH 11. From this study,we conclude that pH elevation could be used both as a preventative treatment to eliminate settlement by dreissenid mussels and as an end ofseason treatment to eliminate adults. The high pH treatment would have to be tailored to the site water quality to prevent formation ofprecipitate during treatment and to minimize corrosive

Soybean growth on fly ash-amended strip mine soils

Energy Technology Data Exchange (ETDEWEB)

Fail, Jr, J L; Wochok, Z S

1977-01-01

The use of fly ash as an amendment for strip mine soils has been studied under field conditions. Soils ranging in pH from 4.0 to 6.0 were tested. The addition of fly ash in all cases was effective as an acid soil neutralizer and substantially enhanced the growth and development of all experimental plants. The parameters used in growth analyses were plant height, dry weight, root/shoot ratios, nodulation, pod production, and nitrogen fixing capacity for legumes.

Composite Ni-Co-fly ash coatings on 5083 aluminium alloy

Energy Technology Data Exchange (ETDEWEB)

Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Georgiou, E.P.; Tsopani, A.; Piperi, L. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece)

2011-03-15

Ni-Co-fly ash coatings were deposited on zincate treated 5083 wrought aluminium alloy substrates with the aid of the electrodeposition technique. Structural and chemical characterization of the produced composite coatings was performed with the aid of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron dispersive X-ray analysis (EDS) techniques. The Ni-Co-fly ash coatings were found to consist of a crystalline Ni-Co solid solution with dispersed fly ash particles. In addition, chemical analysis of the Ni-Co matrix showed that it consisted of 80 wt.% Ni and 20 wt.% Co. The co-deposition of fly ash particles leads to a significant increase of the microhardness of the coating. The corrosion behaviour of the Ni-Co-fly ash/zincate coated aluminium alloy, in a 0.3 M NaCl solution (pH = 3.5), was studied by means of potentiodynamic corrosion experiments.

Modified coal fly ash as low cost adsorbent for removal reactive dyes from batik industry

Directory of Open Access Journals (Sweden)

Taufiq Agus

2018-01-01

Full Text Available The removal of reactive dyes on modified coal fly ash has been investigated during a series of batch adsorption experiments. Physical characteristics of modified coal fly ash was characterized by Brunauer Emmett Teller (BET surface area analysis, X-ray powder diffraction (XRD, Fourier transform infrared spectrophotometer (FT-IR, and scanning electron microscope (SEM. The effects of operational parameters such as initial dye concentration (50–200 mg/L, solution pH (4–10 and adsorbent dosage (50–200 mg/L were studied. The adsorption experiments indicated that modified coal fly ash was effective in removing of Remazol Blue. The percentage removal of dyes increased while the modified fly ash dosage increased. The percentage removal of dyes increased with decreased initial concentration of the dye and also increased with amount of adsorbent used. The optimum of removal of dyes was found to be 94% at initial dye concentration 50 g/mL, modified fly ash dosage 250 g/mL, and pH of 2.0.

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

International Nuclear Information System (INIS)

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. (paper)

Dispersion of fruit flies (Diptera: Tephritidae) at high and low densities and consequences of mismatching dispersions of wild and sterile flies

International Nuclear Information System (INIS)

Meats, A.

2007-01-01

Both wild and released (sterile) Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) and wild Bactrocera papayae (Drew and Hancock) in Australia had patchy distributions and comparisons with predictions of the negative binomial model indicated that the degree of clumping was sometimes very high, particularly at low densities during eradication. An increase of mean recapture rate of sterile B. tryoni on either of 2 trap arrays was not accompanied by a reduction in its coefficient of variation and when recapture rates were high, the percentage of traps catching zero decreased only slightly with increase in recapture rate, indicating that it is not practicable to decrease the heterogeneity of dispersion of sterile flies by increasing the number released. There was often a mismatch between the dispersion patterns of the wild and sterile flies, and the implications of this for the efficiency of the sterile insect technique (SIT) were investigated with a simulation study with the observed degrees of mismatch obtained from the monitoring data and assuming the overall ratio of sterile to wild flies to be 100:1. The simulation indicated that mismatches could result in the imposed rate of increase of wild flies being up to 3.5 times higher than that intended (i.e., 0.35 instead of 0.1). The effect of a mismatch always reduces the efficiency of SIT. The reason for this asymmetry is discussed and a comparison made with host-parasitoid and other systems. A release strategy to counter this effect is suggested. (author) [es

Phosphate removal from digested sludge supernatant using modified fly ash.

Science.gov (United States)

Xu, Ke; Deng, Tong; Liu, Juntan; Peng, Weigong

2012-05-01

The removal of phosphate in digested sludge supernatant by modified coal fly ash was investigated in this study. Modification of the fly ash by the addition of sulfuric acid could significantly enhance its immobilization ability. The experimental results also showed that adsorption of phosphate by the modified fly ash was rapid with the removal percentage of phosphate reaching an equilibrium of 98.62% in less than 5 minutes. The optimum pH for phosphate removal was 9 and the removal percentage increased with increasing adsorbent dosage. The effect of temperature on phosphate removal efficiency was not significant from 20 to 40 degrees C. X-ray diffraction and scanning electron microscope analyses showed that phosphate formed an amorphous precipitate with water-soluble calcium, aluminum, and iron ions in the modified fly ash.

High volume fly ash RCC for dams - I : mixture optimization and mechanical properties

Energy Technology Data Exchange (ETDEWEB)

Jacobsen, S. [PEAB Construction Co., Oslo (Norway); Lahus, O. [Norwegian Building Research Inst., Oslo (Norway)

2001-07-01

Roller compacted concretes (RCC) were developed for the Norwegian Skjerka hydropower project. RCCs were developed to have a high-volume fly ash content to address environmental issues, including the reduction of carbon dioxide emissions associated with dam construction. They also makes good use of waste product and conserve natural resources. This study examined a series of mixtures to determine the appropriateness of using RCC as a competing alternative to the traditional rock fill dam proposed for the Skjerka hydropower project. The main advantage of RCC is speed, allowing a relatively large dam to be constructed in just one summer season, saving financial costs and providing early return on the investment. In addition, fly ash can be used in the structure, using clean and renewable energy. Several procedures to proportion RCC mixtures were proposed, including the optimal paste volume method which is based on the assumption that an optimal RCC should have just enough paste to fill the space between particles when the granular skeleton has reached its maximum density under compaction. With this assumption, RCC tests began in 1998 in the laboratories of the Norwegian Building Research Institute. An ordinary portland cement was used and combined with ordinary low lime fly ash. Both coarse and fine aggregate were used. The tests determined the optimum paste-mortar ratio, the content of coarse aggregates and the production of specimens for test on hardened and fresh concrete. The study showed that the compressive strength of RCC increased with increasing cement/(cement + fly ash) ratio. The permeability coefficient decreased with increasing cement-content and increasing cement/(cement + fly ash) ratio due to the slow pozzolanic reaction of fly ash making a more open pore structure. It was concluded that an optimized mixture can result in a high performance RCC in terms of fresh and hardened concrete properties. 15 refs., 5 tabs., 11 figs.

Combined treatment of SO2 and high resistivity fly ash using a pulse energized electron reactor

International Nuclear Information System (INIS)

Mizuno, A.; Clements, J.S.; Davis, R.H.

1984-01-01

The combined removal of SO 2 and high resistivity fly ash has been demonstrated in a pulse energized electron reactor (PEER). The PEER system which was originally developed for the removal of SO 2 utilizes a positive pulse streamer corona discharge in a non-uniform field geometry. In performance tests on SO 2 , more than 90% was removed with an advantageously small power requirement. Combined treatment performance was demonstrated by introducing high resistivity fly ash into the test gas and the PEER is significantly more efficient than a conventional electrostatic precipitator operated with a dc voltage. Observations show that the PEER agglomerates the fly ash and further that the SO 2 removal efficiency is improved by the presence of fly ash. The electrode configuration and performance results make retrofit consideration attractive

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.

High-performance liquid chromatography of oligoguanylates at high pH

Science.gov (United States)

Stribling, R.; Deamer, D. (Principal Investigator)

1991-01-01

Because of the stable self-structures formed by oligomers of guanosine, standard high-performance liquid chromatography techniques for oligonucleotide fractionation are not applicable. Previously, oligoguanylate separations have been carried out at pH 12 using RPC-5 as the packing material. While RPC-5 provides excellent separations, there are several limitations, including the lack of a commercially available source. This report describes a new anion-exchange high-performance liquid chromatography method using HEMA-IEC BIO Q, which successfully separates different forms of the guanosine monomer as well as longer oligoguanylates. The reproducibility and stability at high pH suggests a versatile role for this material.

Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

Science.gov (United States)

Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

2015-01-01

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. PMID:28793518

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.

Acetate biodegradation by anaerobic microorganisms at high pH and high calcium concentration

International Nuclear Information System (INIS)

Yoshida, Takahiro

2011-01-01

Acetate biodegradation at a high pH and a high calcium concentration was examined to clarify the effect of bacterial activity on the migration of organic 14 C compounds in cementitious repositories. Tamagawa river sediment or Teganuma pond sediment was anaerobically cultured with 5 mM acetate and 10 mM nitrate at pH 9.5-12 at 30 o C. After 20 and 90 days, the acetate concentration of the culture medium was analyzed and found to have decreased below 5 mM at pH ≤ 11. On the other hand, it did not decrease when either sediment was incubated in the absence of nitrate. These results suggest that nitrate-reducing bacteria can biodegrade acetate under more alkaline conditions than the reported pH range in which nitrate-reducing bacteria can exhibit activity. Acetate biodegradation was also examined at a high calcium concentration. Sediments were anaerobically cultured at pH 9.5 with 5 mM acetate and 10 mM nitrate in solution, equilibrated with ordinary Portland cement hydrate, in which the Ca concentration was 14.6 mM. No decrease in acetate concentration after incubation of the sediments was observed, nor was it lower than in the absence of cementitious composition, suggesting that kinetics of acetate biodegradation by anaerobic microorganisms is lowered by a high Ca concentration. - Research highlights: → Acetate biodegradation at a high pH and a high calcium concentration was examined to clarify the effect of bacterial activity on the migration of organic 14 C compounds in cementitious repositories. → Nitrate-reducing bacteria can biodegrade acetate at pH ≤ 11. → Kinetics of acetate biodegradation by anaerobic microorganisms might be lowered by a high Ca concentration.

Influence of several experimental parameters on As and Se leaching from coal fly ash samples

International Nuclear Information System (INIS)

Otero-Rey, Jose R.; Mato-Fernandez, Maria J.; Moreda-Pineiro, Jorge; Alonso-Rodriguez, Elia; Muniategui-Lorenzo, Soledad; Lopez-Mahia, Purificacion; Prada-Rodriguez, Dario

2005-01-01

Coal fly ash leaching process for As and Se is studied. Environmental parameters such as pH, temperature, solid-liquid ratio, particle size and leaching time are taken into account in order to simulate As and Se leaching process for disposal coal fly ash. Analysis of reference materials was carried out by using of hydride generation coupled to atomic fluorescence spectrometry. Plackett-Burman experimental design is used to know the significative parameters, and Box-Behnken experimental design is used to refine the results obtained for these significative parameters. pH and temperature shown a hardly influence in leaching process. Furthermore, leaching time was also significative. According our results, it may be assumed that percentage of As and Se leaching in experimental conditions tested is relatively low for acidic fly ashes

Pressure pressure-balanced pH sensing system for high temperature and high pressure water

International Nuclear Information System (INIS)

Tachibana, Koji

1995-01-01

As for the pH measurement system for high temperature, high pressure water, there have been the circumstances that first the reference electrodes for monitoring corrosion potential were developed, and subsequently, it was developed for the purpose of maintaining the soundness of metallic materials in high temperature, high pressure water in nuclear power generation. In the process of developing the reference electrodes for high temperature water, it was clarified that the occurrence of stress corrosion cracking in BWRs is closely related to the corrosion potential determined by dissolved oxygen concentration. As the types of pH electrodes, there are metal-hydrogen electrodes, glass electrodes, ZrO 2 diaphragm electrodes and TiO 2 semiconductor electrodes. The principle of pH measurement using ZrO 2 diaphragms is explained. The pH measuring system is composed of YSZ element, pressure-balanced type external reference electrode, pressure balancer and compressed air vessel. The stability and pH response of YSZ elements are reported. (K.I.)

Clay formation and metal fixation during weathering of coal fly ash

International Nuclear Information System (INIS)

Zevenbergen, C.; Bradley, J.P.; Reeuwijk, L.P. Van; Shyam, A.K.; Hjelmar, O.; Comans, R.N.J.

1999-01-01

The enormous and worldwide production of coal fly ash cannot be durably isolated from the weathering cycle, and the weathering characteristics of fly ash must be known to understand the long-term environmental impact. The authors studied the weathering of two coal fly ashes and compared them with published data from weathered volcanic ash, it's closest natural analogue. Both types of ash contain abundant aluminosilicate glass, which alters to noncrystalline clay. However, this study reveals that the kinetics of coal fly ash weathering are more rapid than those of volcanic ash because the higher pH of fresh coal fly ash promotes rapid dissolution of the glass. After about 10 years of weathering, the noncrystalline clay content of coal fly ash is higher than that of 250-year-old volcanic ash. The observed rapid clay formation together with heavy metal fixation imply that the long-term environmental impact of coal fly ash disposal may be less severe and the benefits more pronounced than predicted from previous studies on unweathered ash. Their findings suggest that isolating coal fly ash from the weathering cycle may be counterproductive because, in the long-term under conditions of free drainage, fly ash is converted into fertile soil capable of supporting agriculture

Novel porous fly-ash containing geopolymer monoliths for lead adsorption from wastewaters

Energy Technology Data Exchange (ETDEWEB)

Novais, Rui M., E-mail: ruimnovais@ua.pt; Buruberri, L.H.; Seabra, M.P.; Labrincha, J.A.

2016-11-15

Highlights: • Porous fly ash containing-geopolymer monoliths for lead adsorption were developed. • Geopolymers’ porosity and pH of the ion solution controls the adsorption capacity. • Lead adsorption by the geopolymer monoliths up to 6.34 mg/g was observed. • These novel adsorbents can be used in packed beds that are easily collected. • The reuse of biomass fly ash wastes as raw material ensures waste valorization. - Abstract: In this study novel porous biomass fly ash-containing geopolymer monoliths were produced using a simple and flexible procedure. Geopolymers exhibiting distinct total porosities (ranging from 41.0 to 78.4%) and low apparent density (between 1.21 and 0.44 g/cm{sup 3}) were fabricated. Afterwards, the possibility of using these innovative materials as lead adsorbents under distinct conditions was evaluated. Results demonstrate that the geopolymers’ porosity and the pH of the ion solution strongly affect the lead adsorption capacity. Lead adsorption by the geopolymer monoliths ranged between 0.95 and 6.34 mg{sub lead}/g{sub geopolymer}. More porous geopolymers presented better lead removal efficiency, while higher pH in the solution reduced their removal ability, since metal precipitation is enhanced. These novel geopolymeric monoliths can be used in packed beds that are easily collected when exhausted, which is a major advantage in comparison with the use of powdered adsorbents. Furthermore, their production encompasses the reuse of biomass fly-ash, mitigating the environmental impact associated with this waste disposal, while decreasing the adsorbents production costs.

Study on uranium leaching behavior from coal fly ash samples

International Nuclear Information System (INIS)

Police, S.; Maity, S.; Chaudhary, D.K.; Sahu, S.K.; Pandit, G.G.

2017-01-01

Leachability of trace and toxic metals from coal fly ash (FA) poses significant environmental problems especially ground and surface water contamination. In the present study, leachability of U using batch leaching tests (i.e., at various leachate pH values) and using TCLP was studied. Results of pH variation study indicate that, U has higher leachability in acidic medium as compared to slightly alkaline medium. The leachable U concentrations observed in pH variation study are well below the WHO safety limits. In TCLP leachates, the leachable U concentrations are found to be higher than that observed in pH variation study. (author)

Fly ash carbon passivation

Science.gov (United States)

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

2013-05-14

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

Electrodialytic extraction of Cr from water-washed MSWI fly ash by changing pH and redox conditions

DEFF Research Database (Denmark)

Chen, Wan; Kirkelund, Gunvor Marie; Jensen, Pernille Erland

2018-01-01

Electrodialytic process offers a range of possibilities to waste management by electrodialytic separation (EDS) of heavy metals, depending on how the process is designed. Using three EDS cell setups (two two-compartment and one three-compartment) and their combinations, the extraction of Cr from...... rate of 27.5%, is an improvement on the single-step that extracted maximum 3.1%. The highest extraction was obtained due to the combined extraction of Cr(III) under low pH (accompanied with high redox) conditions and Cr(VI) under high pH (low redox) conditions subsequently. The Cr leaching from...... the treated ashes with acidic pH was lower than from those with alkaline pH; after the three-step treatment, Cr leaching was much lower from the coarse fraction (> 50 µm), as compared to the fine (≤ 50 µm) or the unsieved ash. As for the coarse fraction, two/three-step treatment reduced the leaching of Cr...

Attenuation of pyrite oxidation with a fly ash pre-barrier: Reactive transport modelling of column experiments

Energy Technology Data Exchange (ETDEWEB)

Perez-Lopez, R.; Cama, J.; Nieto, J.M.; Ayora, C.; Saaltink, M.W. [University of Huelva, Huelva (Spain). Dept. of Geology

2009-09-15

Conventional permeable reactive barriers (PRBs) for passive treatment of groundwater contaminated by acid mine drainage (AMD) use limestone as reactive material that neutralizes water acidity. However, the limestone-alkalinity potential ceases as inevitable precipitation of secondary metal-phases on grain surfaces occurs, limiting its efficiency. In the present study, fly ash derived from coal combustion is investigated as an alternative alkalinity generating material for the passive treatment of AMD using solution-saturated column experiments. Unlike conventional systems, the utilization of fly ash in a pre-barrier to intercept the non-polluted recharge water before this water reacts with pyrite-rich wastes is proposed. Chemical variation in the columns was interpreted with the reactive transport code RETRASO. In parallel, kinetics of fly ash dissolution at alkaline pH were studied using flow-through experiments and incorporated into the model. In a saturated column filled solely with pyritic sludge-quartz sand (1: 10), oxidation took place at acidic conditions (pH 3.7). According to SO{sub 4}{sup 2-} release and pH, pyrite dissolution occurred favourably in the solution-saturated porous medium until dissolved O{sub 2} was totally consumed. In a second saturated column, pyrite oxidation took place at alkaline conditions (pH 10.45) as acidity was neutralized by fly ash dissolution in a previous level. At this pH Fe release from pyrite dissolution was immediately depleted as Fe-oxy(hydroxide) phases that precipitated on the pyrite grains, forming Fe-coatings (microencapsulation). With time, pyrite microencapsulation inhibited oxidation in practically 97% of the pyritic sludge. Rapid pyrite-surface passivation decreased its reactivity, preventing AMD production in the relatively short term.

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.

Changes of the soil environment affected by fly ash dumping site of the electric power plant

Science.gov (United States)

Weber, Jerzy; Gwizdz, Marta; Jamroz, Elzbieta; Debicka, Magdalena; Kocowicz, Andrzej

2014-05-01

In this study the effect of fly ash dumping site of the electric power plant on the surrounding soil environment was investigated. The fly ash dumping site collect wastes form brown coal combustion of Belchatow electric power station, central Poland. The dumping site is surrounding by forest, where pine trees overgrow Podzols derived from loose quartz sands. The soil profiles under study were located at a distance of 50, 100, 400 and 500 m from the dumping site, while control profiles were located 8 km away from the landfill. In all horizons of soil profiles the mpain hysico-chemical and chemical properties were determined. The humic substances were extracted from ectohumus horizons by Shnitzer's method, purified using XAD resin and freeze-dried. The fulvic acids were passed through a cation exchange column and freeze-dried. Optical density, elemental composition and atomic ratios were determined in the humic and fulvic acids. Organic carbon by KMnO4 oxidation was also determined in the organic soil horizons. The fly ash from the landfill characterized by high salinity and strong alkaline reaction (pH=10), which contributed significantly to the changes of the pH values in soils horizons. The alkalization of soils adjacent to the landfill was found, which manifested in increasing of pH values in the upper soil horizons. The impact of the landfill was also noted in the changes of the soil morphology of Podzols analysed. As a result of the alkalization, Bhs horizons have been converted into a Bs horizons. Leaching of low molecular humus fraction - typical for podzolization - has been minimized as a result of pH changes caused by the impact of the landfill, and originally occurring humic substances in the Bhs horizon (present in the control profiles) have been probably transported out of the soil profile and then into the groundwater.

Removal mechanism of phosphate from aqueous solution by fly ash.

Science.gov (United States)

Lu, S G; Bai, S Q; Zhu, L; Shan, H D

2009-01-15

This work studied the effectiveness of fly ash in removing phosphate from aqueous solution and its related removal mechanism. The adsorption and precipitation of phosphate by fly ash were investigated separately in order to evaluate their role in the removal of phosphate. Results showed that the removal of phosphate by fly ash was rapid. The removal percentage of phosphate in the first 5min reached 68-96% of the maximum removal of phosphate by fly ash. The removal processes of phosphate by fly ash included a fast and large removal representing precipitation, then a slower and longer removal due to adsorption. The adsorption of phosphate on fly ash could be described well by Freundlich isotherm equation. The pH and Ca2+ concentration of fly ash suspension were decreased with the addition of phosphate, which suggests that calcium phosphate precipitation is a major mechanism of the phosphate removal. Comparison of the relative contribution of the adsorption and precipitation to the total removal of phosphate by fly ash showed that the adsorption accounted for 30-34% of the total removal of phosphate, depending on the content of CaO in fly ash. XRD patterns of the fly ash before and after phosphate adsorption revealed that phosphate salt (CaHPO4 x 2H2O) was formed in the adsorption process. Therefore, the removal of phosphate by fly ash can be attributed to the formation of phosphate precipitation as a brushite and the adsorption on hydroxylated oxides. The results suggested that the use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control.

Mechanism of alkalinity lowering and chemical equilibrium model of high fly ash silica fume cement

International Nuclear Information System (INIS)

Hoshino, Seiichi; Honda, Akira; Negishi, Kumi

2014-01-01

The mechanism of alkalinity lowering of a High Fly ash Silica fume Cement (HFSC) under liquid/solid ratio conditions where the pH is largely controlled by the soluble alkali components (Region I) has been studied. This mechanism was incorporated in the chemical equilibrium model of HFSC. As a result, it is suggested that the dissolution and precipitation behavior of SO 4 2- partially contributes to alkalinity lowering of HFSC in Region I. A chemical equilibrium model of HFSC incorporating alkali (Na, K) adsorption, which was presumed as another contributing factor of the alkalinity lowering effect, was also developed, and an HFSC immersion experiment was analyzed using the model. The results of the developed model showed good agreement with the experiment results. From the above results, it was concluded that the alkalinity lowering of HFSC in Region I was attributed to both the dissolution and precipitation behavior of SO 4 2- and alkali adsorption, in addition to the absence of Ca(OH) 2 . A chemical equilibrium model of HFSC incorporating alkali and SO 4 2- adsorption was also proposed. (author)

Evolution of pH in a radwaste repository: internal reactions between concrete constituents

International Nuclear Information System (INIS)

Atkinson, A.; Everitt, N.M.; Guppy, R.M.

1988-01-01

The pH is an important characteristic of the chemical conditions within a radioactive waste repository. A high pH is particularly beneficial from a variety of points of view and this can be assured by the use of cementitious materials within the repository. Reactions between repository components which have an influence on pH have been studied in accelerated laboratory experiments. The reactions studied were those occurring in modified cements (specifically 90% pulverized fly ash/10% ordinary Portland cement and 90% blast furnace slag/10% OPC) and between aqueous calcium hydroxide and both crystalline and amorphous SiO 2 . The experiments indicate that extensive use of fuel ash leads to uncertainty in long term pH which could be as low as 9 to 10 in such cases. Experiments with crystalline calcium silicon hydrate (CSH) minerals suggest that crystallization of amorphous CSH could also lead to pH being lower than the optimum. (author)

Leaching of Nutrient Salts from Fly Ash from Biomass Combustion

DEFF Research Database (Denmark)

Thomsen, Kaj; Vu, Duc Thuong; Stenby, Mette

2005-01-01

Methods to selectively leach nutrient salts from fly ash, while leaving cadmium un-dissolved were studied. Temperature, pH, water to fly ash ratio are all expected to influence the kinetics and the equilibrium boundaries for this process. Three different leaching methods were investigated....... The first method was a counter current moving bed process in four stages. The ash was kept in filter bags and leached with water that was introduced into the bags at 40-50°C. In the second method, fly ash and water was brought into contact in a partially fluidized bed. The third method was a counter current...... moving bed process with agitation/centrifugation. It was found that a satisfactory leaching of the nutrient salts could be achieved with the third method using only two or three stages, depending on the water to fly ash ratio. It is an advantage to perform the process at temperatures above 50°C...

Use of lignite fly ash as an additive in alkaline stabilisation and pasteurisation of wastewater sludge

Energy Technology Data Exchange (ETDEWEB)

Kocaer, F.O.; Alkan, U.; Baskaya, H.S. [Uludag University, Bursa (Turkey). Faculty of Engineering & Architecture

2003-10-01

The possibility of using lignite fly ash in low doses for reducing the pathogen levels in wastewater sludge was investigated. The results showed that using fly ash alone in doses of 40%,80% and 120% (on a dry weight basis), did not produce an alkaline environment for an efficient removal of pathogens. However, using fly ash in conjunction with the minimum amount of quicklime may act as an effective way of fecal coliform removal in both alkaline stabilisation and pasteurisation processes. It was shown that using fly ash in doses of 80% and 120% in alkaline stabilisation and pasteurisation processes prevented the pH decays and regrowth of pathogens during 60 days of storage period. The results of the study confirmed that alkaline pasteurisation process produces a product which is more resistant to pH decays and regrowth of fecal coliforms compared to that of alkaline stabilisation. Consequently, the overall results of this study indicated that the minimum lime and fly ash dosages required to generate a Class B biosolid were 10-15% and 80%, respectively. On the other hand, heating sludge to 50{degree}C prior to the addition of 10-15% quicklime and 80% fly ash followed by further heating to 70{degree}C and then sustaining at this temperature for 30 minutes were sufficient to generate a Class A biosolid.

The use of fly larvae for organic waste treatment.

Science.gov (United States)

Čičková, Helena; Newton, G Larry; Lacy, R Curt; Kozánek, Milan

2015-01-01

The idea of using fly larvae for processing of organic waste was proposed almost 100 years ago. Since then, numerous laboratory studies have shown that several fly species are well suited for biodegradation of organic waste, with the house fly (Musca domestica L.) and the black soldier fly (Hermetia illucens L.) being the most extensively studied insects for this purpose. House fly larvae develop well in manure of animals fed a mixed diet, while black soldier fly larvae accept a greater variety of decaying organic matter. Blow fly and flesh fly maggots are better suited for biodegradation of meat processing waste. The larvae of these insects have been successfully used to reduce mass of animal manure, fecal sludge, municipal waste, food scrapes, restaurant and market waste, as well as plant residues left after oil extraction. Higher yields of larvae are produced on nutrient-rich wastes (meat processing waste, food waste) than on manure or plant residues. Larvae may be used as animal feed or for production of secondary products (biodiesel, biologically active substances). Waste residue becomes valuable fertilizer. During biodegradation the temperature of the substrate rises, pH changes from neutral to alkaline, ammonia release increases, and moisture decreases. Microbial load of some pathogens can be substantially reduced. Both larvae and digested residue may require further treatment to eliminate pathogens. Facilities utilizing natural fly populations, as well as pilot and full-scale plants with laboratory-reared fly populations have been shown to be effective and economically feasible. The major obstacles associated with the production of fly larvae from organic waste on an industrial scale seem to be technological aspects of scaling-up the production capacity, insufficient knowledge of fly biology necessary to produce large amounts of eggs, and current legislation. Technological innovations could greatly improve performance of the biodegradation facilities and

Suppressing Heavy Metal Leaching through Ball Milling of Fly Ash

Directory of Open Access Journals (Sweden)

Zhiliang Chen

2016-07-01

Full Text Available Ball milling is investigated as a method of reducing the leaching concentration (often termed stablilization of heavy metals in municipal solid waste incineration (MSWI fly ash. Three heavy metals (Cu, Cr, Pb loose much of their solubility in leachate by treating fly ash in a planetary ball mill, in which collisions between balls and fly ash drive various physical processes, as well as chemical reactions. The efficiency of stabilization is evaluated by analysing heavy metals in the leachable fraction from treated fly ash. Ball milling reduces the leaching concentration of Cu, Cr, and Pb, and water washing effectively promotes stabilization efficiency by removing soluble salts. Size distribution and morphology of particles were analysed by laser particle diameter analysis and scanning electron microscopy. X-ray diffraction analysis reveals significant reduction of the crystallinity of fly ash by milling. Fly ash particles can be activated through this ball milling, leading to a significant decrease in particle size, a rise in its BET-surface, and turning basic crystals therein into amorphous structures. The dissolution rate of acid buffering materials present in activated particles is enhanced, resulting in a rising pH value of the leachate, reducing the leaching out of some heavy metals.

Chromium removal from tannery wastewater by using of flying ash

International Nuclear Information System (INIS)

Gil P, E.; Saldarriaga M, C.

1998-01-01

A simple and economic method to chromium removal from tannery wastewater by means of flying ash is presented. The chromium removal operation is a discontinuous process that involve the mass of flying ash, time of contact and temperature or ph as variables, their which are optimized through Box-Wilson type experimental design. The results were successful: From an initial fluid whit chromium concentration of 1850m ppm, final concentrations of 0.008 ppm and 0.5 ppm of Cr+3 and Cr+6 respectively were achieved. These post-treatment concentrations are into the approved range definite by Government's Laws to this waste type

Nanoscale insight of high piezoelectricity in high-TC PMN-PH-PT ceramics

Science.gov (United States)

Zhu, Rongfeng; Zhang, Qihui; Fang, Bijun; Zhang, Shuai; Zhao, Xiangyong; Ding, Jianning

2018-03-01

The piezoelectric properties of the high-Curie temperature (high-TC) 0.15Pb(Mg1/3Nb2/3)O3-0.38PbHfO3-0.47PbTiO3 (0.15PMN-0.38PH-0.47PT) ceramics prepared by three different methods were compared. The 0.15PMN-0.38PH-0.47PT ceramics synthesized by the partial oxalate route exhibit the optimum properties, in which d33* = 845.3 pm/V, d33 = 456.2 pC/N, Kp = 67.2%, and TC = 291 °C. The nanoscale origin of the high piezoelectric response of the 0.15PMN-0.38PH-0.47PT ceramics was investigated by piezoresponse force microscopy (PFM) using the ceramics synthesized by the partial oxalate route. Large quantities of fine stripe submicron ferroelectric domains are observed, which form large island domains. In order to give further insights into the piezoelectric properties of the 0.15PMN-0.38PH-0.47PT ceramics from a microscopic point of view, the local poling experiments and local switching spectroscopy piezoresponse force microscopy (SS-PFM) were investigated, from which the local converse piezoelectric coefficient d33*(l) is calculated as 220 pm/V.

Back pain and its consequences among Polish Air Force pilots flying high performance aircraft

Directory of Open Access Journals (Sweden)

Aleksandra Truszczyńska

2014-04-01

Full Text Available Objectives: Back pain in Air Force fast jet pilots has been studied by several air forces and found to be relatively common. The objective of the study was to determine the prevalence and degree of the pain intensity in the cervical, thoracic and lumbar spine, subjective risk factors and their effect on the pilots' performance while flying high maneuver aircrafts and the consequences for cognitive deficiencies. Material and Methods: The study was designed as a retrospective, anonymous questionnaire survey, collecting data on the age, aircraft type, flying hours, pain characteristics, physical activity, etc. The study was participated by 94 pilots aged 28-45 years (mean age: 35.9±3.3 years, actively flying fast jet aircrafts Su-22, Mig-29 and F-16. The estimates regarding the level of the subjective back pain were established using visual analogue scales (VAS. Results: The values of the Cochran and Cox T-test for heterogeneous variances are as follows: for the total number of flying hours: F = 2.53, p = 0.0145, for the pilot's age: F = 3.15, p = 0.003, and for the BMI factor F = 2.73, p = 0.008. Conclusions: Our questionnaire survey showed a significant problem regarding spinal conditions in high performance aircraft pilots. The determination of the risk factors may lead to solving this problem and help eliminate the effect of the unfavorable environment on piloting jet aircrafts. Experiencing back pain during the flight might influence the mission performance and flight safety. The costs of pilots education are enormous and inability to fly, or even disability, leads to considerable economic loss. More research on specific prevention strategies is warranted in order to improve the in-flight working environment of fighter pilots.

Nanowire-templated microelectrodes for high-sensitivity pH detection

DEFF Research Database (Denmark)

Antohe, V.A.; Radu, Adrian; Mátéfi-Tempfli, Mária

2009-01-01

A highly sensitive pH capacitive sensor has been designed by confined growth of vertically aligned nanowire arrays on interdigited microelectrodes. The active surface of the device has been functionalized with an electrochemical pH transducer (polyaniline). We easily tune the device features...... by combining lithographic techniques with electrochemical synthesis. The reported electrical LC resonance measurements show considerable sensitivity enhancement compared to conventional capacitive pH sensors realized with microfabricated interdigited electrodes. The sensitivity can be easily improved...

Preparation of poly-o-phenylenediamine/TiO2/fly-ash cenospheres and its photo-degradation property on antibiotics

International Nuclear Information System (INIS)

Huo Pengwei; Yan Yongsheng; Li Songtian; Li Huaming; Huang Weihong

2010-01-01

A series of poly-o-phenylenediamine/TiO 2 /fly-ash cenospheres(POPD/TiO 2 /fly-ash cenospheres) composites have been prepared from o-phenylenediamine and TiO 2 /fly-ash cenospheres under various polymerization conditions. The properties of the samples were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), specific surface area (BET), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and UV-vis diffuse reflectance spectrum (UV-vis DRS). Photocatalytic activity was studied by degradation of antibiotics waste water under visible light. The results indicate that the photo-induced method is viable for preparing modified photocatalysts, and the modified photocatalysts have good absorption in visible light range. The photocatalysts of POPD/TiO 2 /fly-ash cenospheres which have good performance are prepared at pH 3 and 4, and the polymerized time around 40 min. When the photocatalysts are prepared under the conditions of pH 3 and polymerized time 40 min, the degradation rate of roxithromycin waste water could reach near 60%, and it indicates that the way of POPD modified TiO 2 /fly-ash cenospheres to degrade the antibiotics waste water is viable.

Copper and cadmium adsorption on pellets made from fired coal fly ash

International Nuclear Information System (INIS)

Papandreou, A.; Stournaras, C.J.; Panias, D.

2007-01-01

Studies on the utilization of low cost adsorbents for removal of heavy metals from wastewaters are gaining attention. Fired coal fly ash, a solid by-product that is produced in power plants worldwide in million of tonnes, has attracted researchers' interest. In this work, fly ash was shaped into pellets that have diameter in-between 3-8 mm, high relative porosity and very good mechanical strength. The pellets were used in adsorption experiments for the removal of copper and cadmium ions from aqueous solutions. The effect of agitation rate, equilibration time, pH of solution and initial metal concentration were studied. The adsorption of both cations follows pseudo-second order kinetics reaching equilibrium after an equilibration time of 72 h. The experimental results for copper and cadmium adsorption fit well to a Langmuirian type isotherm. The calculated adsorption capacities of pellets for copper and cadmium were 20.92 and 18.98 mg/g, respectively. Desorption experiments were performed in several extraction media. The results showed that both metals were desorbed substantially from pellets under acidic solutions. For this reason, metal saturated pellets were encapsulated in concrete blocks synthesized from cement and raw pulverized fly ash in order to avoid metal desorption. The heavy metals immobilization after encapsulation in concrete blocks was tested through desorption tests in several aqueous media. The results showed that after 2 months in acidic media with pH 2.88 and 4.98 neither copper nor cadmium were desorbed thus indicating excellent stabilization of heavy metals in the concrete matrix. As a conclusion, the results showed that fly ash shaped into pellets could be considered as a potential adsorbent for the removal of copper and cadmium from wastewaters. Moreover, the paper proposes an efficient and simple stabilization process of the utilized adsorbents thus guarantying their safe disposal in industrial landfills and eliminating the risk of pollution

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.

Removal of fluoride from drinking water using a modified fly ash adsorbent

Energy Technology Data Exchange (ETDEWEB)

Debasis Goswami; Arabinda K. Das

2006-01-15

Fly ash from a coal-fired power station was chemically modified and utilized for the removal of fluoride from drinking water. Two types of beds were used. Bed I was prepared by treatment with 12M HCl followed by neutralization with 5M NaOH solution. The reaction mass was filtered, washed, dried, and crushed to fine powder. Bed I material was mixed with alum and MgCl{sub 2} solutions and treated with 0.9M Na{sub 2}CO{sub 3} until pH reached to 4.5. Mass was again filtered, washed, dried at 120{sup o}C for 4 h and crushed to fine powder. This bed material is Bed II, which was used for defluoridation. Bed I was used to maintain pH (7.5-8.5) of the final effluent. Fluoride (100 ppm) present in both synthetic mixtures and drinking water samples was allowed to pass through Bed II (15 g) absorbent and effluents were found to contain no fluoride but pH of the effluent was 5.4-5.5. To maintain WHO guidelines for drinking water on pH, this effluent was again passed through Bed I. The effectiveness of the modified fly ash bed was satisfactory.

Ge extraction from gasification fly ash

Energy Technology Data Exchange (ETDEWEB)

Oriol Font; Xavier Querol; Angel Lopez-Soler; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)

2005-08-01

Water-soluble germanium species (GeS{sub 2}, GeS and hexagonal-GeO{sub 2}) are generated during coal gasification and retained in fly ash. This fact together with the high market value of this element and the relatively high contents in the fly ashes of the Puertollano Integrated Gasification in Combined Cycle (IGCC) plant directed our research towards the development of an extraction process for this element. Major objectives of this research was to find a low cost and environmentally suitable process. Several water based extraction tests were carried out using different Puertollano IGCC fly ash samples, under different temperatures, water/fly ash ratios, and extraction times. High Ge extraction yields (up to 84%) were obtained at room temperature (25{sup o}C) but also high proportions of other trace elements (impurities) were simultaneously extracted. Increasing the extraction temperature to 50, 90 and 150{sup o}C, Ge extraction yields were kept at similar levels, while reducing the content of impurities, the water/fly ash ratio and extraction time. The experimental data point out the influence of chloride, calcium and sulphide dissolutions on the Ge extraction. 16 refs., 9 figs., 6 tabs.

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.

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...... modelling framework and a detailed mineralogical investigation was performed on the original FA and leached solid residues. The largest amounts of Co, Cu, Pb and Zn were leached at pH 5, generally with the lowest concentrations between pH 9 and 11 and slightly increased concentrations at pH 12. For most...... detected using SEM/EDS and/or TEM/EDS. The leaching of metals was mainly attributed to the dissolution of metallic particles. Partial dissolution of silicate and glass fractions was assumed to significantly influence the release of Ca, Mg, Fe, K, Al and Si as well as Cu, Co and Zn. The formation of illite...

Using Cementitious Materials Such as Fly Ash to Replace a Part of Cement in Producing High Strength Concrete in Hot Weather

Science.gov (United States)

Turuallo, Gidion; Mallisa, Harun

2018-03-01

The use of waste materials in concrete gave many advantages to prove the properties of concrete such as its workability, strength and durability; as well to support sustaianable development programs. Fly ash was a waste material produced from coal combustion. This research was conducted to find out the effect of fly ash as a part replacement of cement to produce high strength concrete. The fly ash, which was used in this research, was taken from PLTU Mpanau Palu, Central Sulawesi. The water-binder ratio used in this research was 0.3 selected from trial mixes done before. The results of this research showed that the strength of fly ash concretes were higher than concrete with PCC only. The replacement of cement with fly ash concrete could be up to 20% to produce high strength concrete.

Polyamine stress at high pH in Escherichia coli K-12

Directory of Open Access Journals (Sweden)

Tate Daniel P

2005-10-01

Full Text Available Abstract Background Polyamines such as spermine and spermidine are required for growth of Escherichia coli; they interact with nucleic acids, and they bind to ribosomes. Polyamines block porins and decrease membrane permeability, activities that may protect cells in acid. At high concentrations, however, polyamines impair growth. They impair growth more severely at high pH, probably due to their increased uptake as membrane-permeant weak bases. The role of pH is critical in understanding polyamine stress. Results The effect of polyamines was tested on survival of Escherichia coli K-12 W3110 in extreme acid or base (pH conditions outside the growth range. At pH 2, 10 mM spermine increased survival by 2-fold, and putrescine increased survival by 30%. At pH 9.8, however, E. coli survival was decreased 100-fold by 10 mM spermine, putrescine, cadaverine, or spermidine. At pH 8.5, spermine decreased the growth rate substantially, whereas little effect was seen at pH 5.5. Spermidine required ten-fold higher concentrations to impair growth. On proteomic 2-D gels, spermine and spermidine caused differential expression of 31 different proteins. During log-phase growth at pH 7.0, 1 mM spermine induced eight proteins, including PykF, GlpK, SerS, DeaD, OmpC and OmpF. Proteins repressed included acetate-inducible enzymes (YfiD, Pta, Lpd as well as RapA (HepA, and FabB. At pH 8.5, spermine induced additional proteins: TnaA, OmpA, YrdA and NanA (YhcJ and also repressed 17 proteins. Four of the proteins that spermine induced (GlpK, OmpA, OmpF, TnaA and five that were repressed (Lpd, Pta, SucB, TpiA, YfiD show similar induction or repression, respectively, in base compared to acid. Most of these base stress proteins were also regulated by spermidine, but only at ten-fold higher concentration (10 mM at high pH (pH 8.5. Conclusion Polyamines increase survival in extreme acid, but decrease E. coli survival in extreme base. Growth inhibition by spermine and

Sorptive removal of cesium-137 and strontium-90 from water by unconventional sorbents. 2. Usage of coal fly ash

International Nuclear Information System (INIS)

Apak, R.; Atun, G.; Gueclue, K.; Tuetem, E.

