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Sample records for gas-promoted oil agglomeration

  1. Development of a Gas-Promoted Oil Agglomeration Process

    SciTech Connect

    C. Nelson; F. Zhang; J. Drzymala; M. Shen; R. Abbott; T. D. Wheelock

    1997-11-01

    The preliminary laboratory-scale development of a gas-promoted, oil agglomeration process for cleaning coal was carried out with scale model mixing systems in which aqueous suspensions of ultrafine coal particles were treated with a liquid hydrocarbon and a small amount of air. The resulting agglomerates were recovered by screening. During a batch agglomeration test the progress of agglomeration was monitored by observing changes in agitator torque in the case of concentrated suspensions or by observing changes in turbidity in the case of dilute suspensions. Dilute suspensions were employed for investigating the kinetics of agglomeration, whereas concentrated suspensions were used for determining parameters that characterize the process of agglomeration. A key parameter turned out to be the minimum time te required to produce compact spherical agglomerates. Other important parameters included the projected area mean particle diameter of the agglomerates recovered at the end of a test as well as the ash content and yield of agglomerates. Batch agglomeration tests were conducted with geometrically similar mixing tanks which ranged in volume from 0.346 to 11.07 liters. Each tank was enclosed to control the amount of air present. A variable speed agitator fitted with a six blade turbine impeller was used for agitation. Tests were conducted with moderately hydrophobic Pittsburgh No. 8 coal and with more hydrophobic Upper Freeport coal using either n-heptane, i-octane, or hexadecane as an agglomerant.

  2. Development of a Gas-Promoted Oil Agglomeration Process

    SciTech Connect

    M. Shen; R. Abbott; T. D. Wheelock

    1998-10-30

    Two series of agglomeration tests were conducted as part of an effort to find a suitable basis for size scale-up of the mixing system used for a gas-promoted oil agglomeration process. In the first series of tests the agitator impeller diameter and speed were varied among runs so as to vary impeller tip speed and agitator power independently while keeping other conditions constant. In the second series of tests the mixing tank size and agitator speed were varied while the ratio of tank diameter to impeller diameter were held constant. All tests were conducted with finely ground Pittsburgh No. 8 coal and with i-octane as the agglomerant. The results of these tests showed that the minimum time te required to produce spherical agglomerates was predominantly a function of the agitator power input per unit volume. In addition, the size of the agglomerates produced in a given time was also strongly dependent on power input. At lower power input levels, the mean size rose as power input increased until a point was reached where agglomerate breakage became important and the mean size decreased. The results also showed that the ash content of the agglomerates produced in a given time tended to decrease with increasing power input. On the other hand, the recovery of clean coal on a dry, ash-free basis was not greatly affected by power input.

  3. Preliminary characterization of a gas-promoted oil agglomeration process

    SciTech Connect

    Drzymala, J.; Wheelock, T.D.

    1996-12-31

    The agglomeration of aqueous suspensions of Pittsburgh No. 8 coal particles with i-octane was studied by employing a scale model mixing system which measured both agitator speed and torque. The progress of agglomeration was monitored by observing changes in agitator torque and was confirmed by examining samples of the suspension with an optical microscope. When a suspension containing 30 w/w% solids was degassed and then conditioned with 20 v/w% i-octane (20 ml i-octane/100 g coal), no agglomeration took place until a small amount of air (e.g., 9 v/w%) was introduced. Subsequent changes in agitator torque indicated that the ensuing process of agglomeration was complex and consisted of several stages involving various interactions between coal particles, oil drops, and gas bubbles. The time required to produce spherical agglomerates was determined for different experimental conditions by conducting a number of agglomeration tests involving different mixing tank sizes and different impeller sizes and speeds. The results indicate that agglomeration time decreases with increasing power input per unit volume and increasing gas concentration.

  4. Development of a Gas-Promoted Oil Agglomeration Process

    SciTech Connect

    M. Shen; T. D. Wheelock

    1998-10-30

    Further agglomeration tests were conducted in a series of tests designed to determine the effects of various parameters on the size and structure of the agglomerates formed, the rate of agglomeration, coal recovery, and ash rejection. For this series of tests, finely ground Pittsburgh No. 8 coal has been agglomerated with i-octane in a closed mixing system with a controlled amount of air present to promote particle agglomeration. The present results provide further evidence of the role played by air. As the concentration of air in the system was increased from 4.5 to 18 v/w% based on the weight of coal, coal recovery and ash rejection both increased. The results also show that coal recovery and ash rejection were improved by increasing agitator speed. On the other hand, coal recovery was not affected by a change in solids concentration from 20 to 30 w/w%.

  5. Coal beneficiation kinetics of a gas-promoted oil agglomeration process

    SciTech Connect

    Zhang, F.; Wheelock, T.D.

    1996-12-31

    The kinetics of a gas-promoted oil agglomeration process were investigated by monitoring the change in the turbidity of an aqueous particle suspension as the particles were agglomerated with heptane in a closed tank fitted with baffles and an agitator. Measured amounts of air and heptane were added to a suspension of Pittsburgh No. 8 coal under vigorous agitation. The subsequent rate of change of particle concentration was taken to be an indication of the rate of agglomeration. The rate was found to be proportional to the particle number concentration raised to a power and dependent on agitator speed and the amounts of air and oil added.

  6. Development of a gas-promoted oil agglomeration process. Quarterly technical progress report, July 1, 1995--September 30, 1995

    SciTech Connect

    Wheelock, T.D.

    1995-12-31

    The preliminary laboratory-scale development of a gas-promoted, oil agglomeration process for cleaning coal advanced in three major research areas. One area of research resulted in the development of a method for measuring the rate of agglomeration of dilute particle suspensions and using the method to relate the rate of agglomeration of coal particles to various key parameters. A second area of research led to the development of a method for monitoring a batch agglomeration process by measuring changes in agitator torque. With this method it was possible to show that the agglomeration of a concentrated coal particle suspension is triggered by the introduction of a small amount of gas. The method was also used in conjunction with optical microscopy to study the mechanism of agglomeration. A third area of research led to the discovery that highly hydrophobic particles in an aqueous suspension can be agglomerated by air alone.

  7. Development of a gas-promoted oil agglomeration process. Technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Wheelock, T.D.

    1995-12-01

    Several scale model mixing systems have been built and are being utilized to study the gas-promoted, oil agglomeration process for cleaning coal. Numerous batch agglomeration tests have been conducted with these systems. During an individual test the progress of agglomeration has been monitored by observing either changes in agitator torque in the case of concentrated particle suspensions or changes in turbidity in the case of dilute suspensions. A mathematical model has been developed for relating the rate of agglomeration of coal particles to the rate of change of turbidity of a dilute particle suspension undergoing agglomeration. The model has been utilized for analyzing and interpreting the results of a number of oil agglomeration tests in which several different system parameters were varied.

  8. Development of a gas-promoted oil agglomeration process. [Quarterly] technical progress report, September 1, 1993--November 30, 1993

    SciTech Connect

    Wheelock, T.D.

    1993-12-31

    The overall purpose of this research project is to carry out the preliminary laboratory-scale development of a gas-promoted, oil agglomeration process for cleaning coal using model mixing systems. Previous research showed that having a gas present in an agitated system used for the agglomeration of an aqueous suspension of coal particles with oil would reduce greatly the required mixing shear rate and power input. To take advantage of this discovery, the present research project was initiated. The project will involve building and testing two model mixing systems which differ in scale but are representative of standard industrial mixing systems used for mixing solid particles, liquid, and gas. These systems will be tested by conducting oil agglomeration tests under various conditions and measuring agitator torque and power as well as agglomeration performance. Special attention will be given to the effects produced by having gas present in the system.

  9. Development of a gas-promoted oil agglomeration process. Quarterly technical progress report, October 1--December 31, 1995

    SciTech Connect

    Wheelock, T.D.

    1996-07-01

    The overall purpose of this research project is to carry out the preliminary laboratory-scale development of a gas-promoted, oil agglomeration process for cleaning coal using model mixing systems. Specific objectives include determining the nature of the gas promotion mechanism, the effects of hydrodynamic factors and key parameters on process performance, and a suitable basis for size scale-up of the mixing system. An investigation of the phenomena which occur during the oil agglomeration of coal particle suspensions showed that the process of agglomeration involves several step which can be identified by changes in agitator torque and by application of optical microscopy. During one of these steps, aggregation of hydrophobic particles and microflocs takes place on the surface of gas bubbles dispersed in the suspension with the result that large flocs or flakes are produced which subsequently evolve into agglomerates. The time required to produce spherical agglomerates appears to be a function of the power input per unit volume with the time decreasing as the power input increases.

  10. Development of a gas-promoted oil agglomeration process. Technical progress report, December 1, 1993--February 28, 1994

    SciTech Connect

    Wheelock, T.D.; Drzymala, J.; Zhang, F.

    1994-05-01

    The overall purpose of this research project is to carry out the preliminary laboratory-scale development of a gas-promoted, oil agglomeration process for cleaning coal using model mixing systems. A model mixing system has been previously designed and constructed for conducting oil agglomeration tests in such a way that agitator speed and torque can be measured as well as agglomeration performance. Equipment is also provided for monitoring the progress of agglomeration during a batch test. This equipment includes a photometric dispersion analyzer for measuring the turbidity of the particle suspension. In order to measure the turbidity a small stream of material is withdrawn from the mixing tank and conducted through an optical cell associated with the photometric dispersion analyzer. The material is then returned to the mixing tank. A peristaltic pump located between the optical cell and the mixing tank is used for circulating the material. During the past quarter a series of shakedown test were carried out to calibrate the equipment and to determine some of its operating characteristics. The accuracy of the agitator speed and torque measuring instrument was checked. Also the gas dispersing effectiveness of the mixing system was investigated. In addition, the effects of agitator speed and solids concentration on agitator torque and power requirements were studied.

  11. Development of a gas-promoted oil agglomeration process. Technical progress report, October 1, 1993--September 30, 1994

    SciTech Connect

    Wheelock, T.D.

    1994-10-01

    During the first year of the project two model mixing systems, which differed in size but were similar in design, were constructed and tested. The systems were equipped for measuring agitator speed and torque and for measuring the turbidity of coal particle suspensions undergoing agglomeration. Preliminary measurements of aqueous suspensions of coal particles showed that the Beer-Lambert law applies to such suspensions at least for low concentrations. Therefore, the measured turbidity can be used as an indicator of particle concentration and a means for monitoring the progress of oil agglomeration. However, the method is not applicable for large particle concentrations so a different technique was tested for monitoring the agglomeration of large concentrations. This technique involves measuring agitator torque and observing changes in torque while agitator speed is held constant. The results of preliminary tests of the technique were encouraging. In these tests significant changes in agitator torque were observed when particle agglomeration took place as long as solids concentration of 25 w/v % or more were utilized. A number of agglomeration tests were conducted using either one or the other of the two monitoring techniques. Both methods showed that even very small amounts of air can promote the oil agglomeration of coal particles suspended in water. Even the amount of air dissolved in water at room temperature and pressure can affect the process providing the air is displaced from the solution by a slightly soluble agglomerant such as heptane. The apparent rate of agglomeration was observed to increase as more air was introduced and also as agitator speed was increased.

  12. Development of a gas-promoted oil agglomeration process. Quarterly technical progress report, July 1--September 30, 1996

    SciTech Connect

    Wheelock, T.D.

    1996-09-01

    The series of agglomeration tests designed to study the agglomeration characteristics of Pittsburgh No. 8 coal with i-octane was continued using a larger agitated tank. This series is designed to determine the effects of various parameters on the size and structure of the agglomerates formed, the rate of agglomeration, coal recovery, and ash rejection. The results reported here show that once spherical agglomerates are formed they continue to grow at almost a constant rate which is proportional to the concentration of i-octane. The constant growth rate is interrupted when spherical agglomerates combine to form large clusters. This only seems to occur with a large concentration of i-octane (e.g., 30 v/w%) and limited agitator power. The present results also show that coal recovery and ash rejection are highly dependent on agglomerate size when the mean agglomerate diameter is less than the size of the openings in the screen used for recovering the agglomerates.

  13. Development of a gas-promoted oil agglomeration process. Quarterly report, October 1, 1996--December 31, 1996

    SciTech Connect

    Wheelock, T.D.

    1996-12-01

    Further agglomeration tests were conducted in a series of tests designed to determine the effects of various parameters on the size and structure of the agglomerates formed, the rate of agglomeration, coal recovery, and ash rejection. For this series of tests, finely ground Pittsburgh No. 8 coal has been agglomerated with i-octane in a closed mixing system with a controlled amount of air present to promote particle agglomeration. The present results provide further evidence of the role played by air. As the concentration of air in the system was increased from 4.5 to 18 v/w% based on the weight of coal, coal recovery and ash rejection both increased. The results also show that coal recovery and ash rejection were improved by increasing agitator speed. On the other hand, coal recovery was not affected by a change in solids concentration from 20 to 30 w/w%.

  14. Low-rank coal oil agglomeration

    DOEpatents

    Knudson, Curtis L.; Timpe, Ronald C.

    1991-01-01

    A low-rank coal oil agglomeration process. High mineral content, a high ash content subbituminous coals are effectively agglomerated with a bridging oil which is partially water soluble and capable of entering the pore structure, and usually coal derived.

  15. Low-rank coal oil agglomeration

    DOEpatents

    Knudson, C.L.; Timpe, R.C.

    1991-07-16

    A low-rank coal oil agglomeration process is described. High mineral content, a high ash content subbituminous coals are effectively agglomerated with a bridging oil which is partially water soluble and capable of entering the pore structure, and is usually coal-derived.

  16. Selective oil agglomeration of lignite

    SciTech Connect

    Halime Abakay Temel; Volkan Bozkurt; Arun Kumar Majumder

    2009-01-15

    In this study, desulfurization and deashing of Adiyaman-Glbai lignite by the agglomeration method were studied. For this purpose, three groups of agglomeration experiments were made. The effects of solid concentration, bridging liquid type and dosage, pH, and screen size on the agglomeration after desliming were investigated in the first group of experiments. The effects of lake water and sea water (the Mediterranean Sea water, the Aegean Sea water, and the Black Sea water) on the agglomeration were investigated in the second group of experiments. The effects of different salts (NaCl, MgCl{sub 2}, and FeCl{sub 3}) on the agglomeration were investigated in the third group of experiments. Agglomeration results showed that the usage of sea waters and soda lake water in the agglomeration medium had a positive effect on the reduction of total sulfur content of agglomerates. In addition, the usage of NaCl, MgCl{sub 2}, and FeCl{sub 3} in the agglomeration medium had a positive effect on the ash content reduction of the agglomerates. 27 refs., 10 figs., 6 tabs.

  17. Low-rank coal oil agglomeration product and process

    DOEpatents

    Knudson, Curtis L.; Timpe, Ronald C.; Potas, Todd A.; DeWall, Raymond A.; Musich, Mark A.

    1992-01-01

    A selectively-sized, raw, low-rank coal is processed to produce a low ash and relative water-free agglomerate with an enhanced heating value and a hardness sufficient to produce a non-decrepitating, shippable fuel. The low-rank coal is treated, under high shear conditions, in the first stage to cause ash reduction and subsequent surface modification which is necessary to facilitate agglomerate formation. In the second stage the treated low-rank coal is contacted with bridging and binding oils under low shear conditions to produce agglomerates of selected size. The bridging and binding oils may be coal or petroleum derived. The process incorporates a thermal deoiling step whereby the bridging oil may be completely or partially recovered from the agglomerate; whereas, partial recovery of the bridging oil functions to leave as an agglomerate binder, the heavy constituents of the bridging oil. The recovered oil is suitable for recycling to the agglomeration step or can serve as a value-added product.

  18. Low-rank coal oil agglomeration product and process

    DOEpatents

    Knudson, C.L.; Timpe, R.C.; Potas, T.A.; DeWall, R.A.; Musich, M.A.

    1992-11-10

    A selectively-sized, raw, low-rank coal is processed to produce a low ash and relative water-free agglomerate with an enhanced heating value and a hardness sufficient to produce a non-degradable, shippable fuel. The low-rank coal is treated, under high shear conditions, in the first stage to cause ash reduction and subsequent surface modification which is necessary to facilitate agglomerate formation. In the second stage the treated low-rank coal is contacted with bridging and binding oils under low shear conditions to produce agglomerates of selected size. The bridging and binding oils may be coal or petroleum derived. The process incorporates a thermal deoiling step whereby the bridging oil may be completely or partially recovered from the agglomerate; whereas, partial recovery of the bridging oil functions to leave as an agglomerate binder, the heavy constituents of the bridging oil. The recovered oil is suitable for recycling to the agglomeration step or can serve as a value-added product.

  19. Basic principles and mechanisms of selective oil agglomeration

    SciTech Connect

    Wheelock, T.D.; Drzymala, J.; Allen, R.W.; Hu, Y.-C.; Tyson, D.; Xiaoping, Qiu; Lessa, A.

    1990-01-01

    Numerous measurements of the heat of immersion of coal were conducting using several different particle size fractions of No. 2 Gas Seam coal from Raleigh County, West Virginia. The heat of immersion was determined in water, methanol, heptane, hexadecane and neohexane (2,2-dimethybutane). A comparison of the results with those determined previously for Illinois No. 6 coal is discussed. A number of potential pyrite depressants for use in oil agglomeration of coal were screened by testing the response of sulfidized mineral pyrite to agglomeration with heptane in the presence of the potential depressant. The following were tested; sodium dithionite, sodium thiosulfate, ferrous sulfate, ferric sulfate, titanous chloride, hydrogen peroxide, Oxone (a form of potassium monopersulfate), pyrogallol, quebracho (colloidal dispersant derived from tree bark), milk whey, and several organic thiols. Ferric chloride was applied to mixtures of Upper Freeport coal and sulfidized mineral pyrite before subjecting the mixtures to agglomeration with heptane. 7 refs., 23 figs., 3 tabs.

  20. Development of a full scale selective oil agglomeration plant

    SciTech Connect

    Donnelly, J.C.; Cooney, B.; Hoare, I.; Waugh, B.; Robinson, R.

    1998-12-31

    A research and development program managed by Australian Mining Investments Limited (AMI) on behalf of an investment syndicate was conducted with the objective of improving the efficiency and economy of the Selective Oil Agglomeration Process (SOAP), and developing viable commercial sized operating plants. Fewer than half the coal preparation plants in Australia beneficiate fine coal by froth flotation, the only viable alternative to SOAP for the recovery of low ash, fine and ultra fine coal. Those plants without flotation generally dispose of the ultra fine material, approximately {minus}100{micro}m in size, as tailings to waste. In the majority of cases this ultra fine waste contains more than 50% relatively low ash coal of saleable quality. It is believed that this coal constitutes a loss of 8--10 million tonnes per annum and that the coal mining industry would welcome a recovery process which has low capital and operating costs and will function automatically with minimal operator attention. The authors carried out a comprehensive literature study of selective oil agglomeration in order to gain a full understanding of the process and to plan the research program. Extensive studies were then undertaken on oil dispersion in the water phase, formation of oil water emulsions with surfactants and the optimization of surfactant selection. Oil and emulsion properties were investigated including stability, viscosity, temperature, concentration of components, time of formation, and cost. This work was followed by characterization studies on coals from the Gunnedah Basin and agglomeration test work on these coals. These agglomeration studies were performed firstly at bench level and then by using a small, 200 kg/hr continuous process development unit. The results were sufficiently encouraging to justify the design and construction of a fully instrumented, PLC controlled, 2 tph pilot plant at Gunnedah Colliery Coal Preparation Plant. Extensive trials were carried out on

  1. Field observations of artificial sand and oil agglomerates

    USGS Publications Warehouse

    Dalyander, Patricia (Soupy); Long, Joseph W.; Plant, Nathaniel G.; McLaughlin, Molly R.; Mickey, Rangley C.

    2015-01-01

    Oil that comes into the surf zone following spills, such as occurred during the 2010 Deepwater Horizon (DWH) blowout, can mix with local sediment to form heavier-than-water sand and oil agglomerates (SOAs), at times in the form of mats a few centimeters thick and tens of meters long. Smaller agglomerates that form in situ or pieces that break off of larger mats, sometimes referred to as surface residual balls (SRBs), range in size from sand-sized grains to patty-shaped pieces several centimeters (cm) in diameter. These mobile SOAs can cause beach oiling for extended periods following the spill, on the scale of years as in the case of DWH. Limited research, including a prior effort by the U.S. Geological Survey (USGS) investigating SOA mobility, alongshore transport, and seafloor interaction using numerical model output, focused on the physical dynamics of SOAs. To address this data gap, we constructed artificial sand and oil agglomerates (aSOAs) with sand and paraffin wax to mimic the size and density of genuine SOAs. These aSOAs were deployed in the nearshore off the coast of St. Petersburg, Florida, during a field experiment to investigate their movement and seafloor interaction. This report presents the methodology for constructing aSOAs and describes the field experiment. Data acquired during the field campaign, including videos and images of aSOA movement in the nearshore (1.5-meter and 0.5-meter water depth) and in the swash zone, are also presented in this report.

  2. Nearshore dynamics of artificial sand and oil agglomerates

    USGS Publications Warehouse

    Dalyander, P. Soupy; Plant, Nathaniel G.; Long, Joseph W.; McLaughlin, Molly R.

    2015-01-01

    Weathered oil can mix with sediment to form heavier-than-water sand and oil agglomerates (SOAs) that can cause beach re-oiling for years after a spill. Few studies have focused on the physical dynamics of SOAs. In this study, artificial SOAs (aSOAs) were created and deployed in the nearshore, and shear stress-based mobility formulations were assessed to predict SOA response. Prediction sensitivity to uncertainty in hydrodynamic conditions and shear stress parameterizations were explored. Critical stress estimates accounting for large particle exposure in a mixed bed gave the best predictions of mobility under shoaling and breaking waves. In the surf zone, the 10-cm aSOA was immobile and began to bury in the seafloor while smaller size classes dispersed alongshore. aSOAs up to 5 cm in diameter were frequently mobilized in the swash zone. The uncertainty in predicting aSOA dynamics reflects a broader uncertainty in applying mobility and transport formulations to cm-sized particles.

  3. Factors affecting the oil agglomeration of Sivas-Divrigi Ulucayir lignite

    SciTech Connect

    Unal, I.; Gorgun Ersan, M.

    2007-07-01

    In the coal industry, the coal particles need to be decreased to a very fine size because of the need of removing inorganic materials from coal. Oil agglomeration is a kind of coal cleaning technique that is used for separation of organic and inorganic parts of fine sized coal. In this study, the oil agglomeration of Sivas-Divrigi (S-D) Ulucayir lignite was carried out by using kerosene, diesel oil, fuel oil, poppy oil, and sunflower oil. The amount of bridging oil was varied from 5% to 25% of the amount of lignite. The effect of oil amount, oil type, solid content, agitation rate and time, pH on agglomeration performance was investigated. Maximum recovery value of 98.18% was observed by using poppy oil. In order to investigate the effect of pH on agglomeration NaOH and HCl is added to the slurry in various amounts. It is decided that the best agglomeration condition is obtained at low pH values. The effect of nonionic surface active agent (Igepal-CA 630) on agglomeration is investigated by adding to the slurry and it is observed that the grade is increased with the amount of surface active agent.

  4. New surfactant for hydrate anti-agglomeration in hydrocarbon flowlines and seabed oil capture.

    PubMed

    Sun, Minwei; Firoozabadi, Abbas

    2013-07-15

    Anti-agglomeration is a promising solution for gas hydrate risks in deepsea hydrocarbon flowlines and oil leak captures. Currently ineffectiveness at high water to oil ratios limits such applications. We present experimental results of a new surfactant in rocking cell tests, which show high efficiency at a full range of water to oil ratios; there is no need for presence of the oil phase. We find that our surfactant at a very low concentration (0.2 wt.% of water) keeps the hydrate particles in anti-agglomeration state. We propose a mechanism different from the established water-in-oil emulsion theory in the literature that the process is effective without the oil phase. There is no need to emulsify the water phase in the oil phase for hydrate anti-agglomeration; with oil-in-water emulsion and without emulsion hydrate anti-agglomeration is presented in our research. We expect our work to pave the way for broad applications in offshore natural gas production and seabed oil capture with very small quantities of an eco-friendly surfactant.

  5. POC-Scale Testing of Oil Agglomeration Techniques and Equipment for Fine Coal Processing

    SciTech Connect

    1998-11-12

    The objective of this project is to develop and demonstrate a Proof-of-Concept (POC) scale oil agglomeration technology capable of increasing the recovery and improving the quality of fine coal strearrts. Two distinct agglomeration devices will be tested, namely, a conventional high shear mixer and a jet processor. To meet the overall objective an eleven task work plan has been designed. The work ranges from batch and continuous bench-scale testing through the design, commissioning and field testing of POC-scale agglomeration equipment.

  6. Remediation of oil-contaminated sand by coal agglomeration using ball milling.

    PubMed

    Shin, Yu-Jen; Shen, Yun-Hwei

    2011-10-01

    The mechanical shear force provided by a less energy intensive device (usually operating at 20-200 rpm), a ball mill, was used toperform coal agglomeration and its effects on remediation of a model fuel oil-contaminated sand were evaluated. Important process parameters such as the amount of coal added, milling time, milling speed and the size of milling elements are discussed. The results suggested that highly hydrophobic oil-coal agglomerates, formed by adding suitable amounts of coal into the oil-contaminated sand, could be mechanically liberated from cleaned sand during ball milling and recovered as a surface coating on the steel balls. Over 90% removal of oil from oil-contaminated sand was achieved with 6 wt% of coal addition and an optimum ball milling time of 20 min and speed of 200 rpm. This novel process has considerable potential for cleaning oil-contaminated sands.

  7. Characterization and separation of ash from CANMET coprocessing residue by oil phase agglomeration techniques

    SciTech Connect

    Majid, A.; Coleman, R.D.; Toll, R.; Pleizier, G.; Deslandes, Y.; Sparks, B.D.; Ikura, M.

    1993-12-31

    CANMET`s coal/heavy oil coprocessing unit yields a solid residue that contains most of the ash originally associated with the feed coal as well as reacted catalyst solids. Removal of these ash solids would make it possible to recycle the material to extinction, thereby increasing production of lighter oils. In this investigation the authors have used surface characterization techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA) and X-ray Photoelectron Spectroscopy (XPS) to characterize toluene insoluble solids associated with the pitch residue, in order to evaluate the separation potential using oil phase agglomeration techniques. Washability studies using float-sink tests were also carried out to determine empirically the level of ash separation attainable. Based on the results of these studies several tests were carried out to beneficiate the organic matter in the residue pitch, by using liquid phase agglomeration techniques. Levels of ash rejection in these tests ranged from 20% to 40%. SEM and EDXA analysis of the agglomerated product and the reject material and Inductively Coupled Plasma (ICP) analysis of the ash from both materials suggest that most of the iron from added catalyst is retained in the agglomerates.