1996-01-01

It has been shown that coal fly ash is a good adsorbent for both radionuclides of 137 Cs and 90 Sr. Radiocesium adsorption is maximal around the neutral region whereas radiostrontium adsorption increases with pH, especially above pH 8. Cesium retention sharply drops with ionic strength while strontium adsorption increases sharply and steadily at low and moderate concentrations of the inert electrolyte, respectively. The suggested mechanisms of radionuclide retention by fly ash is specific adsorption of Cs + and irreversible ion-exchange uptake of Sr 2+ . The isotherm of adsorption is a Langmuir approximation of the B.E.T. multi-layered sorption. Acid pretreatment of fly ash, though not increasing radionuclide sorption capacity, may be useful in preventing the leach-out of other contaminants from the sorbent into water during the adsorption process. (author)

Removal of heavy metals from fly ash leachate using combined bioelectrochemical systems and electrolysis

International Nuclear Information System (INIS)

Tao, Hu-Chun; Lei, Tao; Shi, Gang; Sun, Xiao-Nan; Wei, Xue-Yan; Zhang, Li-Juan; Wu, Wei-Min

2014-01-01

Highlights: • Heavy metals removal from MSWI fly ash with BES and electrolysis was confirmed. • 98.5% of Cu(II), 95.4% of Zn(II) and 98.1% of Pb(II) removal were achieved in reactors. • BESs can remove some heavy metals in fly ash with energy saving. -- Abstract: Based on environmental and energetic analysis, a novel combined approach using bioelectrochemical systems (BES) followed by electrolysis reactors (ER) was tested for heavy metals removal from fly ash leachate, which contained high detectable levels of Zn, Pb and Cu according to X-ray diffraction analysis. Acetic acid was used as the fly ash leaching agent and tested under various leaching conditions. A favorable condition for the leaching process was identified to be liquid/solid ratio of 14:1 (w/w) and leaching duration 10 h at initial pH 1.0. It was confirmed that the removal of heavy metals from fly ash leachate with the combination of BESs and ER is feasible. The metal removal efficiency was achieved at 98.5%, 95.4% and 98.1% for Cu(II), Zn(II), and Pb(II), respectively. Results of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) indicated that Cu(II) was reduced and recovered mainly as metal Cu on cathodes related to power production, while Zn(II) and Pb(II) were not spontaneously reduced in BESs without applied voltage and basically electrolyzed in the electrolysis reactors

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.

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

International Nuclear Information System (INIS)

Pourrut, Bertrand; Lopareva-Pohu, Alena; Pruvot, Christelle; Garcon, Guillaume; Verdin, Anthony; Waterlot, Christophe; Bidar, Geraldine; Shirali, Pirouz

2011-01-01

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 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.

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.

Fly ash: An alternative to powdered activated carbon for the removal ...

African Journals Online (AJOL)

This paper reports the use of powdered activated carbon (PAC) and raw coal fly ash (RFA) in the removal of eosin dye from aqueous solution in batch processes. Operational parameters such as contact time, initial dye concentration, pH and temperature were investigated. Adsorption equilibrium was established in 120 min ...

Self-healing of mechanically-loaded self consolidating concretes with high volumes of fly ash

Energy Technology Data Exchange (ETDEWEB)

Mustafa Sahmaran; Suleyman B. Keskin; Gozde Ozerkan; Ismail O. Yaman [University of Gaziantep, Gaziantep (Turkey). Department of Civil Engineering

2008-11-15

This article discusses the effects of self-healing on self consolidating concretes incorporating high volumes of fly ash (HVFA-SCC) when subjected to continuous water exposure. For this purpose, self consolidating concretes with fly ash replacement ratios of 0%, 35%, and 55% were prepared having a constant water-cementitious material ratio of 0.35. A uniaxial compression load was applied to generate microcracks in concrete where cylindrical specimens were pre-loaded up to 70% and 90% of the ultimate compressive load determined at 28 days. Later, the extent of damage was determined as percentage of loss in mechanical properties and percentage of increase in permeation properties. After pre-loading, concrete specimens were stored in water for a month and the mechanical and permeation properties are monitored at every two weeks. It was observed that HVFA-SCC mixtures initially lost 27% of their strength when pre-loaded up to 90% of their ultimate strength, and after 30 days of water curing that reduction was only 7%, indicating a substantial healing. On the other hand, for SCC specimens without fly ash that were pre-loaded to the same level, the loss in strength was initially 19%, and after a month of moist curing it was only 13%. Similar observations were also made on the permeation properties with greater effects. As the HVFA-SCCs studied have an important amount of unhydrated fly ash available in their microstructure, these observations are attributed to the self-healing of the pre-existing cracks, mainly by hydration of anhydrous fly ash particles on the crack surfaces.

Sorptive removal of cesium-137 and strontium-90 from water by unconventional sorbents. 2. Usage of coal fly ash

Energy Technology Data Exchange (ETDEWEB)

Apak, R.; Atun, G.; Gueclue, K.; Tuetem, E. [Istanbul Univ. (Turkey). Faculty of Engineering

1996-05-01

It has been shown that coal fly ash is a good adsorbent for both radionuclides of {sup 137}Cs and {sup 90}Sr. Radiocesium adsorption is maximal around the neutral region whereas radiostrontium adsorption increases with pH, especially above pH 8. Cesium retention sharply drops with ionic strength while strontium adsorption increases sharply and steadily at low and moderate concentrations of the inert electrolyte, respectively. The suggested mechanisms of radionuclide retention by fly ash is specific adsorption of Cs{sup +} and irreversible ion-exchange uptake of Sr{sup 2+}. The isotherm of adsorption is a Langmuir approximation of the B.E.T. multi-layered sorption. Acid pretreatment of fly ash, though not increasing radionuclide sorption capacity, may be useful in preventing the leach-out of other contaminants from the sorbent into water during the adsorption process. (author).

Treatment of fly ash for use in concrete

Science.gov (United States)

Boxley, Chett [Park City, UT

2012-05-15

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

Properties of fly ashes in wet environment; Flygaskors egenskaper i vaat miljoe

Energy Technology Data Exchange (ETDEWEB)

Broemssen, M. von; Lindstroem, N.; Hedman, K.; Svensson, M.

2009-03-15

This report describes how inorganic elements are mobilised from fly ashes that are placed under water, i.e. what are the properties and processes that governs the mobilisation. This knowledge may serve as basic data for decision making when fly ashes from e.g. bio-, industrial- and municipal solid wastes are to be used in civil engineering applications in wet environments. The composition of ashes varies in a vide range of concentrations and depends on the fuel and the type of incinerator. The main contents of fly ashes are calcium oxide, silicic acid and aluminium compounds. Several environmental hazardous elements are also present in varying concentrations. The pH of fishily is often very high. A number of chemical processes occur when flyashes is mixed with water. When the pH-value increases, mainly due to hydratisation of calcium oxide (CaO), many metals will precipitate as metal hydroxides. The objective of this study was to, within a rather short time period (8 month), describe the processes governing mobilisation of different elements from fly ashes placed under water. The work included chemical equilibrium modelling with PHREEQC, the model was used to determine what minerals may control solubility of different elements. Three fly ashes were used for the study, one flyash from industrial- and municipal waste with no CaO or ammonia added, one flyash from municipal waste with CaO and ammonia added and one fly ash from solid biofuels with chalk added. The fly ashes, ca 300 kg, was mixed with water in 1000 l plastic containers and filled with water. Two batches per flyash were used; i) in the first batch surplus water were not replaced, ii) in the second batch the surplus water was replaced with fresh water five times during the test. Measured pH-values in the batches with industrial and municipal waste were stabilised at a pH-value around 9.5 indicating carbonation is complete. The pH-values in the bio flyash were higher. Four categories of elements were

Physiological effect of accidental fly ash deposition on plants and chemical study of the dusted plant leaves by XRP and EPMA

Energy Technology Data Exchange (ETDEWEB)

Osan, J.; Torok, S.; Torok, K.; Nemeth, L.; Labar, J.L. [KFTI Atomic Energy Research Institute, Budapest (Hungary)

1996-07-01

Studies on the influence of fly ash on the photosynthetic activity of Solidago canadensis L. were carried out in order to determine the importance of this material as an environmental impact agent. Leaf samples were dusted with fly ash and sprayed with water of different pH values simulating acid rain. Fly ash was applied in quantities to model an accidental occasion of an extremely high emission level of fly ash as a result of malfunctioning of the electrostatic filters of fossil fuel-burning power plants. Leaf samples were analysed to trace the distribution of fly ash compounds on the leaf epidermis by means of x-ray fluorescence (XRF) analysis and single-particle electron probe microanalysis (EPMA). Significant reduction of the photosynthetic activity compared with the control group was observed only when the dusted plants were sprayed with acid rain. The trace element study showed that the uptake of toxic elements by plants was not significant. A quartz microcrystal layer in the case of acid treatment was detected by EPMA, and covered the entire leaf surface. It is considered that this layer, in addition to the fly ash particles themselves, absorbed light significantly, which played an important role in the decrease in photosynthetic activity.

Chemical associations and mobilization of heavy metals in fly ash from municipal solid waste incineration.

Science.gov (United States)

Weibel, Gisela; Eggenberger, Urs; Schlumberger, Stefan; Mäder, Urs K

2017-04-01

This study focusses on chemical and mineralogical characterization of fly ash and leached filter cake and on the determination of parameters influencing metal mobilization by leaching. Three different leaching processes of fly ash from municipal solid waste incineration (MSWI) plants in Switzerland comprise neutral, acidic and optimized acidic (+ oxidizing agent) fly ash leaching have been investigated. Fly ash is characterized by refractory particles (Al-foil, unburnt carbon, quartz, feldspar) and newly formed high-temperature phases (glass, gehlenite, wollastonite) surrounded by characteristic dust rims. Metals are carried along with the flue gas (Fe-oxides, brass) and are enriched in mineral aggregates (quartz, feldspar, wollastonite, glass) or vaporized and condensed as chlorides or sulphates. Parameters controlling the mobilization of neutral and acidic fly ash leaching are pH and redox conditions, liquid to solid ratio, extraction time and temperature. Almost no depletion for Zn, Pb, Cu and Cd is achieved by performing neutral leaching. Acidic fly ash leaching results in depletion factors of 40% for Zn, 53% for Cd, 8% for Pb and 6% for Cu. The extraction of Pb and Cu are mainly limited due to a cementation process and the formation of a PbCu 0 -alloy-phase and to a minor degree due to secondary precipitation (PbCl 2 ). The addition of hydrogen peroxide during acidic fly ash leaching (optimized acidic leaching) prevents this reduction through oxidation of metallic components and thus significantly higher depletion factors for Pb (57%), Cu (30%) and Cd (92%) are achieved. The elevated metal depletion using acidic leaching in combination with hydrogen peroxide justifies the extra effort not only by reduced metal loads to the environment but also by reduced deposition costs. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Fly ash as a sorbent for the removal of biologically resistant organic matter

Energy Technology Data Exchange (ETDEWEB)

Vandenbusch, M B; Sell, N J [Wisconsin Public Service Corporation, Green Bay, WI (USA)

1992-02-01

Six different fly ashes, in both an untreated and an acidified form, were studied with respect to their ability to remove colour and organic materials from a municipal waste treatment facility effluent. Colour, fluorescence, and chemical oxygen demand were used to monitor the removal. The apparent predominant mechanism varies with the pH and the chemical characteristics of the ash. These mechanisms include carbon sorption, calcium precipitation of tannins and humics, sorption on the fly ash surface by silica, alumina, and/or iron oxide and, in the acidified situation, coagulation of coloured colloids in the effluent dissolved from the fly ash. Some additional deleterious components are dissolved into the effluent during the treatment process. Many of these materials can, however, be removed by using a two-stage fly ash sorption process. Particularly of interest is the ability to remove over 90% of the boron from the effluent. 13 refs., 10 figs., 9 tabs.

High pH mobile phase effects on silica-based reversed-phase high-performance liquid chromatographic columns

NARCIS (Netherlands)

Kirkland, J.J.; Straten, van M.A.; Claessens, H.A.

1995-01-01

Aqueous mobile phases above pH 8 often cause premature column failure, limiting the utility of silica-based columns for applications requiring high pH. Previous studies suggest that covalently bound silane ligands are hydrolyzed and removed by high-pH mobile phases. However, we found that the

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

KAUST Repository

Yoon, Seyoon; Monteiro, Paulo J.M.; Macphee, Donald E.; Glasser, Fredrik P.; Imbabi, Mohammed Salah-Eldin

2014-01-01

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

Development of autonomous controller system of high speed UAV from simulation to ready to fly condition

Science.gov (United States)

Yudhi Irwanto, Herma

2018-02-01

The development of autonomous controller system that is specially used in our high speed UAV, it’s call RKX-200EDF/TJ controlled vehicle needs to be continued as a step to mastery and to developt control system of LAPAN’s satellite launching rocket. The weakness of the existing control system in this high speed UAV needs to be repaired and replaced using the autonomous controller system. Conversion steps for ready-to-fly system involved controlling X tail fin, adjusting auto take off procedure by adding X axis sensor, procedure of way points reading and process of measuring distance and heading to the nearest way point, developing user-friendly ground station, and adding tools for safety landing. The development of this autonomous controller system also covered a real flying test in Pandanwangi, Lumajang in November 2016. Unfortunately, the flying test was not successful because the booster rocket was blown right after burning. However, the system could record the event and demonstrated that the controller system had worked according to plan.

Activated Carbon-Fly Ash-Nanometal Oxide Composite Materials: Preparation, Characterization, and Tributyltin Removal Efficiency

Directory of Open Access Journals (Sweden)

Olushola S. Ayanda

2013-01-01

Full Text Available The physicochemical properties, nature, and morphology of composite materials involving activated carbon, fly ash, nFe3O4, nSiO2, and nZnO were investigated and compared. Nature and morphology characterizations were carried out by means of scanning electron and transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Other physicochemical characterizations undertaken were CNH analysis, ash content, pH, point of zero charge, and surface area and porosity determination by BET. Experimental results obtained revealed that activated carbon, nSiO2, activated carbon-fly ash, activated carbon-fly ash-nFe3O4, activated carbon-fly ash-nSiO2, and activated carbon-fly ash-nZnO composite materials exhibited net negative charge on their surfaces while fly ash, nFe3O4, and nZnO possessed net positive charge on their surfaces. Relatively higher removal efficiency (>99% of TBT was obtained for all the composite materials compared to their respective precursors except for activated carbon. These composite materials therefore offer great potential for the remediation of TBT in wastewaters.

Trace element toxicity in VA mycorrhizal cucumber grown on weathered coal fly ash

Energy Technology Data Exchange (ETDEWEB)

Dosskey, M.G.; Adriano, D.C. (University of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.)

1993-11-01

Mycorrhizal colonization is widely recognized as enhancing plant growth on severely disturbed sites. A greenhouse pot experiment was conducted to determine if inoculation with vesicular-arbuscular mycorrhizal (VAM) fungi will enhance vegetation establishment on abandoned coal fly ash basinss, Spores of Glomus intraradices (Schenck and Smith) and Glomus etunicatum (Becker and Gerdemann) were added to weathered precipitator ash (EC-0.91 dSm[sup -1], pH 5.0) and to a pasteurized soils of the same pH (Grossarenic Paleudult, 92% sand, 1% organic matter). Some soil and ash were left unamended as non-mycorrhizal controls. Cucumber (Cucumis sativus L. cv. Poinsette 76) seeds were sown, watered regularly, and fertilized periodically with macronutrient solution. By 8 weeks all ash-grown plants exhibited smaller leaves with leaf margin curl and necrosis, and plant biomass was significantly less (0.75x) than soil-grown plants. Based on analysis of 18 elements in plant tissues, toxicity to B, Mn, or Zn could have caused growth suppression, confirming trace element problems for plant growth on fly ash. For plants grown on fly ash, G. etunicatum was the only fungus that colonized roots (20% of root length reduced from 67% on soil) and it suppressed plant growth to 0.80 x that of uninoculated ash-grown plants. Correspondingly, shoot Zn concentration in G. etunicatum-inoculated plants was 3.5 x higher than in uninoculated plants and at generally toxic levels (273 mg kg[sup -1]). Glomus etunicatum had no other significant effects on elemental concentrations. These results indicate that VAM colonization in acid, weathered fly ash suppressed plant growth by facilitating uptake of Zn to toxic levels, and implies a limitation to successful use of VAM for vegetation establishment on abandoned coal fly ash basins.

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.

Molecular detection of Leishmania infection in sand flies in border line of Iran-Turkmenistan: restricted and permissive vectors.

Science.gov (United States)

Bakhshi, H; Oshaghi, M A; Abai, M R; Rassi, Y; Akhavan, A A; Sheikh, Z; Mohtarami, F; Saidi, Z; Mirzajani, H; Anjomruz, M

2013-10-01

A molecular study was carried out to incriminate sand fly vectors of cutaneous leishmaniasis (CL) in rural areas of Sarakhs district, Khorassane-Razavi Province, northeastern Iran, in 2011. Sand flies of Sergentomyia with three species and Phlebotomus with six species respectively comprised 73.3% and 26.7% of the specimens. Phlebotomus papatasi was the most common Phlebotomine species in outdoor and indoor resting places. Leishmania infection was found at least in 17 (22%) specimens including Ph. papatasi (n=9 pool samples), Phlebotomus caucasicus (n=6), Phlebotomus alexandri (n=1), and Sergentomyia sintoni (n=1). The parasites were found comprised Leishmania major (n=5), Leishmania turanica (n=10), and Leishmania gerbilli (n=4). Infection of Ph. papatasi with both L. major and L. turanica supporting the new suggestion indicating that it is not restricted only with L. major. Circulation of L. major by Ph. alexandri, and both L. gerbilli and L. turanica by Ph. caucasicus, in addition to previous data indicating the ability of Ph. alexandri to circulate Leishmania infantum and Leishmania donovani, and Ph. caucasicus to circulate L. major, suggests that these two species can be permissive vectors. The results suggest that Ph. papatasi and Ph. alexandri are the primary and secondary vectors of CL where circulating L. major between human and reservoirs, whereas Ph. caucasicus is circulating L. turanica and L. gerbilli between the rodents in the region. Copyright © 2013 Elsevier Inc. All rights reserved.

Identification of high molecular weight nitroaromatic compounds from coal fly ash

International Nuclear Information System (INIS)

Harris, W.R.; Okamoto, D.J.; Chess, E.K.; Wilson, B.W.

1983-01-01

A large sample of stack-collected coal fly ash was extracted with 60:40 nu/nu benzene:methanol to remove as much of the soluble organic material as possible. This solution was concentrated by gentle evaporation, and was then fractionated on a series of high performance liquid chromatography columns to generate samples suitable for probe mass spectrometric analysis. A series of nitrated derivatives of C 21 H 12 polycyclic aromatic hydrocarbon have been tentatively identified by low and high resolution mass spectrometry and gas chromatography. The series includes a mononitro, two dinitro isomers, and a trinitro derivative

Distribution and occurrence of lithium in high-alumina-coal fly ash

DEFF Research Database (Denmark)

Hu, Pengpeng; Hou, Xinjuan; Zhang, Jianbo

2018-01-01

the generalized gradient approximation (GGA) method indicated that Li occurred in Q3(0Al) and Q3(1Al) structures by reacting with Q4(0Al) and Q4(1Al). Based on the experimental and simulation results, we propose extracting Li during the pre-desilication process by dissolving the glass phase.......High-alumina-coal fly ash (HAFA) with a high Li content is regarded as a potential resource for Li production. To support the development of Li recovery technology from HAFA, the distribution and modes of occurrence of Li in HAFA were investigated. HAFA was separated into magnetic particles, glass...

Use of flying ash in the chromium removal (III) of the liquid effluents of tanneries

International Nuclear Information System (INIS)

Gil Pavas, Edison; Saldarriaga Molina, Carlos

1998-01-01

This study describes a simple and economic method for the removal of chromium (III) from tannery waste waters using flying ash. The process is carried out batch-wise utilizing as variables the mass of flying ash, the time of contact and the temperature or pH. With these variables a Box-Wilson type of experimental design was done, which was then optimized with a statistical program. One as-received flying ash was utilized in the work as well as another one chemically treated. The results show the possibility of lowering the initial concentration in the waste liquor from 1850 ppm to 0,008, complying this way with environmental exigencies about this contaminant

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.

High Temperature Fission Chamber for He- and FLiBe-cooled Reactors

Energy Technology Data Exchange (ETDEWEB)

Bell, Zane W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, Dominic R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lance, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Roger G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warmack, Robert J. Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Harrison, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-01-01

We have evaluated candidate technologies for in-core fission chambers for high-temperature reactors to monitor power level via measurements of neutron flux from start-up through full power at up to 800°C. This research is important because there are no commercially available instruments capable of operating above 550 °C. Component materials and processes were investigated for fission chambers suitable for operation at 800 °C in reactors cooled by molten fluoride salt (FLiBe) or flowing He, with an emphasis placed on sensitivity (≥ 1 cps/nv), service lifetime (2 years at full power), and resistance to direct immersion in FLiBe. The latter gives the instrument the ability to survive accidents involving breach of a thimble. The device is envisioned to be a two-gap, three-electrode instrument constructed from concentric nickel-plated alumina cylinders and using a noble gas–nitrogen fill-gas. We report the results of measurements and calculations of the response of fill gasses, impurity migration in nickel alloy, brazing of the alumina insulator, and thermodynamic calculations.

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.

Low pH Cements

International Nuclear Information System (INIS)

Savage, David; Benbow, Steven

2007-05-01

The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

Low pH Cements

Energy Technology Data Exchange (ETDEWEB)

Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

2007-05-15

The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

PH adjustment of power plant cooling water with flue gas/fly ash

Science.gov (United States)

Brady, Patrick V.; Krumhansl, James L.

2015-09-22

A system including a vessel including a heat source and a flue; a turbine; a condenser; a fluid conduit circuit disposed between the vessel, the turbine and the condenser; and a diverter coupled to the flue to direct a portion of an exhaust from the flue to contact with a cooling medium for the condenser water. A method including diverting a portion of exhaust from a flue of a vessel; modifying the pH of a cooling medium for a condenser with the portion of exhaust; and condensing heated fluid from the vessel with the pH modified cooling medium.

Removal of Copper (II Ions in Aqueous Solutions by Sorption onto Alkali Activated Fly Ash

Directory of Open Access Journals (Sweden)

Darmayanti Lita

2018-01-01

Full Text Available Fly ash is a particulate material produced from coal combustion power plants with major components are silica, alumina, iron oxide, calcium oxide, magnesium oxide, and carbon which are ideal for metal adsorbents. The potential use of fly ash in the wastewater treatment process is obvious because it can be obtained cheaply in large quatities and it can be used as an adsorbent. However, fly ash still shows lower adsorption capacity unless it is activated. In this study, fly ash activated by NaOH 14 M and KOH 14 M solutions. The batch experiments were carried out to study the sorption of copper ions from aqueous on alkali activated fly ash. The influence of initial concentration and contact time were examined at constant pH and dose of adsorbent. The sorption capacity of copper ions increased with the initial concentration and contact time. The sorption capacities followed the order Na1>Ka1>FA. The adsorption isotherm model exhibited that the Langmuir model is very suitable with copper ions adsorption onto fly ash and alkali activated fly ash. Kinetic study shows that adsorption of copper ions onto FA, Na1, and Ka1 follows the pseudo second-order kinetics.

High-Speed Surface Reconstruction of Flying Birds Using Structured Light

Science.gov (United States)

Deetjen, Marc; Lentink, David

2017-11-01

Birds fly effectively through complex environments, and in order to understand the strategies that enable them to do so, we need to determine the shape and movement of their wings. Previous studies show that even small perturbations in wing shape have dramatic aerodynamic effects, but these shape changes have not been quantified automatically at high temporal and spatial resolutions. Hence, we developed a custom 3D surface mapping method which uses a high-speed camera to view a grid of stripes projected onto a flying bird. Because the light is binary rather than grayscale, and each frame is separately analyzed, this method can function at any frame rate with sufficient light. The method is automated, non-invasive, and able to measure a volume by simultaneously reconstructing from multiple views. We use this technique to reconstruct the 3D shape of the surface of a parrotlet during flapping flight at 3200 fps. We then analyze key dynamic parameters such as wing twist and angle of attack, and compute aerodynamic parameters such as lift and drag. While this novel system is designed to quantify bird wing shape and motion, it is adaptable for tracking other objects such as quickly deforming fish, especially those which are difficult to reconstruct using other 3D tracking methods. The presenter needs to leave by 3 pm on the final day of the conference (11/21) in order to make his flight. Please account for this in the scheduling if possible by scheduling the presentation earlier in the day or a different day.

FliO Regulation of FliP in the Formation of the Salmonella enterica Flagellum

Science.gov (United States)

Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Samatey, Fadel A.

2010-01-01

The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO43–125 or FliO1–95 was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO43–125, should contain beta-structure and alpha-helices. FliO43–125-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners. PMID:20941389

FliO regulation of FliP in the formation of the Salmonella enterica flagellum.

Directory of Open Access Journals (Sweden)

Clive S Barker

2010-09-01

Full Text Available The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO₄₃-₁₂₅ or FliO₁-₉₅ was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO₄₃-₁₂₅, should contain beta-structure and alpha-helices. FliO₄₃-₁₂₅-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners.

Characterization and electrodialytic treatment of wood combustion fly ash for the removal of cadmium

International Nuclear Information System (INIS)

Pedersen, A.J.

2003-01-01

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, 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--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 conditions. However, significant amounts of Cd could be extracted at neutral to alkaline conditions using an ammonium citrate solution as a desorption agent. Electrodialytic remediation experiments showed that, under optimised remediation conditions using a mixture of ammonium citrate (0.25 M) and NH 3 (1.25%) as an assisting agent, more than 70% of the initial Cd could be removed from the wood fly ash. The results also indicated that a continuous out-separation of Cd from the aqueous process solutions is possible. Thereby, recycling of the (nutrient rich) process solutions as well as of the remediated ash seems achievable

PhC-4 new high-speed camera with mirror scanning

International Nuclear Information System (INIS)

Daragan, A.O.; Belov, B.G.

1979-01-01

The description of the optical system and the construction of the high-speed PhC-4 photographic camera with mirror scanning of the continuously operating type is given. The optical system of the camera is based on the foursided rotating mirror, two optical inlets and two working sectors. The PhC-4 camera provides the framing rate up to 600 thousand frames per second. (author)

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

2014-01-01

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...

Application of zirconia membranes as high-temperature PH sensors

International Nuclear Information System (INIS)

Neidrach, L.W.

1983-01-01

The zirconia pH sensor behaves much like the classical glass electrode, but it extends the range of measurement to much higher temperatures - about 300 0 vs 120 0 C. It also has virtues over the glass electrode at lower temperatures because of the absence of an ''alkaline error.'' Like the glass electrode, it is insensitive to changes in the redox potential of the environment and, in turn, it exerts no influence on the environment. Such sensors have been finding application in the direct measurement of the pH of geothermal brines, of water in nuclear reactors, and in high-temperature corrosion studies. The sensors can also be used as ''pseudoreference'' electrodes for the measurement of redox and corrosion potentials in high-temperature media

Creating opportunities for science PhDs to pursue careers in high school education.

Science.gov (United States)

Doyle, Kari M H; Vale, Ronald D

2013-11-01

The United States is confronting important challenges at both the early and late stages of science education. At the level of K-12 education, a recent National Research Council report (Successful K-12 STEM Education) proposed a bold restructuring of how science is taught, moving away from memorizing facts and emphasizing hands-on, inquiry-based learning and a deeper understanding of the process of science. At higher levels of training, limited funding for science is leading PhDs to seek training and careers in areas other than research. Might science PhDs play a bigger role in the future of K-12 education, particularly at the high school level? We explore this question by discussing the roles that PhDs can play in high school education and the current and rather extensive barriers to PhDs entering the teaching profession and finally suggest ways to ease the entrance of qualified PhDs into high school education.

Creating opportunities for science PhDs to pursue careers in high school education

Science.gov (United States)

Doyle, Kari M. H.; Vale, Ronald D.

2013-01-01

The United States is confronting important challenges at both the early and late stages of science education. At the level of K–12 education, a recent National Research Council report (Successful K–12 STEM Education) proposed a bold restructuring of how science is taught, moving away from memorizing facts and emphasizing hands-on, inquiry-based learning and a deeper understanding of the process of science. At higher levels of training, limited funding for science is leading PhDs to seek training and careers in areas other than research. Might science PhDs play a bigger role in the future of K–12 education, particularly at the high school level? We explore this question by discussing the roles that PhDs can play in high school education and the current and rather extensive barriers to PhDs entering the teaching profession and finally suggest ways to ease the entrance of qualified PhDs into high school education. PMID:24174464

An overview of quarantine for fruit flies

International Nuclear Information System (INIS)

Frampton, E.R.

2000-01-01

What is meant by 'quarantine for fruit flies'? The Collins dictionary describes 'quarantine' as a period of isolation or detention, especially of persons or animals arriving from abroad, to prevent the spread of disease. In providing an overview of quarantine for fruit flies, a broader definition needs to be applied, that is, the combination of activities required to maintain the fruit fly status of a particular geographical area - perhaps better referred to as a 'quarantine system'. Familiarity with New Zealand's quarantine system for fruit flies (Diptera: Tephritidae) provides a useful basis for subsequent comparison with other countries' systems where some fruit fly species may be present. But, why have 'quarantine for fruit flies'? The multivoltine life history of many species. combined with a relatively long-lived adult stage and highly fecund females, results in a high potential for rapid population increase (Bateman 1979, Fletcher 1987). These factors and the close association of fruit flies with harvested fruit or vegetables explain the high quarantine profile of these insects. However, there is no international requirement for a country to have a quarantine system and unless there are natural quarantine barriers (e.g., mountain range, oceans, deserts) that can be utilised, effective quarantine by an individual country may be an impossible task. The implementation of a successful quarantine system is very expensive and therefore, it would be expected that any benefits attained outweigh the costs (Ivess 1998). Ivess (1998) listed the following benefits from the implementation of an effective quarantine system: minimising production costs (including post harvest treatments), maintaining competitive advantages for market access due to the ongoing freedom from particular pests of quarantine significance, an environment free from many pests harmful to plant health, the maintenance of ecosystems

Comparison of adsorption of Cd(II and Pb(II ions on pure and chemically modified fly ashes

Directory of Open Access Journals (Sweden)

Sočo Eleonora

2016-06-01

Full Text Available The study investigates chemical modifications of coal fly ash (FA treated with HCl or NH4HCO3 or NaOH or Na2edta, based on the research conducted to examine the behaviour of Cd(II and Pb(II ions adsorbed from water solution on treated fly ash. In laboratory tests, the equilibrium and kinetics were examined applying various temperatures (293 - 333 K and pH (2 - 11 values. The maximum Cd(II and Pb(II ions adsorption capacity obtained at 293 K, pH 9 and mixing time 2 h from the Langmuir model can be grouped in the following order: FA-NaOH > FA-NH4HCO3 > FA > FA-Na2edta > FA-HCl. The morphology of fly ash grains was examined via small-angle X-ray scattering (SAXS and images of scanning electron microscope (SEM. The adsorption kinetics data were well fitted by a pseudo-second-order rate model but showed a very poor fit for the pseudofirst order model. The intra-particle model also revealed that there are two separate stages in the sorption process, i.e. the external diffusion and the inter-particle diffusion. Thermodynamics parameters such as free energy, enthalpy and entropy were also determined. A laboratory test demonstrated that the modified coal fly ash worked well for the Cd(II and Pb(II ion uptake from polluted waters.

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.

The reaction of acid mine drainage with fly ash from coal combustion

International Nuclear Information System (INIS)

Kim, A.G.

1999-01-01

The placement of alkaline fly ash in abandoned, reclaimed or active surface coal mines is intended to reduce the amount of acid mine drainage (AMD) produced at such sites by neutralization, inhibition of acid forming bacteria, encapsulation of the pyrite or water diversion. A continuing concern with this application is the potential release of trace elements from the fly ash when it is placed in contact with AMD. To investigate the possible release of antimony, arsenic, barium, boron, cadmium, chromium, cobalt, copper, lead, nickel, selenium, and zinc from fly ash, a series of column leaching tests were conducted. A one kg fly ash sample, placed in a 5-cm by 1 m acrylic columns, was leached at a nominal rate of 250 mL/d for between 30 and 60 days. The leachant solutions were deionized water, and dilute solutions of sulfuric acid and ferric chloride. Leaching tests have been completed on 28 fly ash samples. leachate data, analyzed as the mass extracted with respect to the concentration in the solid, indicate that the release of trace elements is variable, with only barium and zinc extracted at greater than 50 pct of the amount present in the original sample. As a comparison, water quality changes have been monitored at three sites where fly ash grout was injected after reclamation to control AMD. When compared before and after grouting, small increases in pH and decreases in acidity at discharge points were observed. Concentrations of trace metals were found to be comparable in treated and untreated areas. When grouted and ungrouted areas were compared, the effect of the fly ash was shown to be localized in the areas of injection. These studies indicated that when fly ash is used as a reagent to control of AMD, the release of trace elements is relatively small

Producing zeolites from fly ash

International Nuclear Information System (INIS)

Rayalu, S.; Labhestwar, N.K.; Biniwale, R.B.; Udhoji, J.S.; Meshram, S.U.; Khanna, P.

1998-01-01

Fly ash has virtually become a menace of thermal power generation, leading to its devastating effects on the environment. Development of alternate methods of its disposal - especially those with recourse to recovery of valuable materials-has thus become imperative. This paper deals with the utilisation of fly ash for the production of high value-added products, viz., commercial grade zeolites. The physico-chemical and morphological characteristics of fly ash based Zeolite-A (FAZ-A) compares well with commercial Zeolite-A. High calcium binding capacity, appropriate particle/pore size and other detergency characteristics of FAZ-A brings forth its potential as a substitute for phosphatic detergent builder. The technology is extremely versatile, and other products like Zeolite-X, Zeolite-Y, sodalite and mordenite are also amenable for cost effective production with modifications in certain reaction parameters. Low temperature operations, ready availability of major raw materials, simplicity of process and recycling of unused reactants and process water are special features of the process. (author)

Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan.

Science.gov (United States)

Shim, Young-Sook; Rhee, Seung-Whee; Lee, Woo-Keun

2005-01-01

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH)(2) in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb>Cd>Cr, but the order was changed to Pb>Cr>Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only.

Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan

International Nuclear Information System (INIS)

Shim, Young-Sook; Rhee, Seung-Whee; Lee, Woo-Keun

2005-01-01

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH) 2 in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb > Cd > Cr, but the order was changed to Pb > Cr > Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only

Cementing Efficiency of Low Calcium Fly Ash in Fly Ash Concretes

OpenAIRE

T. D. Gunneswara Rao; Mudimby Andal

2014-01-01

Research on the utilization of fly ash will no longer refer the fly ash as a waste material of thermal power plants. Use of fly ash in concrete making, makes the concrete economical as well as durable. The fly ash is being added to the concrete in three ways namely, as partial replacement to cement, as partial replacement to fine aggregates and as admixture. Addition of fly ash to the concrete in any one of the form mentioned above, makes the concrete more workable and durable than the conven...

Synthesis of inorganic polymers using fly ash and primary lead slag.

Science.gov (United States)

Onisei, S; Pontikes, Y; Van Gerven, T; Angelopoulos, G N; Velea, T; Predica, V; Moldovan, P

2012-02-29

The present work reports on the synthesis and properties of inorganic polymers ("geopolymers") made of 100% fly ash from lignite's combustion, 100% primary lead slag and mixtures of the two. In the inorganic polymers with both fly ash and lead slag the main crystalline phases detected are wüstite, magnetite, sodium zinc silicate, quartz, anorthite, and gehlenite; litharge partially dissolves. FTIR analysis in these samples revealed that the main peaks and bands of end members also exist, along with a new amorphous reaction product. In terms of microstructure, both fly ash and lead slag dissolve and contribute in the binding phase whereas the larger particles act as aggregates. For an increasing lead slag in the composition, the binding phase is changing in chemistry and reaches PbO values higher than 50 wt.% for the 100% lead slag inorganic polymer. Regarding the properties of fly ash and lead slag inorganic polymers, compressive strength is higher than 35 MPa in all cases and water absorption diminishes as the lead slag content increases. A comparison of leaching results before and after polymerisation reveals that pH is an important factor as Pb is immobilised in the binding phase, unlike Zn and As. Copyright © 2011 Elsevier B.V. All rights reserved.

Preliminary Characterization of Organic Geochemistry in the Fly-Strickland River System, Papua New Guinea

Science.gov (United States)

Alin, S. R.; Aalto, R.; Remington, S. M.; Richey, J. E.

2003-12-01

The Fly-Strickland fluvial dispersal system comprises one of the largest river basins in tropical Oceania, ranking among the top 20 rivers in the world for water and sediment discharge. From the New Guinea highlands, these rivers flow >1000 km across lowland tropical floodplains to the Gulf of Papua, with an average annual depth of runoff 100 times that of the Amazon. Within the system, the Strickland has greater sediment discharge and a steeper gradient than the Fly, providing an opportunity to investigate biogeochemical differences associated with particulate flux. For eight lowland sites across the Fly-Strickland river system, we analyzed water and suspended sediment (SS) samples for an initial survey of various carbon cycle parameters. Both the Fly and Strickland Rivers were strongly supersaturated with carbon dioxide (2008-10,479 uatm CO2) and undersaturated with oxygen (1.10-5.48 mg/l O2), with the Fly having higher CO2 and lower O2 concentrations than the Strickland River. These pCO2 and O2 concentrations are comparable to and lower than (respectively) typical values in the Amazon. Measured Fly-Strickland alkalinity values fell in the range of 0.893-1.888 meq, and pH measurements were neutral to slightly alkaline (6.916-7.852). In a sample from a sediment-impoverished tributary from Lake Murray to the Strickland (Herbert R.), pH was neutral (7.060), and alkalinity and pCO2 had their lowest observed values at 0.234 meq and 1407 uatm, respectively. Nutrient concentrations were generally higher in the Strickland ([NO3]=3.36+/-0.69 uM, [PO4]=0.09+/-0.10 uM, and [Si(OH)4]=176.6+/-41.7 uM) than in the Fly River ([NO3]=1.09+/-0.04 uM, [PO4]=0.01+/-0.01 uM, and [Si(OH)4]=110.6+/-4.8 uM). NO3 and PO4 concentrations in the Fly-Strickland river system were lower than in the Amazon, and silicate was comparable. SS concentrations were higher in the Strickland than in the Fly (49.4-231.1 mg/l vs. 19.5-59.6 mg/l). Coarse particulates were organic-poor in the Fly and

High-frequency dynamics of ocean pH: a multi-ecosystem comparison.

Directory of Open Access Journals (Sweden)

Gretchen E Hofmann

Full Text Available The effect of Ocean Acidification (OA on marine biota is quasi-predictable at best. While perturbation studies, in the form of incubations under elevated pCO(2, reveal sensitivities and responses of individual species, one missing link in the OA story results from a chronic lack of pH data specific to a given species' natural habitat. Here, we present a compilation of continuous, high-resolution time series of upper ocean pH, collected using autonomous sensors, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, kelp forest to coral reef. These observations reveal a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units. The nature of the observed variability was also highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes. These biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO(2, often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100. Our data provide a first step toward crystallizing the biophysical link between environmental history of pH exposure and physiological resilience of marine organisms to fluctuations in seawater CO(2. Knowledge of this spatial and temporal variation in seawater chemistry allows us to improve the design of OA experiments: we can test organisms with a priori expectations of their tolerance guardrails, based on their natural range of exposure. Such hypothesis-testing will provide a deeper understanding of the effects of OA. Both intuitively simple to understand and powerfully informative, these and similar comparative time series can help guide management efforts to identify areas of marine habitat that can serve as refugia to acidification as well as areas that are particularly vulnerable to future ocean change.

Preliminary study on removing Cs⁺/Sr²⁺ by activated porous calcium silicate-A by-product from high-alumina fly ash recycling industry.

Science.gov (United States)

Chu, Yingying; Wang, Rong; Chen, Mengjun

2015-01-01

¹³⁷Cs⁺/⁹⁰Sr²⁺-containing radioactive wastewater is one of the most important problems that the world has been facing with. A by-product, activated porous calcium silicate, is generated at high levels by the pre-desiliconizing and soda-lime-sintering processes for producing Al₂O₃from high-alumina fly ash. In order to examine if this by-product could be used as an absorbent for removal of ¹³⁷Cs⁺/⁹⁰Sr²⁺ from radioactive wastewater, various parameters, such as pH, adsorbent dose, contact time, and initial concentration, were discussed. Results indicated that the equilibrium reached in about 2 hr. Activated porous calcium silicate was highly pH sensitive and able to remove Cs(+)/Sr²⁺ in a near-neutral environment. The adsorption equilibrium was best described by Freundlich isotherm equations, and the adsorption of Cs⁺/Sr²⁺ was a physical process. The adsorption kinetic data could be better fitted by the pseudo-second-order model, and the adsorption was controlled by multidiffusion. Current study showed that activated porous calcium silicate has a good adsorption of Cs⁺/Sr²⁺ for their removal. However, other characteristics, such as selectivity because of coexisting cations, elution and regeneration, thermal stability, and acid resistance, should be discussed carefully before using it in an actual field.

Applying GIS and high performance agent-based simulation for managing an Old World Screwworm fly invasion of Australia.

Science.gov (United States)

Welch, M C; Kwan, P W; Sajeev, A S M

2014-10-01

Agent-based modelling has proven to be a promising approach for developing rich simulations for complex phenomena that provide decision support functions across a broad range of areas including biological, social and agricultural sciences. This paper demonstrates how high performance computing technologies, namely General-Purpose Computing on Graphics Processing Units (GPGPU), and commercial Geographic Information Systems (GIS) can be applied to develop a national scale, agent-based simulation of an incursion of Old World Screwworm fly (OWS fly) into the Australian mainland. The development of this simulation model leverages the combination of massively data-parallel processing capabilities supported by NVidia's Compute Unified Device Architecture (CUDA) and the advanced spatial visualisation capabilities of GIS. These technologies have enabled the implementation of an individual-based, stochastic lifecycle and dispersal algorithm for the OWS fly invasion. The simulation model draws upon a wide range of biological data as input to stochastically determine the reproduction and survival of the OWS fly through the different stages of its lifecycle and dispersal of gravid females. Through this model, a highly efficient computational platform has been developed for studying the effectiveness of control and mitigation strategies and their associated economic impact on livestock industries can be materialised. Copyright © 2014 International Atomic Energy Agency 2014. Published by Elsevier B.V. All rights reserved.

Campylobacter, Salmonella, and Escherichia coli on broiler carcasses subjected to a high pH scald and low pH postpick chlorine dip.

Science.gov (United States)

Berrang, M E; Windham, W R; Meinersmann, R J

2011-04-01

The objective of this study was to determine the individual and combined effects of a high pH scald and a postpick chlorine dip on bacteria present on broiler carcasses. In each of 3 replications, a flock was sampled at several sites within a commercial broiler processing plant. Carcasses were sampled by whole carcass rinse before and after treated scalding at mean pH 9.89 or control scalding at mean pH 6.88. Other carcasses from the same flock run on both the treated and control scald lines were collected and sampled before and after a chlorine dip tank operated at mean total chlorine level of 83.3 mg/kg and pH 6.04. Rinses were cultured for numbers of Campylobacter and Escherichia coli and presence or absence of Salmonella. High pH scald was more effective than standard scald to lessen the prevalence and numbers of Campylobacter on broiler carcasses; a lower prevalence was maintained through the postpick chlorine dip tank. The pH of the scald tank made no difference in numbers of E. coli recovered from broiler carcasses at any tested point on the processing line. High pH scald was not more effective than standard scald to lessen Salmonella prevalence. Furthermore, it is unclear why the postpick chlorine dip effectively lessened Salmonella prevalence on only the control scald line. Although no evidence exists that these treatments have an additive effect when used in series, each treatment shows some promise individually. Further optimization may result in more effective decontamination of broiler carcasses.