  8. Controlling Agglomeration of Protein Aggregates for Structure Formation in Liquid Oil: A Sticky Business

    PubMed Central

    2017-01-01

    Proteins are known to be effective building blocks when it comes to structure formation in aqueous environments. Recently, we have shown that submicron colloidal protein particles can also be used to provide structure to liquid oil and form so-called oleogels (de VriesA.J. Colloid Interface Sci.2017, 486, 75−83)27693552. To prevent particle agglomeration, a solvent exchange procedure was used to transfer the aggregates from water to the oil phase. The aim of the current paper was to elucidate on the enhanced stability against agglomeration of heat-set whey protein isolate (WPI) aggregates to develop an alternative for the solvent exchange procedure. Protein aggregates were transferred from water to several solvents differing in polarity to investigate the effect on agglomeration and changes in protein composition. We show that after drying protein aggregates by evaporation from solvents with a low polarity (e.g., hexane), the protein powder shows good dispersibility in liquid oil compared to powders dried from solvents with a high polarity. This difference in dispersibility could not be related to changes in protein composition or conformation but was instead related to the reduction of attractive capillary forces between the protein aggregates during drying. Following another route, agglomeration was also prevented by applying high freezing rates prior to freeze-drying. The rheological properties of the oleogels prepared with such freeze-dried protein aggregates were shown to be similar to that of oleogels prepared using a solvent exchange procedure. This Research Article provides valuable insights in how to tune the drying process to control protein agglomeration to allow for subsequent structure formation of proteins in liquid oil. PMID:28225592

  9. Controlling Agglomeration of Protein Aggregates for Structure Formation in Liquid Oil: A Sticky Business.

    PubMed

    de Vries, Auke; Lopez Gomez, Yuly; Jansen, Bas; van der Linden, Erik; Scholten, Elke

    2017-03-22

    Proteins are known to be effective building blocks when it comes to structure formation in aqueous environments. Recently, we have shown that submicron colloidal protein particles can also be used to provide structure to liquid oil and form so-called oleogels ( de Vries , A. J. Colloid Interface Sci. 2017 , 486 , 75 - 83 ) . To prevent particle agglomeration, a solvent exchange procedure was used to transfer the aggregates from water to the oil phase. The aim of the current paper was to elucidate on the enhanced stability against agglomeration of heat-set whey protein isolate (WPI) aggregates to develop an alternative for the solvent exchange procedure. Protein aggregates were transferred from water to several solvents differing in polarity to investigate the effect on agglomeration and changes in protein composition. We show that after drying protein aggregates by evaporation from solvents with a low polarity (e.g., hexane), the protein powder shows good dispersibility in liquid oil compared to powders dried from solvents with a high polarity. This difference in dispersibility could not be related to changes in protein composition or conformation but was instead related to the reduction of attractive capillary forces between the protein aggregates during drying. Following another route, agglomeration was also prevented by applying high freezing rates prior to freeze-drying. The rheological properties of the oleogels prepared with such freeze-dried protein aggregates were shown to be similar to that of oleogels prepared using a solvent exchange procedure. This Research Article provides valuable insights in how to tune the drying process to control protein agglomeration to allow for subsequent structure formation of proteins in liquid oil.

  10. TEM and HRTEM of Soot-in-oil particles and agglomerates from internal combustion engines

    NASA Astrophysics Data System (ADS)

    Fay, M. W.; La Rocca, A.; Shayler, P. J.

    2014-06-01

    Over time, the performance of lubricating oil in a diesel engine is affected by the build-up of carbon soot produced by the combustion process. TEM and HRTEM are commonly used to investigate the characteristics of individual and agglomerated particles from diesel exhaust, to understand the structure and distribution of the carbon sheets in the primary particles and the nanostructure morphology. However, high resolution imaging of soot-in-oil is more challenging, as mineral oil is a contaminant for the electron microscope and leads to instability under the electron beam. In this work we compare solvent extraction and centrifugation techniques for removing the mineral oil contaminant, and the effect on particle size distribution.

  11. Assessing mobility and redistribution patterns of sand and oil agglomerates in the surf zone

    USGS Publications Warehouse

    Dalyander, P. Soupy; Long, Joesph W.; Plant, Nathaniel G.; Thompson, David M.

    2014-01-01

    Heavier-than-water sand and oil agglomerates that formed in the surf zone following the Deepwater Horizon oil spill continued to cause beach re-oiling 3 years after initial stranding. To understand this phenomena and inform operational response now and for future spills, a numerical method to assess the mobility and alongshore movement of these “surface residual balls” (SRBs) was developed and applied to the Alabama and western Florida coasts. Alongshore flow and SRB mobility and potential flux were used to identify likely patterns of transport and deposition. Results indicate that under typical calm conditions, cm-size SRBs are unlikely to move alongshore, whereas mobility and transport is likely during storms. The greater mobility of sand compared to SRBs makes burial and exhumation of SRBs likely, and inlets were identified as probable SRB traps. Analysis of field data supports these model results.

  12. Desulfurization and de-ashing of a mixture of subbituminous coal and gangue minerals by selective oil agglomeration

    SciTech Connect

    Ayhan, F.D.

    2009-11-15

    The aim of this study was to investigate desulfurization and de-ashing of a mixture of subbituminous coal and gangue minerals by the agglomeration method. For this purpose, experimental studies were conducted on a mixture containing subbituminous coal, pyrite, quartz and calcite. The effects of some parameters that markedly influence the effectiveness of selective oil agglomeration, such as solid concentration, pH, bridging liquid type and concentration, and depressant type and amount, were investigated. Agglomeration results showed that the usage of various depressants (Na{sub 2}SiO{sub 3}, FeCl3, corn starch, wheat starch) in the agglomeration medium has a positive effect on the reduction of ash and total sulfur content of agglomerates. It was found that an agglomerate product containing 3.03% total sulfur and 25.01% ash with a total sulfur reduction of 56.71% was obtained from a feed that contained 7% total sulfur and 43.58% ash when FeCl{sub 3} was used in the agglomeration medium.

  13. POC-scale testing of oil agglomeration techniques and equipment for fine coal processing

    SciTech Connect

    W. Pawlak; K. Szymocha

    1998-08-01

    This report covers the technical progress achieved from April 1, 1998 to June 30, 1998 on the POC-Scale Testing of Oil Agglomeration Techniques and Equipment for Fine Coal Processing. Continuous bench-scale runs were carried out with Luscar Mine coal. The main objectives were to optimize process conditions for a proposed jet processor and to compare its performance with a standard high-shear mixer. A total of three runs consisted of 15 testing periods was carried out. Both conditioning devices performed very well with combustible matter recovery exceeding 96%. Slightly higher coal recovery was observed for high-shear mixer, while lower ash contents were achieved when jet processor was used for coal conditioning. During the current reporting period work has been continued and completed on the engineering and design package of a 3 t/h POC-scale agglomeration unit. Preliminary design package prepared by Thermo Design Engineering, a subcontractor to this project, was submitted to DOE for revision and approval.

  14. POC-SCALE TESTING OF OIL AGGLOMERATION TECHNIQUES AND EQUIPMENT FOR FINE COAL PROCESSING

    SciTech Connect

    1998-01-01

    This report covers the technical progress achieved from October 1, 1997 to December 31, 1997 on the POC-Scale Testing of Oil Agglomeration Techniques and Equipment for Fine Coal Processing project. Experimental test procedures and the results related to the processing of coal fines originating from process streams generated at the Shoal Creek Mine preparation plant, owned and operated by the Drummond Company Inc. of Alabama, are described. Two samples of coal fines, namely Cyclone Overflow and Pond Fines were investigated. The batch test results showed that by applying the Aglofloat technology a significant ash removal might be achieved at a very high combustible matter recovery: · for the Cyclone Overflow sample the ash reduction was in the range 50 to 55% at combustible matter recovery about 98% · for the Pond Fines sample the ash reduction was up to 48% at combustible matter recovery up to 85%. Additional tests were carried out with the Alberta origin Luscar Mine coal, which will be used for the parametric studies of agglomeration equipment at the 250 kg/h pilot plant. The Luscar coal is very similar to the Mary Lee Coal Group (processed at Shoal Creek Mine preparation plant) in terms of rank and chemical composition.

  15. Basic principles and mechanisms of selective oil agglomeration. Fossil energy interim report, October 1, 1983--September 30, 1992

    SciTech Connect

    Wheelock, T.D.

    1992-12-31

    Numerous agglomeration tests were conducted with several types of low-ash coal and graphite, high grade mineral pyrite, and other materials. Relatively pure hydrocarbons, including heptane and hexadecane, were used as agglomerants. Access of air to the system was controlled. Particle recovery by agglomeration was observed to depend on a number of system parameters. Among the most important parameters are the hydrophobicity of the particles and the oil dosage, so that the, recovery of solids per unit of oil administered is proportional to the hydrophobicity. The pH and ionic strength of the aqueous suspension affect particle recovery in different ways depending on the surface properties of the particles. On the other hand, the presence of air in the system generally improves particle recovery. The greatest effect of air was observed in a closely related study which showed that air had to be present to produce good agglomerates from a moderately hydrophobic coal in a mixer producing a lower shear rate. The rate of agglomeration was found to be much greater for a strongly hydrophobic coal than for a moderately hydrophobic coal, and the rate was observed to be proportional to the oil dosage. Also the rate was enhanced by the presence of air in the, system. For hydrophobic coals, the rate increased with increasing ionic strength of the aqueous medium, but it was not affected greatly by pH over a wide range. The separation of coal and pyrite particles by selective agglomeration was found to depend on the relative hydrophobicity of the materials, the oil dosage, and the properties of the aqueous medium.

  16. The use of starch to enhance sulfur and ash removal from coal by selective oil agglomeration

    SciTech Connect

    Good, R.J.; Badgujar, M.N.

    1990-01-01

    We have found that the use of starch or gelatin, as an additive in the Otisca T-Process of selective oil agglomeration of coal, leads to a considerable improvement in the reduction of pyritic sulfur and of ash-forming minerals. A patent application has been filed; (Good Badgugar). Improvement in rejection of pyritic sulfur by up to 55% has been found, and improvement in ash rejection by up to 28%. Carbon recovery of 97.5 to 99.1% was obtained when the starch concentration was in the range, 30 to 200 ppM in the water. Three different bituminous coals were used: Upper Freeport, Kentucky No. 9, and Illinois No. 6.

  17. POC-scale testing of oil agglomeration techniques and equipment for fine coal processing

    SciTech Connect

    W. Pawlak; K. Szymocha

    1998-04-01

    This report covers the technical progress achieved from January 1, 1998 to April 31, 1998 on the POC-Scale Testing of Oil Agglomeration Techniques and Equipment for Fine Coal Processing. Experimental work was carried out with two coal fines. One sample originated from pond (Drummond Pond Fines) while the second was pulverized Luscar Mine coal. Both samples were tested at the laboratory batch-scale while only Luscar Mine Coal was processed on the 250 kg/h continuous system. Significant progress was made on optimization of process conditions for Pond Fines. The test results showed that ash could be reduced by about 42% at combustible recovery exiting 94%. It was also found that pond fines required significantly longer conditioning time than freshly pulverized run of mine coal. Continuous bench-scale testing carried out with Luscar Mine coal included rod mill calibration, plant equipment and instrumentation check-up, and parametric studies. Compared with batch-scale tests, the continuous bench-scale process required more bridging oil to achieve similar process performance. During the current reporting period work has been commenced on the final engineering and preparation of design package of 3t/h POC-scale unit.

  18. POC-SCALE TESTING OF OIL AGGLOMERATION TECHNIQUES AND EQUIPMENT FOR FINE COAL PROCESSING

    SciTech Connect

    1998-01-01

    This report covers the technical progress achieved from July 01, 1997 to September 30, 1997 on the POC-Scale Testing Agglomeration Techniques and Equipment for Fine Coal Processing project. Experimental procedures and test data for recovery of fine coal from coal fines streams generated at a commercial coal preparation plant are described. Two coal fines streams, namely Sieve Bend Effluent and Cyclone Overflow were investigated. The test results showed that ash was reduced by more than 50% at combustible matter recovery levels exceeding 95%.

  19. POC-scale testing of oil agglomeration techniques and equipment for fine coal processing: technical progress report no. 3--January 1, 1996-March 31, 1996

    SciTech Connect

    1996-10-01

    The objective of this project is to develop and demonstrate a Proof-of-Concept (POC) scale oil agglomeration technology capable of increasing the recovery and improving the quality of fine coal streams. Two distinct agglomeration devices will be tested, namely, a conventional high shear mixer and a tubular (jet) processor. To meet the overall objective an 11 task work plan has been designed. The work will range from batch and continuous bench-scale testing through the design, commissioning and field testing of POC-scale agglomeration equipment. During the reporting period there were activities under the following tasks: project planning and management; host site selection and plan formulation; preliminary engineering and design of POC equipment; coal characterization and laboratory (batch) and bench-scale testing; and process evaluation. The work on the remaining tasks is scheduled for the next months.

  20. POC-scale testing of oil agglomeration techniques and equipment for fine coal processing. Technical report number 2, October 1--December 31, 1995

    SciTech Connect

    1996-07-01

    The objective of this project is to develop and demonstrate a Proof-of-Concept (POC) scale oil agglomeration technology capable of increasing the recovery and improving the quality of fine coal streams. Two distinct agglomeration devices will be tested, namely, a conventional high shear mixer and a tubular (jet) processor. To meet the overall objective an 11 task work plan has been designed. The work will range from batch and continuous bench-scale testing through the design, commissioning and field testing of POC-scale agglomeration equipment. The project includes the following tasks: Project planning and management; host site selection and plan formulation; preliminary engineering and design of POC equipment; coal characterization and laboratory (batch) and bench-scale testing; final engineering and design of POC equipment; proof-of-concept (POC) equipment procurement and fabrication; POC equipment inspection; POC equipment installation, shakedown and operation; process evaluation; dismantling of the system; final report. Accomplishments to date are described on the site selection, a work plan for bench-scale testing, preliminary engineering and design of POC equipment, and coal characterization.

  1. Mechanisms for selective agglomeration of coals

    SciTech Connect

    Wheelock, T.D.; Drzymala, J.; Allen, R.W.; Hu, Y.-C.; Tyson, D.; Xiaoping, Qiu; Lessa, A.

    1989-05-01

    Work continued on the basic mechanisms which underlie various processes for beneficiating aqueous suspensions of coal by selective agglomeration with oil. A new method was demonstrated for characterizing the agglomerability of coal suspensions. This method utilizes a photometric dispersion analyzer to monitor changes in the turbidity of a particle suspension as increasing amounts of oil are added to the suspension in a batch agglomeration test. Agglomeration of the particles leads to a marked decrease in the turbidity of the suspension. Another experimental technique was also demonstrated for characterizing oil agglomeration. This technique involves measuring the rate of growth of agglomerates in a continuous flow system operating under stead-state conditions. The data are analyzed by means of a population balance. The results of a preliminary set of experiments in which Indiana V seam coal was agglomerated with tetralin seemed to fit a particular growth model very well. Equipment was also constructed for studying the kinetics of agglomeration in a batch process. While earlier work showed that quebracho (a commercially available dispersant) is a strong agglomeration depressant for pyrite, recent experiments with mixtures of Upper Freeport coal and mineral pyrite showed that quebracho does not appear to be sufficiently selective. Further consideration was given to the separation of mixtures of coal and pyrite agglomeration with heptane. 2 refs., 17 figs., 1 tab.

  2. The use of starch to enhance sulfur and ash removal from coal by selective oil agglomeration. Quarterly technical progress report No. 12, July 1--September 30, 1990

    SciTech Connect

    Good, R.J.; Badgujar, M.N.

    1990-12-31

    We have found that the use of starch or gelatin, as an additive in the Otisca T-Process of selective oil agglomeration of coal, leads to a considerable improvement in the reduction of pyritic sulfur and of ash-forming minerals. A patent application has been filed; (Good & Badgugar). Improvement in rejection of pyritic sulfur by up to 55% has been found, and improvement in ash rejection by up to 28%. Carbon recovery of 97.5 to 99.1% was obtained when the starch concentration was in the range, 30 to 200 ppM in the water. Three different bituminous coals were used: Upper Freeport, Kentucky No. 9, and Illinois No. 6.

  3. Fuel agglomerates and method of agglomeration

    DOEpatents

    Wen, Wu-Wey

    1986-01-01

    Solid fuel agglomerates are prepared of particulate coal or other carbonaceous material with a binder having a high humic acid or humate salt content. The humic acid is extracted from oxidized carbonaceous material with a mild aqueous alkali solution of, for instance, ammonia. The particulate material is blended with the extract which serves as the binder for the agglomerates. The water-resistant agglomerates are formed such as by pelletizing, followed by drying to remove moisture and solidify the humic acid binder throughout the agglomerate.

  4. Agglomeration of Dust

    SciTech Connect

    Annaratone, B. M.; Arnas, C.; Elskens, Y.

    2008-09-07

    The agglomeration of the matter in plasma, from the atomic level up to millimetre size particles, is here considered. In general we identify a continuous growth, due to deposition, and two agglomeration steps, the first at the level of tens of nanometres and the second above the micron. The agglomeration of nano-particles is attributed to electrostatic forces in presence of charge polarity fluctuations. Here we present a model based on discrete currents. With increasing grain size the positive charge permanence decreases, tending to zero. This effect is only important in the range of nanometre for dust of highly dispersed size. When the inter-particle distance is of the order of the screening length another agglomeration mechanism dominates. It is based on attractive forces, shadow forces or dipole-dipole interaction, overcoming the electrostatic repulsion. In bright plasma radiation pressure also plays a role.

  5. POC-scale testing of oil agglomeration techniques and equipment for fine coal processing. Quarterly report, July 1--September 30, 1997

    SciTech Connect

    Ignasiak, B.; Pawlak, W.; Szymocha, K.

    1997-12-31

    This report covers the technical progress achieved from July 1, 1997 to September 30, 1997 on the POC-Scale Testing Agglomeration Techniques and Equipment for Fine Coal Processing project. Experimental procedures and test data for recovery of fine coal from coal fines streams generated at a commercial coal preparation plant are described. Two coal fines streams, namely Sieve Bend Effluent and Cyclone Overflow were investigated. The test results showed that ash was reduced by more than 50% at combustible matter recovery levels exceeding 95%.

  6. Micro-agglomerate flotation for deep cleaning of coal

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-04-01

    We are investigating the use of a hybrid process, Micro-agglomerate flotation, which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 [mu]m in size) rather than individual coal particles (1--10 [mu]m) the problems of froth overload and water/mineral carryover should be significantly alleviated.Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response.

  7. Micro-agglomerate flotation for deep cleaning of coal

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-01-01

    We are investigating the use of a hybrid process - Micro-agglomerate flotation - which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 [mu]m in size) rather than individual coal particles (1--10 [mu]m) the problems of froth overload and water/mineral carryover should be significantly alleviated. Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response.

  8. Backscattering of agglomerate particles

    NASA Astrophysics Data System (ADS)

    Zubko, Evgenij; Ovcharenko, Andrey; Bondarenko, Sergey; Shkuratov, Yuriy; Scotto, Cathy S.; Merritt, Charles; Hart, Matthew B.; Eversole, Jay D.; Videen, Gorden W.

    2004-12-01

    We examine how aggregation affects the light-scattering signatures, especially the polarization in the near-backward-scattering direction. We use the discrete dipole approximation (DDA) to study the backscatter of agglomerate particles consisting of oblong monomers. We examine the effects of monomer number and packing structure on the resulting negative polarization branch at small phase angle. We find large a dependence on the orientation of the monomers within the agglomerate and a smaller dependence on the number of monomers, suggesting that the mechanism producing the negative polarization minimum depends strongly on the interactions between the individual monomers. We also examine experimental measurements of substrates composed of biological cells. We find that the light-scattering signatures in the backward direction are not only different for different spore species, but for spores that have been prepared using different methodologies. These signatures are reproducible in different substrates composed of the spores from the same batches.

  9. In vitro dosimetry of agglomerates

    NASA Astrophysics Data System (ADS)

    Hirsch, V.; Kinnear, C.; Rodriguez-Lorenzo, L.; Monnier, C. A.; Rothen-Rutishauser, B.; Balog, S.; Petri-Fink, A.

    2014-06-01

    Agglomeration of nanoparticles in biological fluids is a pervasive phenomenon that leads to difficulty in the interpretation of results from in vitro exposure, primarily due to differing particokinetics of agglomerates to nanoparticles. Therefore, well-defined small agglomerates were designed that possessed different particokinetic profiles, and their cellular uptake was compared to a computational model of dosimetry. The approach used here paves the way for a better understanding of the impact of agglomeration on the nanoparticle-cell interaction.Agglomeration of nanoparticles in biological fluids is a pervasive phenomenon that leads to difficulty in the interpretation of results from in vitro exposure, primarily due to differing particokinetics of agglomerates to nanoparticles. Therefore, well-defined small agglomerates were designed that possessed different particokinetic profiles, and their cellular uptake was compared to a computational model of dosimetry. The approach used here paves the way for a better understanding of the impact of agglomeration on the nanoparticle-cell interaction. Electronic supplementary information (ESI) available: ITC data for tiopronin/Au-NP interactions, agglomeration kinetics at different pHs for tiopronin-coated Au-NPs, UV-Vis spectra in water, PBS and DMEM and temporal correlation functions for single Au-NPs and corresponding agglomerates, calculation of diffusion and sedimentation parameters, modelling of relative cell uptake based on the ISDD model and cytotoxicity of single Au-NPs and their agglomerates, and synthesis and cell uptake of large spherical Au-NPs. See DOI: 10.1039/c4nr00460d

  10. Combustion of an oil palm residue with elevated potassium content in a fluidized-bed combustor using alternative bed materials for preventing bed agglomeration.

    PubMed

    Ninduangdee, Pichet; Kuprianov, Vladimir I

    2015-04-01

    Palm kernel shell (PKS) was burned at 45 kg/s and excess air of 20-80% in a fluidized-bed combustor using alumina, dolomite, and limestone as the bed material. Temperature and gas concentrations were recorded along the reactor centerline as well as at stack. A SEM-EDS analysis was performed to investigate morphology and elemental composition of bed particles. An X-ray fluorescence method was used to determine the composition of used/reused bed materials and PM emitted from the combustor at different operating times. Excess air of 40% seems to be most appropriate for burning PKS in this combustor with an alumina bed, whereas 60% excess air is more suitable when using dolomite and limestone, as ensuring high (98.6-98.9%) combustion efficiency and acceptable CO and NO emissions. By using the selected bed materials, bed agglomeration can be prevented in this combustor. However, the bed materials exhibit substantial time-domain changes in physical and chemical properties.

  11. Crystal growth and agglomeration of calcium sulfite hemihydrate crystals

    SciTech Connect

    Tai, C.Y.; Chen, P.C.

    1995-04-01

    Flue gas desulfurization (FGD) processes are most commonly utilized to remove sulfur dioxide from stack gases of coal- or oil-fired plants. In the simple slurry technology, SO{sub 2} is absorbed by a slurry of lime/limestone to form calcium sulfite crystals of acicular habit and its strong agglomeration, requiring large clarifiers and filters to dewater the sludge to make an acceptable landfill. Crystal growth and agglomeration of calcium sulfite hemihydrate crystals from solution were studied by reacting Ca(OH){sub 2} with NaHSO{sub 3} in a pH-stat semibatch crystallizer. Single platelet crystals and agglomerates of platelet crystals were produced in the pH range from 5.80 to 6.80. The crystallization mechanism changed from primary nucleation to crystal growth in the progressive precipitation. Using the titration curves, the growth rate was calculated from the titration rate at the final stage of operation. The crystal growth rates of calcium sulfate hemihydrate crystals were found to obey the parabolic rate law in the low supersaturation range. Another point to be noted is that the precipitates of calcium sulfite hemihydrate in agitated suspensions have a tendency to form agglomerates. It was found that the degree of agglomeration is a weak function of relative supersaturation and magma density, while the pH value is a key factor that affects the degree of agglomeration. Addition of EDTA also has an effect on the agglomeration of calcium sulfite hemihydrates.

  12. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, October 1--December 30, 1995

    SciTech Connect

    Chandler, S.; Hogg, R.

    1996-04-01

    Goals are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process (combination of oil-agglomeration and froth flotation) and to establish the essential criteria for reagent selection and system design and operation. The research program was organized into the following tasks: interfacial studies, emulsification, agglomerate growth and structure, and agglomerate flotation. Work on the first two tasks has been completed.

  13. Particle Agglomeration in Bipolar Barb Agglomerator Under AC Electric Field

    NASA Astrophysics Data System (ADS)

    Huang, Chao; Ma, Xiuqin; Sun, Youshan; Wang, Meiyan; Zhang, Changping; Lou, Yueya

    2015-04-01

    The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious. To improve agglomeration effectiveness of fine particles, a dual zone electric agglomeration device consisting of a charging chamber and an agglomeration chamber with bipolar barb electrodes was developed. The bipolar barb electric agglomerator with a polar distance of 200 mm demonstrates good agglomeration effectiveness for particles with a size less than 8.0 μm under applied AC electric field. An optimal condition for achieving better agglomeration effectiveness was found to be as follows: flue gas flow velocity of 3.00 m/s, particle concentration of 2.00 g/m3, output voltage of 35 kV and length of the barb of 16 mm. In addition, 4.0-6.0 μm particles have the best effectiveness with the variation of particle volume occupancy of -3.2. supported by the Key Technology R&D Program of Hebei, China (No. 13211207D)

  14. Hydrophobic Agglomeration of Mineral Fines in Aqueous Suspensions and its Application in Flotation: a Review

    NASA Astrophysics Data System (ADS)

    Yang, Bingqiao; Song, Shaoxian

    2014-05-01

    Hydrophobic agglomeration is originated from the hydrophobic attraction between particles, which is essentially different from electrolyte coagulation and polymer flocculation. It is applied to mineral processing in floc-flotation process to improve the recovery of mineral fines. In this paper, the applications of this phenomenon in mineral fines were summarized, including the origin of hydrophobic agglomeration, the main factors affect hydrophobic agglomeration (particle hydrophobicity, shear rate and duration, nonpolar oil and tank geometry), as well as hydrophobic agglomeration based separation processes (carrier flotation and floc-flotation).

  15. Recent Advances in Agglomerated Multigrid

    NASA Technical Reports Server (NTRS)

    Nishikawa, Hiroaki; Diskin, Boris; Thomas, James L.; Hammond, Dana P.

    2013-01-01

    We report recent advancements of the agglomerated multigrid methodology for complex flow simulations on fully unstructured grids. An agglomerated multigrid solver is applied to a wide range of test problems from simple two-dimensional geometries to realistic three- dimensional configurations. The solver is evaluated against a single-grid solver and, in some cases, against a structured-grid multigrid solver. Grid and solver issues are identified and overcome, leading to significant improvements over single-grid solvers.

  16. MTCI acoustic agglomeration particulate control

    SciTech Connect

    Chandran, R.R.; Mansour, M.N.; Scaroni, A.W.; Koopmann, G.H.; Loth, J.L.