Are flying-foxes coming to town? Urbanisation of the spectacled flying-fox (Pteropus conspicillatus in Australia.

Directory of Open Access Journals (Sweden)

Jessica Tait

Full Text Available Urbanisation of wildlife populations is a process with significant conservation and management implications. While urban areas can provide habitat for wildlife, some urbanised species eventually come into conflict with humans. Understanding the process and drivers of wildlife urbanisation is fundamental to developing effective management responses to this phenomenon. In Australia, flying-foxes (Pteropodidae are a common feature of urban environments, sometimes roosting in groups of tens of thousands of individuals. Flying-foxes appear to be becoming increasingly urbanised and are coming into increased contact and conflict with humans. Flying-fox management is now a highly contentious issue. In this study we used monitoring data collected over a 15 year period (1998-2012 to examine the spatial and temporal patterns of association of spectacled flying-fox (Pteropus conspicillatus roost sites (camps with urban areas. We asked whether spectacled flying-foxes are becoming more urbanised and test the hypothesis that such changes are associated with anthropogenic changes to landscape structure. Our results indicate that spectacled flying-foxes were more likely to roost near humans than might be expected by chance, that over the period of the study the proportion of the flying-foxes in urban-associated camps increased, as did the number of urban camps. Increased urbanisation of spectacled flying-foxes was not related to changes in landscape structure or to the encroachment of urban areas on camps. Overall, camps tended to be found in areas that were more fragmented, closer to human habitation and with more urban land cover than the surrounding landscape. This suggests that urbanisation is a behavioural response rather than driven by habitat loss.

High activity antioxidant enzymes protect flying-fox haemoglobin against damage: an evolutionary adaptation for flight?

Science.gov (United States)

Reinke, N B; O'Brien, G M

2006-11-01

Flying-foxes are better able to defend haemoglobin against autoxidation than non-volant mammals such as sheep. When challenged with the common physiological oxidant, hydrogen peroxide, haemolysates of flying-fox red blood cells (RBC) were far less susceptible to methaemoglobin formation than sheep. Challenge with 1-acetyl-2-phenylhydrazine (APH) caused only half as much methaemoglobin formation in flying-fox as in ovine haemolysates. When intact cells were challenged with phenazine methosulfate (PMS), flying-fox RBC partially reversed the oxidant damage, and reduced methaemoglobin from 40 to 20% over 2 h incubation, while ovine methaemoglobin remained at 40%. This reflected flying-fox cells' capacity to replenish GSH fast enough that it did not deplete beyond 50%, while ovine RBC GSH was depleted to around 20%. The greater capacity of flying-foxes to defend haemoglobin against oxidant damage may be explained in part by antioxidant enzymes catalase, superoxide dismutase and cytochrome-b ( 5 ) reductase having two- to four-fold higher activity than in sheep (P foxes.

Excess glycogen does not resolve high ultimate pH of oxidative muscle.

Science.gov (United States)

England, Eric M; Matarneh, Sulaiman K; Oliver, Emily M; Apaoblaza, Ariel; Scheffler, Tracy L; Shi, Hao; Gerrard, David E

2016-04-01

Skeletal muscle glycogen content can impact the extent of postmortem pH decline. Compared to glycolytic muscles, oxidative muscles contain lower glycogen levels antemortem which may contribute to the higher ultimate pH. In an effort to explore further the participation of glycogen in postmortem metabolism, we postulated that increasing the availability of glycogen would drive additional pH decline in oxidative muscles to equivalent pH values similar to the ultimate pH of glycolytic muscles. Glycolysis and pH declines were compared in porcine longissimus lumborum (glycolytic) and masseter (oxidative) muscles using an in vitro system in the presence of excess glycogen. The ultimate pH of the system containing longissimus lumborum reached a value similar to that observed in intact muscle. The pH decline of the system containing masseter samples stopped prematurely resulting in a higher ultimate pH which was similar to that of intact masseter muscle. To investigate further, we titrated powdered longissimus lumborum and masseter samples in the reaction buffer. As the percentage of glycolytic sample increased, the ultimate pH decreased. These data show that oxidative muscle produces meat with a high ultimate pH regardless of glycogen content and suggest that inherent muscle factors associated with glycolytic muscle control the extent of pH decline in pig muscles. Copyright © 2015 Elsevier Ltd. All rights reserved.

Measurement of the Extracellular pH of Adherently Growing Mammalian Cells with High Spatial Resolution Using a Voltammetric pH Microsensor.

Science.gov (United States)

Munteanu, Raluca-Elena; Stǎnicǎ, Luciana; Gheorghiu, Mihaela; Gáspár, Szilveszter

2018-05-15

There are only a few tools suitable for measuring the extracellular pH of adherently growing mammalian cells with high spatial resolution, and none of them is widely used in laboratories around the world. Cell biologists very often limit themselves to measuring the intracellular pH with commercially available fluorescent probes. Therefore, we built a voltammetric pH microsensor and investigated its suitability for monitoring the extracellular pH of adherently growing mammalian cells. The voltammetric pH microsensor consisted of a 37 μm diameter carbon fiber microelectrode modified with reduced graphene oxide and syringaldazine. While graphene oxide was used to increase the electrochemically active surface area of our sensor, syringaldazine facilitated pH sensing through its pH-dependent electrochemical oxidation and reduction. The good sensitivity (60 ± 2.5 mV/pH unit), reproducibility (coefficient of variation ≤3% for the same pH measured with 5 different microsensors), and stability (pH drift around 0.05 units in 3 h) of the built voltammetric pH sensors were successfully used to investigate the acidification of the extracellular space of both cancer cells and normal cells. The results indicate that the developed pH microsensor and the perfected experimental protocol based on scanning electrochemical microscopy can reveal details of the pH regulation of cells not attainable with pH sensors lacking spatial resolution or which cannot be reproducibly positioned in the extracellular space.

High performance flexible pH sensor based on carboxyl-functionalized and DEP aligned SWNTs

International Nuclear Information System (INIS)

Liu, Lu; Shao, Jinyou; Li, Xiangming; Zhao, Qiang; Nie, Bangbang; Xu, Chuan; Ding, Haitao

2016-01-01

Highlights: • The flexible chemiresistive pH sensor based on two-terminal microsensors eliminating the need for a reference electrode, is simple in structure and can be fabricated on a variety of substrates such as PET, PI and PVC. • SWNTs as an ideal one dimensional material are carboxyl-functionalized to make the pH sensor show high sensitivity and outstanding flexibility for practical applications. • DEP technique is used to manipulate and position SWNTs into appropriate locations and desired formations to improve the metal-nanotube interface and highly rapid detection of pH value, resulting in better overall device performance. • Mechanical bendability of the pH sensor, which arises from the combination of flexible PET substrates and SWNTs, offer a significant improvement for applications that are difficult or impossible to achieve with traditional sensors on rigid substrates. - Abstract: The detection and control of the pH is very important in many biomedical and chemical reaction processes. A miniaturized flexible pH sensor that is light weight, robust, and conformable is very important in many applications, such as multifunctional lab-on-a-chip systems or wearable biomedical devices. In this work, we demonstrate a flexible chemiresistive pH sensor based on dielectrophoresis (DEP) aligned carboxyl-functionalized single-walled carbon nanotubes (SWNTs). Decorated carboxyl groups can react with hydrogen (H"+) and hydroxide (OH"−) ions, enabling the sensor to be capable of sensing the pH. DEP is used to deposit well-organized and highly aligned SWNTs in desired locations, which improves the metal-nanotube interface and highly rapid detection of the pH, resulting in better overall device performance. When pH buffer solutions are dropped onto such SWNTs, the H"+ and OH"− ions caninteract with the carboxyl groups and affect the generation of holes and electrons in the SWNTs, leading to resistance variations in the SWNTs. The results shows that the

High performance flexible pH sensor based on carboxyl-functionalized and DEP aligned SWNTs

Energy Technology Data Exchange (ETDEWEB)

Liu, Lu; Shao, Jinyou, E-mail: jyshao@mail.xjtu.edu.cn; Li, Xiangming; Zhao, Qiang; Nie, Bangbang; Xu, Chuan; Ding, Haitao

2016-11-15

Highlights: • The flexible chemiresistive pH sensor based on two-terminal microsensors eliminating the need for a reference electrode, is simple in structure and can be fabricated on a variety of substrates such as PET, PI and PVC. • SWNTs as an ideal one dimensional material are carboxyl-functionalized to make the pH sensor show high sensitivity and outstanding flexibility for practical applications. • DEP technique is used to manipulate and position SWNTs into appropriate locations and desired formations to improve the metal-nanotube interface and highly rapid detection of pH value, resulting in better overall device performance. • Mechanical bendability of the pH sensor, which arises from the combination of flexible PET substrates and SWNTs, offer a significant improvement for applications that are difficult or impossible to achieve with traditional sensors on rigid substrates. - Abstract: The detection and control of the pH is very important in many biomedical and chemical reaction processes. A miniaturized flexible pH sensor that is light weight, robust, and conformable is very important in many applications, such as multifunctional lab-on-a-chip systems or wearable biomedical devices. In this work, we demonstrate a flexible chemiresistive pH sensor based on dielectrophoresis (DEP) aligned carboxyl-functionalized single-walled carbon nanotubes (SWNTs). Decorated carboxyl groups can react with hydrogen (H{sup +}) and hydroxide (OH{sup −}) ions, enabling the sensor to be capable of sensing the pH. DEP is used to deposit well-organized and highly aligned SWNTs in desired locations, which improves the metal-nanotube interface and highly rapid detection of the pH, resulting in better overall device performance. When pH buffer solutions are dropped onto such SWNTs, the H{sup +} and OH{sup −} ions caninteract with the carboxyl groups and affect the generation of holes and electrons in the SWNTs, leading to resistance variations in the SWNTs. The results

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.

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.

Can E. coli fly?

DEFF Research Database (Denmark)

Lindeberg, Yrja Lisa; Egedal, Karen; Hossain, Zenat Zebin

2018-01-01

, and the numbers of flies landing on the exposed rice were counted. Following exposure, the surface of the rice was microbiologically and molecularly analysed for the presence of E. coli and genes of diarrheagenic E. coli and Shigella strains. RESULTS: Rice was at greater risk (p ... with E. coli if flies landed on the rice than if no flies landed on the rice (odds ratio 5·4 (p ...-landings, the average CFU per fly-landing was > 0·6 x 103 CFU. Genes of diarrheagenic E. coli and Shigella species were detected in 39 of 60 (65%) of exposed rice samples. Two fly species were identified; the common housefly (Musca domestica) and the oriental latrine fly (Chrysomya megacephala). CONCLUSION: Flies may...

FliO Regulation of FliP in the Formation of the Salmonella enterica Flagellum

OpenAIRE

Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Samatey, Fadel A.

2010-01-01

The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extrageni...

Leaching of saltstones containing fly ash

International Nuclear Information System (INIS)

Barnes, M.W.; Roy, D.M.; Langton, C.A.

1985-01-01

Two types of fly ash were incorporated in saltstones designed for potential encapsulation of Savannah River Plant low level defense waste. These fly ashes have some cementitious properties while at the same time their presence in substitution for cement slows early hydration. Class C fly ash has a high calcium content and is considered cementitious; Class F fly ash has a low calcium content and is not classified as cementitious. Leach tests were performed and physical properties were measured for saltstones containing each class, to see the differences in the effect of the fly ashes. The four waste ions nitrate, nitrite, sodium and sulfate were shown to leach by diffusion. Effective diffusivities were determined for these ions. Data for nitrate, the most important species from the environmental point of view, are shown in Table A. Saltstones made with Class C fly ash have substantially lower leach rates than those made with Class F fly ash. The leach rates, and therefore the square roots of the effective diffusivities, have been found to be proportional to the pore surface area per unit volume (or the ratio of pore volume to pore radius), to the fraction of waste containing solution, and to the inverse of the fraction of calcium in the saltstone. Rates and diffusivities are not proportional to the water to cement ratio, because this number depends on whether the fly ash is counted as cementitious, as in Class C cement, or not cementitious, as in Class F cement. In fact the relatively small amount of calcium in Class F cement contributes to the cementitious properties overall, though not so much as Class C cement. 4 refs., 2 figs., 6 tabs

Isolation and cultivation of microalgae select for low growth rate and tolerance to high pH

DEFF Research Database (Denmark)

Berge, Terje; Daugbjerg, Niels; Hansen, Per Juel

2012-01-01

Harmful microalgal blooms or red tides are often associated with high levels of pH. Similarly, species and strains of microalgae cultivated in the laboratory with enriched media experience recurrent events of high pH between dilutions with fresh medium. To study the potential for laboratory...... of upper pH tolerance limits were higher in the younger (20 years). These results suggest selection of strains best adapted to tolerate or postpone/avoid events of high pH in the laboratory. Our data have implications for experimental studies of pH response and reaction norms in general of microalgae...

Observations of movement dynamics of flying insects using high resolution lidar

DEFF Research Database (Denmark)

Kirkeby, Carsten Thure; Wellenreuther, Maren; Brydegaard, Mikkel

2016-01-01

insects (wing size cross-section) moved across the field and clustered near the light trap around 22:00 local time, while larger insects (wing size >2.5 mm2 in cross-section) were most abundant near the lidar beam before 22:00 and then moved towards the light trap between 22:00 and 23:30. We......Insects are fundamental to ecosystem functioning and biodiversity, yet the study of insect movement, dispersal and activity patterns remains a challenge. Here we present results from a novel high resolution laser-radar (lidar) system for quantifying flying insect abundance recorded during one...

Mercury release from fly ashes and hydrated fly ash cement pastes

Science.gov (United States)

Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

2018-04-01

The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

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

Effect of total cementitious content on shear strength of high-volume fly ash concrete beams

International Nuclear Information System (INIS)

Arezoumandi, Mahdi; Volz, Jeffery S.; Ortega, Carlos A.; Myers, John J.

2013-01-01

Highlights: ► Existing design standards conservatively predicted the capacity of the HVFAC beams. ► In general, the HVFAC beams exceeded the code predicted shear strengths. ► The cementitious content did not have effect on the shear behavior of the HVFAC beams. - Abstract: The production of portland cement – the key ingredient in concrete – generates a significant amount of carbon dioxide. However, due to its incredible versatility, availability, and relatively low cost, concrete is the most consumed manmade material on the planet. One method of reducing concrete’s contribution to greenhouse gas emissions is the use of fly ash to replace a significant amount of the cement. This paper compares two experimental studies that were conducted to investigate the shear strength of full-scale beams constructed with high-volume fly ash concrete (HVFAC) – concrete with at least 50% of the cement replaced with fly ash. The primary difference between the two studies involved the amount of cementitious material, with one mix having a relatively high total cementitious content (502 kg/m 3 ) and the other mix having a relatively low total cementitious content (337 kg/m 3 ). Both mixes utilized a 70% replacement of portland cement with a Class C fly ash. Each of these experimental programs consisted of eight beams (six without shear reinforcing and two with shear reinforcing in the form of stirrups) with three different longitudinal reinforcement ratios. The beams were tested under a simply supported four-point loading condition. The experimental shear strengths of the beams were compared with both the shear provisions of selected standards (US, Australia, Canada, Europe, and Japan) and a shear database of conventional concrete (CC) specimens. Furthermore, statistical data analyses (both parametric and nonparametric) were performed to evaluate whether or not there is any statistically significant difference between the shear strength of both mixes. Results of these

Fly ash aggregates. Vliegaskunstgrind

Energy Technology Data Exchange (ETDEWEB)

1983-03-01

A study has been carried out into artificial aggregates made from fly ash, 'fly ash aggregates'. Attention has been drawn to the production of fly ash aggregates in the Netherlands as a way to obviate the need of disposal of fly ash. Typical process steps for the manufacturing of fly ash aggregates are the agglomeration and the bonding of fly ash particles. Agglomeration techniques are subdivided into agitation and compaction, bonding methods into sintering, hydrothermal and 'cold' bonding. In sintering no bonding agent is used. The fly ash particles are more or less welded together. Sintering in general is performed at a temperature higher than 900 deg C. In hydrothermal processes lime reacts with fly ash to a crystalline hydrate at temperatures between 100 and 250 deg C at saturated steam pressure. As a lime source not only lime as such, but also portland cement can be used. Cold bonding processes rely on reaction of fly ash with lime or cement at temperatures between 0 and 100 deg C. The pozzolanic properties of fly ash are used. Where cement is applied, this bonding agent itself contributes also to the strength development of the artificial aggregate. Besides the use of lime and cement, several processes are known which make use of lime containing wastes such as spray dry absorption desulfurization residues or fluid bed coal combustion residues. (In Dutch)

Hydration of fly ash cement and microstructure of fly ash cement pastes

Energy Technology Data Exchange (ETDEWEB)

Shiyuan, H.

1981-01-01

The strength development and hydration of fly ash cement and the influence of addition of gypsum on those were studied at normal and elevated temperatures. It was found that an addition of a proper amount of gypsum to fly ash cement could accelerate the pozzolanic reaction between CH and fly ash, and as a result, increase the strength of fly ash cement pastes after 28 days.

Very high volume fly ash green concrete for applications in India.

Science.gov (United States)

Yu, Jing; Mishra, Dhanada K; Wu, Chang; Leung, Christopher Ky

2018-06-01

Safe disposal of fly ash generated by coal-based thermal power plants continues to pose significant challenges around the world and in India in particular. Green structural concrete with 80% cement replaced by local Chinese fly ash has been recently developed to achieve a target characteristic compressive strength of 45 MPa. Such green concrete mixes are not only cheaper in cost, but also embody lower energy and carbon footprint, compared with conventional mixes. This study aims to adopt such materials using no less than 80% fly ash as binder in routine concrete works in countries like India with the commonly used lower target characteristic compressive strength of 30 MPa. It is achieved by the simple and practical method of adjusting the water/binder ratio and/or superplasticiser dosage. The proposed green concrete shows encouraging mechanical properties at 7 days and 28 days, as well as much lower material cost and environmental impact compared with commercial Grade 30 concrete. This technology can play an important role in meeting the huge infrastructure demands in India in a sustainable manner.

Electrodialytic removal of Cd from biomass combustion fly ash

DEFF Research Database (Denmark)

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

2004-01-01

Due to a high concentration of Cd, biomass combustion fly ash often fails to meet the Danish legislative requirements for recycling on agricultural fields. In this work the potential of using the method Electrodialytic Remediation to reduce the concentration of Cd in different biomass combustion....... 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...... four ashes. Final Cd concentrations below 2.0 mg Cd/kg were reached in all ashes within 14 days of remediation and legislative requirements were met. After further optimization of the remediation process on the pre-washed straw ash, limiting concentrations were reached after only 48 hours...

Natural revegetation of coal fly ash in a highly saline disposal lagoon in Hong Kong

Energy Technology Data Exchange (ETDEWEB)

Chu, L.M. [Chinese University of Hong Kong, Hong Kong (China). Dept. of Biology

2008-08-15

Question: What is the relationship of the naturally colonizing vegetation and substrate characteristics in fly ash lagoons? Location: West lagoon, Deep Bay, a 13-ha coastal lagoon in Hong Kong in subtropical Southeast Asia. Methods: Vegetation establishment was examined in a coal fly ash lagoon two years after its abandonment to investigate the distribution of vegetation in relationship to the chemical properties of the fly ash in the lagoon. A greenhouse experiment assessed the limits imposed on plant growth in fly ash. Results: The fly ash was saline, slightly alkaline and very poor in organic matter and nitrogen. Ash from bare and vegetated areas differed significantly in their salinity and extractable concentrations of inorganic nitrogen and various metals. Bare ash had a significantly higher conductivity and extractable sodium, aluminum, manganese, potassium. and lead. In total 11 plant species that belonged to seven families were found growing on the fly ash: all species except the shrub Tamarix chinensis were herbaceous. Using discriminant analysis, the most important factors in distinguishing bare and vegetated ashes were conductivity and sodium. Cluster analysis of bare samples gave two distinct groups, one from the periphery of the lagoon, which had lower sodium, conductivity, organic carbon, potassium and copper, and the other from a second group that contained ashes from the central region of the lagoon. Results of the greenhouse experiment showed that the inhibition of plant growth was significantly correlated with the presence of soluble toxic elements in ash. Conclusion: Toxicity and salinity seem to be the major limiting factors to plant establishment in fly ash, and these factors must be ameliorated for the successful reclamation of these fly ash lagoons.

Production of highly porous glass-ceramics from metallurgical slag, fly ash and waste glass

OpenAIRE

Mangutova Bianka V.; Fidancevska Emilija M.; Milosevski Milosav I.; Bossert Joerg H.

2004-01-01

Glass-ceramics composites were produced based on fly-ash obtained from coal power stations, metallurgical slag from ferronickel industry and waste glass from TV monitors, windows and flasks. Using 50% waste flask glass in combination with fly ash and 20% waste glass from TV screens in combination with slag, E-modulus and bending strength values of the designed systems are increased (system based on fly ash: E-modulus from 6 to 29 GPa, and bending strength from 9 to 75 MPa). The polyurethane f...

Adsorption Kinetics of Fe and Mn with Using Fly Ash from PT Semen Baturaja in Acid Mine Drainage

Directory of Open Access Journals (Sweden)

Indah Purnamasari

2017-11-01

Full Text Available One used method to reduce heavy metal ions in acid mine drainage is to adsorb them by coal fly ash. This research aimed to study the isotherms equilibrium and the adsorpstion kinetics that fit with decreasing metals ion. Acid mine draigane and fly ash were charge into batch coloumn adsorption with specified comparison. Variables investigated were dactivated and activated fly ash, adsorption times (0, 20, 30, 40,50, and 60 minutes, adsorben weights (10, 20, 30, 40, 50, and 60 gram, and pH (1, 3, 5, 7, and 9. The results showed that fly ash can be used to reduce the levels of heavy metal ions Fe and Mn. Coal fly ash adsorption model of acid mine drainage fits to Freundlich adsorption isotherm in all condition. First order pseudo model kinetics is suitable for Fe and Mn adsorption processes. The value of adsorpsi rate constants vary around : Fe and Mn (deactivated fly ash 0.2388 min-1 with R2 = 0.4455 and 0.4173 min-1 with R2 = 0.9781, Fe and Mn (activated fly ash 0.5043 min-1 dengan R2 = 1 and  0.2027 min-1 with R2 = 0.8803.

Characteristics of hot spots of melon fly, Bactrocera (Dacus) cucurbitae Coquillett (Diptera: Tephritidae) in sterile fly release areas on Okinawa island [Japan

International Nuclear Information System (INIS)

Nakamori, H.; Shiga, M.; Kinjo, K.

1993-01-01

The spatio-temporal dynamics of populations of the melon fly, Bactrocera (Dacus) cucurbitae COQUILLETT, in the southern part of Okinawa Island where an eradication program using sterile flies has been conducted, were analyzed in relation to the seasonal succession and abundance of wild and cultivated host fruits. The study areas were classified into four major zones according to the seasonal abundance of flies caught by cue-lure traps and the availability of host fruits including Diplocyclos palmatus, Melothria liukiuensis and Momordica charantia var. pevel. Zone-I is characterized by the continuous presence of host fruits and a relatively-high population density of the melon fly indicated by the cue-lure trap catch of more than 1, 000 flies per 1, 000 traps per day throughout the year. Zone-II has a characteristic decline in both number of host fruits and fly density during the fall-winter period with an annual average of less than 1, 000 flies per 1, 000 traps per day. Zone-III includes areas where host fruits and flies (about 1 fly/trap/day) were relatively abundant only during the winter-spring period. Zone-IV is characterized by constantly low availability of host fruits and low fly density throughout the year. Hot spots, which are defined as areas where the ratio of sterile to wild flies hardly increases despite frequent and intensive release of sterile flies, were found in the Zone-I areas. Therefore, the continuous presence and abundance of host fruits appears to hot spots. For effective control of this species, it is essential to locate such areas and release sterile flies

Preparation Of Pure Carbon From Heavy Oil Fly Ash

International Nuclear Information System (INIS)

ABU ZAID, A.H.M.

2010-01-01

The Egyptian production of heavy oil is approximately 12 million tons of heavy oil per year and approximately 5.3 million tons of this amount is used as fuel in the electric power stations. Based on the fact that the ash content of Egyptian heavy oil is approximately 0.2 %, about 10600 tons of fly ash is produced per/year which causes a lot of environmental problems such as dusting, release of the acidic liquids and heavy metals such as vanadium, nickel, zinc and unburned carbon. Treatment of fly ash by leaching of vanadium and zinc was carried out under different conditions to achieve the best leaching efficiency of both vanadium and zinc by sodium hydroxide. The leaching efficiency obtained was 91% for vanadium and 98% for zinc. This study was concerned with the precipitation of zinc at pH 7.5 as zinc hydroxide and the precipitation of vanadium as ammonium metavanadate at pH 8.5. Leaching of nickel, iron and other elements from the residue was carried out by 2M HCl under different conditions. The achieved leaching efficiency of nickel was 95% where as that of iron was 92%. Precipitation efficiency of both nickel and iron were 99.9%. The residue, which contains mainly unburned carbon, have been washed two times with water and dried at 200 o C then ground to < 300μm. According to the achieved analysis of the obtained carbon, it can be characterized as pure carbon

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)

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.

Ommatidia of blow fly, house fly, and flesh fly: implication of their vision efficiency.

Science.gov (United States)

Sukontason, Kabkaew L; Chaiwong, Tarinee; Piangjai, Somsak; Upakut, Sorawit; Moophayak, Kittikhun; Sukontason, Kom

2008-06-01

This work aims to elucidate the number of ommatidia or facets (the outwardly visible units of each ommatidium) for compound eyes in blow flies [Chrysomya megacephala (F.), Chrysomya rufifacies (Macquart), Chrysomya nigripes (Aubertin), Lucilia cuprina (Wiedemann)], house flies (Musca domestica L.), and flesh flies (Liosarcophaga dux Thomson) by manual counts of the corneal spreads. The head of the fly in each species was soaked in 20% potassium hydroxide solution at room temperature for 7 days, and the clear compound eye was dissected into six small parts, each of which was placed onto a slide and flattened using a coverslip. Images of each part were obtained using a microscope connected to a computer. The printed images of each part were magnified, and the total number of ommatidia per eye was manually counted. For males, the mean number of ommatidia was statistically different among all flies examined: L. dux (6,032) > C. rufifacies (5,356) > C. nigripes (4,798) > C. megacephala (4,376) > L. cuprina (3,665) > M. domestica (3,484). Likewise, the mean number of facets in females was statistically different: L. dux (6,086) > C. megacephala (5,641) > C. rufifacies (5,208) > C. nigripes (4,774) > L. cuprina (3,608) > M. domestica (3433). Scanning electron microscopy analysis of adult flies revealed the sexual dimorphism in the compound eye. Male C. megacephala had large ommatidia in the upper two thirds part and small ommatidia in the lower one third part, whereas only small ommatidia were detected in females. Dense postulate appearance was detected in the external surface of the corneal lens of the ommatidia of C. megacephala, C. rufifacies, and C. nigripes, while a mix of dense postulate appearance and variable groove array length was detected in L. cuprina and M. domestica. The probable functions of ommatidia are discussed with reference to other literature.

High Ph, Ammonia Toxicity, and the Search for Life on the Jovian Planets

Science.gov (United States)

Deal, P. H.; Souza, K. A.; Mack, H. M.

1975-01-01

The effects of pH and ammonia concentration were studied separately, where possible, on a variety of organisms, including some isolated from natural environments of high pH and/or ammonia concentration. Escherichia coli and Bacillus subtilis are both extremely sensitive to ammonia. An aerobic organism (growth up to pH 11.4) from an alkaline spring is more resistant, but exhibits a toxic response to ammonia at a pH much lower than its maximum for growth. The greatest ammonia resistance has been found in an unidentified organism growing at near neutral pH. Even in this case, however, urvival at ammonia concentrations reasonably expected on the Jovian planets is measured in hours. This is two to three orders of magnitude longer than for E. coli. Results support the tentative conclusion that contamination of the Jovian planets with terrestrial organisms that can grow is unlikely. However, the range of toxic response noted, coupled with the observation that terrestrial life has not been exposed to high ammonia concentrations for millions of years, suggests that adaptation to greater ammonia tolerance may be possible.

The Fly Printer - Extended

DEFF Research Database (Denmark)

Beloff, Laura; Klaus, Malena

2016-01-01

Artist talk / Work-in-progress What is the purpose of a machine or an artifact, like the Fly Printer, that is dislocated, that produces images that have no meaning, no instrumentality, that depict nothing in the world? The biological and the cultural are reunited in this apparatus as a possibility...... to break through a common way of depicting the world, trying to find different surfaces and using strange apparatus to insist in the interstice of visibility. The Fly Printer is a printing apparatus in a form of a closed environment that contains a flock of fruit flies. The flies eat special food...... that is prepared for them that is mixed with laser jet printer inks. The flies digest the food and gradually print different color dots onto the paper that is placed under the fly habitat. In the Fly Printer biological organisms are used for replacing a standard part of our common printer technology. The work...

Hidrogenionic potential (pH of the attractant, trap density and control threshold for Ceratitis capitata (DIPTERA: TEPHRITIDAE on Hamlin oranges in São Paulo central region, Brazil

Directory of Open Access Journals (Sweden)

Paulo Eduardo Branco Paiva

2013-06-01

Full Text Available This study evaluated the effect of initial pH values of 4.5, 6.5 and 8.5 of the attractant (protein bait Milhocina® and borax (sodium borate in the field, on the capture of fruit flies in McPhail traps, using 1, 2, 4 and 8 traps per hectare, in order to estimate control thresholds in a Hamlin orange grove in the central region of the state of São Paulo. The most abundant fruit fly species was Ceratitis capitata, comprising almost 99% of the fruit flies captured, of which 80% were females. The largest captures of C. capitata were found in traps baited with Milhocina® and borax at pH 8.5. Captures per trap for the four densities were similar, indicating that the population can be estimated with one trap per hectare in areas with high populations. It was found positive relationships between captures of C. capitata and the number of Hamlin oranges damaged, 2 and 3 weeks after capture. It was obtained equations that correlate captures and damage levels which can be used to estimate control thresholds. The average loss caused in Hamlin orange fruits by C. capitata was 2.5 tons per hectare or 7.5% of production.

Fundamental study of low-NOx combustion fly ash utilization

International Nuclear Information System (INIS)

Suuberg, Eric M.; Hurt, Robert H.

1998-01-01

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 fifty 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

Eco-epidemiology of Novel Bartonella Genotypes from Parasitic Flies of Insectivorous Bats.

Science.gov (United States)

Sándor, Attila D; Földvári, Mihály; Krawczyk, Aleksandra I; Sprong, Hein; Corduneanu, Alexandra; Barti, Levente; Görföl, Tamás; Estók, Péter; Kováts, Dávid; Szekeres, Sándor; László, Zoltán; Hornok, Sándor; Földvári, Gábor

2018-04-29

Bats are important zoonotic reservoirs for many pathogens worldwide. Although their highly specialized ectoparasites, bat flies (Diptera: Hippoboscoidea), can transmit Bartonella bacteria including human pathogens, their eco-epidemiology is unexplored. Here, we analyzed the prevalence and diversity of Bartonella strains sampled from 10 bat fly species from 14 European bat species. We found high prevalence of Bartonella spp. in most bat fly species with wide geographical distribution. Bat species explained most of the variance in Bartonella distribution with the highest prevalence of infected flies recorded in species living in dense groups exclusively in caves. Bat gender but not bat fly gender was also an important factor with the more mobile male bats giving more opportunity for the ectoparasites to access several host individuals. We detected high diversity of Bartonella strains (18 sequences, 7 genotypes, in 9 bat fly species) comparable with tropical assemblages of bat-bat fly association. Most genotypes are novel (15 out of 18 recorded strains have a similarity of 92-99%, with three sequences having 100% similarity to Bartonella spp. sequences deposited in GenBank) with currently unknown pathogenicity; however, 4 of these sequences are similar (up to 92% sequence similarity) to Bartonella spp. with known zoonotic potential. The high prevalence and diversity of Bartonella spp. suggests a long shared evolution of these bacteria with bat flies and bats providing excellent study targets for the eco-epidemiology of host-vector-pathogen cycles.

Optical fiber pH sensors for high temperature water. Final report

International Nuclear Information System (INIS)

McCrae, D.; Saaski, E.

1994-11-01

The goal of this program was the development of an optical pH measurement system capable of operating in a high-temperature aqueous environment. This project built upon a dual-wavelength fiber optic sensing system previously developed by Research International which utilizes light-emitting diodes as light sources and provides remote absorption spectroscopy via a single bidirectional optical fiber. Suitable materials for constructing an optical pH sensing element were identified during the program. These included a sapphire/Ti/Pt/Au thin-film reflector, quartz and sapphire waveguides, a poly(benzimidazole) matrix, and an azo chromophore indicator. By a suitable combination of these design elements, it appears possible to optically measure pH in aqueous systems up to a temperature of about 150 degrees C. A pH sensing system capable of operating in high-purity, low-conductivity water was built using quasi-evanescent wave sensing techniques. The sensing element incorporated a novel, mixed cellulose/cellulose acetate waveguide to which an azo indicator was bound. Testing revealed that the system could reproducibly respond to pH changes arising from 1 ppm differences in the morpholine content of low-conductivity water without influencing the measurement. The sensing system was stable for 150 hrs at room temperature, and no loss or degradation of the pH-responsive optical indicator was seen in 160 hrs at 50 degrees C. However, the prototype polymer waveguide lost transparency at 1.7% per day during this same 50 degrees C test. Additional effort is warranted in the areas of water-compatible waveguides and evanescent-wave detection methods

The Photocatalytic Removal of Ortho Chlorophenol from Aqueous Solution Using Modified Fly Ash - Titanium Dioxide

Directory of Open Access Journals (Sweden)

Mohamad Malakootian

2016-05-01

Full Text Available The photocatalytic process is a useful method for the effective removal of phenolic compounds. Conducted in the spring‒summer 2013 at the Engineering Research Center for Environmental Health, Kerman University of Medical Sciences, this experimental study used a modified fly ash‒TiO2 mixture to enhance the photocatalytic removal efficiency of ortho-chlorophenol. Fly ash obatined from the Thermal Power Plant in Zarand, Kerman, was initially washed with sulfuric acid before being oxidized with potassium permanganate. The mixture of modified fly ash and TiO2 was then used for the removal of ortho-chlorophenol in the presence of UV light and the factors involved in the removal process were optimized. It was found that the ortho-chlorophenol removal efficiency recorded by the mixture of modified fly ash and TiO2 was higher than that by each of the modified fly ash or TiO2/UV alone. It was, further, observed that removal efficiency with a modified fly ash to TiO2 ratio of 3:1 rose to 98.8% under optimum conditions (i.e., pH: 2; contact time: 2 h; room temperature (29±2˚C, and a catalyst dose of 0.6 g. The ortho-chlorophenol removal efficiency in real wastewater from the Coal Wash Plant in Zarand was recorded at 88.4%. Based on the results obtained from simultaneous use of modified fly ash and TiO2, the proposed method may be recommended for industrial applications.

Effect of coal blending on the leaching characteristics of arsenic and selenium in fly ash from fluidized bed coal combustion

Energy Technology Data Exchange (ETDEWEB)

Jiao, F.; Yamada, N.; Sato, A.; Ninomiya, Yoshihiko [Chubu Univ., Aichi (Japan). Dept. of Applied Chemistry; Zhang, L. [Monash Univ., Clayton, VIC (Australia). Dept. of Chemical Engineering

2013-07-01

The capture ability of fly ash to arsenic (As) and selenium (Se) was investigated through the combustion of two single bituminous coals A and B and their mixture (blending ratio of 1:1, wt/wt) in a lab-scale fluidized bed reactor. The leaching characteristics of As and Se in corresponding fly ash were also conducted according to Japanese Industrial Standard (JIS). Speciation of As and Se during fly ash leaching test were predicted from the perspective of thermodynamic equilibrium. The results indicate that, combustion of coal B, containing abundant calcium, possesses a higher capture ability of As and Se than that of coal A through possible chemical reaction between As/Se with CaO. Leaching behavior of As and Se from fly ash is strongly dependent on the pH of the leachate. Free calcium in fly ash generates an alkaline leachate during leaching test and subsequently reduces As and Se leaching, which cause the leaching ratio of As and Se in fly ash derived from the combustion of coal B was much lower, relative to that in coal A. Combustion of blending coal promotes the overall capture ability of the fly ash to As/Se and reduces their leaching from fly ash through the synergy of free CaO between this two kind of fly ash.

Molecular gated-AlGaN/GaN high electron mobility transistor for pH detection.

Science.gov (United States)

Ding, Xiangzhen; Yang, Shuai; Miao, Bin; Gu, Le; Gu, Zhiqi; Zhang, Jian; Wu, Baojun; Wang, Hong; Wu, Dongmin; Li, Jiadong

2018-04-18

A molecular gated-AlGaN/GaN high electron mobility transistor has been developed for pH detection. The sensing surface of the sensor was modified with 3-aminopropyltriethoxysilane to provide amphoteric amine groups, which would play the role of receptors for pH detection. On modification with 3-aminopropyltriethoxysilane, the transistor exhibits good chemical stability in hydrochloric acid solution and is sensitive for pH detection. Thus, our molecular gated-AlGaN/GaN high electron mobility transistor acheived good electrical performances such as chemical stability (remained stable in hydrochloric acid solution), good sensitivity (37.17 μA/pH) and low hysteresis. The results indicate a promising future for high-quality sensors for pH detection.

No-core fiber-based highly sensitive optical fiber pH sensor.

Science.gov (United States)

Bhardwaj, Vanita; Pathak, Akhilesh Kumar; Singh, Vinod Kumar

2017-05-01

The present work describes the fabrication and characterization of an optical fiber pH sensor using a sol–gel technique. The sensing head configuration is incorporated using a short section of no-core fiber, coated with tetraethyl orthosilicate and spliced at the end of a single mode fiber with a bulge. Different types of indicators (bromophenol blue, cresol red, and chlorophenol red) were used to achieve a wide pH range from 2 to 13. High sensitivities of the fabricated device were found to be 1.02 and ? 0.93 ?? nm / pH for acidic and alkaline solutions, respectively. From the characterization results, it was noted that there is an impact of ionic strength and an effect of the temperature of liquid on the response characteristic, which is an advantage of the existing device over the other pH sensors. The fabricated sensor exhibited good reflection spectrum, indicating a blueshift in resonance wavelength for alkaline solutions and a redshift for acidic solutions.

The onion fly

International Nuclear Information System (INIS)

Loosjes, M.

1990-01-01

This paper describes the origin, practical application, problems in application and prospects of control of the onion fly, Delia antiqua (Diptera: Anthomyiidae), in the Netherlands by the Sterile Insect Technique (SIT). The larva of the onion fly is a severe pest in onions in temperate regions. Development of resistance of the onion fly against insecticides caused research on the SIT to be started by the Dutch Government in 1965. This research was on mass-rearing, long-term storage of pupae, sterilization, and release and ratio assessment techniques. By 1979 sufficient information had been turned over to any interested private company. In the case of the onion fly the SIT can be applied like a control treatment instead of chemical control to individual onion fields. This is due to the limited dispersal activity of the flies and the scattered distribution of onion fields in the Netherlands, with 5-10% of the onion growing areas planted with onions

Soluble components of the flagellar export apparatus, FliI, FliJ, and FliH, do not deliver flagellin, the major filament protein, from the cytosol to the export gate.

Science.gov (United States)

Sajó, Ráchel; Liliom, Károly; Muskotál, Adél; Klein, Agnes; Závodszky, Péter; Vonderviszt, Ferenc; Dobó, József

2014-11-01

Flagella, the locomotion organelles of bacteria, extend from the cytoplasm to the cell exterior. External flagellar proteins are synthesized in the cytoplasm and exported by the flagellar type III secretion system. Soluble components of the flagellar export apparatus, FliI, FliH, and FliJ, have been implicated to carry late export substrates in complex with their cognate chaperones from the cytoplasm to the export gate. The importance of the soluble components in the delivery of the three minor late substrates FlgK, FlgL (hook-filament junction) and FliD (filament-cap) has been convincingly demonstrated, but their role in the transport of the major filament component flagellin (FliC) is still unclear. We have used continuous ATPase activity measurements and quartz crystal microbalance (QCM) studies to characterize interactions between the soluble export components and flagellin or the FliC:FliS substrate-chaperone complex. As controls, interactions between soluble export component pairs were characterized providing Kd values. FliC or FliC:FliS did not influence the ATPase activity of FliI alone or in complex with FliH and/or FliJ suggesting lack of interaction in solution. Immobilized FliI, FliH, or FliJ did not interact with FliC or FliC:FliS detected by QCM. The lack of interaction in the fluid phase between FliC or FliC:FliS and the soluble export components, in particular with the ATPase FliI, suggests that cells use different mechanisms for the export of late minor substrates, and the major substrate, FliC. It seems that the abundantly produced flagellin does not require the assistance of the soluble export components to efficiently reach the export gate. Copyright © 2014 Elsevier B.V. All rights reserved.

Arsenic removal from water using a novel amorphous adsorbent developed from coal fly ash.

Science.gov (United States)

Zhang, Kaihua; Zhang, Dongxue; Zhang, Kai

2016-01-01

A novel effective adsorbent of alumina/silica oxide hydrate (ASOH) for arsenic removal was developed through simple chemical reactions using coal fly ash. The iron-modified ASOH with enhancing adsorption activity was further developed from raw fly ash based on the in situ technique. The adsorbents were characterized by X-ray diffraction, Fourier transform infrared spectrometry, scanning electron micrograph, laser particle size and Brunauer-Emmet-Teller surface area. The results show that the adsorbents are in amorphous and porous structure, the surface areas of which are 8-12 times that of the raw ash. The acidic hydrothermal treatment acts an important role in the formation of the amorphous structure of ASOH rather than zeolite crystal. A series of adsorption experiments for arsenic on them were studied. ASOH can achieve a high removal efficiency for arsenic of 96.4% from water, which is more than 2.5 times that of the raw ash. Iron-modified ASOH can enhance the removal efficiency to reach 99.8% due to the in situ loading of iron (Fe). The condition of synthesis pH = 2-4 is better for iron-modified ASOH to adsorb arsenic from water.