    1994-10-01

    The overall objective of this project is to demonstrate pulse combination induced acoustic enhancement of coal ash agglomeration and sulfur capture at conditions typical of direct coal-fired turbines and PFBC hot gas cleanup. MTCI has developed an advanced compact pulse combustor island for direct coal-firing in combustion gas turbines. This combustor island comprises a coal-fired pulse combustor, a combined ash agglomeration and sulfur capture chamber (CAASCC), and a hot cyclone. In the MTCI proprietary approach, the pulse combustion-induced high intensity sound waves improve sulfur capture efficiency and ash agglomeration. The resulting agglomerates allow the use of commercial cyclones and achieve very high particulate collection efficiency. In the MTCI proprietary approach, sorbent particles are injected into a gas stream subjected to an intense acoustic field. The acoustic field serves to improve sulfur capture efficiency by enhancing both gas film and intra-particle mass transfer rates. In addition, the sorbent particles act as dynamic filter foci, providing a high density of stagnant agglomerating centers for trapping the finer entrained (in the oscillating flow field) fly ash fractions. A team has been formed with MTCI as the prime contractor and Penn State University and West Virginia University as subcontractors to MTCI. MTCI is focusing on hardware development and system demonstration, PSU is investigating and modeling acoustic agglomeration and sulfur capture, and WVU is studying aerovalve fluid dynamics. Results are presented from all three studies.

  17. Microbial effects on colloidal agglomeration

    SciTech Connect

    Hersman, L.

    1995-11-01

    Colloidal particles are known to enhance the transport of radioactive metals through soil and rock systems. This study was performed to determine if a soil microorganism, isolated from the surface samples collected at Yucca Mountain, NV, could affect the colloidal properties of day particles. The agglomeration of a Wyoming bentonite clay in a sterile uninoculated microbial growth medium was compared to the agglomeration in the medium inoculated with a Pseudomonas sp. In a second experiment, microorganisms were cultured in the succinate medium for 50 h and removed by centrifugation. The agglomeration of the clay in this spent was compared to sterile uninoculated medium. In both experiments, the agglomeration of the clay was greater than that of the sterile, uninoculated control. Based on these results, which indicate that this microorganism enhanced the agglomeration of the bentonite clay, it is possible to say that in the presence of microorganisms colloidal movement through a rock matrix could be reduced because of an overall increase in the size of colloidal particle agglomerates. 32 refs.

  18. Flocculation, hydrophobic agglomeration and filtration of ultrafine coal

    NASA Astrophysics Data System (ADS)

    Yu, Zhimin

    In coal preparation plant circuits, fine coal particles are aggregated either by oil agglomeration or by flocculation. In a new hydrophobic agglomeration process, recently developed hydrophobic latices are utilized. While the selectivity of such aggregation processes determines the beneficiation results, the degree of aggregation has a strong effect on fine coal filtration. The aim of this research was to study the fundamentals and analyze the common grounds for these processes, including the potential effect of the coal surface properties. The selective flocculation tests, in which three types of coal, which differed widely in surface wettability, and three additives (hydrophobic latices, a semi-hydrophobic flocculant and a typical hydrophilic polyelectrolyte) were utilized, showed that coal wettability plays a very important role in selective flocculation. The abstraction of a hydrophobic latex on coal and silica revealed that the latex had a much higher affinity towards hydrophobic coal than to hydrophilic mineral matter. As a result, the UBC-1 hydrophobic latex flocculated only hydrophobic coal particles while the polyelectrolyte (PAM) flocculated all the tested coal samples and minerals, showing no selectivity in the fine coal beneficiation. The oil agglomeration was tested using kerosene emulsified with various surfactants (e.g. cationic, anionic and non-ionic). Surfactants enhance not only oil emulsification, hence reducing oil consumption (down to 0.25--0.5%), but also entirely change the electrokinetic properties of the droplets and affect the interaction energy between oil droplets and coal particles. Consequently, the results found in the course of the experimental work strongly indicate that even oxidized coals can be agglomerated if cationic surfactants are used to emulsify the oil. Oil agglomeration of the Ford-4 ultrafine coal showed that even at extremely low oil consumption (0.25 to 0.5%), a clean coal product with an ash content around 5% at over

  19. Liquid bridge agglomeration: A fundamental approach to toner deinking

    SciTech Connect

    Snyder, B.A.; Berg, J.C. . Chemical Engineering Dept.)

    1994-05-01

    An alternative agglomeration technique for deinking toner-printed furnishes has been investigated. This technique requires only the addition of an immiscible hydrocarbon oil dispersed in water at dosages of approximately 1% by weight on fiber. The addition is made during repulping: the process appears to be effective at all temperatures of interest (23 C and 70 C are tested) and requires no surfactants or additional chemicals. The result of the oil addition is the agglomeration of the toner particles into spheres of 1 mm to 1 cm in size. These spheres contain the added oil which acts as a binder, holding the toner particles together by liquid bridges. The process is ineffective when the furnish contains highly sized fibers or starched paper, and future work seeks to address these crucial problems.

  20. Acoustic agglomeration methods and apparatus

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B. (Inventor)

    1984-01-01

    Methods are described for using acoustic energy to agglomerate fine particles on the order of one micron diameter that are suspended in gas, to provide agglomerates large enough for efficient removal by other techniques. The gas with suspended particles, is passed through the length of a chamber while acoustic energy at a resonant chamber mode is applied to set up one or more acoustic standing wave patterns that vibrate the suspended particles to bring them together so they agglomerate. Several widely different frequencies can be applied to efficiently vibrate particles of widely differing sizes. The standing wave pattern can be applied along directions transversed to the flow of the gas. The particles can be made to move in circles by applying acoustic energy in perpendicular directions with the energy in both directions being of the same wavelength but 90 deg out of phase.

  1. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, July 1-September 30, 1996

    SciTech Connect

    Chander, S.; Hogg, R.

    1996-12-01

    The goals of this research program are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process and to establish the essential criteria for reagent selection and system design and operation. We are investigating the use of a hybrid process - Micro-agglomerate flotation - which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro- agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30-50 mm in size) rather than individual coal particles (1-10 mm) the problems of froth overload and water/mineral carryover should be significantly alleviated.

  2. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, April 1--June 30, 1993

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-07-01

    The goals of this research program are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process and to establish the essential criteria for reagent selection and system design and operation. The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {mu}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. It is generally recognized that surface-based separation processes such as froth flotation or selective agglomeration offer considerable potential for such applications but there remain many problems in obtaining the required selectivity with acceptable recovery of combustible matter. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. The addition of larger amounts of oil can yield large, strong agglomerates which are easily separated but the selectivity is reduced and reagent costs can become excessive. We are investigating the use of a hybrid process -- Micro-agglomerate flotation -- which is a combination of oil agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates.

  3. Coal beneficiation by gas agglomeration

    DOEpatents

    Wheelock, Thomas D.; Meiyu, Shen

    2003-10-14

    Coal beneficiation is achieved by suspending coal fines in a colloidal suspension of microscopic gas bubbles in water under atmospheric conditions to form small agglomerates of the fines adhered by the gas bubbles. The agglomerates are separated, recovered and resuspended in water. Thereafter, the pressure on the suspension is increased above atmospheric to deagglomerate, since the gas bubbles are then re-dissolved in the water. During the deagglomeration step, the mineral matter is dispersed, and when the pressure is released, the coal portion of the deagglomerated gas-saturated water mixture reagglomerates, with the small bubbles now coming out of the solution. The reagglomerate can then be separated to provide purified coal fines without the mineral matter.

  4. Remediation of Sucarnoochee soil by agglomeration with fine coal

    SciTech Connect

    Narayanan, P.S.; Arnold, D.W.; Rahnama, M.B. )

    1994-01-01

    Fine-sized Blue Creek coal was used to remove high molecular weight hydrocarbons from Sucarnoochee soil, a fine-sized high-organic soil. Fine coal in slurry form was blended with Sucarnoochee soil contaminated with 15.0% by wt of crude oil, and agglomerates were removed in a standard flotation cell. Crude oil in the remediated soil was reduced from the original 15.0% to less than a tenth of a wt% by a two-step process. Oil removal of approx. 99.3% was obtained. An added benefit was that the low-grade coal used in the process was simultaneously upgraded. The final level of cleaning was not affected by initial oil concentration. The process compared favorably with a hot water wash technique used to recovery oils from contaminated soil.

  5. Agglomeration of food powder and applications.

    PubMed

    Dhanalakshmi, K; Ghosal, S; Bhattacharya, S

    2011-05-01

    Agglomeration has many applications in food processing and major applications include easy flow table salt, dispersible milk powder and soup mix, instant chocolate mix, beverage powder, compacted cubes for nutritional-intervention program, health bars using expanded/puffed cereals, etc. The main purpose of agglomeration is to improve certain physical properties of food powders such as bulk density, flowability, dispersability, and stability. Agglomerated products are easy to use by the consumers and hence are preferred over the traditional non-agglomerated products that are usually non-flowable in nature. The properties of food agglomerates and the process of agglomeration like employing pressure, extrusion, rewetting, spray-bed drying, steam jet, heat/sintering, and binders have been reviewed. The physical and instant properties of agglomerated food products have also been discussed.

  6. Agglomeration tendency in dry pharmaceutical granular systems.

    PubMed

    Lachiver, Emilie DesRosiers; Abatzoglou, Nicolas; Cartilier, Louis; Simard, Jean-Sébastien

    2006-10-01

    The agglomeration tendency of dry pharmaceutical mixtures containing various concentrations of Xylitab 100 (Xylitol), calcium carbonate precipitated (CCP) and magnesium stearate (MgSt) was evaluated statistically as a function of mixing time. A Ro-Tap tester was employed to mix the three pharmaceutical components, and the agglomerates formed were measured with respect to their weight and size. An experimental design was devised and applied to structure and then statistically analyze the results. Xylitab was found not to be influential in the formation of agglomerates, but aided in deagglomeration when mixed with other components. CCP and MgSt formed agglomerates over time and showed positive interactions favouring agglomeration. The agglomerates started to fracture when they reached a critical size, at which stage the particles' attraction forces (cohesion forces) were weaker than both gravity and inertia. It has been shown and quantitatively demonstrated that the mixing time and ingredient concentrations of a three-component pharmaceutical mixture can affect agglomeration tendency.

  7. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, October 1, 1994--December 31, 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1995-01-01

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 mm) needed to achieve adequate liberation of the mineral matter from the coal matrix. It is generally recognized that surface-based separation processes such as froth flotation or selective agglomeration offer considerable potential for such applications but there remain many problems in obtaining the required selectivity with acceptable recovery of combustible matter. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. The addition of larger amounts of oil can yield large, strong agglomerates which are easily separated but the selectivity is reduced and reagent costs can become excessive. We are investigating the use of a hybrid process - micro-agglomerate flotation - which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30-50 mm in size) rather than individual coal particles (1-10 mm) the problems of froth overload and water/mineral carryover should be significantly alleviated. Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale.

  8. Powder agglomeration in a microgravity environment

    NASA Technical Reports Server (NTRS)

    Cawley, James D.

    1994-01-01

    This is the final report for NASA Grant NAG3-755 entitled 'Powder Agglomeration in a Microgravity Environment.' The research program included both two types of numerical models and two types of experiments. The numerical modeling included the use of Monte Carlo type simulations of agglomerate growth including hydrodynamic screening and molecular dynamics type simulations of the rearrangement of particles within an agglomerate under a gravitational field. Experiments included direct observation of the agglomeration of submicron alumina and indirect observation, using small angle light scattering, of the agglomeration of colloidal silica and aluminum monohydroxide. In the former class of experiments, the powders were constrained to move on a two-dimensional surface oriented to minimize the effect of gravity. In the latter, some experiments involved mixture of suspensions containing particles of opposite charge which resulted in agglomeration on a very short time scale relative to settling under gravity.

  9. An improved theoretical model of acoustic agglomeration

    SciTech Connect

    Song, L. ); Koopmann, G.H. . Center for Acoustics and Vibration); Hoffmann, T.L. )

    1994-04-01

    An improved theoretical model is developed to describe the acoustic agglomeration of particles entrained in a gas medium. The improvements to the present theories are twofold: first, wave scattering is included in the orthokinetic interaction of particles and second, hydrodynamic interaction, shown to be an important agglomeration mechanism for certain operation conditions, is incorporated into the model. The influence of orthokinetic and hydrodynamic interactions introduce associated convergent velocities that cause particles to approach each other and collide. The convergent velocities are related with an acoustic agglomeration frequency function (AAFF) through a semi-statistical method. This function is the key parameter for the theoretical simulation of acoustic agglomeration.

  10. Micro-agglomerate flotation for deep cleaning of coal. Quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Chander, S.; Hogg, R.

    1995-07-01

    The development, of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 mm) needed to achieve adequate liberation of the mineral matter from the coal matrix. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. This project is concerned with a hydrid process, micro-agglomerate flotation, which is a combination of oil agglomeration and froth flotation.

  11. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Chander, S.; Hogg, R.

    1995-04-01

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 mm) needed to achieve adequate liberation of the mineral matter from the coal matrix. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. The addition of larger amounts of oil can yield large, strong agglomerates which are easily separated but the selectivity is reduced and reagent costs can become excessive. We are investigating the use of a hybrid process - Micro-agglomerate flotation which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30-50 mm in size) rather than individual coal particles (1-10 mm) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response.