Low pH concretes: instantaneous and delayed behaviors under external stress

International Nuclear Information System (INIS)

Leung Pah Hang, Thierry

2015-01-01

In the context of the radioactive wastes disposal in deep geological repository of clay, low-alkalinity and low heat of hydration concretes referenced 'low pH' were designed. The degradation of the properties of the clay can be limited by using these types of concrete. Two types of low pH binder were chosen for this research: the first one is comprised of cement, silica fume and fly ash (TCV) and the other one is comprised of cement, silica fume and slag (TL). The objective of this research is to comprehend the behavior of these concrete in order to ensure the well-placing of the fresh concrete at an industrial scale and good mechanical performances, chemical stability and confining properties. The experimental program focuses on a physico-chemical and mechanical characterization of these recent materials with high pozzolanic addition content. The experimental data are then modeled for the purpose of having a tool that, in the end, is able to predict the behavior of the low pH concretes within the structure. The results show that grinding altogether the three constituents improves the reactivity of the binder and allows a good reproducibility of the low pH design. The most important criterion which is a pH of the interstitial solution below 11 is met at 28 days. The heat measurements at early age show that the low pH concretes are low heat of hydration concretes as well. In the long run, high mechanical performances, low permeabilities and diffusivities were obtained on these materials. The modeling of the hydration, evolution of mechanical properties, damage, creep and hydric transfers is also covered in this thesis. The model of hydration was adjusted to match the hydration of ternary binders by taking into account the effects of the additions such as the heterogeneous nucleation, on the hydration of the cement. As for the other models, the experimental results were used as data input to validate the models on binders with high replacement rates

Survival of the House Fly (Diptera: Muscidae) on Truvia and Other Sweeteners.

Science.gov (United States)

Fisher, Michael L; Fowler, Fallon E; Denning, Steven S; Watson, David W

2017-07-01

The house fly, Musca domestica L. (Diptera: Muscidae), is a disease vector of mechanically transmitted pathogens including bacteria, viruses, and protozoans. Opportunities for pathogen transmission can increase as fly longevity increases. Dietary preferences play an important role in insect longevity; therefore, we investigated house fly preferences, sucrose availability, and caloric constraints on house fly longevity. Experimental goals were: 1) to test the effects of calorie restriction on survival of house flies by manipulating concentrations of erythritol (low caloric content) and sucrose (high caloric content), and comparing commercial sweeteners of differing calorie content, 2) to identify house fly preferences for either erythritol or sucrose, and 3) to evaluate the insecticidal activity or toxicity of erythritol on house flies. Our data show that house flies may prefer high calorie options when given a choice and that house fly longevity likely increases as calorie content increases. Additionally, no significant differences in longevity were observed between the water only control (zero calories) and erythritol treatments. This suggests that decreased survival rates and death could be the result of starvation rather than insecticidal activity. This research furthers our understanding of house fly survival and sugar-feeding behavior. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Adsorptive removal of organics from aqueous phase by acid-activated coal fly ash: preparation, adsorption, and Fenton regenerative valorization of "spent" adsorbent.

Science.gov (United States)

Wang, Nannan; Hao, Linlin; Chen, Jiaqing; Zhao, Qiang; Xu, Han

2018-05-01

Raw coal fly ash was activated to an adsorbent by sulfuric acid impregnation. The activation condition, the adsorption capacity, and the regenerative valorization of the adsorbent were studied. The results show that the optimal preparation conditions of the adsorbent are [H 2 SO 4 ] = 1 mol L -1 , activation time = 30 min, the ratio of coal fly ash to acid = 1:20 (g:mL), calcination temperature = 100 °C. The adsorption of p-nitrophenol on the adsorbent accords with the pseudo-second-order kinetic equation and the adsorption rate constant is 0.089 g mg -1  min -1 . The adsorption on this adsorbent can be considered enough after 35 min, when the corresponding adsorption capacity is 1.07 mg g -1 (85.6% of p-nitrophenol removal). Compared with raw coal fly ash, the adsorbent has a stable adsorption performance at low pH range (pH = 1-6) and the adsorption of p-nitrophenol is an exothermic process. Ninety minutes is required for the regenerative valorization of saturated adsorbent by Fenton process. The regenerative valorization for this saturated adsorbent can reach 89% under the optimal proposed conditions (30 °C, pH = 3, [H 2 O 2 ] = 5.0 mmol L -1 , [Fe 2+ ] = 5.5 mmol L -1 ). Within 15 experimental runs, the adsorbent has a better and better stability with the increase of experimental runs. Finally, the mechanism of activating coal fly ash is proposed, being verified by the results of the SEM and BET test.

The influence of sex and fly species on the development of trypanosomes in tsetse flies.

Directory of Open Access Journals (Sweden)

Lori Peacock

Full Text Available Unlike other dipteran disease vectors, tsetse flies of both sexes feed on blood and transmit pathogenic African trypanosomes. During transmission, Trypanosoma brucei undergoes a complex cycle of proliferation and development inside the tsetse vector, culminating in production of infective forms in the saliva. The insect manifests robust immune defences throughout the alimentary tract, which eliminate many trypanosome infections. Previous work has shown that fly sex influences susceptibility to trypanosome infection as males show higher rates of salivary gland (SG infection with T. brucei than females. To investigate sex-linked differences in the progression of infection, we compared midgut (MG, proventriculus, foregut and SG infections in male and female Glossina morsitans morsitans. Initially, infections developed in the same way in both sexes: no difference was observed in numbers of MG or proventriculus infections, or in the number and type of developmental forms produced. Female flies tended to produce foregut migratory forms later than males, but this had no detectable impact on the number of SG infections. The sex difference was not apparent until the final stage of SG invasion and colonisation, showing that the SG environment differs between male and female flies. Comparison of G. m. morsitans with G. pallidipes showed a similar, though less pronounced, sex difference in susceptibility, but additionally revealed very different levels of trypanosome resistance in the MG and SG. While G. pallidipes was more refractory to MG infection, a very high proportion of MG infections led to SG infection in both sexes. It appears that the two fly species use different strategies to block trypanosome infection: G. pallidipes heavily defends against initial establishment in the MG, while G. m. morsitans has additional measures to prevent trypanosomes colonising the SG, particularly in female flies. We conclude that the tsetse-trypanosome interface works

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

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...... fly ash, such as washing with water to quickly recover the highly soluble salts (mainly K and Cl), and treatment of the washed fly ash with elevated heavy metal content resulted from washing by electrodialytic remediation (EDR). The finding that SiO2 (quartz) accounted for a significant portion...

Temperature Effects on Olive Fruit Fly Infestation in the FlySim Cellular Automata Model

Science.gov (United States)

Bruno, Vincenzo; Baldacchini, Valerio; di Gregorio, Salvatore

FlySim is a Cellular Automata model developed for simulating infestation of olive fruit flies (Bactrocera Oleae) on olive (Olea europaea) groves. The flies move into the groves looking for mature olives where eggs are spawn. This serious agricultural problem is mainly tackled by using chemical agents at the first signs of the infestation, but organic productions with no or few chemicals are strongly requested by the market. Oil made with infested olives is poor in quality, nor olives are suitable for selling in stores. The FlySim model simulates the diffusion of flies looking for mature olives and the growing of flies due to atmospheric conditions. Foreseeing an infestation is the best way to prevent it and to reduce the need of chemicals in agriculture. In this work we investigated the effects of temperature on olive fruit flies and resulting infestation during late spring and summer.

Degradation of fly ash concrete under the coupled effect of carbonation and chloride aerosol ingress

International Nuclear Information System (INIS)

Liu, Jun; Qiu, Qiwen; Chen, Xiaochi; Wang, Xiaodong; Xing, Feng; Han, Ningxu; He, Yijian

2016-01-01

Highlights: • Carbonation affects the chloride profile in concrete under chloride aerosol attack. • The chloride binding capacity can be reduced by the presence of carbonation. • Carbonation increases the rate of chloride diffusion for chloride aerosol ingress. • Chloride aerosol ingress reduces the carbonation depth and increases the pH value. • The use of fly ash in concrete enhances the resistance of chloride aerosol ingress. - Abstract: This paper presents an experimental investigation regarding the coupled effect of carbonation and chloride aerosol ingress on the durability performance of fly ash concrete. Test results demonstrate that carbonation significantly affects the chloride ingress profile, reduces the chloride binding capacity, and accelerates the rate of chloride ion diffusion. On the other hand, the carbonation rate of fly ash concrete is reduced by the presence of chlorides aerosol. The interaction nature between concrete carbonation and chloride aerosol ingress is also demonstrated by the microscopic analysis results obtained from scanning electron microscope and mercury intrusion porosimetry.

Effects of high medium pH on growth, metabolism and transport in Saccharomyces cerevisiae.

Science.gov (United States)

Peña, Antonio; Sánchez, Norma Silvia; Álvarez, Helber; Calahorra, Martha; Ramírez, Jorge

2015-03-01

Growth of Saccharomyces cerevisiae stopped by maintaining the pH of the medium in a pH-stat at pH 8.0 or 9.0. Studying its main physiological capacities and comparing cells after incubation at pH 6.0 vs. 8.0 or 9.0, we found that (a) fermentation was moderately decreased by high pH and respiration was similar and sensitive to the addition of an uncoupler, (b) ATP and glucose-6-phosphate levels upon glucose addition increased to similar levels and (c) proton pumping and K(+) transport were also not affected; all this indicating that energy mechanisms were preserved. Growth inhibition at high pH was also not due to a significant lower amino acid transport by the cells or incorporation into proteins. The cell cycle stopped at pH 9.0, probably due to an arrest as a result of adjustments needed by the cells to contend with the changes under these conditions, and microarray experiments showed some relevant changes to this response. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Principal chemical properties of artificial soil composed of fly ash and furfural residue

Energy Technology Data Exchange (ETDEWEB)

Feng, Y.J.; Li, F.; Wang, X.L.; Liu, X.M.; Zhang, L.N. [Shandong Agricultural University, Tai An (China). College of Resources & Environments

2006-10-15

To solve soil shortage in reclaiming subsided land of coal mines, the principal chemical properties of artificial soil formed by mixing organic furfural residue and inorganic fly ash were examined. The results indicated that the artificial soil was suitable for agriculture use after irrigation and desalination, the available nutrients in the artificial soil could satisfy the growth demand of plants, and the pH tended to the neutrality.

Flying insects and Campylobacter

DEFF Research Database (Denmark)

Hald, Birthe; Sommer, Helle Mølgaard; Skovgård, Henrik

Campylobacter in flies Flies of the Muscidae family forage on all kind of faeces – various fly species have different preferences. M domestica prefer pigs, horses and cattle faeces, animals which are all known to frequently excrete Campylobacter. As a result, the insects pick up pathogenic micro...

Mercury concentration in black flies Simulium spp. (Diptera, Simuliidae) from soft-water streams in Ontario, Canada

International Nuclear Information System (INIS)

Harding, K.M.; Gowland, J.A.; Dillon, P.J.

2006-01-01

Total Hg in Simulium spp. (Diptera, Simuliidae) was measured in 17 soft-water streams in the District of Muskoka and Haliburton County (Ontario, Canada) during 2003 and 2004. Black flies contained 0.07-0.64 μg/g total Hg (dry weight). The methylmercury concentration was measured in 6 samples of the 17, and ranged from 58% to 93% of total Hg. The concentration of total Hg is much higher than has been found in other filter feeding insects, and represents a significant potential source of Hg to fish. Mercury concentrations in Simulium spp. at different sites were strongly positively correlated with dissolved organic carbon, and the proportion of land within each catchment that was wetland. There was also a strong negative correlation with pH. By examining Hg concentration in filter feeding insects we have found a significant entry point for Hg and MeHg into the food web. - Accumulation of total mercury by black fly larvae is affected by stream pH, DOC and wetland area in the stream catchment

Mercury concentration in black flies Simulium spp. (Diptera, Simuliidae) from soft-water streams in Ontario, Canada

Energy Technology Data Exchange (ETDEWEB)

Harding, K.M. [Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada); Gowland, J.A. [Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada); Dillon, P.J. [Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada)]. E-mail: pdillon@trentu.ca

2006-10-15

Total Hg in Simulium spp. (Diptera, Simuliidae) was measured in 17 soft-water streams in the District of Muskoka and Haliburton County (Ontario, Canada) during 2003 and 2004. Black flies contained 0.07-0.64 {mu}g/g total Hg (dry weight). The methylmercury concentration was measured in 6 samples of the 17, and ranged from 58% to 93% of total Hg. The concentration of total Hg is much higher than has been found in other filter feeding insects, and represents a significant potential source of Hg to fish. Mercury concentrations in Simulium spp. at different sites were strongly positively correlated with dissolved organic carbon, and the proportion of land within each catchment that was wetland. There was also a strong negative correlation with pH. By examining Hg concentration in filter feeding insects we have found a significant entry point for Hg and MeHg into the food web. - Accumulation of total mercury by black fly larvae is affected by stream pH, DOC and wetland area in the stream catchment.

Removal of chloride from MSWI fly ash.

Science.gov (United States)

Chen, Wei-Sheng; Chang, Fang-Chih; Shen, Yun-Hwei; Tsai, Min-Shing; Ko, Chun-Han

2012-10-30

The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basis for construction materials. Water-soluble chlorides such as potassium chloride (KCl), sodium chloride (NaCl), and calcium chloride hydrate (CaCl(2) · 2H(2)O) in fly ash are easily washed away. However, calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach away at room temperature. The roasting and washing-flushing processes were applied to remove chloride content in this study. Additionally, air and CO(2) were introduced into the washing process to neutralize the hazardous nature of chlorides. In comparison with the water flushing process, the roasting process is more efficient in reducing the process of solid-liquid separation and drying for the reuse of Cl-removed fly ash particles. In several roasting experiments, the removal of chloride content from fly ash at 1050°C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid ratio of 1:10 the water-flushing process can almost totally remove water-soluble chloride (97% chloride removal efficiency). Analyses of mineralogical change also prove the efficiency of the fly ash roasting and washing mechanisms for chloride removal. Copyright © 2012 Elsevier B.V. All rights reserved.

Recovery of iron oxide from coal fly ash

Science.gov (United States)

Dobbins, Michael S.; Murtha, Marlyn J.

1983-05-31

A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

OpenAIRE

Md. Rajibur Rahaman Khan; Shin-Won Kang

2016-01-01

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal?s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The...

Proceedings from the 2nd International Symposium on Formation Flying Missions and Technologies

Science.gov (United States)

2004-01-01

Topics discussed include: The Stellar Imager (SI) "Vision Mission"; First Formation Flying Demonstration Mission Including on Flight Nulling; Formation Flying X-ray Telescope in L2 Orbit; SPECS: The Kilometer-baseline Far-IR Interferometer in NASA's Space Science Roadmap Presentation; A Tight Formation for Along-track SAR Interferometry; Realization of the Solar Power Satellite using the Formation Flying Solar Reflector; SIMBOL-X : Formation Flying for High-Energy Astrophysics; High Precision Optical Metrology for DARWIN; Close Formation Flight of Micro-Satellites for SAR Interferometry; Station-Keeping Requirements for Astronomical Imaging with Constellations of Free-Flying Collectors; Closed-Loop Control of Formation Flying Satellites; Formation Control for the MAXIM Mission; Precision Formation Keeping at L2 Using the Autonomous Formation Flying Sensor; Robust Control of Multiple Spacecraft Formation Flying; Virtual Rigid Body (VRB) Satellite Formation Control: Stable Mode-Switching and Cross-Coupling; Electromagnetic Formation Flight (EMFF) System Design, Mission Capabilities, and Testbed Development; Navigation Algorithms for Formation Flying Missions; Use of Formation Flying Small Satellites Incorporating OISL's in a Tandem Cluster Mission; Semimajor Axis Estimation Strategies; Relative Attitude Determination of Earth Orbiting Formations Using GPS Receivers; Analysis of Formation Flying in Eccentric Orbits Using Linearized Equations of Relative Motion; Conservative Analytical Collision Probabilities for Orbital Formation Flying; Equations of Motion and Stability of Two Spacecraft in Formation at the Earth/Moon Triangular Libration Points; Formations Near the Libration Points: Design Strategies Using Natural and Non-Natural Ares; An Overview of the Formation and Attitude Control System for the Terrestrial Planet Finder Formation Flying Interferometer; GVE-Based Dynamics and Control for Formation Flying Spacecraft; GNC System Design for a New Concept of X

Tolerance of house fly, Musca domestica L. (Diptera: Muscidae) to dichlorvos (76% EC) an insecticide used for fly control in the tsunami-hit coastal villages of southern India.

Science.gov (United States)

Srinivasan, R; Jambulingam, P; Gunasekaran, K; Boopathidoss, P S

2008-02-01

The Directorate of Public Health (DPH), Tamil Nadu, in southern India employed spraying of dichlorvos (76% EC) for quick elimination of fly concentrations in the tsunami-hit coastal villages at the concentration of 304g (a.i.)/10,000m(2). However, nuisance of house flies remained high particularly in temporary shelters and centralized relief kitchens. Susceptibility of house fly, Musca domestica to dichlorvos was determined in the laboratory to provide information for an effective management of this pest. Various concentrations of dichlorvos (76% EC) viz., 0.1, 0.2, 0.4, 0.6 and 0.8microg (a.i.) per fly, were tested using topical application against F(1) progenies of house flies collected 12 months after insecticide applications from different habitats in the tsunami-hit coastal villages. Fly mortality was recorded at 24h post treatment. Parallel controls were maintained for comparison. Mortality of the house flies varied between 17.5% and 100% and increased with an increase in dosage of the insecticide. Mortality was >80% at 0.6 and 0.8microg (a.i.) per fly. The LD(50) of dichlorvos tested against flies collected from different villages varied from 0.218microg (a.i.) to 0.235microg (a.i.) per fly and the LD(90) varied from 0.574microg (a.i.) to 0.639microg (a.i.) per fly. House flies collected from a rural village, Thirukanur that had never been exposed for insecticide treatment in the past one decade, when tested, the mortality varied between 92.5% and 100% and increased with concentration of dichlorvos. Mortality was >90% from 0.2microg (a.i.) per fly and the LD(50) was 0.0399microg (a.i.)/fly, while the LD(90) was 0.1604microg (a.i.)/fly. The LD(90) values of the flies collected from the tsunami-hit villages were 3.5-3.9 times higher than that of the flies collected from Thirukanur. Fly abundance remained high in tsunami-hit villages with no marked reduction, suggesting that the flies had developed tolerance to dichlorvos. It is suggested that for an effective

Production of highly porous glass-ceramics from metallurgical slag, fly ash and waste glass

Directory of Open Access Journals (Sweden)

Mangutova Bianka V.

2004-01-01

Full Text Available Glass-ceramics composites were produced based on fly-ash obtained from coal power stations, metallurgical slag from ferronickel industry and waste glass from TV monitors, windows and flasks. Using 50% waste flask glass in combination with fly ash and 20% waste glass from TV screens in combination with slag, E-modulus and bending strength values of the designed systems are increased (system based on fly ash: E-modulus from 6 to 29 GPa, and bending strength from 9 to 75 MPa. The polyurethane foam was used as a pore creator which gave the material porosity of 70(5% (fly ash-glass composite and a porosity of 65( 5% (slag-glass composite. E-modulus values of the designed porous systems were 3.5(1.2 GPa and 8.1(3 GPa, while the bending strength values were 6.0(2 MPa and 13.2(3.5 MPa, respectively. These materials could be used for the production of tiles, wall bricks, as well as for the construction of air diffusers for waste water aeration.

Energetic cost of bot fly parasitism in free-ranging eastern chipmunks.

Science.gov (United States)

Careau, Vincent; Thomas, Donald W; Humphries, Murray M

2010-02-01

The energy and nutrient demands of parasites on their hosts are frequently invoked as an explanation for negative impacts of parasitism on host survival and reproductive success. Although cuterebrid bot flies are among the physically largest and most-studied insect parasites of mammals, the only study conducted on metabolic consequences of bot fly parasitism revealed a surprisingly small effect of bot flies on host metabolism. Here we test the prediction that bot fly parasitism increases the resting metabolic rate (RMR) of free-ranging eastern chipmunks (Tamias striatus), particularly in juveniles who have not previously encountered parasites and have to allocate energy to growth. We found no effect of bot fly parasitism on adults. In juveniles, however, we found that RMR strongly increased with the number of bot fly larvae hosted. For a subset of 12 juveniles during a year where parasite prevalence was particularly high, we also compared the RMR before versus during the peak of bot fly prevalence, allowing each individual to act as its own control. Each bot fly larva resulted in a approximately 7.6% increase in the RMR of its host while reducing juvenile growth rates. Finally, bot fly parasitism at the juvenile stage was positively correlated with adult stage RMR, suggesting persistent effects of bot flies on RMR. This study is the first to show an important effect of bot fly parasitism on the metabolism and growth of a wild mammal. Our work highlights the importance of studying cost of parasitism over multiple years in natural settings, as negative effects on hosts are more likely to emerge in periods of high energetic demand (e.g. growing juveniles) and/or in harsh environmental conditions (e.g. low food availability).

Design and construction of a remote piloted flying wing. B.S. Thesis

Science.gov (United States)

Costa, Alfred J.; Koopman, Fritz; Soboleski, Craig; Trieu, Thai-Ba; Duquette, Jaime; Krause, Scott; Susko, David; Trieu, Thuyba

1994-01-01

Currently, there is a need for a high-speed, high-lift civilian transport. Although unconventional, a flying wing could fly at speeds in excess of Mach 2 and still retain the capacity of a 747. The design of the flying wing is inherently unstable since it lacks a fuselage and a horizontal tail. The project goal was to design, construct, fly, and test a remote-piloted scale model flying wing. The project was completed as part of the NASA/USRA Advanced Aeronautics Design Program. These unique restrictions required us to implement several fundamental design changes from last year's Elang configuration including wing sweepback and wingtip endplates. Unique features such as a single ducted fan engine, composite structural materials, and an electrostatic stability system were incorporated. The result is the Banshee '94. Our efforts will aid future projects in design and construction techniques so that a viable flying wing can become an integral part of the aviation industry.

Effects of eucalyptol on house fly (Diptera: Muscidae and blow fly (Diptera: Calliphoridae

Directory of Open Access Journals (Sweden)

Sukontason Kabkaew L.

2004-01-01

Full Text Available The effects of eucalyptol were evaluated against the house fly, Musca domestica L., and blow fly, Chrysomya megacephala (F.. The bioassay of adults, using topical application, indicated that M. domestica males were more susceptible than females, with the LD50 being 118 and 177 mg/fly, respectively. A higher LD50 of C. megacephala was obtained; 197 mg/fly for males and 221 mg/fly for females. Living flies of both species yielded a shorter life span after being treated with eucalyptol. The bioassay of larvae, using the dipping method on the third instar, showed that M. domestica was more susceptible than C. megacephala, with their LC50 being 101 and 642 mg/ml, respectively. The emergence of adults, which had been treated with eucalyptol in larvae, decreased only in M. domestica. Having the volatile property, fumigation or impregnated paper test of eucalyptol or the efficacy of repellence or attractiveness merits further investigations to enhance bio-insecticidal efficacy.

WAYS OF ACQUIRING FLYING PHOBIA.

Science.gov (United States)

Schindler, Bettina; Vriends, Noortje; Margraf, Jürgen; Stieglitz, Rolf-Dieter

2016-02-01

The few studies that have explored how flying phobia is acquired have produced contradictory results. We hypothesized that classical conditioning plays a role in acquiring flying phobia and investigated if vicarious (model) learning, informational learning through media, and experiencing stressful life events at the time of onset of phobia also play a role. Thirty patients with flying phobia and thirty healthy controls matched on age, sex, and education were interviewed with the Mini-DIPS, the short German version of the Anxiety Disorders Interview Schedule (DSM-IV diagnostic criteria) and the Fear-of-Flying History Interview. Fifty Percent of patients with flying phobia and 53% of healthy controls reported frightening events in the air. There was no significant difference between the two samples. Thus there were not more classical conditioning events for patients with flying phobia. There also was no significant difference between the two samples for vicarious (model) learning: 37% of flying phobia patients and 23% of healthy controls felt influenced by model learning. The influence of informational learning through media was significantly higher for the clinical sample (70%) than for the control group (37%). Patients with flying phobia experienced significantly more stressful life events in the period of their frightening flight experience (60%) than healthy controls (19%). Frightening experiences while flying are quite common, but not everybody develops a flying phobia. Stressful life events and other factors might enhance conditionability. Informational learning through negative media reports probably reinforces the development of flying phobia. Clinical implications are discussed. © 2015 Wiley Periodicals, Inc.

Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

Energy Technology Data Exchange (ETDEWEB)

Visa, Maria, E-mail: maria.visa@unitbv.ro; Chelaru, Andreea-Maria, E-mail: andreea.chelaru1@yahoo.com

2014-06-01

Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO{sub 2}/Al{sub 2}O{sub 3} over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

Hydrothermally modified fly ash for heavy metals and dyes removal in advanced wastewater treatment

International Nuclear Information System (INIS)

Visa, Maria; Chelaru, Andreea-Maria

2014-01-01

Fly ash resulted from coal burning is a waste that can be used in wastewater treatment for removal of dyes and heavy metals by adsorption. Class “F” fly ash (FA), collected from the Central Heat and Power (CHP) Plant Brasov (Romania), with oxides composition SiO 2 /Al 2 O 3 over 2.4 was used for obtaining a new substrate with good adsorption capacity for dyes and heavy metals from wastewater. A new material was obtained from modified fly ash with NaOH and hexadecyltrimethylammonium bromide (HTAB) a cationic surfactant. Contact time, optimum amount of substrate and the pH corresponding to 50 mL solution of pollutants were the parameters optimized for obtaining the maximum efficiency in the adsorption process. The optimized adsorption parameters were further used in thermodynamic and kinetic studies of the adsorption processes. The adsorption kinetic mechanisms, and the substrate capacities are further discussed correlated with the surface structure (XRD), composition (EDS, FTIR), and morphology (SEM, AFM). The results indicate that the novel nano-substrate composite with fly ash modified can be used as an efficient and low cost adsorbent for simultaneous removal of dyes and heavy metals, the resulted water respects the discharge regulations.

Visualization of Projectile Flying at High Speed in Dusty Atmosphere

Science.gov (United States)

Masaki, Chihiro; Watanabe, Yasumasa; Suzuki, Kojiro

2017-10-01

Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in such environment was experimentally simulated by using the ballistic range. At high-speed collision of particles on the projectile surface, they may be reflected with cracking into smaller pieces. On the other hand, the projectile surface will be damaged by the collision. To obtain the fundamental characteristics of such complicated phenomena, a projectile was launched at the velocity up to 400 m/s and the collective behaviour of particles around projectile was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on only the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 400μm diameter were scattered and formed a sheet of particles in the test chamber by using two-dimensional funnel with a narrow slit. The projectile was launched into the particle sheet in the tangential direction, and the high-speed camera captured both projectile and particle motions. From the movie, the interaction between the projectile and particle sheet was clarified.

High-throughput mosquito and fly bioassay system for natural and artificial substrates treated with residual insecticides.

Science.gov (United States)

Aldridge, Robert L; Wynn, W Wayne; Britch, Seth C; Allan, Sandra A; Walker, Todd W; Geden, Christopher J; Hogsette, Jerome A; Linthicum, Kenneth J

2013-03-01

A high-throughput bioassay system to evaluate the efficacy of residual pesticides against mosquitoes and muscid flies with minimal insect handling was developed. The system consisted of 4 components made of readily available materials: 1) a CO2 anaesthetizing chamber, 2) a specialized aspirator, 3) a cylindrical flat-bottomed glass bioassay chamber assembly, and 4) a customized rack.

High yielding mutants of blackgram variety 'PH-25'

International Nuclear Information System (INIS)

Misra, R.C.; Mohapatra, B.D.; Panda, B.S.

2001-01-01

Seeds of blackgram (Vigna mungo L.) variety 'PH-5' were treated with chemical mutagens ethyl methanesulfonate (EMS), nitrosoguanidine (NG), maleic hydrazide (MH) and sodium azide (NaN 3 ), each at 3 different concentrations. Thirty six mutant lines developed from mutagenic treatments along with parent varieties were tested in M 4 generation. The mutants showed wide variation in most of the traits and multivariante D 2 analysis showed genetic divergence among themselves. Twenty of the thirty mutants showed genetic divergence from parent. Ten selected high yielding mutants were tested in M 5 . Yield and other productive traits of five high yielding mutants in M 4 and M 5 are presented

Adsorption of Chrysoidine R by using fly ash in batch process

International Nuclear Information System (INIS)

Matheswaran, Manickam; Karunanithi, Thirugnanam

2007-01-01

This investigation deals with effective utilization of fly ash as adsorbent for the removal of Chrysoidine R from the aqueous solution. The fly ash is a major byproduct generated in coal-based thermal power plants and has good potential for use as an adsorbent. A series of experiments were carried out in a batch adsorption technique to obtain the effect of process variables viz. contact time, pH (2, 4, 6 and 8) initial concentration of the dye (400, 600, 800 and 1000 mg L -1 ), amount of the adsorbent (125, 250, 375 and 500 mg L -1 ), and temperature (303, 313, 323 and 333 K) on adsorption. The concentration of dye was determined by spectrophotometer. The results showed that as the amount of the adsorbent was increased, the percentage of dye removal increased accordingly; higher adsorption percentage was observed at lower concentration of chrysoidine. The adsorption data were analyzed using Langmuir and Freundlich isotherms. The adsorption was found to obey pseudo-first order kinetics. An intra particle diffusion model was used to fit the experimental data. The thermodynamic parameters such as standard change in free energy, enthalpy and entropy of adsorption have been calculated. Adsorption of Chrysoidine R on fly ash was found to be an exothermic reaction

On-the-Fly Control of High-Harmonic Generation Using a Structured Pump Beam

Science.gov (United States)

Hareli, Liran; Lobachinsky, Lilya; Shoulga, Georgiy; Eliezer, Yaniv; Michaeli, Linor; Bahabad, Alon

2018-05-01

We demonstrate experimentally a relatively simple yet powerful all-optical enhancement and control technique for high harmonic generation. This is achieved by using as a pump beam two different spatial optical modes interfering together to realize tunable periodic quasi-phase matching of the interaction. With this technique, we demonstrate on-the-fly quasi-phase matching of harmonic orders 29-41 at ambient gas pressure levels of 50 and 100 Torr, where an up to 100-fold enhancement of the emission is observed. The technique is scalable to different harmonic orders and ambient pressure conditions.

Are flying wildlife attracted to (or do they avoid) wind turbines?

Energy Technology Data Exchange (ETDEWEB)

Larkin, Ronald [Univ. of Illinois, Urbana, IL (United States). Board of Trustees

2010-03-31

A DOE-sponsored research project found strong evidence that flying wildlife avoid or are attracted to commercial-scale wind turbines from a distance. Some nocturnally migrating birds avoid flying near turbines and few or none change flight paths to approach them. High-flying bats less often avoid flying near turbines and some are attracted to them from a distance, although bats’ flight paths were often complex and convoluted. The findings are being prepared for submission to a peer-reviewed scientific journal (Larkin, in prep 2013).

Importance of Campylobacter jejuni FliS and FliW in Flagella Biogenesis and Flagellin Secretion

Directory of Open Access Journals (Sweden)

Katarzyna A. Radomska

2017-06-01

Full Text Available Flagella-driven motility enables bacteria to reach their favorable niche within the host. The human foodborne pathogen Campylobacter jejuni produces two heavily glycosylated structural flagellins (FlaA and FlaB that form the flagellar filament. It also encodes the non-structural FlaC flagellin which is secreted through the flagellum and has been implicated in host cell invasion. The mechanisms that regulate C. jejuni flagellin biogenesis and guide the proteins to the export apparatus are different from those in most other enteropathogens and are not fully understood. This work demonstrates the importance of the putative flagellar protein FliS in C. jejuni flagella assembly. A constructed fliS knockout strain was non-motile, displayed reduced levels of FlaA/B and FlaC flagellin, and carried severely truncated flagella. Pull-down and Far Western blot assays showed direct interaction of FliS with all three C. jejuni flagellins (FlaA, FlaB, and FlaC. This is in contrast to, the sensor and regulator of intracellular flagellin levels, FliW, which bound to FlaA and FlaB but not to FlaC. The FliS protein but not FliW preferred binding to glycosylated C. jejuni flagellins rather than to their non-glycosylated recombinant counterparts. Mapping of the binding region of FliS and FliW using a set of flagellin fragments showed that the C-terminal subdomain of the flagellin was required for FliS binding, whereas the N-terminal subdomain was essential for FliW binding. The separate binding subdomains required for FliS and FliW, the different substrate specificity, and the differential preference for binding of glycosylated flagellins ensure optimal processing and assembly of the C. jejuni flagellins.

Mass rearing methods for fruit fly

International Nuclear Information System (INIS)

Dominguez Gordillo, J.C.

1999-01-01

The most common rearing methods used for mass rearing of fruit flies, with emphasis on those of economic importance in Mexico such as Anastrepha ludens (the Mexican fruit fly). Anastrepha obliqua (the mango and plum fruit fly) and the exotic fruit fly Ceratitis capitata (the Mediterranean fruit fly) are described here. (author)

Comparative leaching of six toxic metals from raw and chemically stabilized MSWI fly ash using citric acid.

Science.gov (United States)

Wang, Huawei; Fan, Xinxiu; Wang, Ya-Nan; Li, Weihua; Sun, Yingjie; Zhan, Meili; Wu, Guizhi

2018-02-15

The leaching behavior of six typical toxic metals (Pb, Zn, Cr, Cd, Cu and Ni) from raw and chemically stabilized (phosphate and chelating agent) municipal solid waste incineration (MSWI) fly ash were investigated using citric acid. Leaching tests indicated that phosphate stabilization can effectively decrease the leaching of Zn, Cd and Cr; whereas chelating agent stabilization shows a strong ability to lower the release of Pb, Cd and Cu, but instead increases the solubility of Zn and Cr at low pH conditions. Sequential extraction results suggested that the leaching of Pb, Zn and Cd in both the stabilized MSWI fly ash samples led to the decrease in Fe/Mn oxide fraction and the increase in exchangeable and carbonate fractions. The leaching of Cr was due to the decrease in exchangeable, carbonate and Fe/Mn oxide fractions in phosphate-stabilized and chelating agent-stabilized MSWI fly ash. The leaching of Cu in both stabilized MSWI fly ash was greatly ascribed to the decrease in Fe/Mn oxide and oxidisable fractions. Moreover, predicted curves by geochemical model indicated that both stabilized MSWI fly ash have the risk of releasing toxic metals under strong acid environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Susceptibility of low-chill blueberry cultivars to oriental fruit fly, mediterranean fruit fly, and melon fly (Diptera: Tephritidae)

Science.gov (United States)

Forced infestation studies were conducted to determine if fruits of southern highbush blueberries (Vaccinium corymbosum L. hybrids) are hosts for three invasive tephritid fruit flies. Fruits of 17 blueberry cultivars were exposed to gravid female flies of Bactrocera dorsalis (Hendel) (oriental frui...

THE EFFECT OF SINGLE AND HYBRID FIBRES ON FIBRE REINFORCED SELF COMPACTING CONCRETE PRODUCED WITH HIGH LEVEL OF FLY ASH USAGE

OpenAIRE

BOZKURT, Nusret; YAZICIOĞLU, Salih; GÖNEN, Tahir

2013-01-01

The aim of this paper is to present results of investigation carried out on fresh and mechanical properties of Fibre Reinforced Self Compacting Concrete (FRSCC) produced with fly ash which is an industrial waste material. Concrete industry is an important one between the industry branches for sustainability. In this study, high level of fly ash was used to reduce Portland Cement (PC) consumption as well as CO2 emission through the use of that waste material. For this purpose, a control Self C...

The study on the pH behavior of the HFSC leached solution. The development of model considering the pozzolanic reaction

International Nuclear Information System (INIS)

Yoshida, Yasushi; Mihara, Morihiro

2005-09-01

The development of low alkalinity cement (high fly-ash contained silica-fume cement, HFSC) has been carried out in JNC. Low alkalinity for this cement is achieved by adding pozzolan materials to ordinary portland cement and Ca ion attributed to high alkalinity is consumed by forming CHS gel. This report shows the calculation model to predict the composition for HFSC reacted solution which considers cement mineral dissolution/precipitation as equilibrium reactions and dissolution for pozzolan material as a kinetic reaction. The dissolution kinetic equation for pozzolan material is also derived from leaching experiment. This calculation model is applied to the leaching experiment where powdered HFSC was reacted with distilled water. As a result of comparison between calculation and experimental measurement at the early stage for leaching the tendency for pH, pH decrease from 12.5 to 11.5 drastically, could be interpreted by this calculation model, however, after this drastic pH decreasing pH predicted by calculation model also shows drastic decrease whereas pH for experiment decreased mildly around pH 11.5. It could be thought that this difference between experiment and calculation is caused by inappropriate modelling for CSH gel dissolution/precipitation of C/S value lower than 1.0. For this C/S range thermodynamic data for intermediate and end member for solid solution for CSH gel and in addition the reaction kinetic for CSH gel should be examined in detail. (author)

Feeding and rearing behaviour in tsetse flies

International Nuclear Information System (INIS)

Otieno, L.H.; Youdeowei, Y.

1980-01-01

Batwing membrane was used to study salivation and feeding behaviour of tsetse flies. Probing and salivation were observed to be stimulated by tarsal contact with the membrane. Salivation and feeding responses varied from day to day with characteristic alternating high and low responses. The feeding process was invariably accompanied by a resting period. Attempts to rear G. morsitans artificially through the use of batwing membrane showed that the flies needed an initial adjustment period to in vitro maintenance. (author)

U.S. Geological Survey flies high for now

Science.gov (United States)

Clinton is asking Congress to keep the U.S. Geological Survey (USGS) alive and well in FY 1996. With a proposed 2.6% increase to $586 million, the Clinton request flies in the face of the Republican Contract with America that calls for abolishing the survey.Indeed, Clinton has made it clear that the onus will be on Congress if it wants to make major cuts at USGS. As Secretary of the Interior Bruce Babbitt puts it: “Good science is essential to good management.”

High rate sulfate reduction at pH 6 in a Ph-auxostat submerged membrane bioreactor fed with formate

NARCIS (Netherlands)

Bijmans, M.F.M.; Peeters, T.W.T.; Lens, P.N.L.; Buisman, C.J.N.

2008-01-01

Many industrial waste and process waters contain high concentrations of sulfate, which can be removed by sulfate-reducing bacteria (SRB). This paper reports on mesophilic (30 °C) sulfate reduction at pH 6 with formate as electron donor in a membrane bioreactor with a pH-auxostat dosing system. A

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

African Journals Online (AJOL)

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Casting, as a liquid phase process, is capable of producing products with ... materials, including stiffness, strength and wear resistance and reduce the density. .... been destroyed; and in this 10h milling stage the fly ash is in cold welding ..... 2004, Nanostructures and Nano materials- Synthesis, properties and Applications, ...

A study on the practicability of highly containing fly ash and silica fume cement

International Nuclear Information System (INIS)

Owada, Hitoshi; Mihara, Morihiro; Iriya, Keishiro; Matsui, Jun

2000-01-01

Cementitious materials have been planed to be used for the geological disposal of high-level radioactive waste and TRU waste. Degrading of host rock and buffer material induced by high pH leachate, however, is pointed out as one of technical issues. The authors have been developing a low alkalinity cement (the pH of the leachate of this cement is about 11) as an enhanced material to reduce the effect of the high pH problem. In this study, the applicability of low alkalinity cement developed to solve this problem was evaluated. The fluidity of the mortar was sufficient to fill the aperture in a structure filled with coarse aggregate. The concrete using the low alkalinity cement was also enough to fill a structure with the reinforcing steel. The compressive strength of a test-piece produced by the JIS method and of a core collected from the trial structure were over 60 MPa. These evaluation results show that developed low alkalinity cement had higher performances in mechanical properties and execution characteristics than JIS ordinary Portland cement. (author)

Mechanical Properties of High Volume Fly Ash Concrete Reinforced with Hybrid Fibers

Directory of Open Access Journals (Sweden)

Rooban Chakravarthy

2016-01-01

Full Text Available Fly ash substitution to cement is a well-recognized approach to reduce CO2 emissions. Although fly ash concrete is prone to brittle behavior, researchers have shown that addition of fibers could reduce brittle behavior. Previous research efforts seem to have utlised a single type of fiber or two types of fibers. In this research, three types of fibers, steel, polypropylene, and basalt as 0%, 0.50%, 0.75%, and 1% by volume of concrete, were mixed in varying proportions with concrete specimens substituted with 50% fly ash (class F. All specimens were tested for compressive strength, indirect tensile strength, and flexural strength over a period of 3 to 56 days of curing. Test results showed that significant improvement in mechanical properties could be obtained by a particular hybrid fiber reinforcement combination (1% steel fiber, 0.75% polypropylene fiber, and 0.75% basalt fiber. The strength values were observed to exceed previous research results. Workability of concrete was affected when the fiber combination exceeded 3%. Thus a limiting value for adding fibers and the combination to achieve maximum strengths have been identified in this research.

Enhanced electrochemomechanical activity of polyaniline films towards high pH region: contribution of Donnan effect

International Nuclear Information System (INIS)

Takashima, Wataru; Nakashima, Megumi; Pandey, Shyam S.; Kaneto, Keiichi

2004-01-01

Enhancement of electrochemomechanical deformation (ECMD) and expansion of ECMD activity towards high pH have been simultaneously achieved in the electrolytes equilibrated with HCl and NaCl solutions for polyaniline (PANI) film. The maximum deformation has been reached to 6.7% in the mixture of 3 M HCl and 3 M NaCl equilibrated at pH 3 at ambient temperature. By comparing the fact that the ECMD magnitude is 3.2% in 1 M HCl equilibrated at pH 0.5, the simple judicious selection of electrolyte condition leads to the enhancement of ECMD magnitude by around two times. The concentration dependence on both electrical conductivity and absorption spectra elucidates the increase of protonation ratio as a function of electrolyte concentration. The results indicate that the high concentration retains both the electrochemical and ECMD activities in PANI film towards high pH region, which is the enhanced functionality of PANI supported by Donnan effect

pH dependent green synthesis of gold nanoparticles by completely C6-carboxylated curdlan under high temperature and various pH conditions.

Science.gov (United States)

Qiu, Wen-Yi; Wang, Kai; Wang, Yao-Yao; Ding, Zhi-Chao; Wu, Li-Xia; Cai, Wu-Dan; Yan, Jing-Kun

2018-01-01

A C6-carboxylated curdlan (C6-Cc) obtained from 4-acetamido-TEMPO-mediated oxidation of curdlan was used both as a reducing and stabilizing agent for green synthesis of pH-responsive AuNPs, which was carried out by controlling the pH of the C6-Cc solution at a high temperature (100°C). C6-Cc presented a semi-flexible random coil chain in the aqueous medium at pH 5.5 and became more expanded and rigid in alkaline conditions (pH 7.1-12.0), though the primary chemical structure of C6-Cc was virtually unchanged with the pH variation. The AuNPs prepared with C6-Cc at various pHs were characterized by various instrumental measurements. The shapes and sizes of AuNPs were found to be strongly dependent on the pH of the C6-Cc solution. The C6-Cc-decorated AuNPs exhibited a more well-dispersed spherical morphology with smaller particle sizes under alkaline conditions (pH 7.1-12.0). Through this study, a facile, simple, and green method has been demonstrated for preparation of stimuli-sensitive AuNPs using biocompatible polyanionic polysaccharides. Copyright © 2017 Elsevier B.V. All rights reserved.

The sensitivity of particle pH to NH3: Can high NH3 cause London Fog conditions?

Science.gov (United States)

Weber, R. J.; Guo, H.; Nenes, A.

2017-12-01

High ammonia emissions from agriculture or other sources have been suggested to elevate ambient particle pH levels to near neutral acidity (pH=7), a condition that promotes rapid SO2 oxidation by NO2 to form aerosol sulfate concentration consistent with "London fog" levels. This mechanism has been used to explain pollution haze events in China. Predicted pH for locations in the US and Europe show fine particles are highly acidic with pH typically less than 2. The results are consistent with measured ammonia and nitric acid gas-particle partitioning, validating predicted pH levels. Using these data sets from representative sites around the world we conduct a thermodynamic analysis of aerosol pH and its sensitivity to ammonia levels. We find that particle pH, regardless of ammonia levels, is always acidic even for the unusually high ammonia levels found in highly polluted Asian cities, Beijing (pH=4.5) and Xi'an (pH=5), locations where sulfate production from NOx is proposed. These results indicate that sulfur dioxide oxidation through a NO2-mediated pathway is not likely in China, nor any other region of the world (e.g., US, Mediterranean) since the fine aerosol is consistently acidic. The mildly acidic conditions would, however, permit rapid oxidation of sulfur dioxide through transition metal chemistry. The limited alkalinity from the carbonate buffer in dust and seasalt can provide the only likely set of conditions where NO2-mediated oxidation of SO2 outcompetes with other well-established pathways.

Arsenic and mercury partitioning in fly ash at a Kentucky power plant

Energy Technology Data Exchange (ETDEWEB)

Tanaporn Sakulpitakphon; James C. Hower; Alan S. Trimble; William H. Schram; Gerald A. Thomas [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

2003-08-01

Coal and fly ash samples were collected from a 500-MW unit at a Kentucky power plant, with the objective of studying the distribution of arsenic, mercury, and other trace elements in fly ash. The coal feed was low-sulfur, high volatile A bituminous central West Virginia coal. The plant produced a relatively low-carbon fly ash. In contrast to power plants with high-mercury feed coal, the fly ashes from the lower-mercury feed coal had low mercury values, generally not exceeding 0.01 ppm Hg. Mercury capture by fly ash varies with both the amount and type of carbon and the collection temperature; mercury capture is more efficient at lower temperatures. Arsenic in the feed coal and in the flue gas is of concern to the utility, because of the potential for catalyst poisoning in the selective catalytic reduction system (in the planning stage at the time of the sampling). Arsenic is captured in the fly ash, increasing in concentration in the more-distant (from the boiler) reaches of the electrostatic precipitator system. 16 refs., 2 figs., 5 tabs.

High pH ammonia toxicity, and the search for life on the Jovian planets.

Science.gov (United States)

Deal, P H; Souza, K A; Mack, H M

1975-10-01

Jovian plants have enviroments apparently suitable for the evolution of life, but nevertheless, present severe challenges to organisms. One such challenge arises from the presence of ammonia. Ammonia is an efficient biocide, its effect being dependent on pH as well as on concentration. The effects of pH and ammonia concentration were studied separately, where possible, on a variety of organisms, including some isolated from natural enviornments of high pH and/or ammonia concentration. Escherichia coli and Bacillus subtilis are both extremely sensitive to ammonia. An aerobic organism (growth up to pH 11.4) from an alkaline spring is more resistant, but exhibits a toxic response to ammonia at a pH much lower than its maximum for growth. The greatest ammonia resistance has been found in an unidentified organism growing at near neutral pH. Even in this case, however, survival at ammonia concentrations reasonably expected on the Jovian planets is measured in hours. This is, nevertheless, two to three orders of magnitude longer than for E. coli. Our data support the tentative conclusion that contamination of the Jovian planets with terrestrial organisms that can grow is unlikely. However, the range of toxic response noted, coupled with the observation that terrestrial life has not been exposed to high ammonia concentrations for millions of years, suggests that adaptation to greater ammonia tolerance may be possible.

Activity of Proteus mirabilis FliL is viscosity dependent and requires extragenic DNA.

Science.gov (United States)

Lee, Yi-Ying; Patellis, Julius; Belas, Robert

2013-02-01

Proteus mirabilis is a urinary tract pathogen and well known for its ability to move over agar surfaces by flagellum-dependent swarming motility. When P. mirabilis encounters a highly viscous environment, e.g., an agar surface, it differentiates from short rods with few flagella to elongated, highly flagellated cells that lack septa and contain multiple nucleoids. The bacteria detect a surface by monitoring the rotation of their flagellar motors. This process involves an enigmatic flagellar protein called FliL, the first gene in an operon (fliLMNOPQR) that encodes proteins of the flagellar rotor switch complex and flagellar export apparatus. We used a fliL knockout mutant to gain further insight into the function of FliL. Loss of FliL results in cells that cannot swarm (Swr(-)) but do swim (Swm(+)) and produces cells that look like wild-type swarmer cells, termed "pseudoswarmer cells," that are elongated, contain multiple nucleoids, and lack septa. Unlike swarmer cells, pseudoswarmer cells are not hyperflagellated due to reduced expression of flaA (the gene encoding flagellin), despite an increased transcription of both flhD and fliA, two positive regulators of flagellar gene expression. We found that defects in fliL prevent viscosity-dependent sensing of a surface and viscosity-dependent induction of flaA transcription. Studies with fliL cells unexpectedly revealed that the fliL promoter, fliL coding region, and a portion of fliM DNA are needed to complement the Swr(-) phenotype. The data support a dual role for FliL as a critical link in sensing a surface and in the maintenance of flagellar rod integrity.

Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report C : shear behavior of HVFA reinforced concrete.

Science.gov (United States)

2012-10-01

Concrete is the most widely used man-made material on the planet. Unfortunately, producing Portland cement generates carbon dioxide (a greenhouse gas) at roughly a pound for pound ratio. High-volume fly ash (HVFA) concrete concrete with at least ...

The potential of four woody species for the revegetation of fly ash deposits from the ‘Nikola Tesla-a’ thermoelectric plant (Obrenovac, Serbia

Directory of Open Access Journals (Sweden)

Kostić Olga

2012-01-01

Full Text Available Four woody species, Tamarix tentandra Pallas, Populus alba L. and Robinia pseudoacacia L. (planted and Amorpha fruticosa L. (naturally colonized were studied at two fly ash deposit lagoons, weathered 3 (L1 and 11 years (L2. All species were assessed in terms of their invasive ability, photosynthetic efficiency, photosynthetic pigments and damage symptoms, while the characteristics of the habitat were assessed in terms of trace element content and the pH and EC of the ash. A reduced vitality of all populations growing on the ash was observed, except for the naturally colonized A. fruticosa. High vitality on all sites, except at L2, increased chlorophyll content and absence of damage symptoms indicates a tolerance in relation to the uptake of toxic elements from the ash. Therefore, the characteristics of naturally colonized species can be used for modeling future actions of biological restoration of fly ash deposits.

Ph3CCOOSnPh3.Ph3PO AND Ph3CCOOSnPh3.Ph3AsO: SYNTHESIS AND INFRARED STUDY

Directory of Open Access Journals (Sweden)

ABDOU MBAYE

2014-08-01

Full Text Available The mixture of ethanolic solutions of Ph3CCOOSnPh3 and Ph3PO or Ph3AsO gives Ph3CCOOSnPh3.Ph3PO and Ph3CCOOSnPh3.Ph3AsO adducts which have been characterized by infrared spectroscopy. A discrete structure is suggested for both, the environment around the tin centre being trigonal bipyramidal, the triphenylacetate anion behaving as a mondentate ligand.

Intragastric pH and pressure profiles after intake of the high-caloric, high-fat meal as used for food effect studies.

Science.gov (United States)

Koziolek, M; Schneider, F; Grimm, M; Modeβ, Chr; Seekamp, A; Roustom, T; Siegmund, W; Weitschies, W

2015-12-28

The intraluminal conditions of the fed stomach are critical for drug release from solid oral dosage forms and thus, often associated with the occurrence of food effects on oral bioavailability. In this study, intragastric pH and pressure profiles present after the ingestion of the high-caloric, high-fat (964 kcal) FDA standard breakfast were investigated in 19 healthy human subjects by using the telemetric SmartPill® capsule system (26 × 13 mm). Since the gastric emptying of such large non-digestible objects is typically accomplished by the migrating motor complex phase III activity, the time required for recurrence of fasted state motility determined the gastric emptying time (GET). Following the diet recommendations of the FDA guidance on food effect studies, the mean GET of the telemetric motility capsule was 15.3 ± 4.7 h. Thus, the high caloric value of the standard breakfast impeded gastric emptying before lunch in 18 out of 19 subjects. During its gastric transit, the capsule was exposed to highly dynamic conditions in terms of pH and pressure, which were mainly dependent on further meal and liquid intake, as well as the intragastric capsule deposition behavior. Maximum pH values in the stomach were measured immediately after capsule intake. The median pH value of the 5 min period after capsule ingestion ranged between pH 3.3 and 5.3. Subsequently, the pH decreased relatively constantly and reached minimum values of pH 0-1 after approximately 4 h. The maximum pressure within the stomach amounted to 293 ± 109 mbar and was clearly higher than the maximum pressure measured at the ileocaecal junction (60 ± 35 mbar). The physiological data on the intraluminal conditions within the fed stomach generated in this study will hopefully contribute to a better understanding of food effects on oral drug product performance.

Functionalized magnetic mesoporous silica nanoparticles for U removal from low and high pH groundwater

Energy Technology Data Exchange (ETDEWEB)

Li, Dien, E-mail: dien.li@srs.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Egodawatte, Shani [Department of Chemistry, University of Iowa, Iowa City, IA 52242 (United States); Kaplan, Daniel I. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Larsen, Sarah C. [Department of Chemistry, University of Iowa, Iowa City, IA 52242 (United States); Serkiz, Steven M. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Seaman, John C. [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States)

2016-11-05

Highlights: • Magnetic mesoporous silica nanoparticles were functionalized with organic molecules. • The functionalized nanoparticles had high surface areas and consistent pore sizes. • The functionalized nanoparticles were easily separated due to their magnetism. • They exhibited high capacity for uranium removal from low- or high-pH groundwater. - Abstract: U(VI) species display limited adsorption onto sediment minerals and synthetic sorbents in pH <4 or pH >8 groundwater. In this work, magnetic mesoporous silica nanoparticles (MMSNs) with magnetite nanoparticle cores were functionalized with various organic molecules using post-synthetic methods. The functionalized MMSNs were characterized using N{sub 2} adsorption-desorption isotherms, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), {sup 13}C cross polarization and magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy, and powder X-ray diffraction (XRD), which indicated that mesoporous silica (MCM-41) particles of 100–200 nm formed around a core of magnetic iron oxide, and the functional groups were primarily grafted into the mesopores of ∼3.0 nm in size. The functionalized MMSNs were effective for U removal from pH 3.5 and 9.6 artificial groundwater (AGW). Functionalized MMSNs removed U from the pH 3.5 AGW by as much as 6 orders of magnitude more than unfunctionalized nanoparticles or silica and had adsorption capacities as high as 38 mg/g. They removed U from the pH 9.6 AGW as much as 4 orders of magnitude greater than silica and 2 orders of magnitude greater than the unfunctionalized nanoparticles with adsorption capacities as high as 133 mg/g. These results provide an applied solution for treating U contamination that occurs at extreme pH environments and a scientific foundation for solving critical industrial issues related to environmental stewardship and nuclear power production.

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

OpenAIRE

J.N Akhtar; J.Alam; 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...

Flying Qualities (Qualites de Vol)

Science.gov (United States)

1991-02-01

CIIANAIT DUMINIIG MA𔃼I1 FXCURSIOH /~o --- ~A 0- /10 CMFIGURE 4 AL-PHA-JETr ELEVATOR CONTROL CINEMATIC ; LP HEINi" KINEMATIC HORIZONTAL STABILIZER...ih-flight simulation is the ultimale assessment techntque providing high realism , flexibility, and credibility. rhe utilization (,f an in-fli:,ht si...1london, UK ()PERATIONAL H-ELICOPTER IIN - FLIGHT SIMULATOR (HIGH REALISM ) I(HIGH FLEAiBILITY Fligt t A tehrtqueTechnology implementation Flight t

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.

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique.

Science.gov (United States)

Khan, Md Rajibur Rahaman; Kang, Shin-Won

2016-11-09

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal's pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R² is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry-Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors.

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

Science.gov (United States)

Khan, Md. Rajibur Rahaman; Kang, Shin-Won

2016-01-01

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal’s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R2 is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry–Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors. PMID:27834865

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.

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.

A study on the effect of nano silica on compressive strength of high volume fly ash mortars and concretes

International Nuclear Information System (INIS)

Shaikh, F.U.A.; Supit, S.W.M.; Sarker, P.K.

2014-01-01

Highlights: • The addition of NS compensates low early age compressive strength of HVFA system. • NS also contributes to later age compressive strength gain of HVFA system. • The XRD results confirm the reduction of CH in HVFA paste due to addition of NS. - Abstract: This paper presents the effect of nano silica (NS) on the compressive strength of mortars and concretes containing different high volume fly ash (HVFA) contents ranging from 40% to 70% (by weight) as partial replacement of cement. The compressive strength of mortars is measured at 7 and 28 days and that for concretes is measured at 3, 7, 28, 56 and 90 days. The effects of NS in microstructure development and pozzolanic reaction of pastes containing above HVFA contents are also studied through backscattered electron (BSE) image and X-ray diffraction (XRD) analysis. Results show that among different NS contents ranging from 1% to 6%, cement mortar containing 2% NS exhibited highest 7 and 28 days compressive strength. This NS content (2%) is then added to the HVFA mortars and concretes and the results show that the addition of 2% NS improved the early age (7 days) compressive strength of mortars containing 40% and 50% fly ash by 5% and 7%, respectively. However, this improvement is not observed at high fly ash contents beyond 50%. On the other hand, all HVFA mortars exhibited improvement in 28 days compressive strength due to addition of 2% NS and the most significant improvement is noticed in mortars containing more than 50% fly ash. In HVFA concretes, the improvement of early age (3 days) compressive strength is also noticed due to addition of 2% NS. The BSE and XRD analysis results also support the above findings

A role for flies (Diptera) in the transmission of Campylobacter to broilers?

DEFF Research Database (Denmark)

Royden, A.; Wedley, A.; Merga, J. Y.

2016-01-01

·22% [2/902, 95% confidence interval (CI) 0–0·53] were positive by culture for Campylobacter spp. Additionally, 1293 flies were grouped by family and cultured in 127 batches: 4/127 (3·15%, 95% CI 0·11-6·19) from three broiler farms were positive for Campylobacter. Multilocus sequence typing of isolates...... flies are proven carriers of Campylobacter and their ingress into broiler houses may contribute to its transmission to broiler chickens. However, this has not been investigated in the UK. Campylobacter was cultured from 2195 flies collected from four UK broiler farms. Of flies cultured individually, 0......, despite the low prevalence of Campylobacter cultured from flies, the risk of transmission by this route may be high, particularly during summer when fly populations are greatest....

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.

An examination of endoparasites and fecal testosterone levels in flying squirrels (Glaucomys spp.) using high performance liquid chromatography-ultra-violet (HPLC-UV).

Science.gov (United States)

Waksmonski, Sarah N; Huffman, Justin M; Mahan, Carolyn G; Steele, Michael A

2017-08-01

The immuno-competence hypothesis proposes that higher levels of testosterone increases the susceptibility to parasitism. Here we examined the testosterone levels in two species of flying squirrels ( Glaucomys ): one known to regularly host a nematode species ( Strongyloides robustus ) without ill effects ( G. volans ) and a closely related species that is considered negatively affected by the parasite. We quantified fecal testosterone levels in northern and southern flying squirrels ( G. sabrinus, G. volans ) with high-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV), and compared levels to endoparasites detected in individual squirrels. Qualitatively, we found highest levels of testosterone in male northern flying squirrels infected with Strongyloides robustus . This analytical approach represents an alternative and equally reliable method to using enzyme-linked immunosorbent assay (ELISA), for detecting and quantifying fecal testosterone levels.

An examination of endoparasites and fecal testosterone levels in flying squirrels (Glaucomys spp. using high performance liquid chromatography-ultra-violet (HPLC-UV

Directory of Open Access Journals (Sweden)

Sarah N. Waksmonski

2017-08-01

Full Text Available The immuno-competence hypothesis proposes that higher levels of testosterone increases the susceptibility to parasitism. Here we examined the testosterone levels in two species of flying squirrels (Glaucomys: one known to regularly host a nematode species (Strongyloides robustus without ill effects (G. volans and a closely related species that is considered negatively affected by the parasite. We quantified fecal testosterone levels in northern and southern flying squirrels (G. sabrinus, G. volans with high-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV, and compared levels to endoparasites detected in individual squirrels. Qualitatively, we found highest levels of testosterone in male northern flying squirrels infected with Strongyloides robustus. This analytical approach represents an alternative and equally reliable method to using enzyme-linked immunosorbent assay (ELISA, for detecting and quantifying fecal testosterone levels.

High sensitivity pH sensing on the BEOL of industrial FDSOI transistors

Science.gov (United States)

Rahhal, Lama; Ayele, Getenet Tesega; Monfray, Stéphane; Cloarec, Jean-Pierre; Fornacciari, Benjamin; Pardoux, Eric; Chevalier, Celine; Ecoffey, Serge; Drouin, Dominique; Morin, Pierre; Garnier, Philippe; Boeuf, Frederic; Souifi, Abdelkader

2017-08-01

In this work we demonstrate the use of Fully Depleted Silicon On Insulator (FDSOI) transistors as pH sensors with a 23 nm silicon nitride sensing layer built in the Back-End-Of-Line (BEOL). The back end process to deposit the sensing layer and fabricate the electrical structures needed for testing is detailed. A series of tests employing different pH buffer solutions has been performed on transistors of different geometries, controlled via the back gate. The main findings show a shift of the drain current (ID) as a function of the back gate voltage (VB) when different pH buffer solutions are probed in the range of pH 6 to pH 8. This shift is observed at VB voltages swept from 0 V to 3 V, demonstrating the sensor operation at low voltage. A high sensitivity of up to 250 mV/pH unit (more than 4-fold larger than Nernstian response) is observed on FDSOI MOS transistors of 0.06 μm gate length and 0.08 μm gate width. She is currently working as a Postdoctoral researcher at Institut des nanotechnologies de Lyon in collaboration with STMicroelectronics and Université de Sherbrook (Canada) working on ;Integration of ultra-low-power gas and pH sensors with advanced technologies;. Her research interest includes selection, machining, optimisation and electrical characterisation of the sensitive layer for a low power consumption gas sensor based on advanced MOS transistors.

Two-Step Method for Preparation of NaA-X Zeolite Blend from Fly Ash for Removal of Cesium ions

International Nuclear Information System (INIS)

El-Naggar, M.R.; El-Kamash, A.M.; El-Dessouky, M.I.; Ghonaim, A.K.

2008-01-01

Pure zeolites can be synthesized from silica extracts obtained from fly ash by alkaline leaching. The extraction potential of industrial by-product fly ash was investigated under repeated fusion process conditions. The amount of extracted silica was 131.43 g/kg ash while the amount extracted alumina was limited to 41.72 g/kg ash. The results of zeolite synthesis from the Si-bearing extracts demonstrated that pure zeolites with high cation exchange capacity (4.624 m eq/g) can be produced. The sorption potential of synthesized A-X zeolite blend for the removal of cesium ions has been investigated. The influences of ph, contact time and temperature have been reported. Thermodynamic parameters such as changes in Gibbs free energy (δG degree), enthalpy (δH degree) and entropy (δS degree) were calculated. A comparison of kinetic models applied to the sorption data was evaluated for pseudo-first order, pseudo-second order and homogeneous particle diffusion models. The results showed that both the pseudo-second order and the homogeneous particle diffusion models were found to best correlate the experimental rate data

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.

Fate of pharmaceuticals and pesticides in fly larvae composting

Energy Technology Data Exchange (ETDEWEB)

Lalander, C., E-mail: cecilia.lalander@slu.se [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Senecal, J.; Gros Calvo, M. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Ahrens, L.; Josefsson, S.; Wiberg, K. [Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (Sweden); Vinnerås, B. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden)

2016-09-15

A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (< 10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. - Highlights: • Degradation of pharmaceuticals and pesticides in fly larvae composting (FLC). • Half-life considerably shorter in FLC than in control with no larvae. • Half-life of carbamazepine was less than two days in FLC. • No bioaccumulation in larvae detected. • FLC could impede the spreading of pharmaceuticals and pesticide in the environment.

Fate of pharmaceuticals and pesticides in fly larvae composting

International Nuclear Information System (INIS)

Lalander, C.; Senecal, J.; Gros Calvo, M.; Ahrens, L.; Josefsson, S.; Wiberg, K.; Vinnerås, B.

2016-01-01

A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (< 10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. - Highlights: • Degradation of pharmaceuticals and pesticides in fly larvae composting (FLC). • Half-life considerably shorter in FLC than in control with no larvae. • Half-life of carbamazepine was less than two days in FLC. • No bioaccumulation in larvae detected. • FLC could impede the spreading of pharmaceuticals and pesticide in the environment.

Plant nutrition on fly-ash

Energy Technology Data Exchange (ETDEWEB)

Rees, W J; Sidrak, G H

1956-12-01

Experiments were performed to determine the plant nutritional potential of fly ash. Chemical analysis indicates that it contains all the essential nutrients. It is deficient in nitrogen and only manganese and aluminum appear to be available in quantities toxic to plants. Barley and spinach grown on fly ash accumulate excessive quantities of Al and Mn in their leaves and exhibit symptoms of toxicities of these metals. Atriplex hastata grows vigorously on the ash, has a high Al and Mn leaf content, but does not show toxicity symptoms. Atriplex, barley and spinach grown at reduced N levels gave lower yields than the normal controls, but symptoms of N deficiency which were evident in barley and spinach were not observed in Atriplex. 17 references, 2 figures, 14 tables.

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.

Competitiveness of irradiated methyl eugenol fed oriental fruit fly, Bactrocera philippinensis

International Nuclear Information System (INIS)

Resilva, Sotero; Obra, Glenda B.

2001-01-01

The effectiveness of methyl eugenol feeding in the sexual competitiveness of oriental fruit fly, Bactrocera philippinensis was studied. Addition of methyl eugenol concentration up to 0.5 ml per liter diet revealed no significant difference base on different quality control parameters used in the study. Results of mating tests showed high number of mated pairs were collected on flies fed with methyl eugenol both on the larvae and adult stage as compared with the untreated flies. Although no significant difference was observed between the larval and adult methyl eugenol-fed flies, the number of mated pairs slightly increased in the former than the latter in all mating tests conducted. (Author)

[Study on mercury re-emissions during fly ash utilization].

Science.gov (United States)

Meng, Yang; Wang, Shu-Xiao

2012-09-01

The amount of fly ash produced during coal combustion is around 400 million tons per year in China. About 65%-68% of fly ash is used in building material production, road construction, architecture and agriculture. Some of these utilization processes include high temperature procedures, which may lead to mercury re-emissions. In this study, experiments were designed to simulate the key process in cement production and steam-cured brick production. A temperature programmed desorption (TPD) method was used to study the mercury transformation in the major utilization processes. Mercury re-emission during the fly ash utilization in China was estimated based on the experimental results. It was found that mercury existed as HgCl2 (Hg2 Cl2), HgS and HgO in the fly ash. During the cement production process, more than 98% of the mercury in fly ash was re-emitted. In the steam-curing brick manufacturing process, the average mercury re-emission percentage was about 28%, which was dominated by the percentage of HgCl2 (Hg2 Cl2). It is estimated that the mercury re-emission during the fly ash utilization have increased from 4.07 t in 2002 to 9.18 t in 2008, of which cement industry contributes about 96.6%.

Bartonellae are Prevalent and Diverse in Costa Rican Bats and Bat Flies.

Science.gov (United States)

Judson, S D; Frank, H K; Hadly, E A

2015-12-01

Species in the bacterial genus, Bartonella, can cause disease in both humans and animals. Previous reports of Bartonella in bats and ectoparasitic bat flies suggest that bats could serve as mammalian hosts and bat flies as arthropod vectors. We compared the prevalence and genetic similarity of bartonellae in individual Costa Rican bats and their bat flies using molecular and sequencing methods targeting the citrate synthase gene (gltA). Bartonellae were more prevalent in bat flies than in bats, and genetic variants were sometimes, but not always, shared between bats and their bat flies. The detected bartonellae genetic variants were diverse, and some were similar to species known to cause disease in humans and other mammals. The high prevalence and sharing of bartonellae in bat flies and bats support a role for bat flies as a potential vector for Bartonella, while the genetic diversity and similarity to known species suggest that bartonellae could spill over into humans and animals sharing the landscape. © 2015 Blackwell Verlag GmbH.

Noninvasive analysis of microbiome dynamics in the fruit fly Drosophila melanogaster.

Science.gov (United States)

Fink, Christine; Staubach, Fabian; Kuenzel, Sven; Baines, John F; Roeder, Thomas

2013-11-01

The diversity and structure of the intestinal microbial community has a strong influence on life history. To understand how hosts and microbes interact, model organisms with comparatively simple microbial communities, such as the fruit fly (Drosophila melanogaster), offer key advantages. However, studies of the Drosophila microbiome are limited to a single point in time, because flies are typically sacrificed for DNA extraction. In order to test whether noninvasive approaches, such as sampling of fly feces, could be a means to assess fly-associated communities over time on the same cohort of flies, we compared the microbial communities of fly feces, dissected fly intestines, and whole flies across three different Drosophila strains. Bacterial species identified in either whole flies or isolated intestines were reproducibly found in feces samples. Although the bacterial communities of feces and intestinal samples were not identical, they shared similarities and obviously the same origin. In contrast to material from whole flies and intestines, feces samples were not compromised by Wolbachia spp. infections, which are widespread in laboratory and wild strains. In a proof-of-principle experiment, we showed that simple nutritional interventions, such as a high-fat diet or short-term starvation, had drastic and long-lasting effects on the micobiome. Thus, the analysis of feces can supplement the toolbox for microbiome studies in Drosophila, unleashing the full potential of such studies in time course experiments where multiple samples from single populations are obtained during aging, development, or experimental manipulations.

Testing candidate genes for attention-deficit/hyperactivity disorder in fruit flies using a high throughput assay for complex behavior

DEFF Research Database (Denmark)

Rohde, Palle Duun; Madsen, Lisbeth Strøm; Arvidson, Sandra Marie Neumann

2016-01-01

Fruit flies are important model organisms for functional testing of candidate genes in multiple disciplines, including the study of human diseases. Here we use a high-throughput locomotor activity assay to test the response on activity behavior of gene disruption in Drosophila melanogaster. The aim...

The Role of Clay Swelling and Mineral Neoformation in the Stabilization of High Plasticity Soils Treated with the Fly Ash- and Metakaolin-Based Geopolymers

Directory of Open Access Journals (Sweden)

Mahmoud A. Mahrous

2018-04-01

Full Text Available In the southern U.S. states, expansive soils are frequently encountered, presenting an important hazard in geotechnical engineering. This research relies on mineralogical and geochemical clues to explain the swelling behavior of smectite-rich, high-plasticity soils, documented in a series of geomechanical swelling tests that were performed on the soils stabilized with the metakaolin (MKG and fly ash (FAG based geopolymers. These geopolymers were mixed with the soil at several concentration levels. The lowest swelling percentage was shown to correspond to the sample stabilized with 12% FAG and was attributed to the neoformation of calcium silicate hydrates that acted as a cementitious material, preventing the soil from expanding by occupying the pore space, thus binding the clay particles together. Conversely, the 12% MKG-stabilized soil exhibited enormous expansion, which was explained by montmorillonite swelling to the point that it gradually began to lose its structural periodicity. The relatively high abundance of the newly formed feldspathoids in MKG-treated samples is believed to have greatly contributed to the overall soil expansion. Finally, the cation exchange capacity tests showed that the percentage of Na+ and Ca2+, as well as the pH value, exercised strong control on the swelling behavior of smectitic soils.

Spectrophotometric high-precision seawater pH determination for use in underway measuring systems

Directory of Open Access Journals (Sweden)

S. Aßmann

2011-10-01

Full Text Available Autonomous sensors are required for a comprehensive documentation of the changes in the marine carbon system and thus to differentiate between its natural variability and anthropogenic impacts. Spectrophotometric determination of pH – a key variable of the seawater carbon system – is particularly suited to achieve precise and drift-free measurements. However, available spectrophotometric instruments are not suitable for integration into automated measurement systems (e.g. FerryBox since they do not meet the major requirements of reliability, stability, robustness and moderate cost. Here we report on the development and testing of a~new indicator-based pH sensor that meets all of these requirements. This sensor can withstand the rough conditions during long-term deployments on ships of opportunity and is applicable to the open ocean as well as to coastal waters with a complex matrix and highly variable conditions. The sensor uses a high resolution CCD spectrometer as detector connected via optical fibers to a custom-made cuvette designed to reduce the impact of air bubbles. The sample temperature can be precisely adjusted (25 °C ± 0.006 °C using computer-controlled power supplies and Peltier elements thus avoiding the widely used water bath. The overall setup achieves a measurement frequency of 1 min⁻¹ with a precision of ±0.0007 pH units, an average offset of +0.0005 pH units to a reference system, and an offset of +0.0081 pH units to a certified standard buffer. Application of this sensor allows monitoring of seawater pH in autonomous underway systems, providing a key variable for characterization and understanding of the marine carbon system.

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

High Sensitive pH Sensor Based on AlInN/GaN Heterostructure Transistor

Directory of Open Access Journals (Sweden)

Yan Dong

2018-04-01

Full Text Available The AlInN/GaN high-electron-mobility-transistor (HEMT indicates better performances compared with the traditional AlGaN/GaN HEMTs. The present work investigated the pH sensor functionality of an analogous HEMT AlInN/GaN device with an open gate. It was shown that the Al0.83In0.17N/GaN device demonstrates excellent pH sense functionality in aqueous solutions, exhibiting higher sensitivity (−30.83 μA/pH for AlInN/GaN and −4.6 μA/pH for AlGaN/GaN and a faster response time, lower degradation and good stability with respect to the AlGaN/GaN device, which is attributed to higher two-dimensional electron gas (2DEG density and a thinner barrier layer in Al0.83In0.17N/GaN owning to lattice matching. On the other hand, the open gate geometry was found to affect the pH sensitivity obviously. Properly increasing the width and shortening the length of the open gate area could enhance the sensitivity. However, when the open gate width is too larger or too small, the pH sensitivity would be suppressed conversely. Designing an optimal ratio of the width to the length is important for achieving high sensitivity. This work suggests that the AlInN/GaN-based 2DEG carrier modulated devices would be good candidates for high-performance pH sensors and other related applications.

High Sensitive pH Sensor Based on AlInN/GaN Heterostructure Transistor.

Science.gov (United States)

Dong, Yan; Son, Dong-Hyeok; Dai, Quan; Lee, Jun-Hyeok; Won, Chul-Ho; Kim, Jeong-Gil; Chen, Dunjun; Lee, Jung-Hee; Lu, Hai; Zhang, Rong; Zheng, Youdou

2018-04-24

The AlInN/GaN high-electron-mobility-transistor (HEMT) indicates better performances compared with the traditional AlGaN/GaN HEMTs. The present work investigated the pH sensor functionality of an analogous HEMT AlInN/GaN device with an open gate. It was shown that the Al 0.83 In 0.17 N/GaN device demonstrates excellent pH sense functionality in aqueous solutions, exhibiting higher sensitivity (−30.83 μA/pH for AlInN/GaN and −4.6 μA/pH for AlGaN/GaN) and a faster response time, lower degradation and good stability with respect to the AlGaN/GaN device, which is attributed to higher two-dimensional electron gas (2DEG) density and a thinner barrier layer in Al 0.83 In 0.17 N/GaN owning to lattice matching. On the other hand, the open gate geometry was found to affect the pH sensitivity obviously. Properly increasing the width and shortening the length of the open gate area could enhance the sensitivity. However, when the open gate width is too larger or too small, the pH sensitivity would be suppressed conversely. Designing an optimal ratio of the width to the length is important for achieving high sensitivity. This work suggests that the AlInN/GaN-based 2DEG carrier modulated devices would be good candidates for high-performance pH sensors and other related applications.

Assessment on the decolourization of textile dye (Reactive Yellow) using Pseudomonas sp. immobilized on fly ash: Response surface methodology optimization and toxicity evaluation.

Science.gov (United States)

Roy, Uttariya; Sengupta, Shubhalakshmi; Banerjee, Priya; Das, Papita; Bhowal, Avijit; Datta, Siddhartha

2018-06-18

This study focuses on the investigation of removal of textile dye (Reactive Yellow) by a combined approach of sorption integrated with biodegradation using low cost adsorbent fly ash immobilized with Pseudomonas sp. To ensure immobilization of bacterial species on treated fly ash, fly ash with immobilized bacterial cells was characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and fluorescence microscopy. Comparative batch studies were carried out using Pseudomonas sp, fly ash and immobilized Pseudomonas sp on flyash and were observed that immobilized Pseudomonas sp on flyash acted as better decolourizing agent. The optimized pH, temperature, and immobilized adsorbent dosage for highest percentage of dye removal were observed to be pH 6, 303 K, 1.2 g/L in all the cases. At optimum condition, the highest percentage of dye removal was found to be 88.51%, 92.62% and 98.72% for sorption (flyash), biodegradation (Pseudomonas sp) and integral approach (Pseudomonas sp on flyash) respectively. Optimization of operating parameters of textile dye decolourization was done by response surface methodology (RSM) using Design Expert 7 software. Phytotoxicity evaluation with Cicer arietinum revealed that seeds exposed to untreated dye effluents showed considerably lower growth, inhibited biochemical, and enzyme parameters with compared to those exposed to treated textile effluents. Thus this immobilized inexpensive technique could be used for removal of synthetic dyes present in textile wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Analysis list: FLI1 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available FLI1 Blood,Bone,Muscle + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/targe...t/FLI1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/FLI1.5.tsv http://dbarchive.biosciencedb...c.jp/kyushu-u/hg19/target/FLI1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/FLI1.Blood.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/FLI1.Bone.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/FLI1.Muscle.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Bl

The Effect of pH and High-Pressure Homogenization on Droplet Size

Directory of Open Access Journals (Sweden)

Ah Pis Yong

2017-12-01

Full Text Available The aims of this study are to revisit the effect of high pressure on homogenization and the influence of pH on the emulsion droplet sizes. The high-pressure homogenization (HPH involves two stages of processing, where the first stage involves in blending the coarse emulsion by a blender, and the second stage requires disruption of the coarse emulsion into smaller droplets by a high-pressure homogenizer. The pressure range in this review is in between 10-500 MPa. The homogenised droplet sizes can be reduced by increasing the homogenization recirculation, and there is a threshold point beyond that by applying pressure only, the size cannot be further reduced. Normally, homogenised emulsions are classified by their degree of kinetic stability. Dispersed phase present in the form of droplets while continuous phase also known as suspended droplets. With a proper homogenization recirculation and pressure, a more kinetically stable emulsion can be produced. The side effects of increasing homogenization pressure are that it can cause overprocessing of the emulsion droplets where the droplet sizes become larger rather than the expected smaller size. This can cause kinetic instability in the emulsion. The droplet size is usually measured by dynamic light scattering or by laser light scattering technique. The type of samples used in this reviews are such as chocolate and vanilla based powders; mean droplet sizes samples; basil oil; tomato; lupin protein; oil; skim milk, soymilk; coconut milk; tomato homogenate; corn; egg-yolk, rapeseed and sunflower; Poly(4-vinylpyridine/silica; and Complex 1 until complex 4 approaches from author case study. A relationship is developed between emulsion size and pH. Results clearly show that lower pH offers smaller droplet of emulsion and the opposite occurs when the pH is increased.

Engineering properties of fly ash concrete

International Nuclear Information System (INIS)

Hilmi Mahmud

1999-01-01

This paper presents some of the engineering properties of Malaysian fly ash concrete. Workability, compressive, flexural, tensile splitting, drying shrinkage, elastic modulus and non destructive tests were performed on fly ash and control OPC concrete specimens. Data show that concrete containing 25% fly ash replacement of cement exhibit superior or similar engineering properties to that normal concrete without fly ash. These encouraging results demonstrated the technical merits of incorporating fly ash in concrete and should pave the way for wide scale use of this versatile material in the Malaysian construction industry. (author)

Ultrastructural findings in the brain of fruit flies (Drosophila melanogaster) and mice exposed to high-energy particle radiation

International Nuclear Information System (INIS)

D'Amelio, F.; Kraft, L.M.; D'Antoni-D'Amelio, E.; Benton, E.V.; Miquel, J.

1984-01-01

Effects of high energy, heavy particle (HZE) radiation were studied in the brain of the fruit fly (Drosophila melanogaster) exposed to argon (40Ar) or krypton (84Kr) ions. In the flies exposed to argon the fluence ranged from 6 X 10(4) to 8 X 10(7) particles/cm2. The insects were killed 35 days after exposure. Extensive tissue fragmentation was observed at the higher fluence employed. At fluences ranging from 5 X 10(6) (one hit/two cell bodies) to 9 X 10(4) (one hit/90 cell bodies) particles/cm2, swelling of the neuronal cytoplasm and focally fragmented membranes was observed. Marked increase of glial lamellae around nerve cell processes was seen at fluences ranging from one hit/six to one hit/135 cell bodies. In the flies irradiated with krypton, the fluences employed were 5.8 X 10(3) and 2.2 X 10(6) particles/cm2. Acute and late effects were evaluated. In the flies killed 36 hours after exposure (acute effects) to either fluence, glycogen particles were found in the neuroglial compartment. The granules were no longer present in flies killed 35 days later (late effects). From these studies it appears that the Drosophila brain is a useful model to investigate radiation damage to mature neurons, neuroglia, and therefore, to the glio-neuronal metabolic unit. In a separate study, the synaptic profiles of the neuropil in layers II-III of the frontal cerebral cortex of anesthesized adult LAFl mice were quantitatively appraised after exposure to argon (40Ar) particles. The absorbed dose ranged from 0.05 to 5 gray (Gy) plateau. It was determined that the sodium pentobarbital anesthesia per se results in a significant decrease in synaptic profile length one day after anesthetization, with return to normal values after 2-28 days. Irradiation with 0.05-5 Gy argon particles significantly inhibited the synaptic shortening effect of anesthesia at one day after exposure

Stabilizing sodium hypochlorite at high pH: effects on soft tissue and dentin.

Science.gov (United States)

Jungbluth, Holger; Marending, Monika; De-Deus, Gustavo; Sener, Beatrice; Zehnder, Matthias

2011-05-01

When sodium hypochlorite solutions react with tissue, their pH drops and tissue sorption decreases. We studied whether stabilizing a NaOCl solution at a high pH would increase its soft-tissue dissolution capacity and effects on the dentin matrix compared with a standard NaOCl solution of the same concentration and similar initial pH. NaOCl solutions were prepared by mixing (1:1) a 10% stock solution with water (standard) or 2 mol/L NaOH (stabilized). Physiological saline and 1 mol/L NaOH served as the controls. Chlorine content and alkaline capacity of NaOCl solutions were determined. Standardized porcine palatal soft-tissue specimens and human root dentin bars were exposed to test and control solutions. Weight loss percentage was assessed in the soft-tissue dissolution assay. Three-point bending tests were performed on the root dentin bars to determine the modulus of elasticity and flexural strength. Values between groups were compared using one-way analysis of variance with the Bonferroni correction for multiple testing (α pH level of 7.5, respectively. The stabilized NaOCl dissolved significantly more soft tissue than the standard solution, and the pH remained high. It also caused a higher loss in elastic modulus and flexure strength (P < .05) than the control solutions, whereas the standard solution did not. NaOH-stabilized NaOCl solutions have a higher alkaline capacity and are thus more proteolytic than standard counterparts. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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.

Mercury capture by selected Bulgarian fly ashes: Influence of coal rank and fly ash carbon pore structure on capture efficiency

Energy Technology Data Exchange (ETDEWEB)

Kostova, I.J.; Hower, J.C.; Mastalerz, M.; Vassilev, S.V. [University of Kentucky, Lexington, KY (United States). Center of Applied Energy Research

2011-01-15

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.

Sealing layer of fly ashes and sewage sludge and vegetation establishment in treatment of mine tailings impoundments; Flygaska och roetslam som taetskikt vid efterbehandling av sandmagasin med vegetationsetablering

Energy Technology Data Exchange (ETDEWEB)

Greger, Maria; Neuschuetz, Clara [Stockholm Univ. (Sweden). Dept. of Botany; Isaksson, Karl-Erik [Boliden Mineral AB (Sweden)

2006-02-15

ashes that have been used, and Stockholm Vatten AB, who has produced the sewage sludge. The main conclusions from this study are: It is practically possible to construct a sealing layer of fly ash upon mine tailings, and to establish plants by sowing in a protective cover of sewage sludge. Transferral of plantlets into the sludge is, however, problematic. Addition of sewage sludge to ash-containing sealing layers has several drawbacks. When sewage sludge freezes it is not possible to mix with ashes and thereby form a satisfactory sealing layer, with the method used in this study. Such sealing layer can thus not be constructed winter-time, which is the time when large amounts of ashes are produced and the mine tailings are firm enough to work upon. Furthermore, addition of sewage sludge to sealing layers increases the risk of root penetration and do not seem to have as great impact on the sealing layer permeability as has earlier been considered. Concentrations of many elements are higher in drainage water from mine waste covered with fly ash compared to drainage water from mine waste covered with sludge or mixtures of ash and sludge. Sewage sludge thus seems to have a preventive effect on metal leakage caused by the ash. Sealing layers made of fly ash have good resistance to root penetration due to high density and high degree of packing. Moreover, many ashes are toxic to plant roots as a result of high pH and alkalinity, and high levels of toxic substances, such as heavy metals. Addition of sewage sludge increases the risk of root penetration, since the sludge contains plant nutrients, for instance nitrogen, as well as it may decrease the density and possible toxicity of the ash sealing layer. The energy crop Reed Canary-grass generally reduces the leakage of nutrient elements from sewage sludge and fly ash, partly by decreasing the amount of drainage water, but also by changing the conditions in the substrate, for instance by changing the pH and redox potential. If

Mechanical Properties and Shear Strengthening Capacity of High Volume Fly Ash-Cementitious Composite

Science.gov (United States)

Joseph, Aswin K.; Anand, K. B.