  12. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, 1 April--30 June 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1994-07-01

    The authors are investigating the use of a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation. The basic concepts is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 {mu}m in size) rather than individual coal particles (1--10 {mu}m) the problems of froth overload water/mineral carryover should be significantly alleviated. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response. The research program has been organized into several specific tasks: Task 1, interfacial studies; Task 2, emulsification; Task 3, agglomerate growth and structure; and Task 4, agglomerate flotation. This report summarizes the status of Tasks 2, 3, and 4.

  13. Micro-agglomerate flotation for deep cleaning of coal. Final report

    SciTech Connect

    Chander, S.; Hogg, R.

    1997-01-15

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {micro}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. In this investigation a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation was studied. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles and to use froth flotation to separate these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units will be relatively large agglomerates (30--50 {micro}m in size) rather than fine coal particles (1--10 {micro}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is demonstrated in this study that the process is very sensitive to fluctuations in operating parameters. It is necessary to maintain precise control over the chemistry of the liquid phases as well as the agitation conditions in order to promote selectivity. Both kinetics as well as thermodynamic factors play a critical role in determining overall system response.

  14. Engineering development of selective agglomeration. Final report

    SciTech Connect

    Not Available

    1993-04-01

    This report presents the findings of the project entitled ``Engineering Development of Selective Agglomeration.`` The purpose is to develop selective agglomeration technology to a commercially acceptable level by 1993. Engineering development included bench-scale process development, component development adaptation or modification of existing unit operations, proof-of-concept (POC) module design, fabrication, testing, data evaluation, and conceptual design of a commercial facility. The information obtained during POC operation resulted in a technical and economic design base sufficient to support construction and operation of a commercial plant. Throughout this project performance targets for the engineering development of selective agglomeration process were to achieve 85% or greater Btu recovery at 85% or greater pyritic sulfur rejection (PSR). Additional objectives included producing a final clean-coal product with an ash content of 6% or less which is suitable for conventional coal handling systems. The selective agglomeration process, as applied to coal cleaning, is based on differences in the surface chemistry of coal and its associated impurities. Coal particles are hydrophobic (i.e., repel water) while the majority of its impurities are hydrophilic (i.e., stabilized in water). During selective agglomeration, a liquid (the agglomerant) that is immiscible with water is introduced into a coal-water slurry and agitated to disperse it in the slurry, thereby allowing it to come into contact with all particles in the slurry. The coal particles, due to their hydrophobic nature, are attracted to the agglomerant phase. The hydrophilic mineral impurities remain in the water phase. Continued agitation of the agglomerant-coated coal particles causes them to coalesce to form agglomerates. Once the agglomerates are formed, they are separated from the mineral matter-bearing aqueous phase by subsequent processing steps.

  15. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, July 1--September 30, 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1994-10-01

    The goals of this research program are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process and to establish the essential criteria for reagent selection and system design and operation. We are investigating the use of a hybrid process -- Micro-agglomerate flotation -- which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 {mu}m in size) rather than individual coal particles (1--10 {mu}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. The research program has been organized into several specific tasks : interfacial studies; emulsification; agglomerate growth and structure; and agglomerate flotation. Accomplishments are reported.

  16. Modeling of particle agglomeration in nanofluids

    NASA Astrophysics Data System (ADS)

    Krishna, K. Hari; Neti, S.; Oztekin, A.; Mohapatra, S.

    2015-03-01

    Agglomeration strongly influences the stability or shelf life of nanofluid. The present computational and experimental study investigates the rate of agglomeration quantitatively. Agglomeration in nanofluids is attributed to the net effect of various inter-particle interaction forces. For the nanofluid considered here, a net inter-particle force depends on the particle size, volume fraction, pH, and electrolyte concentration. A solution of the discretized and coupled population balance equations can yield particle sizes as a function of time. Nanofluid prepared here consists of alumina nanoparticles with the average particle size of 150 nm dispersed in de-ionized water. As the pH of the colloid was moved towards the isoelectric point of alumina nanofluids, the rate of increase of average particle size increased with time due to lower net positive charge on particles. The rate at which the average particle size is increased is predicted and measured for different electrolyte concentration and volume fraction. The higher rate of agglomeration is attributed to the decrease in the electrostatic double layer repulsion forces. The rate of agglomeration decreases due to increase in the size of nano-particle clusters thus approaching zero rate of agglomeration when all the clusters are nearly uniform in size. Predicted rates of agglomeration agree adequate enough with the measured values; validating the mathematical model and numerical approach is employed.

  17. Modeling of particle agglomeration in nanofluids

    SciTech Connect

    Krishna, K. Hari; Neti, S.; Oztekin, A.; Mohapatra, S.

    2015-03-07

    Agglomeration strongly influences the stability or shelf life of nanofluid. The present computational and experimental study investigates the rate of agglomeration quantitatively. Agglomeration in nanofluids is attributed to the net effect of various inter-particle interaction forces. For the nanofluid considered here, a net inter-particle force depends on the particle size, volume fraction, pH, and electrolyte concentration. A solution of the discretized and coupled population balance equations can yield particle sizes as a function of time. Nanofluid prepared here consists of alumina nanoparticles with the average particle size of 150 nm dispersed in de-ionized water. As the pH of the colloid was moved towards the isoelectric point of alumina nanofluids, the rate of increase of average particle size increased with time due to lower net positive charge on particles. The rate at which the average particle size is increased is predicted and measured for different electrolyte concentration and volume fraction. The higher rate of agglomeration is attributed to the decrease in the electrostatic double layer repulsion forces. The rate of agglomeration decreases due to increase in the size of nano-particle clusters thus approaching zero rate of agglomeration when all the clusters are nearly uniform in size. Predicted rates of agglomeration agree adequate enough with the measured values; validating the mathematical model and numerical approach is employed.

  18. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, January 1--March 31, 1993

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-04-01

    We are investigating the use of a hybrid process, Micro-agglomerate flotation, which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 {mu}m in size) rather than individual coal particles (1--10 {mu}m) the problems of froth overload and water/mineral carryover should be significantly alleviated.Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response.

  19. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, September 30--December 31, 1992

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-01-01

    We are investigating the use of a hybrid process - Micro-agglomerate flotation - which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 {mu}m in size) rather than individual coal particles (1--10 {mu}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response.

  20. Percolative fragmentation and spontaneous agglomeration

    SciTech Connect

    Hurt, R.; Davis, K.

    1999-03-01

    Captive particle imaging experiments were performed on over 200 coal and char particles in the pulverized size range from four coals of various rank at oxygen concentration from 3--19 mol% and at gas temperatures of about 1250 K. Despite wide variations in single-particle behavior, the data set reveals two clear trends that provide new information on the nature of char combustion. First, the low-rank coal chars are observed to maintain their high reactivity through the late stages of combustion, thus avoiding the near-extinction events and long burnout tails observed for bituminous coal chars. Secondly, percolative fragmentation in the late stages of combustion is a rare event under these conditions. Some particles reach a percolation threshold rate in combustion, but typically undergo spontaneous agglomeration rather than liberation of the incipient fragments. It is concluded that percolative fragmentation behavior in the pulverized size range is determined not only by solid-phase connectivity, but also by a real competition between disruptive and cohesive forces present at the time of formation of the colloidal-sized incipient fragments.

  1. Bed material agglomeration during fluidized bed combustion

    SciTech Connect

    Brown, R.C.; Dawson, M.R.; Noble, S.

    1993-02-01

    The purpose of this project is to determine the physical and chemical reactions which led to the undesired agglomeration of bed material during fluidized bed combustion and to relate these reactions to specific causes. Survey of industrial-scale fluidized bed combustors is being conducted to determine the occurrence of bed agglomeration and the circumstances under which agglomeration took place. This task should be finished by the end of February. Samples of bed material, agglomerate material, and boiler deposits are being requested from boiler operators as part of the survey. Once received, these sample will be analyzed to determine chemical and mineralogic composition. The bulk chemical determination will be performed using x-ray fluorescence and inductively coupled plasma-optical emission (ICP). Mineralogy will be detected by x-ray diffraction (XRD). Chemical and mineral reactions will be determined by scanning electron microscopy, optical microscopy, and electron microprobe.

  2. Agglomeration of microparticles in complex plasmas

    SciTech Connect

    Du, Cheng-Ran; Thomas, Hubertus M.; Ivlev, Alexei V.; Konopka, Uwe; Morfill, Gregor E.

    2010-11-15

    Agglomeration of highly charged microparticles was observed and studied in complex plasma experiments carried out in a capacitively coupled rf discharge. The agglomeration was caused by strong waves triggered in a particle cloud by decreasing neutral gas pressure. Using a high-speed camera during this unstable regime, it was possible to resolve the motion of individual microparticles and to show that the relative velocities of some particles were sufficiently high to overcome the mutual Coulomb repulsion and hence to result in agglomeration. After stabilizing the cloud again through the increase of the pressure, we were able to observe the aggregates directly with a long-distance microscope. We show that the agglomeration rate deduced from our experiments is in good agreement with theoretical estimates. In addition, we briefly discuss the mechanisms that can provide binding of highly charged microparticles in a plasma.

  3. Advances in food powder agglomeration engineering.

    PubMed

    Cuq, B; Gaiani, C; Turchiuli, C; Galet, L; Scher, J; Jeantet, R; Mandato, S; Petit, J; Murrieta-Pazos, I; Barkouti, A; Schuck, P; Rondet, E; Delalonde, M; Dumoulin, E; Delaplace, G; Ruiz, T

    2013-01-01

    Food powders are used in everyday life in many ways and offer technological solutions to the problem of food production. The natural origin of food powders, diversity in their chemical composition, variability of the raw materials, heterogeneity of the native structures, and physicochemical reactivity under hydrothermal stresses contribute to the complexity in their behavior. Food powder agglomeration has recently been considered according to a multiscale approach, which is followed in the chapter layout: (i) at the particle scale, by a presentation of particle properties and surface reactivity in connection with the agglomeration mechanisms, (ii) at the mechanisms scale, by describing the structuration dynamics of agglomerates, (iii) at the process scale, by a presentation of agglomeration technologies and sensors and by studying the stress transmission mode in the powder bed, and finally (iv) by an integration of the acquired knowledge, thanks to a dimensional analysis carried out at each scale.

  4. Diffusion and reaction in microbead agglomerates.

    PubMed

    Nunes Kirchner, Carolina; Träuble, Markus; Wittstock, Gunther

    2010-04-01

    Scanning electrochemical microscopy has been used to analyze the flux of p-aminonophenol (PAP) produced by agglomerates of polymeric microbeads modified with galactosidase as a model system for the bead-based heterogeneous immunoassays. With the use of mixtures of enzyme-modified and bare beads in defined ratio, agglomerates with different saturation levels of the enzyme modification were produced. The PAP flux depends on the intrinsic kinetics of the galactosidase, the local availability of the substrate p-aminophenyl-beta-D-galactopyranoside (PAPG), and the external mass transport conditions in the surrounding of the agglomerate and the internal mass transport within the bead agglomerate. The internal mass transport is influenced by the diffusional shielding of the modified beads by unmodified beads. SECM in combination with optical microscopy was used to determine experimentally the external flux. These data are in quantitative agreement with boundary element simulation considering the SECM microelectrode as an interacting probe and treating the Michaelis-Menten kinetics of the enzyme as nonlinear boundary conditions with two independent concentration variables [PAP] and [PAPG]. The PAPG concentration at the surface of the bead agglomerate was taken as a boundary condition for the analysis of the internal mass transport condition as a function of the enzyme saturation in the bead agglomerate. The results of this analysis are represented as PAP flux per contributing modified bead and the flux from freely suspended galactosidase-modified beads. These numbers are compared to the same number from the SECM experiments. It is shown that depending on the enzyme saturation level a different situation can arise where either beads located at the outer surface of the agglomerate dominate the contribution to the measured external flux or where the contribution of buried beads cannot be neglected for explaining the measured external flux.

  5. Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders.

    PubMed

    Willemsz, Tofan A; Hooijmaijers, Ricardo; Rubingh, Carina M; Tran, Thanh N; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

    2012-01-23

    Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity. Achieving sufficient blend uniformity requires that the blending conditions are able to break up agglomerates, which is often an abrasion process. This study was based on the assumption that the abrasion rate of agglomerates determines the required blending time. It is shown that the kinetic energy density of the moving powder bed is a relevant parameter which correlates with the abrasion rate of agglomerates. However, aspects related to the strength of agglomerates should also be considered. For this reason the Stokes abrasion number (St(Abr)) has been defined. This parameter describes the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. The St(Abr) number is shown to predict the abrasion potential of agglomerates in the dry-mixing process. It appeared possible to include effects of filler particle size and impeller rotational rate into this concept. A clear relationship between abrasion rate of agglomerates and the value of St(Abr) was demonstrated.

  6. Selective agglomeration of a Pittsburgh Seam coal with isooctane

    SciTech Connect

    Lai, R.; Killmeyer, R.; Utz, B.; Richardson, A.; Sinha, K.