2018-02-01

This paper discusses development of Poly Vinyl Alcohol (PVA) fibre reinforced cementitious composites taking into account environmental sustainability. Composites with fly ash to cement ratios from 0 to 3 are investigated in this study. The mechanical properties of HVFA-cement composite are discussed in this paper at PVA fiber volume fraction maintained at 1% of total volume of composite. The optimum replacement of cement with fly ash was found to be 75%, i.e. fly ash to cement ratio (FA/C) of 3. The increase in fiber content from 1% to 2% showed better mechanical performance. A strain capacity of 2.38% was obtained for FA/C ratio of 3 with 2% volume fraction of fiber. With the objective of evaluating the performance of cementitious composites as a strengthening material in reinforced concrete beams, the beams deficient in shear capacity were strengthened with optimal mix having 2% volume fraction of fiber as the strengthening material and tested under four-point load. The reinforced concrete beams designed as shear deficient were loaded to failure and retrofitted with the composite in order to assess the efficiency as a repair material under shear.

Plant growth and trace-element uptake on acidic coal refuse amended with lime or fly ash

Energy Technology Data Exchange (ETDEWEB)

Jastrow, J.D. (Argonne National Lab., IL); Zimmerman, C.A.; Dvorak, A.J.; Hinchman, R.R.

1981-04-01

Two commonly used revegetation species, Kentucky 31 tall fescue (Festuca arundinacea Schreb.) and Lincoln smooth brome (Bromus inermis Leyss.), were grown for 60 days in pots containing coarse coal mine refuse (referred to as gob, pH = 3.5) amended with either lime or alkaline powerplant fly ash. Both species were also grown in pots containing a silt loam surface soil as a control. Morphological growth parameters were measured over time; dry weights and shoot/root ratios were determined at harvest. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn in the plant shoots were determined by atomic absorption spectrophotometry. Plant growth of both species was not as good on either lime- or fly ash-amended gob as it was on surface soil; however, more vigorous growth occurred on lime-amended gob than on fly ash-amended gob. Significant differences (rho < 0.05) in the tissue concentrations of Cd, Co, Fe, Hg, Mn, Pb, V, and Zn were found among the plants grown on the three substrates. Except for Hg and Pb, these elements were higher in plants grown on at least one of the amended-gob substrates than in plants grown on surface soil. Significant substrate differences were not observed for Al, As, Cr, Cu, Ni, and Se. The tissue concentrations of some elements - notably Al, Cu, Fe, Mn, V, and Zn - were high enough in plants from one or more of the substrates to either approach or exceed concentrations which have been reported to be associated with toxic effects in some plant species.

Flying fish accelerate at 5 G to leap from the water surface

Science.gov (United States)

Yang, Patricia; Phonekeo, Sulisay; Xu, Ke; Chang, Shui-Kai; Hu, David

2013-11-01

Flying fish can both swim underwater and glide in air. Transitioning from swimming to gliding requires penetration of the air-water interface, or breaking the ``surface tension barrier,'' a formidable task for juvenile flying fish measuring 1 to 5 cm in length. In this experimental investigation, we use high-speed videography to characterize the kinematics of juvenile flying fish as they leap from the water surface. During this process, which lasts 0.05 seconds, flying fish achieve body accelerations of 5 times earth's gravity and gliding speeds of 1.3 m/s, an order of magnitude higher than their steady swimming speed. We rationalize this anomalously high speed on the basis of the hydrodynamic and surface tension forces and torques experienced by the fish. Specifically, leaping fish experience skin friction forces only on the submerged part of their body, permitting them to achieve much higher speeds than in steady underwater swimming. We also perform experiments using a towed flying fish mimc to determine optimality of various parameters in this process, including body angle and start position with respect to the water surface.

Low-pH concrete: design, characterisation and durability; Les betons bas pH - formulation, caracterisation et etude a long terme

Energy Technology Data Exchange (ETDEWEB)

Codina, M

2007-09-15

Using of Portland cement in association with clay in a deep geological repository could present some difficulties. The clay properties may be altered by the high pH conditions set by the cement pore water. Moreover, a high temperature rise caused by cement hydration in massive concrete elements could induce microcracking of the material. Investigations have thus been carried out to formulate low alkalinity and low-heat blended cements referred as 'low-pH' binders, which would show an improved compatibility with the repository environment and which could be used to elaborate high-strength concrete. A list of specifications to be checked by the concrete materials has been defined including pore solution pH around 11, temperature rise during hydration less than 20 C, moderate shrinkage and high compression strength (superior to 70 MPa). Several systems comprising Portland cement, a pozzolana (silica fume or fly ash) and blast furnace slag were compared. All blends were characterized by high amounts of additions, the OPC fractions ranging only from 20 to 60%. The pore solution pH values of the blended pastes were within the range [11.7 - 12.2] after one year of hydration. The decrease in pH as compared to a reference made with OPC was due to a i) strong reduction of the alkali concentration in the pore water, ii) depletion or decrease of the portlandite content in the blends and iii) enrichment of C-S-H with silica. These low pH binders were successfully used to prepare high strength concretes (pH pore-water values within the range [10.7 - 11.6] according to the binders) with usual tools of civil engineering. Finally, leaching tests carried out in pure water indicated a very slow decalcification (reduced by a factor 4) of the blended pastes, as compared to a Portland cement paste. The mineralogical evolution and leached fluxes could be modelled by using a coupled reactive transport code (HYTEC). (author)

Low-pH concrete: design, characterisation and durability; Les betons bas pH - formulation, caracterisation et etude a long terme

Energy Technology Data Exchange (ETDEWEB)

Codina, M

2007-09-15

Using of Portland cement in association with clay in a deep geological repository could present some difficulties. The clay properties may be altered by the high pH conditions set by the cement pore water. Moreover, a high temperature rise caused by cement hydration in massive concrete elements could induce microcracking of the material. Investigations have thus been carried out to formulate low alkalinity and low-heat blended cements referred as 'low-pH' binders, which would show an improved compatibility with the repository environment and which could be used to elaborate high-strength concrete. A list of specifications to be checked by the concrete materials has been defined including pore solution pH around 11, temperature rise during hydration less than 20 C, moderate shrinkage and high compression strength (superior to 70 MPa). Several systems comprising Portland cement, a pozzolana (silica fume or fly ash) and blast furnace slag were compared. All blends were characterized by high amounts of additions, the OPC fractions ranging only from 20 to 60%. The pore solution pH values of the blended pastes were within the range [11.7 - 12.2] after one year of hydration. The decrease in pH as compared to a reference made with OPC was due to a i) strong reduction of the alkali concentration in the pore water, ii) depletion or decrease of the portlandite content in the blends and iii) enrichment of C-S-H with silica. These low pH binders were successfully used to prepare high strength concretes (pH pore-water values within the range [10.7 - 11.6] according to the binders) with usual tools of civil engineering. Finally, leaching tests carried out in pure water indicated a very slow decalcification (reduced by a factor 4) of the blended pastes, as compared to a Portland cement paste. The mineralogical evolution and leached fluxes could be modelled by using a coupled reactive transport code (HYTEC). (author)

Utilisation of different types of coal fly ash in the production of ceramic tiles

OpenAIRE

KocKal, N. U.

2012-01-01

The influence of varying proportions of different types of fly ash (used in place of feldspar) and different sintering temperatures on the sintered properties of ceramic tile bodies was evaluated. The results indicated that sintering ceramic tiles with a high fly ash content at a high temperature caused a decrease in the properties because of bloating. The ceramic samples containing a higher amount of fly ash that were sintered at low temperature exhibited lower water absorption, larger shrin...

Histone deacetylase-mediated regulation of endolysosomal pH.

Science.gov (United States)

Prasad, Hari; Rao, Rajini

2018-05-04

The pH of the endolysosomal system is tightly regulated by a balance of proton pump and leak mechanisms that are critical for storage, recycling, turnover, and signaling functions in the cell. Dysregulation of endolysosomal pH has been linked to aging, amyloidogenesis, synaptic dysfunction, and various neurodegenerative disorders, including Alzheimer's disease. Therefore, understanding the mechanisms that regulate luminal pH may be key to identifying new targets for managing these disorders. Meta-analysis of yeast microarray databases revealed that nutrient-limiting conditions inhibited the histone deacetylase (HDAC) Rpd3 and thereby up-regulated transcription of the endosomal Na + /H + exchanger Nhx1, resulting in vacuolar alkalinization. Consistent with these findings, Rpd3 inhibition by the HDAC inhibitor and antifungal drug trichostatin A induced Nhx1 expression and vacuolar alkalinization. Bioinformatics analysis of Drosophila and mouse databases revealed that caloric control of the Nhx1 orthologs DmNHE3 and NHE6, respectively, is also mediated by HDACs. We show that NHE6 is a target of the transcription factor cAMP-response element-binding protein (CREB), a known regulator of cellular responses to low-nutrient conditions, providing a molecular mechanism for nutrient- and HDAC-dependent regulation of endosomal pH. Of note, pharmacological targeting of the CREB pathway to increase NHE6 expression helped regulate endosomal pH and correct defective clearance of amyloid Aβ in an apoE4 astrocyte model of Alzheimer's disease. These observations from yeast, fly, mouse, and cell culture models point to an evolutionarily conserved mechanism for HDAC-mediated regulation of endosomal NHE expression. Our insights offer new therapeutic strategies for modulation of endolysosomal pH in fungal infection and human disease. © 2018 Prasad and Rao.

Evaluation of the effects of coal fly ash amendments on the toxicity of a contaminated marine sediment

Energy Technology Data Exchange (ETDEWEB)

Burgess, R.M.; Perron, M.M.; Friedman, C.L.; Suuberg, E.M.; Pennell, K.G.; Cantwell, M.G.; Pelletier, M.C.; Ho, K.T.; Serbst, J.R.; Ryba, S.A. [US EPA, Narragansett, RI (USA). Office for Research and Development

2009-01-15

Approaches for cleaning up contaminated sediments range from dredging to in situ treatment. In this study, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7-d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspected that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of postoxidation treatment to reduce nitrous oxide emissions. Relatively simple methods exist to remove ammonia from fly ash before use, and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. No evidence was seen of the release of the metals cadmium, copper, nickel, or lead from the fly ashes. A preliminary 28-d polychaete bioaccumulation study with one of the high-carbon fly ashes and a reference sediment was also performed. Although preliminary, no evidence was seen of adverse effects to worm growth or lipid content or of accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon content could represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments.

Selection for Resistance to Imidacloprid in the House Fly (Diptera: Muscidae)

Science.gov (United States)

House flies, Musca domestica L., continue to be a primary pest of livestock facilities worldwide. This pest also has shown a propensity for pesticide resistance development when under high selection pressures. In this study a house fly strain, FDm was created by a 20% contribution from each of fiv...

Flying Cities

DEFF Research Database (Denmark)

Ciger, Jan

2006-01-01

The Flying Cities artistic installation brings to life imaginary cities made from the speech input of visitors. In this article we describe the original interactive process generating real time 3D graphics from spectators' vocal inputs. This example of cross-modal interaction has the nice property....... As the feedback we have received when presenting Flying Cities was very positive, our objective now is to cross the bridge between art and the potential applications to the rehabilitation of people with reduced mobility or for the treatment of language impairments....

Flying Cities

DEFF Research Database (Denmark)

Herbelin, Bruno; Lasserre, Sebastien; Ciger, Jan

2008-01-01

Flying Cities is an artistic installation which generates imaginary cities from the speech of its visitors. Thanks to an original interactive process analyzing people's vocal input to create 3D graphics, a tangible correspondence between speech and visuals opens new possibilities of interaction....... This cross-modal interaction not only supports our artistic messages, but also aims at providing anyone with a pleasant and stimulating feedback from her/his speech activity. As the feedback we have received when presenting Flying Cities was very positive, our objective is now to cross the bridge between art...

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

, 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...... lasting 14 days with L/S 10, up to 60 % Cd, 45 % Zn, 20 % Ni and Ba was removed. Regardless of the remediation time and L/S ratio, the fraction of soluble Ba, Cr and Pb decreased due to the electrodialytic remediation. The electrodialytic remediation method showed potential as a treatment method...

Transmission of Leishmania infantum in the Canine Leishmaniasis Focus of Mont-Rolland, Senegal: Ecological, Parasitological and Molecular Evidence for a Possible Role of Sergentomyia Sand Flies.

Directory of Open Access Journals (Sweden)

Massila Wagué Senghor

2016-11-01

Full Text Available Leishmania (L. infantum is the causative agent in an endemic focus of canine leishmaniasis in the Mont-Rolland district (Thiès, Senegal. In this area, the transmission cycle is well established and more than 30% of dogs and 20% of humans are seropositive for L. infantum. However, the sand fly species involved in L. infantum transmission cycle are still unknown. Between 2007 and 2010, 3654 sand flies were collected from different environments (indoor, peridomestic, farming and sylvatic areas to identify the main L. infantum vector(s. Nine sand fly species were identified. The Phlebotomus genus (n = 54 specimens; Phlebotomus (Ph duboscqi and Phlebotomus (Ph. rodhaini was markedly under-represented in comparison to the Sergentomyia genus (n = 3600 specimens; Sergentomyia (Se adleri, Se. clydei, Se. antennata, Se. buxtoni, Se. dubia, Se. schwetzi and Se. magna. Se. dubia and Se. schwetzi were the dominant species indoor and in peridomestic environments, near humans and dogs. Blood-meal analysis indicated their anthropophilic behavior. Some Se. schwetzi specimens fed also on dogs. The dissection of females in the field allowed isolating L. infantum from sand flies of the Sergentomyia genus (0.4% of Se. dubia and 0.79% of Se. schwetzi females. It is worth noting that one Se. dubia female not engorged and not gravid revealed highly motile metacyclic of L. infantum in the anterior part of the midgut. PCR-based diagnosis and sequencing targeting Leishmania kinetoplast DNA (kDNA highlighted a high rate of L. infantum-positive females (5.38% of Se. dubia, 4.19% of Se. schwetzi and 3.64% of Se. magna. More than 2% of these positive females were unfed, suggesting the parasite survival after blood-meal digestion or egg laying. L. infantum prevalence in Se. schwetzi was associated with its seroprevalence in dogs and humans and L. infantum prevalence in Se. dubia was associated with its seroprevalence in humans. These evidences altogether strongly suggest that

Studies on mating competition of irradiated melon flies

International Nuclear Information System (INIS)

Limohpasmanee, W.

1994-01-01

Mating competition is the key factor for fruit flies control by using sterile insect technique project. Mass rearing and irradiation can reduce the mating competition of fruit flies. This experiment has purpose to evaluate the mating competition of the irradiated melon fly. The results show that mating competition values of irradiated melon flies were 0.36 and 0.24 when they mated with normal and irradiated females. Both normal male and female can mate more frequency than irradiated flies. (Z=1.322, P<0.05; Z=1.851, P<0.05). The results show that quality of mass rearing and irradiated melon fly was lower than the normal flies. So that quality of irradiated fly must be improved and the number of released flies as less must be higher than natural flies 6 time

Sulfate and Chloride Resistance of High Fluidity Concrete including Fly Ash and GGBS for NPP

International Nuclear Information System (INIS)

Noh, Jea Myoung; Cho, Myung Sug

2010-01-01

Fly ash mixed concrete has been used for NPP concrete structures in Korea in order to prevent aging and improve durability since the Shin.Kori no.1,2 in 2005. Concentrated efforts to develop technology for the streamlining of construction work and to affect labor savings have been conducted in construction. The application of high fluidity concrete for nuclear power plants has been the research subject with the aim of further rationalization of construction works. Since high fluidity concrete can have the characteristics of high density and high strength without compaction. However, high fluidity concrete can cause thermal cracking by heat of hydration. For this reason, the amount of pozzolan binder should be increased in high fluidity concrete for nuclear power plants. In this study, the resistance of high fluidity concrete on sulfate and chloride was compared with that of the concrete currently using for nuclear power plants

Updating Physical and Chemical Characteristics of Fly Ash for Use in Concrete

Science.gov (United States)

2017-12-22

When incorporated in concrete mixtures, fly ashes are known to influence both its fresh and hardened properties. An accurate and quick technique to predict the extent of this influence based on the characteristics of fly ash would be highly beneficia...

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.

Preparation of fly ash based zeolite for removal of fluoride from drinking water

Science.gov (United States)

Panda, Laxmidhar; Kar, Biswabandita; Dash, Subhakanta

2018-05-01

Fluoride contamination of drinking water is a worldwide phenomenon and scientists are working relentlessly to find ways to remove fluoride from drinking water. Out of the different methods employed for removal fluoride from drinking water adsorption process is the most suitable because in this process the adsorbent is regenerated and the process is cost effective. In the present study fly ash is used as the raw material, which is treated with alkali (NaOH) to form NaP1 zeolite. This zeolite is then subjected to characterization by standard procedures. It is found that the synthesized zeolite has more crystalline character than the raw fly ash and has also more voids and channels on its surface. The surface of the synthesized zeolite is modified with calcium chloride and the same is employed for removal of fluoride under varying pH, contact time, initial concentration of fluoride, temperature and adsorbent dose etc so as to assess the suitably or otherwise of the synthesized product.

Antibacterial and antifungal effect of high pH and paraffin wax ...

African Journals Online (AJOL)

The antibacterial and antifungal effects of high pH (9, 10) and paraffin wax were determined. Determination of antibacterial and antifungal activity of the combined treatments was achieved by aerobic mesophilic count of bacteria and fungi on the surface of the tomatoes, peppers and oranges using serial dilution and pour ...

Long photoperiods sustain high pH in Arctic kelp forests.

Science.gov (United States)

Krause-Jensen, Dorte; Marbà, Núria; Sanz-Martin, Marina; Hendriks, Iris E; Thyrring, Jakob; Carstensen, Jacob; Sejr, Mikael Kristian; Duarte, Carlos M

2016-12-01

Concern on the impacts of ocean acidification on calcifiers, such as bivalves, sea urchins, and foraminifers, has led to efforts to understand the controls on pH in their habitats, which include kelp forests and seagrass meadows. The metabolism of these habitats can lead to diel fluctuation in pH with increases during the day and declines at night, suggesting no net effect on pH at time scales longer than daily. We examined the capacity of subarctic and Arctic kelps to up-regulate pH in situ and experimentally tested the role of photoperiod in determining the capacity of Arctic macrophytes to up-regulate pH. Field observations at photoperiods of 15 and 24 hours in Greenland combined with experimental manipulations of photoperiod show that photoperiods longer than 21 hours, characteristic of Arctic summers, are conducive to sustained up-regulation of pH by kelp photosynthesis. We report a gradual increase in pH of 0.15 units and a parallel decline in pCO 2 of 100 parts per million over a 10-day period in an Arctic kelp forest over midsummer, with ample scope for continued pH increase during the months of continuous daylight. Experimental increase in CO 2 concentration further stimulated the capacity of macrophytes to deplete CO 2 and increase pH. We conclude that long photoperiods in Arctic summers support sustained up-regulation of pH in kelp forests, with potential benefits for calcifiers, and propose that this mechanism may increase with the projected expansion of Arctic vegetation in response to warming and loss of sea ice.

Utah Fly's Eye detector

Energy Technology Data Exchange (ETDEWEB)

Baltrusaitis, R.M.; Cady, R.; Cassiday, G.L.; Cooper, R.; Elbert, J.W.; Gerhardy, P.R.; Ko, S.; Loh, E.C.; Salamon, M.; Steck, D.; Sokolsky, P.

1985-10-15

We report the details of the design, operation and performance of the University of Utah Fly's Eye detector which was built to record the passage of ultra-high energy cosmic rays through the atmosphere via atmospheric fluorescence. Emphasized in the presentation are (1) light production by charged particles in the atmosphere, (2) kinematics of an EAS as seen by the Fly's Eye, (3) signal to noise considerations and its impact on detector design, (4) details of detector hardware and software, (5) detector calibration, (6) techniques employed in measurement of shower longitudinal development profiles and primary particle energy, and (7) assessment of detector performance by a comparison of Monte Carlo and real data distributions. (orig.).

Bloodstream form pre-adaptation to the tsetse fly inTrypanosoma brucei

Directory of Open Access Journals (Sweden)

Eva eRico

2013-11-01

Full Text Available African trypanosomes are sustained in the bloodstream of their mammalian hosts by their extreme capacity for antigenic variation. However, for life cycle progression, trypanosomes also must generate transmission stages called stumpy forms that are pre-adapted to survive when taken up during the bloodmeal of the disease vector, tsetse flies. These stumpy forms are rather different to the proliferative slender forms that maintain the bloodstream parasitaemia. Firstly, they are non proliferative and morphologically distinct, secondly, they show particular sensitivity to environmental cues that signal entry to the tsetse fly and, thirdly, they are relatively robust such that they survive the changes in temperature, pH and proteolytic environment encountered within the tsetse midgut. These characteristics require regulated changes in gene expression to pre-adapt the parasite and the use of environmental sensing mechanisms, both of which allow the rapid initiation of differentiation to tsetse midgut procyclic forms upon transmission. Interestingly, the generation of stumpy forms is also regulated and periodic in the mammalian blood, this being governed by a density-sensing mechanism whereby a parasite-derived signal drives cell cycle arrest and cellular development both to optimise transmission and to prevent uncontrolled parasite multiplication overwhelming the host.In this review we detail recent developments in our understanding of the molecular mechanisms that underpin the production of stumpy forms in the mammalian bloodstream and their signal perception pathways both in the mammalian bloodstream and upon entry into the tsetse fly. These discoveries are discussed in the context of conserved eukaryotic signalling and differentiation mechanisms. Further, their potential to act as targets for therapeutic strategies that disrupt parasite development either in the mammalian bloodstream or upon their transmission to tsetse flies is also discussed.

Formation and utilization of fly ash

Energy Technology Data Exchange (ETDEWEB)

Vargyai, J

1974-01-01

General problems of slag and fly ash formation and utilization are discussed. The ever-increasing energy demand, and the comeback of coal as an energy carrier in power plants call for efficient solutions to the problem of slag and fly ash. Slag and fly ash are used for concrete in which they partly replace cement. Other possible uses are the amelioration of acid soils, fireclay manufacture, road construction, and tiles. It is possible to recover metals, such as vanadium, iron, aluminum, and radioactive materials from certain types of fly ash and slag. The utilization of fly ash is essential also with respect to the abatement of entrainment from dumps.

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.

prevalence of biting and non-biting flies in relation to species

African Journals Online (AJOL)

USER

support high abundance of biting flies due to the favourable conditions within the forest for breeding, refuge and easy migration of adult females to animal cages to seek for blood meal. Table 1: Abundance of Biting Flies in Relation to Species in the Jos Museum. Zoological Garden. Site. Stomoxys calcitrans. Haematopota.

Bacterial diversity of the American sand fly Lutzomyia intermedia using high-throughput metagenomic sequencing.

Science.gov (United States)

Monteiro, Carolina Cunha; Villegas, Luis Eduardo Martinez; Campolina, Thais Bonifácio; Pires, Ana Clara Machado Araújo; Miranda, Jose Carlos; Pimenta, Paulo Filemon Paolucci; Secundino, Nagila Francinete Costa

2016-08-31

Parasites of the genus Leishmania cause a broad spectrum of diseases, collectively known as leishmaniasis, in humans worldwide. American cutaneous leishmaniasis is a neglected disease transmitted by sand fly vectors including Lutzomyia intermedia, a proven vector. The female sand fly can acquire or deliver Leishmania spp. parasites while feeding on a blood meal, which is required for nutrition, egg development and survival. The microbiota composition and abundance varies by food source, life stages and physiological conditions. The sand fly microbiota can affect parasite life-cycle in the vector. We performed a metagenomic analysis for microbiota composition and abundance in Lu. intermedia, from an endemic area in Brazil. The adult insects were collected using CDC light traps, morphologically identified, carefully sterilized, dissected under a microscope and the females separated into groups according to their physiological condition: (i) absence of blood meal (unfed = UN); (ii) presence of blood meal (blood-fed = BF); and (iii) presence of developed ovaries (gravid = GR). Then, they were processed for metagenomics with Illumina Hiseq Sequencing in order to be sequence analyzed and to obtain the taxonomic profiles of the microbiota. Bacterial metagenomic analysis revealed differences in microbiota composition based upon the distinct physiological stages of the adult insect. Sequence identification revealed two phyla (Proteobacteria and Actinobacteria), 11 families and 15 genera; 87 % of the bacteria were Gram-negative, while only one family and two genera were identified as Gram-positive. The genera Ochrobactrum, Bradyrhizobium and Pseudomonas were found across all of the groups. The metagenomic analysis revealed that the microbiota of the Lu. intermedia female sand flies are distinct under specific physiological conditions and consist of 15 bacterial genera. The Ochrobactrum, Bradyrhizobium and Pseudomonas were the common genera. Our results detailing

Utilization of fly ash for stabilization/solidification of heavy metal contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Dermatas, D.; Meng, X. [Stevens Inst. of Technology, Hoboken, NJ (United States)

1995-12-01

Pozzolanic-based stabilization/solidification (S/S) is an effective, yet economic technological alternative to immobilize heavy metals in contaminated soils and sludges. Fly ash waste materials were used along with quicklime (CaO) to immobilize lead, trivalent and hexavalent chromium present in contaminated clayey sand soils. The degree of heavy metal immobilization was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) as well as controlled extraction experiments. These leaching test results along with X-ray diffraction (XRD), scanning electron microscope and energy dispersive x-ray (SEM-EDX) analyses were also implemented to elucidate the mechanisms responsible for immobilization of the heavy metals under study. Finally, the reusability of the stabilized waste forms in construction applications was also investigated by performing unconfined compressive strength and swell tests. Results suggest that the controlling mechanism for both lead and hexavalent chromium immobilization is surface adsorption, whereas for trivalent chromium it is hydroxide precipitation. Addition of fly ash to the contaminated soils effectively reduced heavy metal leachability well below the non-hazardous regulatory limits. However, quicklime addition was necessary in order to attain satisfactory immobilization levels. Overall, fly ash addition increases the immobilization pH region for all heavy metals tested, and significantly improves the stress-strain properties of the treated solids, thus allowing their reuse as readily available construction materials. The only potential problem associated with this quicklime/fly ash treatment is the excessive formation of the pozzolanic product ettringite in the presence of sulfates. Ettringite, when brought in contact with water, may cause significant swelling and subsequent deterioration of the stabilized matrix. Addition of minimum amounts of barium hydroxide was shown to effectively eliminate ettringite formation.

Analysis list: Fli1 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available Fli1 Blood,Embryo + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Fli1....1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Fli1.5.tsv http://dbarchive.biosciencedbc.jp/kyu...shu-u/mm9/target/Fli1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Fli1.Blood.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/colo/Fli1.Embryo.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/colo/Blood.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Embryo.gml ...

Behavior of HPC with Fly Ash after Elevated Temperature

Directory of Open Access Journals (Sweden)

Huai-Shuai Shang

2013-01-01

Full Text Available For use in fire resistance calculations, the relevant thermal properties of high-performance concrete (HPC with fly ash were determined through an experimental study. These properties included compressive strength, cubic compressive strength, cleavage strength, flexural strength, and the ultrasonic velocity at various temperatures (20, 100, 200, 300, 400 and 500∘C for high-performance concrete. The effect of temperature on compressive strength, cubic compressive strength, cleavage strength, flexural strength, and the ultrasonic velocity of the high-performance concrete with fly ash was discussed according to the experimental results. The change of surface characteristics with the temperature was observed. It can serve as a reference for the maintenance, design, and the life prediction of high-performance concrete engineering, such as high-rise building, subjected to elevated temperatures.

Technical progress review of extraction of uranium from fly ash

International Nuclear Information System (INIS)

Gao Renxi; Gao Junning; Wu Qingming; Chen Gang; Wan Hongjin; Zhang Ziyue

2014-01-01

The increasing of fly ash in coal-fired power plants at home and abroad year by year and the potential impacts to the environment attracted media attention. Although the extraction of uranium from the fly ash in coal-fired power plants had optional process from technique aspect and sufficient preliminary researches, but considering the low grade of the uranium in fly ash and particularity of the mineral composition, it is easy to have a high cost of extraction. As a consequence, it is not included in the development plan of uranium mining and metallurgy. The present applications of fly ash are only building materials, building roads and pit valley backfill, the resource utilization rate was low and was still in its early stages of development and application. In view of this, the research advances and the latest development trends of extraction of uranium from fly ash at home and abroad were introduced from the technical aspect, and the beneficial analyzes of the prospect and advices to this industry were given. (authors)

Intracellular product recycling in high succinic acid producing yeast at low pH

NARCIS (Netherlands)

Wahl, S.A.; Bernal Martinez, C.; Zhao, Zheng; van Gulik, W.M.; Jansen, Mickel L.A.

2017-01-01

Background: The metabolic engineering of Saccharomyces cerevisiae for the production of succinic acid has progressed dramatically, and a series of high-producing hosts are available. At low cultivation pH and high titers, the product transport can become bidirectional, i.e. the acid is reentering

Analysis of metal Bioleaching from thermal power plant fly ash by Aspergillus niger 34770 culture supernatant and reduction of phytotoxicity during the process.

Science.gov (United States)

Jadhav, Umesh U; Hocheng, Hong

2015-01-01

Aspergillus niger culture supernatant is used for bioleaching process. Before starting bioleaching process, fly ash was washed with distilled water. This removed 100 % sodium, 47 % (±0.45) boron, 38.07 % (±0.12) calcium, 29.89 % (±0.78) magnesium, and 11.8 % (±0.05) potassium. The pH was reduced from 10.5 to 8.5 after water washing. During bioleaching process, around 100 % metal removal was achieved in 4 h for all metals except chromium 93 % (±1.18), nickel 83 % (±0.32), arsenic 78 % (±0.52), and lead 70 % (±0.20). The process parameters including temperature, shaking speed, and solid/liquid ratio were optimized for bioleaching process. Experiments were conducted to evaluate effect of fly ash on growth of mung bean (Vigna radiata). At 20 g/100 ml fly ash concentration no germination of V. radiata seeds was observed. With an increasing concentration of untreated fly ash, a gradual decrease in root/shoot length was observed. After bioleaching process 78 % (±0.19) germination of V. radiata was observed with 20 g/100 ml fly ash. This study will help to develop an efficient process to remove the toxic metals from fly ash.

Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report D : creep, shrinkage, and abrasion resistance of HVFA concrete.

Science.gov (United States)

2012-10-01

The main objective of this study was to determine the effect on shrinkage, creep, : and abrasion resistance of high-volume fly ash (HVFA) concrete. The HVFA concrete : test program consisted of comparing the shrinkage, creep, and abrasion performance...

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

KAUST Repository

Celik, Kemal; Meral, Cagla; Mancio, Mauricio; Mehta, P. Kumar; Monteiro, Paulo J.M.

2014-01-01

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.

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.

Proximate and biochemical characterization of burrito (Bachydeuterus auritus) and flying gurnard (Dactylopterus volitans).

Science.gov (United States)

Abbey, Lawrence D; Glover-Amengor, Mary; Atikpo, Margaret Ottah; Howell, Nazlin K

2017-05-01

With limited protein resources and depleting commercial fish species there is the need to improve utilization of some of the lesser known species which are underutilized, for example, big eye grunt (burrito), Bachydeuterus auritus, and the flying gurnard ( Dactylopterus volitans ), (other names Cephalocanthus volitans (local) Pampansre ). This study was to characterize some of the proximate and biochemical properties of burrito and the flying gurnard so as to evaluate their potential for use in human nutrition and other value-added products. Proximate and chemical analysis were determined by the methods of AOAC. Fatty acid profiles were determined following the method of Saaed and Howell (1999). Amino acid profiles for the species were determined according to Bidlingmeyer et al. (1987). The protein content of both the water soluble and salt soluble protein extracts of the fish species were determined by the Bradford Protein Assay method (Bradford 1976). Rancidity of the fish species was assessed by thiobarbituric acid reactive substances (TBARS) and Peroxide value (PV) as described by Saeed and Howell (1999). Burrito contained 18% protein, whereas the flying gurnard contained 22.3%. Calcium content was 296 mg/100 g for burrito and 185 mg/100 g for flying gurnard, whereas iron content was 4.1 mg/100 g and 1.0 mg/100 g for burrito and the flying gurnard, respectively. Palmitic acid (C16) was 27% and 14.3% for the flying gurnard and burrito, respectively. C17: 1ω8 was 3% in the flying gurnard and 0.2% in burrito. Oleic (C18:1ω9) was 17% in the flying gurnard and 6% in burrito. C20:4ω6 was 1.6% in the flying gurnard and 3% in burrito. Docosahexaenoic acid (C22:6ω3) was 4.9% in the flying gurnard and 4.0% in burrito. Both burrito and the flying gurnard are of high nutritional quality as they had a high protein content, good general amino acid profile and abundance of polyunsaturated fatty acids.

Long photoperiods sustain high pH in Arctic kelp forests

DEFF Research Database (Denmark)

Krause-Jensen, Dorte; Marbà, Núria; Sanz-Martin, M.

2016-01-01

Concern on the impacts of ocean acidification on calcifiers, such as bivalves, sea urchins, and foraminifers, has led to efforts to understand the controls on pH in their habitats, which include kelp forests and seagrass meadows. The metabolism of these habitats can lead to diel fluctuation in pH...... with increases during the day and declines at night, suggesting no net effect on pH at time scales longer than daily. We examined the capacity of subarctic and Arctic kelps to up-regulate pH in situ and experimentally tested the role of photoperiod in determining the capacity of Arctic macrophytes to up......-regulate pH. Field observations at photoperiods of 15 and 24 hours in Greenland com- bined with experimental manipulations of photoperiod show that photoperiods longer than 21 hours, characteristic of Arctic summers, are conducive to sustained up-regulation of pH by kelp photosynthesis. We report a gradual...

Leaching characteristics of rare metal elements and chlorine in fly ash from ash melting plants for metal recovery.

Science.gov (United States)

Jung, Chang-Hwan; Osako, Masahiro

2009-05-01

In terms of resource recovery and environmental impact, melting furnace fly ash (MFA) is attracting much attention in Japan due to its high metal content. The study aims to obtain fundamental information on using a water extraction method not only to concentrate valuable rare metals but also to remove undesirable substances such as chlorine for their recovery from MFA. The composition and leaching characteristics of MFA was investigated. The results revealed that the metal content in MFA is nearly equal to raw ore quality. The content of Ag, In, Pd, Pb, and Zn is, in fact, higher than the content of raw ore. As for leaching behavior, Ag, Bi, In, Ga, Ge, Sb, Sn, and Te showed the lowest release at a neutral pH range. Pd was leached constantly regardless of pH, but its concentration was quite low. On the other hand, most of the Tl was easily leached, revealing that water extraction is not appropriate for Tl recovery from MFA. Major elements Cl, Ca, Na, and K, occupying about 70% of MFA, were mostly leached regardless of pH. Base metal elements Cu, Pb, and Zn showed minimum solubility at a neutral pH. The leaching ratio of target rare metal elements and base metal elements suggests that the optimal pH for water extraction is 8-10, at which the leaching concentration is minimized. The water extraction process removed most of the Cl, Ca, Na, and K, and the concentration of rare metals and base metals increased by four or five times.

Design of a high altitude long endurance flying-wing solar-powered unmanned air vehicle

Science.gov (United States)

Alsahlani, A. A.; Johnston, L. J.; Atcliffe, P. A.

2017-06-01

The low-Reynolds number environment of high-altitude §ight places severe demands on the aerodynamic design and stability and control of a high altitude, long endurance (HALE) unmanned air vehicle (UAV). The aerodynamic efficiency of a §ying-wing configuration makes it an attractive design option for such an application and is investigated in the present work. The proposed configuration has a high-aspect ratio, swept-wing planform, the wing sweep being necessary to provide an adequate moment arm for outboard longitudinal and lateral control surfaces. A design optimization framework is developed under a MATLAB environment, combining aerodynamic, structural, and stability analysis. Low-order analysis tools are employed to facilitate efficient computations, which is important when there are multiple optimization loops for the various engineering analyses. In particular, a vortex-lattice method is used to compute the wing planform aerodynamics, coupled to a twodimensional (2D) panel method to derive aerofoil sectional characteristics. Integral boundary-layer methods are coupled to the panel method in order to predict §ow separation boundaries during the design iterations. A quasi-analytical method is adapted for application to flyingwing con¦gurations to predict the wing weight and a linear finite-beam element approach is used for structural analysis of the wing-box. Stability is a particular concern in the low-density environment of high-altitude flight for flying-wing aircraft and so provision of adequate directional stability and control power forms part of the optimization process. At present, a modified Genetic Algorithm is used in all of the optimization loops. Each of the low-order engineering analysis tools is validated using higher-order methods to provide con¦dence in the use of these computationally-efficient tools in the present design-optimization framework. This paper includes the results of employing the present optimization tools in the design of a

Determination of hexachlorobutadiene, pentachlorobenzene, and hexachlorobenzene in waste incineration fly ash using ultrasonic extraction followed by column cleanup and GC-MS analysis.

Science.gov (United States)

Zhang, Haiyan; Jiang, Lei; Zhou, Xin; Zeng, Tao; He, Zhiqiao; Huang, Xinwen; Chen, Jianmeng; Song, Shuang

2018-03-01

Hexachlorobutadiene (HCBD) was listed as a new controlling persistent organic pollutant in the Stockholm Convention because of its wide industrial applications and potential genotoxicity and carcinogenicity. However, only limited information exists on the release of HCBD from unintentional sources, such as waste incineration. Identification and quantification of HCBD in fly ash, one of the major outputs of waste incineration, is imperative. This work presents a simple method for determining HCBD in waste incineration fly ash based on ultrasonic extraction coupled with a silica gel-Florisil column cleanup followed by gas chromatography-mass spectrometry detection. Two typical persistent organic pollutants, pentachlorobenzene (PeCB) and hexachlorobenzene (HCB), were measured simultaneously. The parameters that influence the extraction efficiency and the quality of instrument detection were studied. Under the optimum experimental conditions, high sensitivity (detection limit 0.25-0.53 ng g -1 ), acceptable recoveries (64.0-71.4%) at spiking levels of 5-500 ng g -1 , and good repeatability [relative standard deviation (n = 3) of 14% or less] were achieved for all target analytes. The validation of this method was performed by analysis of six real fly ash samples from different waste incinerators in eastern China. The concentrations of HCBD detected in these samples (1.39-97.6 ng g -1 ) were comparable to those of PeCB (1.22-150 ng g -1 ) and HCB (0.82-120 ng g -1 ), indicating that the residual HCBD as well as PeCB and HCB in waste incineration fly ash should not be ignored. The results confirm for the first time that waste incineration is an unintentional source of HCBD in China. Graphical abstract An analytical method for hexachlorobutadiene, pentachlorobenzene, and hexachlorobenzene in fly ash from waste incineration. GC-MS gas chromatography-mass spectrometry, Ph-d10 phenanthrene-d 10 .

On-the-fly reduction of open loops

Energy Technology Data Exchange (ETDEWEB)

Buccioni, Federico; Pozzorini, Stefano; Zoller, Max [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland)

2018-01-15

Building on the open-loop algorithm we introduce a new method for the automated construction of one-loop amplitudes and their reduction to scalar integrals. The key idea is that the factorisation of one-loop integrands in a product of loop segments makes it possible to perform various operations on-the-fly while constructing the integrand. Reducing the integrand on-the-fly, after each segment multiplication, the construction of loop diagrams and their reduction are unified in a single numerical recursion. In this way we entirely avoid objects with high tensor rank, thereby reducing the complexity of the calculations in a drastic way. Thanks to the on-the-fly approach, which is applied also to helicity summation and for the merging of different diagrams, the speed of the original open-loop algorithm can be further augmented in a very significant way. Moreover, addressing spurious singularities of the employed reduction identities by means of simple expansions in rank-two Gram determinants, we achieve a remarkably high level of numerical stability. These features of the new algorithm, which will be made publicly available in a forthcoming release of the OpenLoops program, are particularly attractive for NLO multi-leg and NNLO real-virtual calculations. (orig.)

On-the-fly reduction of open loops

Science.gov (United States)

Buccioni, Federico; Pozzorini, Stefano; Zoller, Max

2018-01-01

Building on the open-loop algorithm we introduce a new method for the automated construction of one-loop amplitudes and their reduction to scalar integrals. The key idea is that the factorisation of one-loop integrands in a product of loop segments makes it possible to perform various operations on-the-fly while constructing the integrand. Reducing the integrand on-the-fly, after each segment multiplication, the construction of loop diagrams and their reduction are unified in a single numerical recursion. In this way we entirely avoid objects with high tensor rank, thereby reducing the complexity of the calculations in a drastic way. Thanks to the on-the-fly approach, which is applied also to helicity summation and for the merging of different diagrams, the speed of the original open-loop algorithm can be further augmented in a very significant way. Moreover, addressing spurious singularities of the employed reduction identities by means of simple expansions in rank-two Gram determinants, we achieve a remarkably high level of numerical stability. These features of the new algorithm, which will be made publicly available in a forthcoming release of the OpenLoops program, are particularly attractive for NLO multi-leg and NNLO real-virtual calculations.