    1992-01-01

    The Pittsburgh Energy Technology Center initiated a research program in 1989 to investigate the fundamentals of selective agglomeration as applied to the cleaning of coals. The results of the initial study with Bruceton mine, Pittsburgh seam coal, using isooctane as an agglomerant, have been published. Subsequent to the successful reduction of the ash content of Bruceton coal to less than 0.9% after two cleaning stages, the study was extended to compare a coal from the same seam, but from Ohio. In the previous parameter optimization tests with Bruceton coal, particle size and slurry pH were found to be important parameters governing coal cleanability. Other researchers have obtained similar conclusions of the effects of particle size and coal slurry pH on the cleanability of various coals. In this study, the effects of these parameters on the cleanability of Powhatan coal were examined. Particle size reduction kinetics was examined first. Effects of size reduction (degree of mineral matter liberation), oil (isooctane)-to-coal ratio, and slurry pH on mineral matter rejection and combustible recovery were also examined. A petrographic comparison was conducted on the Powhatan and Bruceton coals to examine the degree of pyrite liberation as a function of particle size to elucidate why one coal from the same seam can be cleaned significantly better than another. (VC)

  7. Soft- and hard-agglomerate aerosols made at high temperatures.

    PubMed

    Tsantilis, Stavros; Pratsinis, Sotiris E

    2004-07-06

    Criteria for aerosol synthesis of soft-agglomerate, hard-agglomerate, or even nonagglomerate particles are developed on the basis of particle sintering and coalescence. Agglomerate (or aggregate) particles are held together by weak, physical van der Waals forces (soft agglomerates) or by stronger chemical or sintering bonds (hard agglomerates). Accounting for simultaneous gas phase chemical reaction, coagulation, and sintering during the formation and growth of silica (SiO2) nanoparticles by silicon tetrachloride (SiCl4) oxidation and neglecting the spread of particle size distribution, the onset of hard-agglomerate formation is identified at the end of full coalescence, while the onset of soft-agglomerate formation is identified at the end of sintering. Process conditions such as the precursor initial volume fraction, maximum temperature, residence time, and cooling rate are explored, identifying regions for the synthesis of particles with a controlled degree of agglomeration (ratio of collision to primary particle diameters).

  8. Method for providing improved solid fuels from agglomerated subbituminous coal

    DOEpatents

    Janiak, Jerzy S.; Turak, Ali A.; Pawlak, Wanda; Ignasiak, Boleslaw L.

    1989-01-01

    A method is provided for separating agglomerated subbituminous coal and the heavy bridging liquid used to form the agglomerates. The separation is performed by contacting the agglomerates with inert gas or steam at a temperature in the range of 250.degree. to 350.degree. C. at substantially atmospheric pressure.

  9. Encapsulation of hazardous wastes into agglomerates

    SciTech Connect

    Guloy, A.

    1992-01-28

    The objective of this study was to investigate the feasibility of using the cementitious properties and agglomeration characteristics of coal conversion byproducts to encapsulate and immobilize hazardous waste materials. The intention was to establish an economical way of co-utilization and co-disposal of wastes. In addition, it may aid in the eradication of air pollution problems associated with the fine-powdery nature of fly ash. Encapsulation into agglomerates is a novel approach of treating toxic waste. Although encapsulation itself is not a new concept, existing methods employ high-cost resins that render them economically unfeasible. In this investigation, the toxic waste was contained in a concrete-like matrix whereby fly ash and other cementitious waste materials were utilized. The method incorporates the principles of solidification, stabilization and agglomeration. Another aspect of the study is the evaluation of the agglomeration as possible lightweight aggregates. Since fly ash is commercially used as an aggregate, it would be interesting to study the effect of incorporating toxic wastes in the strength development of the granules. In the investigation, the fly ash self-cementation process was applied to electroplating sludges as the toxic waste. The process hoped to provide a basis for delisting of the waste as hazardous and, thereby greatly minimize the cost of its disposal. Owing to the stringent regulatory requirements for hauling and disposal of hazardous waste, the cost of disposal is significant. The current practice for disposal is solidifying the waste with portland cement and dumping the hardened material in the landfill where the cost varies between $700--950/ton. Partially replacing portland cement with fly ash in concrete has proven beneficial, therefore applying the same principles in the treatment of toxic waste looked very promising.

  10. Agglomeration and Sedimentation of MWCNTS in Chloroform

    NASA Astrophysics Data System (ADS)

    Eremin, Yu. S.; Kolesnikova, A. A.; Grekhov, A. M.

    The kinetics of agglomeration of multiwalled carbon nanotubes dispersed in chloroform has been studied by the methods of optical spectroscopy and dynamic light scattering. With the use of the models of the diffusion of cylindrical particles, the sizes of particles obtained by this method can be recalculated to the DLS data and the concentration at which the dispersion of individual МWCNTs occurs can be determined.

  11. Agglomeration rate and action forces between atomized particles of agglomerator and inhaled-particles from coal combustion.

    PubMed

    Wei, Feng; Zhang, Jun-ying; Zheng, Chu-guang

    2005-01-01

    In order to remove efficiently haled-particles emissions from coal combustions, a new way was used to put forward the process of agglomeration and the atomization was produced by the nozzle and then sprayed into the flue before precipitation devices of power station boiler in order to make inhaled-particles agglomerate into bigger particles, which can be easily removed but not change existing running conditions of boiler. According to this idea, a model is set up to study agglomeration rate and effect forces between fly ash inhaled-particles and atomized agglomerator particles. The developed agglomeration rate was expressed by relative particle number decreasing speed per unit volume. The result showed that viscosity force and flow resistance force give main influences on agglomeration effect of inhaled-particles, while springiness force and gravity have little effect on agglomeration effect of theirs. Factors influencing the agglomeration rate and effect forces are studied, including agglomerator concentration, agglomerator flux and agglomerator density, atomized-particles diameters and inhaled-particles diameter and so on.

  12. Chemiluminescence in the Agglomeration of Metal Clusters

    PubMed

    König; Rabin; Schulze; Ertl

    1996-11-22

    The agglomeration of copper or silver atoms in a matrix of noble gas atoms to form small clusters may be accompanied by the emission of visible light. Spectral analysis reveals the intermediate formation of electronically excited atoms and dimers as the source of the chemiluminescence. A mechanism is proposed, according to which the gain in binding energy upon cluster formation may even lead to the ejection of excited fragments as a result of unstable intermediate configurations. A similar concept was introduced in the field of nuclear reactions by Niels Bohr 60 years ago.

  13. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, July 1, 1995--September 30, 1995

    SciTech Connect

    Chander, S.; Hogg, R.

    1995-07-01

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 mm) needed to achieve adequate liberation of the mineral matter from the coal matrix. It is generally recognized that surface-based separation processes such as froth flotation or selective agglomeration offer considerable potential for such applications but there remain many problems in obtaining the required selectivity with acceptable recovery of combustible matter. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. The addition of larger amounts of oil can yield large, strong agglomerates which are easily separated but the selectivity is reduced and reagent costs can become excessive.

  14. Apparatus and method for compacting, degassing and carbonizing carbonaceous agglomerates

    SciTech Connect

    Theodore, F.W.

    1980-08-19

    An apparatus for compacting, degassing and carbonizing carbonaceous agglomerates is described. The apparatus comprises a rotary kiln having an agglomerate inlet means for introducing green agglomerates into the kiln near the inlet of the kiln and a heating medium inlet for introducing a heating medium comprising a finely divided solid into the kiln at a preselected location intermediate the inlet end of the kiln and the outlet end of the kiln to produce a mixture at a temperature above the carbonizing temperature of the agglomerates and a sieve positioned to receive the products from the rotary kiln and separate the heating medium and the compacted, degassed, carbonized agglomerate product. A method for producing compacted, degassed, carbonized carbonaceous agglomerates by the use of the apparatus is also disclosed.

  15. Multifrequency scanning probe microscopy study of nanodiamond agglomerates

    NASA Astrophysics Data System (ADS)

    Aravind, Vasudeva; Lippold, Stephen; Li, Qian; Strelcov, Evgheny; Okatan, Baris; Legum, Benjamin; Kalinin, Sergei; Clarion University Team; Oak Ridge National Laboratory Team

    Due to their rich surface chemistry and excellent mechanical properties and non-toxic nature, nanodiamond particles have found applications such as biomedicine, tribology and lubrication, targeted drug delivery systems, tissue scaffolds and surgical implants. Although single nanodiamond particles have diameters about 4-5nm, they tend to form agglomerates. While these agglomerates can be useful for some purposes, many applications of nanodiamonds require single particle, disaggregated nanodiamonds. This work is oriented towards studying forces and interactions that contribute to agglomeration in nanodiamonds. In this work, using multifrequency scanning probe microscopy techniques, we show that agglomerate sizes can vary between 50-100nm in raw nanodiamonds. Extremeties of particles and Interfaces between agglomerates show dissipative forces with scanning probe microscope tip, indicating agglomerates could act as points of increased adhesion, thus reducing lubricating efficiency when nanodiamonds are used as lubricant additives. This research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.

  16. Analysis and synthesis of solutions for the agglomeration process modeling

    NASA Astrophysics Data System (ADS)

    Babuk, V. A.; Dolotkazin, I. N.; Nizyaev, A. A.

    2013-03-01

    The present work is devoted development of model of agglomerating process for propellants based on ammonium perchlorate (AP), ammonium dinitramide (ADN), HMX, inactive binder, and nanoaluminum. Generalization of experimental data, development of physical picture of agglomeration for listed propellants, development and analysis of mathematical models are carried out. Synthesis of models of various phenomena taking place at agglomeration implementation allows predicting of size and quantity, chemical composition, structure of forming agglomerates and its fraction in set of condensed combustion products. It became possible in many respects due to development of new model of agglomerating particle evolution on the surface of burning propellant. Obtained results correspond to available experimental data. It is supposed that analogical method based on analysis of mathematical models of particular phenomena and their synthesis will allow implementing of the agglomerating process modeling for other types of metalized solid propellants.

  17. Method for producing ceramic particles and agglomerates

    DOEpatents

    Phillips, Jonathan; Gleiman, Seth S.; Chen, Chun-Ku

    2001-01-01

    A method for generating spherical and irregularly shaped dense particles of ceramic oxides having a controlled particle size and particle size distribution. An aerosol containing precursor particles of oxide ceramics is directed into a plasma. As the particles flow through the hot zone of the plasma, they melt, collide, and join to form larger particles. If these larger particles remain in the hot zone, they continue melting and acquire a spherical shape that is retained after they exit the hot zone, cool down, and solidify. If they exit the hot zone before melting completely, their irregular shape persists and agglomerates are produced. The size and size distribution of the dense product particles can be controlled by adjusting several parameters, the most important in the case of powder precursors appears to be the density of powder in the aerosol stream that enters the plasma hot zone. This suggests that particle collision rate is responsible for determining ultimate size of the resulting sphere or agglomerate. Other parameters, particularly the gas flow rates and the microwave power, are also adjusted to control the particle size distribution.

  18. Rapid determination of plasmonic nanoparticle agglomeration status in blood.

    PubMed

    Jenkins, Samir V; Qu, Haiou; Mudalige, Thilak; Ingle, Taylor M; Wang, Rongrong; Wang, Feng; Howard, Paul C; Chen, Jingyi; Zhang, Yongbin

    2015-05-01

    Plasmonic nanomaterials as drug delivery or bio-imaging agents are typically introduced to biological systems through intravenous administration. However, the potential for agglomeration of nanoparticles in biological systems could dramatically affect their pharmacokinetic profile and toxic potential. Development of rapid screening methods to evaluate agglomeration is urgently needed to monitor the physical nature of nanoparticles as they are introduced into blood. Here, we establish novel methods using darkfield microscopy with hyperspectral detection (hsDFM), single particle inductively-coupled plasma mass spectrometry (spICP-MS), and confocal Raman microscopy (cRM) to discriminate gold nanoparticles (AuNPs) and their agglomerates in blood. Rich information about nanoparticle agglomeration in situ is provided by hsDFM monitoring of the plasmon resonance of primary nanoparticles and their agglomerates in whole blood; cRM is an effective complement to hsDFM to detect AuNP agglomerates in minimally manipulated samples. The AuNPs and the particle agglomerates were further distinguished in blood for the first time by quantification of particle mass using spICP-MS with excellent sensitivity and specificity. Furthermore, the agglomeration status of synthesized and commercial NPs incubated in blood was successfully assessed using the developed methods. Together, these complementary methods enable rapid determination of the agglomeration status of plasmonic nanomaterials in biological systems, specifically blood.

  19. Method for recovering light hydrocarbons from coal agglomerates

    DOEpatents

    Huettenhain, Horst; Benz, August D.; Getsoian, John

    1991-01-01

    A method and apparatus for removing light hydrocarbons, such as heptane, from coal agglomerates includes an enclosed chamber having a substantially horizontal perforate surface therein. The coal agglomerates are introduced into a water bath within the chamber. The agglomerates are advanced over the surface while steam is substantially continuously introduced through the surface into the water bath. Steam heats the water and causes volatilization of the light hydrocarbons, which may be collected from the overhead of the chamber. The resulting agglomerates may be collected at the opposite end from the surface and subjected to final draining processes prior to transportation or use.

  20. Modeling of crushed ore agglomeration for heap leach operations

    NASA Astrophysics Data System (ADS)

    Dhawan, Nikhil

    The focus of this dissertation is modeling of the evolution of size distribution in batch agglomeration drum. There has been no successful work on modeling of crushed ore agglomeration although the framework for population balance modeling of pelletization and granulation is readily available. In this study three different batch agglomeration drums were used to study the agglomeration kinetics of copper, gold and nickel ores. The agglomerate size distribution is inherently subject to random fluctuation due the very nature of the process. Yet, with careful experimentation and size analysis the evolution of size distribution can be followed. The population balance model employing the random coalesce model with a constant rate kernel was shown to work well in a micro and lab scale agglomerator experiments. In small drums agglomerates begin to break in a short time, whereas the growth is uniform in the lab scale drum. The experimental agglomerate size distributions exhibit self-preserving size spectra which confirms the applicability of coalescence rate based model. The same spectra became a useful fact for predicting the size distribution with an empirical model. Since moisture is a principal variable, the absolute deviation from optimum moisture was used as the primary variable in the empirical model. Having established a model for the size distribution, the next step was to delve into the internal constituents of each agglomerate size class. To this end, an experimental scheme known as dip test was devised. The outcome of the test was the size distribution of progeny particles which make up a given size class of agglomerate. The progeny size distribution was analyzed with a model that partitions the particles into a host and guest category. The ensuing partition coefficient is a valuable in determining how a particle in a size class participates in larger agglomerates. This dissertation lays out the fundamentals for applying the population balance concept to batch

  1. Development and Application of Agglomerated Multigrid Methods for Complex Geometries

    NASA Technical Reports Server (NTRS)

    Nishikawa, Hiroaki; Diskin, Boris; Thomas, James L.