Amelioration of soil PAH and heavy metals by combined application of fly ash and biochar

Science.gov (United States)

Masto, Reginald; George, Joshy; Ansari, Md; Ram, Lal

2016-04-01

Generation of electricity through coal combustion produces huge quantities of fly ash. Sustainable disposal and utilization of these fly ash is a major challenge. Fly ash along with other amendments like biochar could be used for amelioration of soil. In this study, fly ash and biochar were used together for amelioration of polycyclic aromatic hydrocarbon (PAH) contaminated soil. Field experiment was conducted to investigate the effects of fly ash and biochar on the amelioration of soil PAH, and the yield of Zea mays. The treatments were control, biochar (4 t/ha), fly ash (4 t/ha), ash + biochar ( 2 + 2 t/ha). Soil samples were collected after the harvest of maize crop and analysed for chemical and biological parameters. Thirteen PAHs were analysed in the postharvest soil samples. Soil PAHs were extracted in a microwave oven at 120 °C using hexane : acetone (1:1) mixture. The extracted solutions were concentrated, cleaned and the 13 PAHs [Acenaphthene (Ace), fluorene (Flr), phenanthrene (Phn), anthracene(Ant), pyrene(Pyr), benz(a)anthracene (BaA), chrysene (Chy), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene, benzo(g,h,i)perylene (BghiP), dibenzo(a,h)anthracene, and indeno(1,2,3-cd)pyrene)(Inp)] were analysed using GC-MS. The mean pH increased from 6.09 in control to 6.64 and 6.58 at biochar and fly ash treated soils, respectively. N content was not affected, whereas addition of biochar alone and in combination with fly ash, has significantly increased the soil organic carbon content. P content was almost double in combined (9.06 mg/kg) treatment as compared to control (4.32 mg/kg). The increase in K due to biochar was 118%, whereas char + ash increased soil K by 64%. Soil heavy metals were decreased: Zn (-48.4%), Ni (-41.4%), Co (-36.9%), Cu (-35.7%), Mn (-34.3%), Cd (-33.2%), and Pb (-30.4%). Soil dehydrogenase activity was significantly increased by ash and biochar treatments and the maximum activity was observed for the combined

Histamine formation in flying fish contaminated with Staphylococcus xylosus

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Hsien-Feng Kung

2016-06-01

Full Text Available Abstract Histamine is the main causative agent of scombroid poisoning. However, unlike scombroid fish, histamine poisoning due to consumption of flying fish has never been reported. In this study, the white muscle of flying fish had high levels of free histidine at approximately 423.9 mg/100 g, and was inoculated with Staphylococcus xylosus Q2 isolated from dried flying fish at 5.0 log CFU/g and stored at −20 to 35°C to investigate histamine-related quality. The histamine contents quickly increased to higher than 50 mg/100 g in samples stored at 25 and 35°C within 12 h as well as stored at 15°C within 48 h. However, bacterial growth and histamine formation were controlled by cold storage of the samples at 4°C or below. Once the frozen flying fish samples stored at −20°C for 2 months were thawed and stored at 25°C after 24 h, histamine started to accumulate rapidly (>50 mg/100 g of fish. Therefore, flying fish muscle was a good substrate for histamine formation by bacterial histidine decarboxylation at elevated temperatures (>15°C when it is contaminated with S. xylosus. In conclusion, since the improperly contaminated flying fish muscle with S. xylosus could lead to production of hazardous levels of histamine over time when stored at temperatures >15°C, the flying fish should be stored below 4 °C or below to control proliferation of S. xylosus, and TVBN and histamine production.

Turnover-dependent inactivation of the nitrogenase MoFe-protein at high pH.

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Yang, Kun-Yun; Haynes, Chad A; Spatzal, Thomas; Rees, Douglas C; Howard, James B

2014-01-21

Proton uptake accompanies the reduction of all known substrates by nitrogenase. As a consequence, a higher pH should limit the availability of protons as a substrate essential for turnover, thereby increasing the proportion of more highly reduced forms of the enzyme for further study. The utility of the high-pH approach would appear to be problematic in view of the observation reported by Pham and Burgess [(1993) Biochemistry 32, 13725-13731] that the MoFe-protein undergoes irreversible protein denaturation above pH 8.65. In contrast, we found by both enzyme activity and crystallographic analyses that the MoFe-protein is stable when incubated at pH 9.5. We did observe, however, that at higher pHs and under turnover conditions, the MoFe-protein is slowly inactivated. While a normal, albeit low, level of substrate reduction occurs under these conditions, the MoFe-protein undergoes a complex transformation; initially, the enzyme is reversibly inhibited for substrate reduction at pH 9.5, yet in a second, slower process, the MoFe-protein becomes irreversibly inactivated as measured by substrate reduction activity at the optimal pH of 7.8. The final inactivated MoFe-protein has an increased hydrodynamic radius compared to that of the native MoFe-protein, yet it has a full complement of iron and molybdenum. Significantly, the modified MoFe-protein retains the ability to specifically interact with its nitrogenase partner, the Fe-protein, as judged by the support of ATP hydrolysis and by formation of a tight complex with the Fe-protein in the presence of ATP and aluminum fluoride. The turnover-dependent inactivation coupled to conformational change suggests a mechanism-based transformation that may provide a new probe of nitrogenase catalysis.

Feasible metabolisms in high pH springs of the Philippines.

Science.gov (United States)

Cardace, Dawn; Meyer-Dombard, D'Arcy R; Woycheese, Kristin M; Arcilla, Carlo A

2015-01-01

A field campaign targeting high pH, H2-, and CH4-emitting serpentinite-associated springs in the Zambales and Palawan Ophiolites of the Philippines was conducted in 2012-2013, and enabled description of several springs sourced in altered pillow basalts, gabbros, and peridotites. We combine field observations of pH, temperature, conductivity, dissolved oxygen, and oxidation-reduction potential with analyses of major ions, dissolved inorganic carbon, dissolved organic carbon, and dissolved gas phases in order to model the activities of selected phases important to microbial metabolism, and to rank feasible metabolic reactions based on energy yield. We document changing geochemical inventories in these springs between sampling years, and examine how the environment supports or prevents the function of certain microbial metabolisms. In all, this geochemistry-based assessment of feasible metabolisms indicates methane cycling, hydrogen oxidation, some iron and sulfur metabolisms, and ammonia oxidation are feasible reactions in this continental site of serpentinization.

Removal of uranium from simulated fly ash by chloride volatilization method

International Nuclear Information System (INIS)

Nobuaki, Sato; Yoshikatsu, Tochigi; Toshiki, Fukui; Takeo, Fujino

2003-01-01

Fly ash is generated from LWR nuclear power plant as a low-level waste, which is contaminated with a small amount of radioactive materials, composed mainly of uranium oxide. The constituents of the fly ash are similar to those of the ore; the major components of the ash are oxides of silicon, aluminum, sodium, magnesium, zinc, iron sodium and uranium. In this study, removal of uranium from the simulated fly ash, of which composition was U 3 O 8 : 10, CaO:25, SiO 2 : 25, Al 2 O 3 : 20, MgO: 10, ZnO:5, Fe 2 O 3 : 3 and Na 2 CO 3 : 2 wt%, by chloride volatilization method was examined. The simulated fly ash was chlorinated by the same manner as the dry way processing for the ore; namely, the ash was heated in a flow of chlorine in the presence of carbon at high temperatures. In the case of volatilization of uranium from U 3 O 8 and a simulated fly ash by chlorination using chlorine and carbon, it was seen that uranium of both samples showed similar volatilization behaviour: The volatilization ratio of uranium (VU) increased with increasing temperature from 800 to 1100 C. The VU value attained 99.9% at 1100 C. Iron, silicon and zinc showed similar behaviour to uranium, namely, they vaporized completely. The volatilization ratio of aluminum, magnesium and sodium were still high in a range 80-90%. The volatilization ratio of calcium was ∼40% under the same chlorination condition, though it changed to chloride. For recovery of uranium from fly ash by chlorination using chlorine in the presence of carbon, high volatilization ratio of uranium can be achieved at high temperatures. Volatilization ratio of other components also increases, which decreases the amount of decontaminated residue resulting in the reducing of decontamination effect. Selection of heating condition is important. (author)

Molybdenum (6) determination by the method of high-frequency and pH titration

International Nuclear Information System (INIS)

Lukianets, I.G.; Kulish, N.G.

1981-01-01

A possibility to determine Mo(6) using the method of high frequency and pH-metric titration is investigated. By means of the high frequency contact R-cell Mo(6) titration is performed using different precipitators: 8-oxiquinoline, lead nitrate and acetate and silver nitrate. It is established that the best conditions are achieved during titration of 67.2-1343 mg/10 ml Mo(6) with lead acetate (pH 4.5-6.5). Relative standard deviation Ssub(r) constitutes 0.005 pH-metric titration of Mo(6) with complexone 3 is studied. The range of Mo(6) concentrations determined constitutes 13.43-134.3 mg at pH initial value of 3.5-5.5. Relative standard deviation Ssub(r) constitutes 0.003. Techniques of molybdenum determination in ferromolybdenum using the method of high frequency and pH-metric titration are developed [ru

A wide range and highly sensitive optical fiber pH sensor using polyacrylamide hydrogel

Science.gov (United States)

Pathak, Akhilesh Kumar; Singh, Vinod Kumar

2017-12-01

In the present study we report the fabrication and characterization of no-core fiber sensor (NCFS) using smart hydrogel coating for pH measurement. The no-core fiber (NCF) is stubbed between two single-mode fibers with SMA connector before immobilizing of smart hydrogel. The wavelength interrogation technique is used to calculate the sensitivity of the proposed sensor. The result shows a high sensitivity of 1.94 nm/pH for a wide range of pH values varied from 3 to 10 with a good linear response. In addition to high sensitivity, the fabricated sensor provides a fast response time with a good stability, repeatability and reproducibility.

Virtual Lab Experiment: Physics Educational Technology (PhETPhoto Electric Effect for Senior High School

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Supurwoko Supurwoko

2017-12-01

Full Text Available This paper introduced these Physics Educational Technology (PhET Simulation and demonstrated their utility for Senior High School Students. The PhET simulations are very involved, interactive animated environments that create a unique opportunity for students. In each case, we demonstrate that discussion simulations are more productive, for developing student conceptual understanding  for photo electric effect than traditional discussion without simulations. During the discussion with PhET simulation, students can construct their  understanding about concepts photo electric effect within this framework. Students learn by building on their prior understanding through a series of constrained and supportives exploration. The simulations support an interactive approach and constrain students productively.

Characterization of coal fly ash components by laser-induced breakdown spectroscopy

International Nuclear Information System (INIS)

Ctvrtnickova, Tereza; Mateo, Mari-Paz; Yanez, Armando; Nicolas, Gines

2009-01-01

The high sensitivity of laser-induced breakdown spectroscopy (LIBS) for the detection of most of the fly ash components enables the analysis of these residues produced during the combustion of coal. Fly ash consists of oxides (SiO 2 , Al 2 O 3 , Fe 2 O 3 , CaO...) and unburnt carbon which is the major determinant of combustion efficiency in coal fired boilers. For example, an excessive amount of residual carbon dispersed in the fly ash means a significant loss of energy (Styszko et al., 2004). Standard methods employed for the analysis of fly ash make not possible a control of boiler in real time. LIBS technique can significantly reduce the time of analysis, in some cases even an online detection can be performed. For this reason, some studies have been addressed in order to demonstrate the capability of the laser-induced breakdown spectroscopy technique for the detection of carbon content in high pressure conditions typical of thermal power plants (Noda et al., 2002) and for the monitoring of unburnt carbon for the boiler control in real time (Kurihara et al., 2003). In particular, the content of unburnt carbon is a valuable indicator for the control of fly ash quality and for the boiler combustion. Depending on this unburnt carbon content, fly ash can be disposed as an industrial waste or as a raw material for the production of concrete in the construction sector. In this study, analyses were performed on specimens of various forms of preparation. Pressed pellets were prepared with two different binders. Presented results concern the nature and amount of the binder used to pelletize the powder, and the laser-induced breakdown spectroscopy parameters and procedure required to draw calibration curves of elements from the fly ash. Analysis 'on tape' was performed in order to establish the experimental conditions for the future 'online analysis'.

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

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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%.

Tsetse salivary gland proteins 1 and 2 are high affinity nucleic acid binding proteins with residual nuclease activity.

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Guy Caljon

Full Text Available Analysis of the tsetse fly salivary gland EST database revealed the presence of a highly enriched cluster of putative endonuclease genes, including tsal1 and tsal2. Tsal proteins are the major components of tsetse fly (G. morsitans morsitans saliva where they are present as monomers as well as high molecular weight complexes with other saliva proteins. We demonstrate that the recombinant tsetse salivary gland proteins 1&2 (Tsal1&2 display DNA/RNA non-specific, high affinity nucleic acid binding with K(D values in the low nanomolar range and a non-exclusive preference for duplex. These Tsal proteins exert only a residual nuclease activity with a preference for dsDNA in a broad pH range. Knockdown of Tsal expression by in vivo RNA interference in the tsetse fly revealed a partially impaired blood digestion phenotype as evidenced by higher gut nucleic acid, hematin and protein contents.

Studies on the sand fly fauna (Diptera: Psychodidae) in high-transmission areas of cutaneous leishmaniasis in the Republic of Suriname

Science.gov (United States)

2013-01-01

Background Sand flies (Diptera: Psychodidae) are the vectors of Leishmania parasites, the causative agents of leishmaniasis. Cutaneous leishmaniasis is an increasing public health problem in the Republic of Suriname and is mainly caused by Leishmania (Vianna) guyanensis, but L. (V.) braziliensis, L. (L.) amazonensis, and L. (V.) naiffi also infect humans. Transmission occurs predominantly in the forested hinterland of the country. Information regarding the potential vectors of leishmaniasis in Suriname is limited. This study aims to broaden the knowledge about vectors involved in the transmission of cutaneous leishmaniasis in Suriname. For this purpose, sand flies were characterized in various foci of cutaneous leishmaniasis in the country, the districts of Para, Brokopondo, and Sipaliwini. Methods Sand flies were collected in areas around mining plots and villages using CDC light traps in the period between February 2011 and March 2013. They were categorized by examination of the spermathecea (females) and the external genitalia (males). Results A total of 2,743 sand fly specimens belonging to 34 different species were captured, including four species (Lutzomyia aragaoi, Lu. ayrozai, Lu. damascenoi, and Lu. sordellii) that had never before been described for Suriname. Five percent of the catch comprised Lu. squamiventris sensu lato, one female of which was positive with L. (V.) braziliensis and was captured in a gold mining area in Brokopondo. Other sand fly species found positive for Leishmania parasites were Lu. trichopyga, Lu. ininii, and Lu. umbratilis, comprising 32, 8, and 4%, respectively, of the catch. These were captured at gold mining areas in Brokopondo and Sipaliwini, but the Leishmania parasites they had ingested could not be identified due to insufficient amounts of DNA. Conclusions The sand fly fauna in Suriname is highly diverse and comprises Lutzomyia species capable of transmitting Leishmania parasites. Four new Lutzomyia species have been found

Continuous CO2 capture and MSWI fly ash stabilization, utilizing novel dynamic equipment

International Nuclear Information System (INIS)

Jiang Jianguo; Du Xuejuan; Chen Maozhe; Zhang Chang

2009-01-01

Novel dynamic equipment with gas in and out continuously was developed to study the capture capacity of CO 2 . Municipal solid waste incineration (MSWI) fly ash has a high capture rate of CO 2 in CO 2 -rich gas. Fly ash can sequester pure CO 2 rapidly, and its capacity is 16.3 g CO 2 /100 g fly ash with no water added and 21.4 g CO 2 /100 g fly ash with 20% water added. For simulated incineration gas containing 12% CO 2 , the capture rate decreased and the capacity was 13.2 g CO 2 /100 g fly ash with no water added and 18.5 g CO 2 /100 g fly ash with 20% water added. After accelerated carbonation, the C and O contents increased, indicating CO 2 capture in the fly ash; CO 2 combines with Ca(OH) 2 to form CaCO 3 , which increased the CaCO 3 content from 12.5 to 54.3%. The leaching of Pb markedly decreased from 24.48 to 0.111 mg/L. - Novel dynamic equipment designed to capture CO 2 by fly ash is more suitable for engineering application.

Flying car design and testing

OpenAIRE

Klein, S.; Smrcek, L.

2009-01-01

This paper is primarily concerned with the inverted design process and manufacture of a flying car prototype which can overcome the problem of traffic management in the world today. A possible solution to the problem of overcrowded roads would be to design a flying or hovering car. Given technological advances in aircraft construction, navigation and operation, flying cars or personal aircraft are now a feasible proposition. The viability of such a concept was investigated in terms of produci...

Evaluation of coal combustion byproducts as soil liming materials - their influence on soil pH and enzyme activities

Energy Technology Data Exchange (ETDEWEB)

McCarty, G W; Siddaramappa, R; Wright, R J; Codling, E E; Gao, G

1994-03-01

To evaluate coal combustion byproducts as liming materials and address issues related to soil quality, the authors compared the influence of different amounts of four combustion byproducts (fly ash and bed ash from a fluidized bed combustion furnace, lime-injected multistage burner residue, and spray dryer residue) and CaCO[sub 3] on soil pH and activities of urease, phosphatase, arylsulfatase, and dehydrogenase in an acidic soil. Studies comparing the influence of the combustion byproducts and CaCO[sub 3] on soil pH showed that on weight basis of application, substantial differences were observed in the ability of these materials to influence soil pH but that such differences decreased markedly after the data were transformed to a CaCO[sub 3] equivalent basis of application. Analysis of covariance for these transformed data indicated that whereas the liming abilities of fly ash and CaCO[sub 3] were not significantly different when compared on the CaCO[sub 3] equivalent basis, those of bed ash, multistage burner residue, and spray dryer residue were less than that of CaCO[sub 3]. Studies comparing the influence of the byproducts and CaCO[sub 3] on soil enzyme activities showed that the effect of these liming materials on the enzyme activities studied was largely due to their influence on soil pH. These studies showed that the combustion byproducts tested functioned as soil liming materials in a manner similar to that of CaCO[sub 3] and seemed to have little adverse effect on soil quality.

Clean up fly ash from coal burning plants by new isolated fungi Fusarium oxysporum and Penicillium glabrum.

Science.gov (United States)

Ertit Taştan, Burcu

2017-09-15

In Turkey approximately 45 million tons of coals are burned in a year and 19.3 million tons of fly ash have emerged. The bioremediation of heavy metals or different elements from fly ash makes them bio-available. However, in previous studies, requiring of long operational time and failing to show tolerance to high pulp densities of fly ash of selected fungal species makes them impractical. In this work, bioremediation of fly ash by new isolated fungi Fusarium oxysporum and Penicillium glabrum were investigated in one step and two step bioremediation process. Ca, Si, Fe and S were found to be considerable amount in studied fly ashes by ED-XRF element analysis. The bioremediation yields of Mo (100%), S (64.36%) Ni (50%) and Cu (33.33%) by F. oxysporum were high. The remediated elements by P. glabrum in fly ash were Mo (100%), S (57.43%), Ni (25%), Si (24.66%), V (12.5%), Ti (5%) and Sr (3.2%). The isolation of high fly ash resistant fungi and reduction of the bioremediation time will allow the practical applications of the bioremediation technology when it is scaled up. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inheritance of Resistance to Sorghum Shoot Fly, Atherigona soccata in Sorghum, Sorghum bicolor (L. Moench

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Mohammed eRiyazaddin

2016-04-01

glossy score and plant vigor score with high σ2g, additive variance, predictability ratio, and GCA/SCA showed predominance of additive type of gene action indicating importance of heterosis breeding followed by simple selection in breeding shoot fly-resistant sorghums. Most of the traits exhibited high broadsense heritability, indicating high inheritance of shoot fly resistance traits.

Alkali content of fly ash : measuring and testing strategies for compliance : [tech transfer summary].

Science.gov (United States)

2015-04-01

This study investigated the test methods used to determine the : alkali content of fly ash. It also evaluated if high-alkali fly ash : exacerbates alkali-silica reaction in laboratory tests and field : concrete.

Adsorption of anionic dyes from aqueous solutions onto coal fly ash and zeolite synthesized from coal fly ash

International Nuclear Information System (INIS)

Carvalho, Terezinha Elizabeth Mendes de

2010-01-01

Coal fly ash, a waste generated in coal-fired electric power plant, was used to synthesize zeolite by hydrothermal treatment with NaOH solution. The fly ash (CL-2) and this synthesized zeolite (ZM-2) that was characterized as hydroxy-sodalite were used as adsorbents for anionic dyes indigo carmine (IC), and reactive orange 16 (RO16) from aqueous solutions. Effects of contact time, initial dye concentration, pH, adsorbent mass, and temperature were evaluated in the adsorption processes. The kinetics studies indicated that the adsorption followed the pseudo-second order kinetics and that surface adsorption and intraparticle diffusion were involved in the adsorption mechanism. The thermodynamics parameters demonstrated that the adsorption was spontaneous for all adsorption processes. The enthalpy data confirmed the endothermic nature for all adsorption processes except for IC/ZM-2 system which was exothermic. The entropy data showed an increased disorder at the solid/solution interface during the adsorption for all systems except for IC/ZM-2 whose negative entropy value indicated a decreased disorder at the interface. The adsorption isotherms were closely fitted to the Langmuir linear equation. The maximum adsorption capacities were 1.48 mg/g for the IC/CL-2 system; 1.13 mg/g for IC/ZM-2; 0.96 mg/g for RO16/CL-2, and 1.14 mg/g for RO16/ZM-2 at room temperature. The desorption study carried out with water, with acid aqueous solutions, and with an alkali aqueous solution showed to be inefficient both for recovering the dyes and regenerating the adsorbents. (author)

Seasonal variation in the prevalence of sand flies infected with Leishmania donovani.

Science.gov (United States)

Tiwary, Puja; Kumar, Dinesh; Mishra, Mukesh; Singh, Rudra Pratap; Rai, Madhukar; Sundar, Shyam

2013-01-01

Visceral Leishmaniasis (VL) is a life threatening neglected infectious disease in the Indian subcontinent, transmitted by the bite of female sand flies. Estimation of the infectivity in the vector population, collected in different seasons, may be useful to better understanding the transmission dynamics of VL as well as to plan vector control measures. We collected sand flies from highly endemic regions of Bihar state, India for one year over three seasons. The species of the sand flies were confirmed by species-specific PCR-RFLP. Leishmania donovani infection was investigated in 1397 female Phlebotomus argentipes using PCR, targeting the Leishmania specific minicircle of the kDNA region. Further, the parasitic load in the infected sand flies was measured using quantitative PCR. Though sand flies were most abundant in the rainy season, the highest rate of infection was detected in the winter season with 2.84% sand flies infected followed by the summer and rainy seasons respectively. This study can help in vector elimination programmes and to reduce disease transmission.

Influence of fly ash fineness on water requirement and shrinkage of blended cement mortars

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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.

Feasible Metabolic Schema Associated with High pH Springs in the Philippines

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DAWN eCARDACE

2015-02-01

Full Text Available A field campaign targeting high pH springs in the Zambales and Palawan Ophiolites of the Philippines was conducted in 2012-2013, and enabled description of several springs sourced in altered pillow basalts, gabbros, and peridotites. We combine field observations of pH, temperature, conductivity, dissolved oxygen, and oxidation-reduction potential with analyses of major ions, dissolved inorganic carbon, dissolved organic carbon, and dissolved gas phases in order to model the activities of selected phases important to microbial metabolism, and to evaluate feasible metabolic reactions based on energy yield. We document changing geochemical inventories in these springs, and examine how the environment supports or prevents the function of certain microbial metabolisms.

Laboratory investigations of insecticide impregnated materials for the control of New World screwworm flies

International Nuclear Information System (INIS)

Harris, E.G.; Brown, M.; Smith, S.

1992-01-01

In laboratory tests, New World screwworm flies were found to be at least three orders of magnitude less susceptible to the insecticides deltamethrin, alphacypermethrin and cyfluthrin than are tsetse flies. Deltamethrin was the most toxic of the three insecticides to screwworm flies. For topical application, the LD50s for deltamethrin 20% suspension concentrate were 33 ng and 25 ng for male and female screwworm flies respectively, compared with 0.04 ng for tsetse, G.m. morsitans. In various tests simulating contact of screwworm flies with cloth or netting targets impregnated with insecticide, 100% kill was only achieved with 3.2% deltamethrin and contact times of at least 10 sec, although 100% knockdown for up to 24 hours was obtained with lower concentrations. No repellent effect was observed at the higher concentrations. Cloth targets impregnated with a high dose of insecticide and baited with an attractant could be effective against NWS flies, especially if after ''knockdown'' flies are removed by predators. 1 fig., 9 tabs

Cementification for radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide

International Nuclear Information System (INIS)

Miyamoto, Shinya; Sato, Tatsuaki; Sasoh, Michitaka; Sakurai, Jiro; Takada, Takao

2005-01-01

For the cementification of radioactive waste that has large concentrations of sodium sulfate and radioactive nuclide, a way of fixation for sulfate ion was studied comprising the pH control of water in contact with the cement solid, and the removal of the excess water from the cement matrix to prevent hydrogen gas generation with radiolysis. It was confirmed that the sulfate ion concentration in the contacted water with the cement solid is decreased with the formation of ettringite or barium sulfate before solidification, the pH value of the pore water in the cement solid can control less than 12.5 by the application of zeolite and a low-alkali cement such as alumina cement or fly ash mixed cement, and removal of the excess water from the cement matrix by heating is possible with aggregate addition. Consequently, radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide can be solidified with cementitious materials. (author)

Fly ash as a binder in aggregate base courses

International Nuclear Information System (INIS)

Zenieris, P.; Laguros, J.G.

1988-01-01

The benefit of adding up to 35 wt% Class C high calcium fly ash to various types of fine and coarse aggregate pavement mixes is described and quantified. The mixes, which were compacted to maximum dry density at optimum moisture content, had variable compressive strengths during the first 28 day of curing; after that they assumed a relatively uniform pattern of strength gain reaching values as high as 11 MPa (1600 psi). Mixes containing 15% fly ash gave unacceptably low strengths. XRD measurements indicated massive formation of ettringite, transforming to monosulfoaluminate and the poorly crystallized hydrated phases of C-A-H, C-A-S-H and C-S-H. This transformation helps explain the gain in strength of the mixes with extended curing. SEM observations depicted progressive packing and densification of the skeletal matrix as the hexagonal phases and C-S-H gained higher crystallinity and formed aggregate masses. Furthermore, these observations suggest that fly ash acts predominantly as a chemical binder and partly as a filler in the aggregate mixes tested

Modelling of chemical evolution of low pH cements at long term

International Nuclear Information System (INIS)

El Bitouri, Y.; Buffo-Lacarriere, L.; Sellier, A.; Bourbon, X.

2015-01-01

In the context of the underground radioactive waste repository, low-pH cements were developed to reduce interactions between concrete and clay barrier. These cements contain high proportions of mineral additions like silica fume, fly ash or blast furnace slag for example. The high ratio of cement replacement by pozzolanic additions allows to reduce the pH by a global reduction of Ca/Si ratio of the hydrates (according to the one observed on CEM I pastes). In order to predict the short term development of the hydration for each component of this cement, a multiphasic hydration model, previously developed, is used. The model predicts the evolution of hydration degree of each anhydrous phase and consequently the quantity of each hydrate in paste (CH, aluminates, CSH with different Ca/Si ratios). However, this model is not suitable to determine the long term mineralogical and chemical evolution of the material, due to the internal change induced by chemical imbalance between initial hydrates. In order to evaluate the chemical characteristics of low pH cement based materials, and thus assess its chemical stability in the context of radioactive waste storage, a complementary model of chemical evolution at long term is proposed. This original model is based on 'solid-solution' principles. It assumes that the microdiffusion of calcium plays a major role to explain how the different Ca/Si ratio of initial C-S-H tends together toward a medium stabilized value. The main mechanisms and full development of the model equations are presented first. Next, a comparison of the model with experimental data issue from EDS (Energy Dispersive X-ray Spectroscopy) analysis on low pH cement allows to test the model. (authors)

Comparison of sequential and single extraction in order to estimate environmental impact of metals from fly ash

Directory of Open Access Journals (Sweden)

Tasić Aleksandra M.

2016-01-01

Full Text Available The aim of this paper was to simulate leaching of metals from fly ash in different environmental conditions using ultrasound and microwave-assisted extraction techniques. Single-agent extraction and sequential extraction procedures were used to determine the levels of different metals leaching. The concentration of metals (Al, Fe, Mn, Cd, Co, Cr, Ni, Pb, Cu, As, Be in fly ash extracts were measured by Inductively Coupled Plasma-Atomic Emission Spectrometry. Single-agent extractions of metals were conducted during sonication times of 10, 20, 30, 40 and 50 min. Single-agent extraction with deionized water was also undertaken by exposing samples to microwave radiation at the temperature of 50°C. The sequential extraction was undertaken according to the BCR procedure which was modified and applied to study the partitioning of metals in coal fly ash. The microwave-assisted sequential extraction was performed at different extraction temperatures: 50, 100 and 150°C. The partitioning of metals between the individual fractions was investigated and discussed. The efficiency of the extraction process for each step was examined. In addition, the results of the microwave-assisted sequential extraction are compared to the results obtained by standard ASTM method. The mobility of most elements contained in fly ash is markedly pH sensitive. [Projekat Ministarstva nauke Republike Srbije, br. 172030, br. 176006 i br. III43009

Composites Based on Fly Ash and Clay

International Nuclear Information System (INIS)

Fidancevska, E.; Jovanov, V.; Angusheva, B.; Srebrenkoska, V.

2014-01-01

Fly ash is a waste generated from the coal combustion during the production of electricity in the thermal power plants. It presents industrial by-product containing Technologically Enhanced Natural Occurring Radioactive Materials (TENORM) with the great potential for valorisation. Fly ash is successfully utilized in cement and concrete industry, also in ceramics industry as component for manufacturing bricks and tiles, and recently there are many investigations for production of glass-ceramics from fly ash. Although the utilization of fly ash in construction and civil engineering is dominant, the development of new alternative application for its further exploitation into new products is needed. This work presents the possibility for fly ash utilization for fabricating dense composites based on clay and fly ash with the potential to be used in construction industry

Preliminary treatment of MSW fly ash as a way of improving electrodialytic remediation

DEFF Research Database (Denmark)

Ferreira, Célia Maria Dias; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2008-01-01

In the current work electrodialytic remediation (EDR) was applied to remove heavy metals from municipal solid waste (MSW) fly ash, a hazardous waste collected during flue gas treatment. Tests were conducted to evaluate if EDR could be improved by introducing a preliminary treatment in which very...... soluble salts were removed. Three different preliminary treatments were conducted with different L:S ratios and pH. Treatment in which metal release and L/S ratio were lower was selected for EDR. Electrodialytic remediation was performed at a constant current of 38 mA, for 14 days, using gluconate...... as a solubilisation enhancement agent. Conductivity and pH were monitored and electrolyte samples were collected every 4 days to evaluate metal release over time. It was found that the preliminary treatment reduces fouling of the ion-exchange membranes used in EDR and drastically increases the removal of metals...

OpenFlyData: an exemplar data web integrating gene expression data on the fruit fly Drosophila melanogaster.

Science.gov (United States)

Miles, Alistair; Zhao, Jun; Klyne, Graham; White-Cooper, Helen; Shotton, David

2010-10-01

Integrating heterogeneous data across distributed sources is a major requirement for in silico bioinformatics supporting translational research. For example, genome-scale data on patterns of gene expression in the fruit fly Drosophila melanogaster are widely used in functional genomic studies in many organisms to inform candidate gene selection and validate experimental results. However, current data integration solutions tend to be heavy weight, and require significant initial and ongoing investment of effort. Development of a common Web-based data integration infrastructure (a.k.a. data web), using Semantic Web standards, promises to alleviate these difficulties, but little is known about the feasibility, costs, risks or practical means of migrating to such an infrastructure. We describe the development of OpenFlyData, a proof-of-concept system integrating gene expression data on D. melanogaster, combining Semantic Web standards with light-weight approaches to Web programming based on Web 2.0 design patterns. To support researchers designing and validating functional genomic studies, OpenFlyData includes user-facing search applications providing intuitive access to and comparison of gene expression data from FlyAtlas, the BDGP in situ database, and FlyTED, using data from FlyBase to expand and disambiguate gene names. OpenFlyData's services are also openly accessible, and are available for reuse by other bioinformaticians and application developers. Semi-automated methods and tools were developed to support labour- and knowledge-intensive tasks involved in deploying SPARQL services. These include methods for generating ontologies and relational-to-RDF mappings for relational databases, which we illustrate using the FlyBase Chado database schema; and methods for mapping gene identifiers between databases. The advantages of using Semantic Web standards for biomedical data integration are discussed, as are open issues. In particular, although the performance of open

PH measurement under pressure and at high temperatures; Mesure du pH sous pression et a temperature elevee

Energy Technology Data Exchange (ETDEWEB)

Fournie, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Le Peintre, M; Mahieu, C [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France)

1961-07-01

In the first part the development and operation of a glass electrode under pressure at room temperature is described. The pressure equilibrium between the inside and outside of the glass membrane several centimetres thick is obtained instantaneously by means of a siphon. The use of a silicone oil as electrical insulator makes possible the working of the glass electrode with the siphon at high pressures (100 kg/cm{sup 2}). In the second part, we determined the pH of various buffer solutions up to 250 deg. C using a cell of our design having two hydrogen electrodes. The values thus obtained for the buffer solutions make it possible to verify and calibrate the pH electrodes independently of the oxido-reduction potential of the medium. In the third part we give the results obtained up to 200 deg. C with the glass electrodes developed in conjunction with the Societe St Gobain. (author) [French] Dans une premiere partie, nous exposons la mise au point et le fonctionnement d'une electrode en verre sous pression a la temperature ordinaire. L'equilibrage instantane de la pression a l'interieur et a l'exterieur de la membrane en verre de quelques diziemes de millimetres d'epaisseur s'effectue par l'intermediaire d'un siphon. L'emploi d'une huile de silicone comme isolant electrique a permis le fonctionnement de l'electrode en verre a siphon sous haute pression (1000 kg/cm{sup 2}). Dans une deuxieme partie, nous avons determine jusqu'a 250 deg. C les valeurs du pH des diverses solutions tampons avec une cellule de notre conception a deux electrodes d'hydrogene. Les valeurs des solutions tampons ainsi obtenues permettent de verifier et d'etalonner les electrodes a pH independantes du potentiel d'oxydo-reduction du milieu. Dans une troisieme partie, nous relatons les resultats obtenus jusqu'a 200 deg. C avec les electrodes en verre mis au point en collaboration avec la Societe Saint-Gobain. (auteur)

Flies without centrioles.

Science.gov (United States)

Basto, Renata; Lau, Joyce; Vinogradova, Tatiana; Gardiol, Alejandra; Woods, C Geoffrey; Khodjakov, Alexey; Raff, Jordan W

2006-06-30

Centrioles and centrosomes have an important role in animal cell organization, but it is uncertain to what extent they are essential for animal development. The Drosophila protein DSas-4 is related to the human microcephaly protein CenpJ and the C. elegans centriolar protein Sas-4. We show that DSas-4 is essential for centriole replication in flies. DSas-4 mutants start to lose centrioles during embryonic development, and, by third-instar larval stages, no centrioles or centrosomes are detectable. Mitotic spindle assembly is slow in mutant cells, and approximately 30% of the asymmetric divisions of larval neuroblasts are abnormal. Nevertheless, mutant flies develop with near normal timing into morphologically normal adults. These flies, however, have no cilia or flagella and die shortly after birth because their sensory neurons lack cilia. Thus, centrioles are essential for the formation of centrosomes, cilia, and flagella, but, remarkably, they are not essential for most aspects of Drosophila development.

High Sensitivity pH Sensor Based on Porous Silicon (PSi) Extended Gate Field-Effect Transistor.

Science.gov (United States)

Al-Hardan, Naif H; Abdul Hamid, Muhammad Azmi; Ahmed, Naser M; Jalar, Azman; Shamsudin, Roslinda; Othman, Norinsan Kamil; Kar Keng, Lim; Chiu, Weesiong; Al-Rawi, Hamzah N

2016-06-07

In this study, porous silicon (PSi) was prepared and tested as an extended gate field-effect transistor (EGFET) for pH sensing. The prepared PSi has pore sizes in the range of 500 to 750 nm with a depth of approximately 42 µm. The results of testing PSi for hydrogen ion sensing in different pH buffer solutions reveal that the PSi has a sensitivity value of 66 mV/pH that is considered a super Nernstian value. The sensor considers stability to be in the pH range of 2 to 12. The hysteresis values of the prepared PSi sensor were approximately 8.2 and 10.5 mV in the low and high pH loop, respectively. The result of this study reveals a promising application of PSi in the field for detecting hydrogen ions in different solutions.

Interspecific Mating between Wild and Sterile Fruit Flies of Oriental Fruit Fly, Bactrocera dorsalis (Hendel) with Guava Fruit Fly, Bactrocera correcta (Bezzi) in Cages

International Nuclear Information System (INIS)

Pransopon, Prapon; Sutantawong, Manon

2003-06-01

Copulation and sperm transfer were observed between wild flies and sterile flies of Bactrocera dorsalis (Hendel) and Bactrocera correcta (Bezzi) in cages. 8-day old pupae of B. dorsalis and B. correcta were irradiated with gamma rays at 90 and 80 gray respectively. Wild flies from infested fruits and sterile flies from artificial diet in the labolatory were used for testing. The experiments were conducted 3 treatments and 3 replications. The ratio of sterile male : wild male: wild female were 3:1:1 by using sterile male of B. dorsalis: wild male of B. correcta : wild female of B. correcta and sterile male of B. correcta: wild male of B. dorsalis: wild female of B. dorsalis as 60:20:20 flies respectively. The experiment found 69 pairs of copulation consisting of 3 mating pairs(4.3%) of wild male with wild female of B. dorsalis, 22 mating pairs (31.9%) of wild male with wild female of B. correcta, 2 mating pairs(2.9%) of sterile male of B dorsalis with wild female of B. correcta, 42 mating pairs(60.9%) of sterile male of B. correcta with wild female of B. dorsalis. The cages which ratio 1:1 consisted of wild B. dorsalis and wild B. correcta (male and female = 50:50 flies) were observed and found that 43 pairs of copulation such as 2 mating pairs (4.6%) of wild male with wild female of B. dorsalis, 26 mating pairs (60.5%) of wild male with wild female of B. correcta, 2 mating pairs(2.9%) of sterile male of B. dorsalis with wild female of B. correcta and 15 mating pairs(34.9%) of wild male of B. correcta with wild female of B. dorsalis. Mated female flies were separated from male flies. Egg hatch and sperm were checked. The hatchability of normal copulation of B. dorsalis and B. correcta were 81 and 90%. The average sperm level in spermathecae of normal copulation of B. dorsalis and B. correcta were 2.2 and 2.3 respectively but had no sperm in their spemathecae of females of interspecific copulations Mating behavior of both species began in the evening before sunset at

FlyMAD: rapid thermogenetic control of neuronal activity in freely walking Drosophila.

Science.gov (United States)

Bath, Daniel E; Stowers, John R; Hörmann, Dorothea; Poehlmann, Andreas; Dickson, Barry J; Straw, Andrew D

2014-07-01

Rapidly and selectively modulating the activity of defined neurons in unrestrained animals is a powerful approach in investigating the circuit mechanisms that shape behavior. In Drosophila melanogaster, temperature-sensitive silencers and activators are widely used to control the activities of genetically defined neuronal cell types. A limitation of these thermogenetic approaches, however, has been their poor temporal resolution. Here we introduce FlyMAD (the fly mind-altering device), which allows thermogenetic silencing or activation within seconds or even fractions of a second. Using computer vision, FlyMAD targets an infrared laser to freely walking flies. As a proof of principle, we demonstrated the rapid silencing and activation of neurons involved in locomotion, vision and courtship. The spatial resolution of the focused beam enabled preferential targeting of neurons in the brain or ventral nerve cord. Moreover, the high temporal resolution of FlyMAD allowed us to discover distinct timing relationships for two neuronal cell types previously linked to courtship song.

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.

Dental plaque pH variation with regular soft drink, diet soft drink and high energy drink: an in vivo study.

Science.gov (United States)

Jawale, Bhushan Arun; Bendgude, Vikas; Mahuli, Amit V; Dave, Bhavana; Kulkarni, Harshal; Mittal, Simpy

2012-03-01

A high incidence of dental caries and dental erosion associated with frequent consumption of soft drinks has been reported. The purpose of this study was to evaluate the pH response of dental plaque to a regular, diet and high energy drink. Twenty subjects were recruited for this study. All subjects were between the ages of 20 and 25 and had at least four restored tooth surfaces present. The subjects were asked to refrain from brushing for 48 hours prior to the study. At baseline, plaque pH was measured from four separate locations using harvesting method. Subjects were asked to swish with 15 ml of the respective soft drink for 1 minute. Plaque pH was measured at the four designated tooth sites at 5, 10 and 20 minutes intervals. Subjects then repeated the experiment using the other two soft drinks. pH was minimum for regular soft drink (2.65 ± 0.026) followed by high energy drink (3.39 ± 0.026) and diet soft drink (3.78 ± 0.006). The maximum drop in plaque pH was seen with regular soft drink followed by high energy drink and diet soft drink. Regular soft drink possesses a greater acid challenge potential on enamel than diet and high energy soft drinks. However, in this clinical trial, the pH associated with either soft drink did not reach the critical pH which is expected for enamel demineralization and dissolution.

Hydrolytic stability of heavy metal compounds in fly ash of a heat power plant

International Nuclear Information System (INIS)

Suslova, E.P.; Pertsikov, I.Z.

1991-01-01

Ash and slag from solid fuels are utilized widely in building materials and road surfaces, and in agriculture for soil acidulation. For all these uses it is important to know the amount and form of heavy metal compounds contained in ash and their likely behavior when ash and slag wastes are utilized. Studying the behavior of heavy metals in ash residues at contact with water media is important also because, for most trace elements, the authors lack experimental data that would enable us to predict their behavior after prolonged storage and industrial utilization. The present paper describes a study of lixiviation (at various pH in static conditions) of heavy metals form fly ash obtained by burning Azeisk coal. Homogenized ash selected from electric filter sections 1-4 was used, which has the following composition (%): SiO 2 59.8; Al 2 O 3 ; Fe 23 O 3 7.1; CaO 4.1; MgO 1.3; other 2.8. In a neutral medium, Ni, Cu, Zn, Pb, and Mn lixiviation was slight, amounting to 0.01-0.4%. During coal combustion, these elements apparently form compounds that are slightly soluble in water, although it is also possible that ash retains high adsorptivity for heavy metals. As a result, in these conditions the reverse process of sorption of heavy metals from the solution by fly ash is also possible, which would reduce the heavy metal concentration in the solution

Beam Profile Measurement with Flying Wires at the Fermilab Recycler Ring

CERN Document Server

Hu, Martin; Krider, John; Lorman, Eugene; Marchionni, Alberto; Pishchalnikov, Yu M; Pordes, Stephen; Slimmer, David; Wilson, Peter R; Zagel, James

2005-01-01

The Fermilab Recycler Ring is a high vacuum fixed energy antiproton storage ring with stochastic and electron cooling systems. Flying wires were installed at the Fermilab Recycler Ring for transverse beam profile measurement. The following note describes the system configuration, calibration and resolution of the flying wire system, as well as analysis of the transverse beam profile in the presence of both cooling systems.

[Study on treatment of methylene blue wastewater by fly ash adsorption-Fenton and thermal regeneration].

Science.gov (United States)

Bai, Yu-Jie; Zhang, Ai-Li; Zhou, Ji-Ti

2012-07-01

The physicochemical properties of water-washed fly ash (FA) and acid modified fly ash (M-FA) were investigated. The adsorption of methylene blue by FA and M-FA were studied by batch experiments. Two methods, Fenton-drive oxidation regeneration and thermal regeneration, were used for regeneration of the used FA and M-FA. The result showed that the rate of adsorption process followed the second order kinetics and the adsorption followed Langmuir isotherms. The adsorption equilibrium time was 30 min, and the equilibrium adsorption capacity of FA and M-FA were 4.22 mg x g(-1) and 5.98 mg x g(-1) respectively. The adsorption capability of M-FA was higher than that of FA. In the range of pH 2-12, the adsorption capacity of M-FA increased with the increase of pH, whereas the adsorption capacity of FA decreased slowly until the pH 8 and then increased. Electrostatic adsorption was the major factor on the adsorption capacity. Around 61% and 55% percentage regeneration (PR) were obtained for FA and M-FA respectively when 78.4 mmol x L(-1) H2O2 and 0.72 mmol x L(-1) Fe2+ were used. When the condition of thermal regeneration was 400 degrees C and 2 h, a positive correlation can be found between the PRs of FA and regeneration times, the PRs were 102%, 104% and 107% in three cycles of adsorption-thermal regeneration process. However a negative correlation can be found between the PRs of M-FA and regeneration times, the PRs were 82%, 75% and 74% in three cycles of adsorption-thermal regeneration process. The PR of FA was higher than that of M-FA, and thermal regeneration was superior to Fenton-drive regeneration.

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.

Fly-by-light flight control system technology development plan

Science.gov (United States)

Chakravarty, A.; Berwick, J. W.; Griffith, D. M.; Marston, S. E.; Norton, R. L.

1990-01-01

The results of a four-month, phased effort to develop a Fly-by-Light Technology Development Plan are documented. The technical shortfalls for each phase were identified and a development plan to bridge the technical gap was developed. The production configuration was defined for a 757-type airplane, but it is suggested that the demonstration flight be conducted on the NASA Transport Systems Research Vehicle. The modifications required and verification and validation issues are delineated in this report. A detailed schedule for the phased introduction of fly-by-light system components has been generated. It is concluded that a fiber-optics program would contribute significantly toward developing the required state of readiness that will make a fly-by-light control system not only cost effective but reliable without mitigating the weight and high-energy radio frequency related benefits.

Ionization waves of arbitrary velocity driven by a flying focus

Science.gov (United States)

Palastro, J. P.; Turnbull, D.; Bahk, S.-W.; Follett, R. K.; Shaw, J. L.; Haberberger, D.; Bromage, J.; Froula, D. H.

2018-03-01

A chirped laser pulse focused by a chromatic lens exhibits a dynamic, or flying, focus in which the trajectory of the peak intensity decouples from the group velocity. In a medium, the flying focus can trigger an ionization front that follows this trajectory. By adjusting the chirp, the ionization front can be made to travel at an arbitrary velocity along the optical axis. We present analytical calculations and simulations describing the propagation of the flying focus pulse, the self-similar form of its intensity profile, and ionization wave formation. The ability to control the speed of the ionization wave and, in conjunction, mitigate plasma refraction has the potential to advance several laser-based applications, including Raman amplification, photon acceleration, high-order-harmonic generation, and THz generation.

Properties of Fly Ash Blocks Made from Adobe Mould

Science.gov (United States)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-06-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

Properties of Fly Ash Blocks Made from Adobe Mould

Science.gov (United States)

Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

2018-02-01

Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

Efficacy of Different Sampling Methods of Sand Flies (Diptera: Psychodidae in Endemic Focus of Cutaneous Leishmaniasis in Kashan District, Isfahan Province, Iran.

Directory of Open Access Journals (Sweden)

Marzieh Hesam-Mohammadi

2014-12-01

Full Text Available The aim of the study was to evaluate and compare the efficiency and practicality of seven trapping methods for adult phlebotominae sand flies. The results of this investigation provide information to determine the species composition and nocturnal activity pattern of different sand fly species.The study was carried out in both plain region (about 5km far from northeast and mountainous region (about 40km far from southwest of Kashan City. Seven traps were selected as sampling methods and sand flies were collected during 5 interval times starting July to September 2011 and from 8:00PM to 6:00AM in outdoors habitats. The traps include: sticky traps (4 papers for 2 hours, Disney trap, Malaise, CDC and CO2 light traps, Shannon traps (black and white nets and animal-baited trap.A total of 1445 sand flies belonging to 15 species of Phlebotomus spp. and five of Sergentomyia spp. were collected. Females and males comprised 44.91% and 55.09% of catches, respectively. Of the collected specimens, Se. sintoni was found to be the most prevalent (37.86% species, while Ph. papatasi, accounted for 31.76% of the sand flies.Disney trap and sticky traps exhibited the most productivity than other traps. In addition, in terms of the efficiency of sampling method, these two trapping methods appeared to be the most productive for both estimating the number of sand flies and the species composition in the study area.

The Use Of Local Product Yeast For Substitution Torula Yeast In The Formulation Of Artificial Diet Fruit Fly Larvae Bactrocera Carambolae Drew and Hancock

International Nuclear Information System (INIS)

Sikumbang, I.; Nasution, A.I.; Indarwatmi, M.; Kuswandi, A.N.

2000-01-01

The use of local product yeast I.e brewer yeast, yeast of tapai (fermented cassava), yeast of tempe (fermented soy beam), and brem(intoxicating beverage made of fermented rice) after cooked and uncooked were used to substitute torula yeast to reduce cost production for mass-rearing of fruit fly had been carried out. Artificial diet formulation consisted of torula yeast, wheat bran, nipagin, sodium benzoate, cane sugar, water and HCI ti make pH of 4. One kilogram of diet was inoculated with 1 ml of fruit fly eggs. Parameters of the experiment were, the number of pupae, weight of pupae, percentage of pupae and the percentage of viable fly. The results showed that the number of pupae were 6356 for brewers yeast with cooked and 0.942 gram/100 pupae for brem. Percentage viable emergence fly were 70%, 18.25% and 15.25% for brewers yeast with cooked and uncooked respectively. Cost production for 1.000.000 using cooked brewer yeast was reduced about Rp.179,200 or cost efficiency were 55.56%

High Sensitivity pH Sensor Based on Porous Silicon (PSi Extended Gate Field-Effect Transistor

Directory of Open Access Journals (Sweden)

Naif H. Al-Hardan

2016-06-01

Full Text Available In this study, porous silicon (PSi was prepared and tested as an extended gate field-effect transistor (EGFET for pH sensing. The prepared PSi has pore sizes in the range of 500 to 750 nm with a depth of approximately 42 µm. The results of testing PSi for hydrogen ion sensing in different pH buffer solutions reveal that the PSi has a sensitivity value of 66 mV/pH that is considered a super Nernstian value. The sensor considers stability to be in the pH range of 2 to 12. The hysteresis values of the prepared PSi sensor were approximately 8.2 and 10.5 mV in the low and high pH loop, respectively. The result of this study reveals a promising application of PSi in the field for detecting hydrogen ions in different solutions.

Physics-Based Virtual Fly-Outs of Projectiles on Supercomputers

National Research Council Canada - National Science Library

Sahu, Jubaraj

2006-01-01

...) have been successfully fully coupled on high performance computing (HPC) platforms for Virtual Fly-Outs of guided munitions identical to actual free flight tests in the aerodynamic experimental facilities...

Plant growth on 'fly ash'

Energy Technology Data Exchange (ETDEWEB)

Holliday, R; Hodgson, D R; Townsend, W N; Wood, J W

1958-04-12

Plants were grown in plot and pot experiments to assess the toxicity of the fly ash. It was found that plants grouped into three classes: tolerant, moderately tolerant, and sensitive. Boron was found to be a major compoent of the toxic principle of fly ash.

Synthesis of a nano-crystalline solid acid catalyst from fly ash and its catalytic performance

Energy Technology Data Exchange (ETDEWEB)

Chitralekha Khatri; Ashu Rani [Government P.G. College, Kota (India). Environmental Chemistry Laboratory

2008-10-15

The synthesis of nano-crystalline activated fly ash catalyst (AFAC) with crystallite size of 12 nm was carried out by chemical and thermal treatment of fly ash, a waste material generated from coal-burning power plants. Fly ash was chemically activated using sulfuric acid followed by thermal activation at 600{sup o}C. The variation of surface and physico-chemical properties of the fly ash by activation methods resulted in improved acidity and therefore, catalytic activity for acid catalyzed reactions. The AFAC was characterized by X-ray diffraction, FT-IR spectroscopy, N{sub 2}-adsorption-desorption isotherm, scanning electron microscopy, flame atomic absorption spectrophotometry and sulfur content by CHNS/O elemental analysis. It showed amorphous nature due to high silica content (81%) and possessed high BET surface area (120 m{sup 2}/g). The catalyst was found to be highly active solid acid catalyst for liquid phase esterification of salicylic acid with acetic anhydride and methanol giving acetylsalicylic acid and methyl salicylate respectively. A maximum yield of 97% with high purity of acetylsalicylic acid (aspirin) and a very high conversion 87% of salicylic acid to methyl salicylate (oil of wintergreen) was obtained with AFAC. The surface acidity and therefore, catalytic activity in AFAC was originated by increased silica content, hydroxyl content and higher surface area as compared to fly ash. The study shows that coal generated fly ash can be converted into potential solid acid catalyst for acid catalyzed reactions. Furthermore, this catalyst may replace conventional environmentally hazardous homogeneous liquid acids making an ecofriendly; solvent free, atom efficient, solid acid based catalytic process. 27 refs., 5 figs., 2 tabs.

Future fly ash marketing; Flugaschevermarktung in der Zukunft

Energy Technology Data Exchange (ETDEWEB)

Mauder, R.; Hugot, A. [Evonik Power Minerals GmbH, Dinslaken (Germany)

2008-07-01

It can be assumed that the fly ash production volumes will undergo a marked increase over the next few years. The conditions of fly ash production will improve as a result of modern and refurbished power plants, yielding a positive effect on the quality of fly ashes. Other vital parameters of future fly ash marketing are fly ash logistics and the infrastructure of power plants. Basically, economic utilisation of the increased production volumes is possible; however, new and long-term strategies are necessary. (orig.)

Impaired drug absorption due to high stomach pH: a review of strategies for mitigation of such effect to enable pharmaceutical product development.

Science.gov (United States)

Mitra, Amitava; Kesisoglou, Filippos

2013-11-04

Published reports have clearly shown that weakly basic drugs which have low solubility at high pH could have impaired absorption in patients with high gastric pH thus leading to reduced and variable bioavailability. Since such reduction in exposure can lead to significant loss of efficacy, it is imperative to (1) understand the behavior of the compound as a function of stomach pH to inform of any risk of bioavailability loss in clinical studies and (2) develop a robust formulation which can provide adequate exposure in achlorhydric patients. In this review paper, we provide an overview of the factors that can cause high gastric pH in human, discuss clinical and preclinical pharmacokinetic data for weak bases under conditions of normal and high gastric pH, and give examples of formulation strategies to minimize or mitigate the reduced absorption of weakly basic drugs under high gastric pH conditions. It should be noted that the ability to overcome pH sensitivity issues is highly compound dependent and there are no obvious and general solutions to overcome such effect. Further, we discuss, along with several examples, the use of biopharmaceutical tools such as in vitro dissolution, absorption modeling, and gastric pH modified animal models to assess absorption risk of weak bases in high gastric pH and also the use of these tools to enable development of formulations to mitigate such effects.

Microstructure and mechanical properties of aluminum–fly ash nano composites made by ultrasonic method

International Nuclear Information System (INIS)

Narasimha Murthy, I.; Venkata Rao, D.; Babu Rao, J.

2012-01-01

Highlights: ► Nano structured fly ash has been produced by 30 h milling time. ► Al–fly ash nano composites were produced by ultrasonic cavitation route. ► A homogeneous distribution of nano fly ash particles was observed in the matrix. ► No additional contamination in the nano composites from the atmosphere. ► Presence of nano fly ash leads to improvement in the strength of the composites. -- Abstract: In this paper an attempt has been made to modify the micro sized fly ash into nano structured fly ash using high energy ball mill. Ball milling was carried out for the total duration of 30 h. The sample was taken out after every 5 h of milling for characterizing. The nano structured fly ash was characterized for its crystallite size and lattice strain by using X-ray diffractometer. It was found that a steady decrease in the crystallite size and increased lattice strain was observed with milling time; the crystallite size at 30 h milling time was found to be 23 nm. The fresh fly ash particles are mostly spherical in shape; whereas the shape of the 30 h milled fly ash particles is irregular and the surface morphology is rough. Al–fly ash nano composites were produced by ultrasonic cavitation route successfully. Scanning electron microscopy images of nano composites reveal a homogeneous distribution of the nano fly ash particles in the AA 2024 matrix. Energy dispersive spectroscopy analysis of nano composites reveals that the fabricated nano composite did not contain any additional contamination from the atmosphere. As the amount of nano fly ash is increasing the hardness of the composite also increasing. The nano fly ash addition leads to improvement in the compression strength of the composites.

Cylindrical Electrolyser Enhanced Electrokinetic Remediation of Municipal Solid Waste Incineration Fly Ashes

Science.gov (United States)

Huang, Tao; Zhou, Lulu; Tao, Junjun; Liu, Longfei

2018-01-01

The paper discusses enhancement and efficiency of removing spiked heavy metal (HM) contaminants from the municipal solid waste incineration (MSWI) fly ashes in the cylindrical electrolyser device. The characterization parameters of the electrolyte solution pH, electric current, electrical conductivity, voltage gradient were discussed after the experiment. The chemical speciation of HMs was analysed between the original samples and remediated ones by BCR sequential extraction. The detoxification efficiencies of Zn, Pb, Cu and Cd in the column-uniform device were compared with that in the traditional rectangular apparatus. The pH value changed smoothly with small amplitude of oscillation in general in cathode and anode compartments except the initial break. The electrical current rapidly increased on the first day of the experiment and steadily declined after that and the electrical conductivity presented a clear rising trend. The residual partition of detoxified samples were obviously lifted which was much higher than the analysis data of the raw materials. The pH and the electrical conductivity in sample region were distributed more uniformly and the blind area was effectively eliminated in the electrolytic cells which was indirectly validated by the contrastive detoxification result of the spiked HMs between the rectangular and cylindrical devices.

Adsorption characteristics of Cs"+ onto artificial zeolites synthesized from coal fly ash and diatomite

International Nuclear Information System (INIS)

Johan, Erni; Yoshida, Kohei; Itagaki, Yoshiteru; Aono, Hiromichi; Munthali, Moses Wazingwa; Matsue, Naoto

2015-01-01

The radioactive decontamination of water, soil and other materials requires cheap and effective adsorbents. Artificial zeolites synthesized from an industrial waste (coal fly ash: Na-P1 type zeolite) and a natural material (diatomite: mordenite type zeolite) have a high Cs"+ adsorptivity in the adsorption experiments using 0.1 g of the zeolite and 50 mL of up to 7.5 mM CsCl. The coexisting cation suppressed the Cs"+ adsorption onto the zeolites, and the effect of the suppression was in the order, K"+ > Na"+ > Ca"2"+ > Mg"2"+. A thermodynamic analysis proved that the Cs"+ adsorption onto the two zeolites was exothermic favoring a lower temperature. The artificial mordenite showed a greater Cs"+ adsorption strength, higher distribution coefficient and lower ΔG°, especially at low Cs"+ concentrations. Adsorption isotherm analysis by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models showed a greater Cs"+ adsorption selectivity for the artificial mordenite even at a low pH. (author)

Characterization of upgraded hydrogel biochar from blended rice husk with coal fly ash

Science.gov (United States)

Ahmad, Nurul Farhana; Alias, Azil Bahari; Talib, Norhayati; Rashid, Zulkifli Abd; Ghani, Wan Azlina Wan Ab Karim

2017-12-01

Rice husk biochar (RB) blended with coal fly ash (CFA) is used as a material to develop hydrogel for heavy metal removal. This combination, namely hydrogel rice husk biochar-coal fly ash (HRB-CFA) composite is synthesized by embedding the biochar into acrylamide (AAM) as monomer, with N,N'-Methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator. While activated carbon (AC) remains an expensive material, HRB-CFA is attracting great interest for its use in the absorption of organic contaminants due to its low material cost and importance as renewable source for securing future energy supply in the environmental system. Although the CFA does not have the surface area as high as AC, certain metallic components that are naturally present in the CFA can play the catalytic role in the removal of heavy metal from wastewater. The percentage of heavy metal removal is depends on the parameters that influence the sorption process; the effect of pH solution, dosage of adsorbent, initial concentration of solution, and contact time. The aim of this study is to characterize HRB-CFA by performing several analyses such as the Brunauer-Emmett-Teller (BET), thermogravimetric (TGA) and field emission scanning electron microscopy (FESEM) methods. The results obtained revealed that the best hydrogel ratio is 0.5:0.5 of blended RB and CFA, as proven by BET surface area, pore volume and pore size of 3.5392 m2/g, 0.00849 cm3/g and 90.566 Å, and the surface morphology showed an increase in porosity size.

Radon exhalation study from cement, cement slabs and concrete slabs with variation in fly ash

International Nuclear Information System (INIS)

Sharma, Nisha; Singh, Jaspal

2012-01-01

Fly ash is a waste product from coal-fired power plants. Fly ash has become a subject of world-wide interest in recent years because of its diverse uses, e.g. in the manufacture of concrete for building purposes, for the filling of underground cavities, or as a component of building material. The fly ash may contain enhanced levels of the natural radionuclides in the uranium and thorium series and by using the fly ash in building materials, the radiation levels in houses may thus be technologically enhanced. Because of its relatively high radionuclide contents (including 226 Ra), fly ash may, however, present a potential hazard to the population through its radon emanation, which would be highly undesirable. Since fly ash is frequently used as a building material, the idea of the experiment was to mix fly ash in different proportions in the cement in the powder form, cemented slabs and concrete slabs to study the combined behaviors. Alpha sensitive LR-115 type II plastic track detector, commonly known as Solid State Nuclear Track Detectors (SSNTDs), were used to measure the radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The chemical etching in NaOH at 60°C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon concentrations were determined. In case of cement in the powder form and in cemented slab, starting from the pure cement, fly ash was added up to 70% by weight. In this case the radon exhalation rate has increased by addition of fly ash in the cement and in case of concrete slabs by the addition of fly ash in the cement the radon exhalation increases up to 60% and then decreases. Therefore, on the basis of our investigations we concluded that in general radon exhalation rate increases with the addition of fly ash. (author)

Evaluation of surveillance methods for monitoring house fly abundance and activity on large commercial dairy operations.

Science.gov (United States)

Gerry, Alec C; Higginbotham, G E; Periera, L N; Lam, A; Shelton, C R

2011-06-01

Relative house fly, Musca domestica L., activity at three large dairies in central California was monitored during the peak fly activity period from June to August 2005 by using spot cards, fly tapes, bait traps, and Alsynite traps. Counts for all monitoring methods were significantly related at two of three dairies; with spot card counts significantly related to fly tape counts recorded the same week, and both spot card counts and fly tape counts significantly related to bait trap counts 1-2 wk later. Mean fly counts differed significantly between dairies, but a significant interaction between dairies sampled and monitoring methods used demonstrates that between-dairy comparisons are unwise. Estimate precision was determined by the coefficient of variability (CV) (or SE/mean). Using a CV = 0.15 as a desired level of estimate precision and assuming an integrate pest management (IPM) action threshold near the peak house fly activity measured by each monitoring method, house fly monitoring at a large dairy would require 12 spot cards placed in midafternoon shaded fly resting sites near cattle or seven bait traps placed in open areas near cattle. Software (FlySpotter; http://ucanr.org/ sites/FlySpotter/download/) using computer vision technology was developed to count fly spots on a scanned image of a spot card to dramatically reduce time invested in monitoring house flies. Counts provided by the FlySpotter software were highly correlated to visual counts. The use of spot cards for monitoring house flies is recommended for dairy IPM programs.

Effects of Iodide and Hydrogen Peroxide on Measuring High Temperature pH in Various Lithium Borate Buffer Solutions

Energy Technology Data Exchange (ETDEWEB)

Hwang, Jae Sik; Yun, Myung Hee; Yeon, Jei Won; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-10-15

In a reactor coolant system of nuclear power plants, the need for reliable high temperature pH electrodes has resulted from interests in the corrosion and corrosion product behaviors of the structural materials in a high temperature coolant system. In developing the electrodes for measuring the high temperature pH of aqueous solutions, it is necessary to note two major problems: the chemical stability of an electrode against other chemical impurities, and an electrode's integrity as the temperature and pressure are varied between operational extremes. Over the past decade Macdonald et al. and Danielson et al. have developed many ceramic membrane pH electrodes based on a yttrium stabilized zirconium oxide. However, there are still many experimental difficulties associated with the problems in obtaining electrochemical information across different pressure boundaries and against many kinds of chemical impurities caused by the radiolysis of water and the leakage of a fuel clad. In the present work, we investigated the effects of the environmental factors on a high temperature pH. The selected environmental factors are as follows: system pressure, and chemical species such as iodide and hydrogen peroxide ions.

Can Escherichia coli fly? The role of flies as transmitters of E. coli to food in an urban slum in Bangladesh.

Science.gov (United States)

Lindeberg, Yrja Lisa; Egedal, Karen; Hossain, Zenat Zebin; Phelps, Matthew; Tulsiani, Suhella; Farhana, Israt; Begum, Anowara; Jensen, Peter Kjaer Mackie

2018-01-01

To investigate the transmission of faecal bacteria by flies to food under natural settings. Over a period of 2 months, paired (exposed and non-exposed) containers with cooked rice were placed on the ground in kitchen areas in an urban slum area in Dhaka, Bangladesh, and the numbers of flies landing on the exposed rice were counted. Following exposure, the surface of the rice was microbiologically and molecularly analysed for the presence of Escherichia coli and genes of diarrhoeagenic E. coli and Shigella strains. Rice was at greater risk (P E. coli if flies landed on the rice than if no flies landed on the rice (odds ratio 5·4 (P 0·6 × 103 CFU. Genes of diarrhoeagenic E. coli and Shigella species were detected in 39 of 60 (65%) of exposed rice samples. Two fly species were identified: the common housefly (Musca domestica) and the oriental latrine fly (Chrysomya megacephala). Flies may transmit large quantities of E. coli to food under field settings. The findings highlight the importance of implementing control measures to minimise exposure of food to flies to ensure food safety. Fly control measures should be considered for the prevention of diarrhoeal diseases caused by E. coli. © 2017 John Wiley & Sons Ltd.

Diurnal variation in ruminal pH on the digestibility of highly digestible perennial ryegrass during continuous culture fermentation.

Science.gov (United States)

Wales, W J; Kolver, E S; Thorne, P L; Egan, A R

2004-06-01

Dairy cows grazing high-digestibility pastures exhibit pronounced diurnal variation in ruminal pH, with pH being below values considered optimal for digestion. Using a dual-flow continuous culture system, the hypothesis that minimizing diurnal variation in pH would improve digestion of pasture when pH was low, but not at a higher pH, was tested. Four treatments were imposed, with pH either allowed to exhibit normal diurnal variation around an average pH of 6.1 or 5.6, or maintained at constant pH. Digesta samples were collected during the last 3 d of each of four, 9-d experimental periods. A constant pH at 5.6 compared with a constant pH of 6.1 reduced the digestibility of organic matter (OM), neutral detergent (NDF), and acid detergent fiber (ADF) by 7, 14, and 21%, respectively. When pH was allowed to vary (averaging 5.6), digestion of OM, NDF, and ADF were reduced by 15,30, and 36%, respectively, compared with pH varying at 6.1. There was little difference in digestion parameters when pH was either constant or varied with an average pH of 6.1. However, when average pH was 5.6, maintaining a constant pH significantly increased digestion of OM, NDF, and ADF by 5, 25, and 24% compared with a pH that exhibited normal diurnal variation. These in vitro results show that gains in digestibility and potential milk production can be made by minimizing diurnal variation in ruminal pH, but only when ruminal pH is low (5.6). However, larger gains in productivity can be achieved by increasing average daily ruminal pH from 5.6 to 6.1.

Loss of FliL alters Proteus mirabilis surface sensing and temperature-dependent swarming.

Science.gov (United States)

Lee, Yi-Ying; Belas, Robert

2015-01-01

Proteus mirabilis is a dimorphic motile bacterium well known for its flagellum-dependent swarming motility over surfaces. In liquid, P. mirabilis cells are 1.5- to 2.0-μm swimmer cells with 4 to 6 flagella. When P. mirabilis encounters a solid surface, where flagellar rotation is limited, swimmer cells differentiate into elongated (10- to 80-μm), highly flagellated swarmer cells. In order for P. mirabilis to swarm, it first needs to detect a surface. The ubiquitous but functionally enigmatic flagellar basal body protein FliL is involved in P. mirabilis surface sensing. Previous studies have suggested that FliL is essential for swarming through its involvement in viscosity-dependent monitoring of flagellar rotation. In this study, we constructed and characterized ΔfliL mutants of P. mirabilis and Escherichia coli. Unexpectedly and unlike other fliL mutants, both P. mirabilis and E. coli ΔfliL cells swarm (Swr(+)). Further analysis revealed that P. mirabilis ΔfliL cells also exhibit an alteration in their ability to sense a surface: e.g., ΔfliL P. mirabilis cells swarm precociously over surfaces with low viscosity that normally impede wild-type swarming. Precocious swarming is due to an increase in the number of elongated swarmer cells in the population. Loss of fliL also results in an inhibition of swarming at <30°C. E. coli ΔfliL cells also exhibit temperature-sensitive swarming. These results suggest an involvement of FliL in the energetics and function of the flagellar motor. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Effect of using FLiBe and FLiNaBe molten salts bearing plutonium fluorides on the neutronic performance of PACER

International Nuclear Information System (INIS)

Acir, Adem

2012-01-01

In this paper, the effects of using FLiBe and FLiNaBe Molten Salts Bearing Plutonium Fluorides on the neutronic performance of the PACER are investigated. The optimum radial thickness for tritium self-sufficiency of the blankets addition of plutonium fluorides to FLiNaBe (LiF-/NaF BeF 2 ) and FLiBe (LiF-/BeF 2 ) of a dual purpose modified PACER concept are determined. The calculations are carried out with the one dimensional transport code XSDRNPM/SCALE5. The tritium breeding capacities of FLiNaBe and FLiBe with addition of plutonium fluorides in molten salt zone are investigated and compared. The optimum molten salt zone thickness is computed as 155 cm for tritium self-sufficiency of the blankets using FLiBe +1% PuF 4 whereas, the optimum thickness with FLiNaBe +1% PuF 4 is calculated as 170 cm. In addition, neutron transport calculations have been performed to evaluate the energy multiplication factor, total fission rate, displacement per atom and helium gas generation for optimal radial thickness in the blanket. Also, the tritium production and the radiation damage limits should be evaluated together in a fusion blanket for determining the optimum thickness of molten salt layer. (orig.)

Assessment of high performance concrete containing fly ash and calcium nitrite based corrosion inhibitor as a mean to prevent the corrosion of reinforcing steel

International Nuclear Information System (INIS)

Montes-García, P; Jiménez-Quero, V; López-Calvo, H

2015-01-01

This research analyses the effectiveness of the water-to-cement ratio (w/c), fly ash and a calcium nitrite based corrosion inhibitor to prevent the corrosion of reinforcing steel embedded in high performance concrete. The interactive effect between the inhibitor and fly ash was evaluated because the occurrence of a negative effect when both ingredients are added together in a concrete mixture has been reported. All the concrete mixtures studied in this investigation had 8.2% of silica fume. Twenty seven prismatic concrete specimens were fabricated with dimensions of 55 × 230 × 300 mm each containing two steel rods embedded for the purpose of corrosion monitoring. The specimens were exposed to a simulated marine environment with two daily cycles of wetting and drying for one year. To evaluate the deterioration of the specimens corrosion potentials and linear polarization resistance tests were carried out. The results indicate that the use of a low w/c, the addition of fly ash and the addition of the corrosion inhibitor contributed to the reduction of the corrosion of steel in the concrete specimens. The results further suggest that the combination of fly ash and corrosion inhibitor does not promote the deterioration of the concrete matrix

The specificity of host-bat fly interaction networks across vegetation and seasonal variation.

Science.gov (United States)

Zarazúa-Carbajal, Mariana; Saldaña-Vázquez, Romeo A; Sandoval-Ruiz, César A; Stoner, Kathryn E; Benitez-Malvido, Julieta

2016-10-01

Vegetation type and seasonality promote changes in the species composition and abundance of parasite hosts. However, it is poorly known how these variables affect host-parasite interaction networks. This information is important to understand the dynamics of parasite-host relationships according to biotic and abiotic changes. We compared the specialization of host-bat fly interaction networks, as well as bat fly and host species composition between upland dry forest and riparian forest and between dry and rainy seasons in a tropical dry forest in Jalisco, Mexico. Bat flies were surveyed by direct collection from bats. Our results showed that host-bat fly interaction networks were more specialized in upland dry forest compared to riparian forest. Bat fly species composition was different between the dry and rainy seasons, while host species composition was different between upland dry forest and riparian forest. The higher specialization in upland dry forest could be related to the differences in bat host species composition and their respective roosting habits. Variation in the composition of bat fly species between dry and rainy seasons coincides with the seasonal shifts in their species richness. Our study confirms the high specialization of host-bat fly interactions and shows the importance of biotic and abiotic factors to understand the dynamics of parasite-host interactions.

Estimation of Hydrazine Decomposition on Measuring the High-Temperature pH in Hydrazine/ETA Solutions at 553 K

International Nuclear Information System (INIS)

Hwang, Jae Sik; Yeon, Jei Won; Yun, Myung Hee; Song, Kyu Seok; Lee, Sang Ill

2010-01-01

Hydrazine is one of the most excellent oxygen scavengers used in the secondary circuit of nuclear power plants. Furthermore, in some pants, the hydrazine is used as a source of hydrogen required to suppress radiolysis of the coolant water in the primary loop. When hydrazine was exposed in the high temperature and high pressure water, it can be decomposed into the various products such as NH 3 , N 2 , H 2 , and NO 3 ions. As the result, the pH of solution containing hydrazine in the condition of the high temperature and high pressure can be changed by those decomposed products. In the present work, we investigated the decomposition behavior of hydrazine in ETA (ethanol amine) solution. In addition, we measured the high temperature pH at 553 K on the various hydrazine/ETA solutions for confirming the applicability of the yttria stabilized zirconia (YSZ)- based pH electrode in secondary circuit of the nuclear power plants

Synthesis of zeolite from coal fly ashes with different silica-alumina composition

Energy Technology Data Exchange (ETDEWEB)

Miki Inada; Yukari Eguchi; Naoya Enomoto; Junichi Hojo [Kyushu University, Fukuoka (Japan). Department of Chemistry and Biochemistry, Graduate School of Engineering

2005-02-01

Coal fly ashes can be converted into zeolites by hydrothermal alkaline treatment. This study focuses on the effect of Si/Al molar ratio of the fly ash source on the type of formed zeolite, which also is affected by the alkaline condition. The fly ashes were mixed with an aqueous NaOH solution and hydrothermally treated at about 100{degree}C. Zeolite Na-P1 and/or hydroxy-sodalite appeared after the treatment. Zeolite Na-P1 predominantly formed from silica-rich fly ash at a low-NaOH concentration. The cation exchange capacity of the product with a large content of zeolite Na-P1 reached a value of 300 meq/100 g. The type of the product was controlled by addition of aerosil silica or alumina. It was found that silica addition effectively enhances the formation of zeolite Na-P1, even at a high-NaOH concentration. These results were discussed on the basis of a formation mechanism of zeolite from coal fly ash through dissolution-precipitation process. 10 refs., 6 figs., 1 tab.

Flying the Needles: Flight Deck Automation Erodes Fine-Motor Flying Skills Among Airline Pilots.

Science.gov (United States)

Haslbeck, Andreas; Hoermann, Hans-Juergen

2016-06-01

The aim of this study was to evaluate the influence of practice and training on fine-motor flying skills during a manual instrument landing system (ILS) approach. There is an ongoing debate that manual flying skills of long-haul crews suffer from a lack of flight practice due to conducting only a few flights per month and the intensive use of automation. However, objective evidence is rare. One hundred twenty-six randomly selected airline pilots had to perform a manual flight scenario with a raw data precision approach. Pilots were assigned to four equal groups according to their level of practice and training by fleet (short-haul, long-haul) and rank (first officer, captain). Average ILS deviation scores differed significantly in relation to the group assignments. The strongest predictor variable was fleet, indicating degraded performance among long-haul pilots. Manual flying skills are subject to erosion due to a lack of practice on long-haul fleets: All results support the conclusion that recent flight practice is a significantly stronger predictor for fine-motor flying performance than the time period since flight school or even the total or type-specific flight experience. Long-haul crews have to be supported in a timely manner by adequate training tailored to address manual skills or by operational provisions like mixed-fleet flying or more frequent transitions between short-haul and long-haul operation. © 2016, Human Factors and Ergonomics Society.

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

A Dual-Mode Large-Arrayed CMOS ISFET Sensor for Accurate and High-Throughput pH Sensing in Biomedical Diagnosis.

Science.gov (United States)

Huang, Xiwei; Yu, Hao; Liu, Xu; Jiang, Yu; Yan, Mei; Wu, Dongping

2015-09-01

The existing ISFET-based DNA sequencing detects hydrogen ions released during the polymerization of DNA strands on microbeads, which are scattered into microwell array above the ISFET sensor with unknown distribution. However, false pH detection happens at empty microwells due to crosstalk from neighboring microbeads. In this paper, a dual-mode CMOS ISFET sensor is proposed to have accurate pH detection toward DNA sequencing. Dual-mode sensing, optical and chemical modes, is realized by integrating a CMOS image sensor (CIS) with ISFET pH sensor, and is fabricated in a standard 0.18-μm CIS process. With accurate determination of microbead physical locations with CIS pixel by contact imaging, the dual-mode sensor can correlate local pH for one DNA slice at one location-determined microbead, which can result in improved pH detection accuracy. Moreover, toward a high-throughput DNA sequencing, a correlated-double-sampling readout that supports large array for both modes is deployed to reduce pixel-to-pixel nonuniformity such as threshold voltage mismatch. The proposed CMOS dual-mode sensor is experimentally examined to show a well correlated pH map and optical image for microbeads with a pH sensitivity of 26.2 mV/pH, a fixed pattern noise (FPN) reduction from 4% to 0.3%, and a readout speed of 1200 frames/s. A dual-mode CMOS ISFET sensor with suppressed FPN for accurate large-arrayed pH sensing is proposed and demonstrated with state-of-the-art measured results toward accurate and high-throughput DNA sequencing. The developed dual-mode CMOS ISFET sensor has great potential for future personal genome diagnostics with high accuracy and low cost.

Flying Training Capacity Model: Initial Results

National Research Council Canada - National Science Library

Lynch, Susan

2005-01-01

OBJECTIVE: (1) Determine the flying training capacity for 6 bases: * Sheppard AFB * Randolph AFB * Moody AFB * Columbus AFB * Laughlin AFB * Vance AFB * (2) Develop versatile flying training capacity simulation model for AETC...

Louse flies on birds of Baja California

OpenAIRE

Tella, José Luis; Rodríguez-Estrella, Ricardo; Blanco, Guillermo

2000-01-01

Louse flies were collected from 401 birds of 32 species captured in autumn of 1996 in Baja California Sur (México). Only one louse fly species (Microlynchia pusilla) was found. It occurred in four of the 164 common ground doves (Columbina passerina) collected. This is a new a host species for this louse fly.

Stepwise adsorption of phenanthrene at the fly ash-water interface as affected by solution chemistry: experimental and modeling studies.

Science.gov (United States)

An, Chunjiang; Huang, Guohe

2012-11-20

Fly ash (FA) is predominantly generated from coal-fired power plants. Contamination during disposal of FA can cause significant environmental problems. Knowledge about the interaction of FA and hydrophobic organic pollutants in the environment is very limited. This study investigated the adsorption of phenanthrene at the interface of FA and water. The performance of phenanthrene adsorption on FA and the effects of various aqueous chemistry conditions were evaluated. The adsorption isotherms exhibited an increasing trend in the adsorbed amounts of phenanthrene, while a stepwise pattern was apparent. A stepwise multisite Langmuir model was developed to simulate the stepwise adsorption process. The adsorption of phenanthrene onto FA was noted to be spontaneous at all temperatures. The thermodynamic results indicated that the adsorption was an exothermic process. The adsorption capacity gradually decreased as pH increased from 4 to 8; however, this trend became less significant when pH was changed from 8 to 10. The binding affinity of phenanthrene to FA increased after the addition of humic acid (HA). The pH variation was also responsible for the changes of phenanthrene adsorption on FA in the presence of HA. High ionic strength corresponded to low mobility of phenanthrene in the FA-water system. Results of this study can help reveal the migration patterns of organic contaminants in the FA-water system and facilitate environmental risk assessment at FA disposal sites.

Eradicating tsetse flies: Senegal nears first victory

International Nuclear Information System (INIS)

Dixit, Aabha

2015-01-01

After a four-year eradication programme including nuclear techniques, the Niayes region of Senegal is now almost free of the tsetse fly, which used to decimate livestock. “I have not seen a single tsetse fly for a year now,” said cattle farmer Oumar Sow. “This is in contrast to earlier, when they increased in numbers, especially during the cold season. The flies were really a nuisance to our animals and we had to carefully select the time for milking. Now, there is no problem with that.” The tsetse fly is a bloodsucking insect that kills more than three million livestock in sub-Saharan Africa every year, costing the agriculture industry more than US $4 billion annually. The tsetse fly transmits parasites that cause a wasting disease called nagana in cattle. In some parts of Africa the fly also causes over 75 000 cases of human ‘sleeping sickness’, which affects the central nervous system, and causes disorientation, personality changes, slurred speech, seizures, difficulty walking and talking, and ultimately death.

Modeling a Million-Node Slim Fly Network Using Parallel Discrete-Event Simulation

Energy Technology Data Exchange (ETDEWEB)

Wolfe, Noah; Carothers, Christopher; Mubarak, Misbah; Ross, Robert; Carns, Philip

2016-05-15

As supercomputers close in on exascale performance, the increased number of processors and processing power translates to an increased demand on the underlying network interconnect. The Slim Fly network topology, a new lowdiameter and low-latency interconnection network, is gaining interest as one possible solution for next-generation supercomputing interconnect systems. In this paper, we present a high-fidelity Slim Fly it-level model leveraging the Rensselaer Optimistic Simulation System (ROSS) and Co-Design of Exascale Storage (CODES) frameworks. We validate our Slim Fly model with the Kathareios et al. Slim Fly model results provided at moderately sized network scales. We further scale the model size up to n unprecedented 1 million compute nodes; and through visualization of network simulation metrics such as link bandwidth, packet latency, and port occupancy, we get an insight into the network behavior at the million-node scale. We also show linear strong scaling of the Slim Fly model on an Intel cluster achieving a peak event rate of 36 million events per second using 128 MPI tasks to process 7 billion events. Detailed analysis of the underlying discrete-event simulation performance shows that a million-node Slim Fly model simulation can execute in 198 seconds on the Intel cluster.

Characteristic fly-ash particles from oil-shale combustion found in lake sediments

International Nuclear Information System (INIS)

Alliksaar, T.; Hoerstedt, P.; Renberg, I.

1998-01-01

Fly-ash particles accumulate in sediments and can be used to assess spatial distribution and temporal trends of atmospheric deposition of pollutants derived from high temperature combustion of fossil fuels. Previous work has concerned fly-ash derived from oil and coal. Oil-shale is the main fossil fuel used in Estonia and a major source of atmospheric pollution in the Baltic states. To assess if oil-shale power plants produce specific fly-ash particles scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were used to compare fly-ash particles from oil-shale combustion with particles from oil and coal combustion. Two types were analysed, large black (10-30μm) and small glassy (< 5 μm) spheroidal particles. Although article morphology to some extent is indicative of the fuel burnt, morphological characters are not sufficient to differentiate between particles of different origin. However, the results indicate that with EDX analysis the fly-ash from oil-shale can be distinguished form oil and coal derived particles in environmental samples. Concentrations of large black and small glassy spheroidal fly-ash particles in a sediment core from an Estonian lake showed similar trends to oil-shale combustion statistics from Estonian power plants. 27 refs., 6 figs., 2 tabs

The Mexican Fruit Fly Eradication Programme

Energy Technology Data Exchange (ETDEWEB)

Reyes F, Jesus; Santiago M, Guillermo; Hernandez M, Porfirio [Comision Nacional de Sanidad Agropecuaria (Mexico)

2000-07-01

The goal of the Mexican Fruit Fly Eradication Programme is to control, suppress or eradicate from Mexico four species of fruit flies of economic and quarantine importance (Anastrepha ludens Loew, A. obliqua Macquart, A. serpentina Wied. and A. striata Schiner). These pests cause damage amounting to US$710 million per year. In addition to this cost, there are other expenses from pest control actions and the loss of international markets, because fruit importing countries have established stringent quarantine measures to restrict the entry of these pests. For purposes of the programme's implementation, Mexico was divided into three working zones, defined by agro-ecological characteristics, the number of fruit fly species present and the size of fruit growing regions. In addition, a cost:benefit analysis was carried out which indicated that the rate of return, in a 12-year time frame, might be as much as 33:1 in Northern Mexico, and 17:1 in the rest of the country, for an area over 100,000 hectares. Eradication technology involves: 1) surveys of pest populations by trapping and host fruit harvesting to monitor the presence and density of fruit flies, 2) reduction of pest populations applying cultural practices and using selective bait sprays, 3) mass release of sterile flies and augmentative release of parasitoids to eliminate populations and, 4) enforcement of quarantine measures to protect fruit fly free areas.

The Mexican Fruit Fly Eradication Programme

International Nuclear Information System (INIS)

Reyes F, Jesus; Santiago M, Guillermo; Hernandez M, Porfirio

2000-01-01

The goal of the Mexican Fruit Fly Eradication Programme is to control, suppress or eradicate from Mexico four species of fruit flies of economic and quarantine importance (Anastrepha ludens Loew, A. obliqua Macquart, A. serpentina Wied. and A. striata Schiner). These pests cause damage amounting to US$710 million per year. In addition to this cost, there are other expenses from pest control actions and the loss of international markets, because fruit importing countries have established stringent quarantine measures to restrict the entry of these pests. For purposes of the programme's implementation, Mexico was divided into three working zones, defined by agro-ecological characteristics, the number of fruit fly species present and the size of fruit growing regions. In addition, a cost:benefit analysis was carried out which indicated that the rate of return, in a 12-year time frame, might be as much as 33:1 in Northern Mexico, and 17:1 in the rest of the country, for an area over 100,000 hectares. Eradication technology involves: 1) surveys of pest populations by trapping and host fruit harvesting to monitor the presence and density of fruit flies, 2) reduction of pest populations applying cultural practices and using selective bait sprays, 3) mass release of sterile flies and augmentative release of parasitoids to eliminate populations and, 4) enforcement of quarantine measures to protect fruit fly free areas

Aerodynamic characteristics of flying fish in gliding flight.