    2010-01-01

    We report progress in the development of agglomerated multigrid techniques for fully un- structured grids in three dimensions, building upon two previous studies focused on efficiently solving a model diffusion equation. We demonstrate a robust fully-coarsened agglomerated multigrid technique for 3D complex geometries, incorporating the following key developments: consistent and stable coarse-grid discretizations, a hierarchical agglomeration scheme, and line-agglomeration/relaxation using prismatic-cell discretizations in the highly-stretched grid regions. A signi cant speed-up in computer time is demonstrated for a model diffusion problem, the Euler equations, and the Reynolds-averaged Navier-Stokes equations for 3D realistic complex geometries.

  2. Rapid Determination of Plasmonic Nanoparticle Agglomeration Status in Blood

    PubMed Central

    Jenkins, Samir V.; Qu, Haiou; Mudalige, Thilak; Ingle, Taylor; Wang, RongRong; Wang, Feng; Howard, Paul C.; Chen, Jingyi; Zhang, Yongbin

    2015-01-01

    Plasmonic nanomaterials as drug delivery or bio-imaging agents are typically introduced to biological systems through intravenous administration. However, the potential for agglomeration of nanoparticles in biological systems could dramatically affect their pharmacokinetic profile and toxic potential. Development of rapid screening methods to evaluate agglomeration is urgently needed to monitor the physical nature of nanoparticles as they are introduced into blood. Here, we establish novel methods using darkfield microscopy with hyperspectral detection (hsDFM), single particle inductively-coupled plasma mass spectrometry (spICP-MS), and confocal Raman microscopy (cRM) to discriminate gold nanoparticles (AuNPs) and their agglomerates in blood. Rich information about nanoparticle agglomeration in situ is provided by hsDFM monitoring of the plasmon resonance of primary nanoparticles and their agglomerates in whole blood; cRM is an effective complement to hsDFM to detect AuNP agglomerates in minimally manipulated samples. The AuNPs and the particle agglomerates were further distinguished in blood for the first time by quantification of particle mass using spICP-MS with excellent sensitivity and specificity. Furthermore, the agglomeration status of synthesized and commercial NPs incubated in blood was successfully assessed using the developed methods. Together, these complementary methods enable rapid determination of the agglomeration status of plasmonic nanomaterials in biological systems, specifically blood. PMID:25771013

  3. Influence of excipients and processing conditions on the development of agglomerates of racecadotril by crystallo-co-agglomeration

    PubMed Central

    Garala, Kevin; Patel, Jaydeep; Patel, Anjali; Raval, Mihir; Dharamsi, Abhay

    2012-01-01

    Purpose: The purpose of the present investigation was to improve the flow and mechanical properties of racecadotril by a crystallo-co-agglomeration (CCA) technique. Direct tableting is a requirement of pharmaceutical industries. Poor mechanical properties of crystalline drug particles require wet granulation which is uneconomical, laborious, and tedious. Materials and Methods: The objective of this work was to study the influence of various polymers/excipients and processing conditions on the formation of directly compressible agglomerates of the water-insoluble drug, racecadotril, an antidiarrheal agent. The agglomerates of racecadotril were prepared using dichloromethane (DCM)–water as the crystallization system. DCM acted as a good solvent for racecadotril as well as a bridging liquid for the agglomeration of the crystallized drug and water as the nonsolvent. The prepared agglomerates were tested for micromeritic and mechanical properties. Results: The process yielded ~90 to 96% wt/ wt spherical agglomerates containing racecadotril with the diameter between 299 and 521 μ. A higher rotational speed of crystallization system reduces the size of the agglomerates and disturbs the sphericity. Spherical agglomerates were generated with a uniform dispersion of the crystallized drug. CCA showed excellent flowability and crushing strength. Conclusion: Excipients and processing conditions can play a key role in preparing spherical agglomerates of racecadotril by CCA, an excellent alternative to the wet granulation process to prepare intermediates for direct compression. PMID:23580935

  4. Pulse combusted acoustic agglomeration apparatus and process

    DOEpatents

    Mansour, Momtaz N.; Chandran, Ravi

    1994-01-01

    An improved apparatus and process for removal of particulates entrained in a gas stream are provided. The removal process employs a pulse combustor to provide an acoustic pressure wave to acoustically enhance agglomeration of particulates which may be collected and removed using a conventional separation apparatus. The apparatus may be employed as a direct fired system for improved operation of gas-operated equipment such as a gas turbine, or may, alternatively, be employed as an add-on subsystem for combustion exhaust clean-up. Additionally, added particulates may include a sorbent for effecting sorption of other contaminants such as sulfur. Various other particulates for contaminant removal may also be introduced into the system as exemplified by alkali-gettering agents.

  5. Pulse combusted acoustic agglomeration apparatus and process

    DOEpatents

    Mansour, Momtaz N.

    1993-01-01

    An improved apparatus and process for removal of particulates entrained in a gas stream are provided. The removal process employs a pulse combustor to provide an acoustic pressure wave to acoustically enhance bimodal agglomeration of particulates which may be collected and removed using a conventional separation apparatus. A particulate having a size different from the size of the particulate in the gas stream to be cleaned is introduced into the system to effectuate the bimodal process. The apparatus may be employed as a direct fired system for improved operation of gas-operated equipment such as a gas turbine, or may, alternatively, be employed as an add-on subsystem for combustion exhaust clean-up. Additionally, the added particulate may be a sorbent for effecting sorption of other contaminants such as sulfur. Various other particulates for contaminant removal may also be introduced into the system as exemplified by alkali-gettering agents.

  6. Agglomeration multigrid for viscous turbulent flows

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.; Venkatakrishnan, V.

    1994-01-01

    Agglomeration multigrid, which has been demonstrated as an efficient and automatic technique for the solution of the Euler equations on unstructured meshes, is extended to viscous turbulent flows. For diffusion terms, coarse grid discretizations are not possible, and more accurate grid transfer operators are required as well. A Galerkin coarse grid operator construction and an implicit prolongation operator are proposed. Their suitability is evaluated by examining their effect on the solution of Laplace's equation. The resulting strategy is employed to solve the Reynolds-averaged Navier-Stokes equations for aerodynamic flows. Convergence rates comparable to those obtained by a previously developed non-nested mesh multigrid approach are demonstrated, and suggestions for further improvements are given.

  7. Soot agglomeration in isolated, free droplet combustion

    NASA Technical Reports Server (NTRS)

    Choi, M. Y.; Dryer, F. L.; Green, G. J.; Sangiovanni, J. J.

    1993-01-01

    Under the conditions of an isolated, free droplet experiment, hollow, carbonaceous structures, called soot spheres, were observed to form during the atmospheric pressure, low Reynolds number combustion of 1-methylnaphthalene. These structures which are agglomerates composed of smaller spheroidal units result from both thermophoretic effects induced by the envelope flame surrounding each drop and aerodynamic effects caused by changes in the relative gas/drop velocities. A chemically reacting flow model was used to analyze the process of sootshell formation during microgravity droplet combustion. The time-dependent temperature and gas property field surrounding the droplet was determined, and the soot cloud location for microgravity combustion of n-heptane droplets was predicted. Experiments showed that the sooting propensity of n-alkane fuel droplets can be varied through diluent substitution, oxygen-index variations, and ambient pressure reductions.

  8. Overpopulated, Underdeveloped Urban Agglomerations: Tomorrow’s Unstable Operating Environment

    DTIC Science & Technology

    2012-05-08

    DATES COVERED (From - To) 4. TITLE AND SUBTITLE Overpopulated , Underdeveloped Urban Agglomerations: Tomorrow’s 5a. CONTRACT NUMBER...ABSTRACT This paper asserts that a unique future operational environment is developing: overpopulated , underdeveloped urban agglomerations. A...proposed definition for this operating environment is (or would be) an overpopulated urban area which is located within a developing or underdeveloped

  9. Novel Binders and Methods for Agglomeration of Ore

    SciTech Connect

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-09-30

    Heap leaching is one of the methods being used to recover metal from low grade ore deposits. The main problem faced during heap leaching is the migration of fine grained particles through the heap, forming impermeable beds which result in poor solution flow. The poor solution flow leads to less contact between the leach solution and the ore, resulting in low recovery rates. Agglomeration of ore into coarse, porous masses prevents fine particles from migrating and clogging the spaces and channels between the larger ore particles. Currently, there is one facility in the United States which uses agglomeration. This operation agglomerates their ore using leach solution (raffinate), but is still experiencing undesirable metal recovery from the heaps due to agglomerate breakdown. The use of a binder, in addition to the leach solution, during agglomeration would help to produce stronger agglomerates that did not break down during processing. However, there are no known binders that will work satisfactorily in the acidic environment of a heap, at a reasonable cost. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. Increasing copper recovery in heap leaching by the use of binders and agglomeration would result in a significant decrease in the amount of energy consumed. Assuming that 70% of all the leaching heaps would convert to using agglomeration technology, as much as 1.64*10{sup 12} BTU per year would be able to be saved if a 25% increase in copper recovery was experienced, which is equivalent to saving approximately 18% of the energy currently being used in leaching heaps. For every week a leach cycle was decreased, a savings of as much as 1.23*10{sup 11} BTU per week would result. This project has identified several acid-resistant binders and agglomeration procedures. These binders and experimental procedures will be able to be used for use in improving the energy efficiency of

  10. Bed material agglomeration during fluidized bed combustion. Final report

    SciTech Connect

    Brown, R.C.; Dawson, M.R.; Smeenk, J.L.

    1996-01-01

    The purpose of this project is to determine the physical and chemical reactions which lead to the undesired agglomeration of bed material during fluidized bed combustion of coal and to relate these reactions to specific causes. A survey of agglomeration and deposit formation in industrial fluidized bed combustors (FBCs) indicate that at least five boilers were experiencing some form of bed material agglomeration. Deposit formation was reported at nine sites with deposits most commonly at coal feed locations and in cyclones. Other deposit locations included side walls and return loops. Three general types of mineralogic reactions were observed to occur in the agglomerates and deposits. Although alkalies may play a role with some {open_quotes}high alkali{close_quotes} lignites, we found agglomeration was initiated due to fluxing reactions between iron (II) from pyrites and aluminosilicates from clays. This is indicated by the high amounts of iron, silica, and alumina in the agglomerates and the mineralogy of the agglomerates. Agglomeration likely originated in the dense phase of the FBC bed within the volatile plume which forms when coal is introduced to the boiler. Secondary mineral reactions appear to occur after the agglomerates have formed and tend to strengthen the agglomerates. When calcium is present in high amounts, most of the minerals in the resulting deposits are in the melilite group (gehlenite, melilite, and akermanite) and pyroxene group (diopside and augite). During these solid-phase reactions, the temperature of formation of the melilite minerals can be lowered by a reduction of the partial pressure of CO{sub 2} (Diopside + Calcite {r_arrow}Akermanite).

  11. Operational source receptor calculations for large agglomerations

    NASA Astrophysics Data System (ADS)

    Gauss, Michael; Shamsudheen, Semeena V.; Valdebenito, Alvaro; Pommier, Matthieu; Schulz, Michael

    2016-04-01

    For Air quality policy an important question is how much of the air pollution within an urbanized region can be attributed to local sources and how much of it is imported through long-range transport. This is critical information for a correct assessment of the effectiveness of potential emission measures. The ratio between indigenous and long-range transported air pollution for a given region depends on its geographic location, the size of its area, the strength and spatial distribution of emission sources, the time of the year, but also - very strongly - on the current meteorological conditions, which change from day to day and thus make it important to provide such calculations in near-real-time to support short-term legislation. Similarly, long-term analysis over longer periods (e.g. one year), or of specific air quality episodes in the past, can help to scientifically underpin multi-regional agreements and long-term legislation. Within the European MACC projects (Monitoring Atmospheric Composition and Climate) and the transition to the operational CAMS service (Copernicus Atmosphere Monitoring Service) the computationally efficient EMEP MSC-W air quality model has been applied with detailed emission data, comprehensive calculations of chemistry and microphysics, driven by high quality meteorological forecast data (up to 96-hour forecasts), to provide source-receptor calculations on a regular basis in forecast mode. In its current state, the product allows the user to choose among different regions and regulatory pollutants (e.g. ozone and PM) to assess the effectiveness of fictive emission reductions in air pollutant emissions that are implemented immediately, either within the agglomeration or outside. The effects are visualized as bar charts, showing resulting changes in air pollution levels within the agglomeration as a function of time (hourly resolution, 0 to 4 days into the future). The bar charts not only allow assessing the effects of emission

  12. Physical properties of soils in Rostov agglomeration

    NASA Astrophysics Data System (ADS)

    Gorbov, S. N.; Bezuglova, O. S.; Abrosimov, K. N.; Skvortsova, E. B.; Tagiverdiev, S. S.; Morozov, I. V.

    2016-08-01

    Physical properties of natural and anthropogenically transformed soils of Rostov agglomeration were examined. The data obtained by conventional methods and new approaches to the study of soil physical properties (in particular, tomographic study of soil monoliths) were used for comparing the soils of different functional zones of the urban area. For urban territories in the steppe zone, a comparison of humus-accumulative horizons (A, Asod, Ap, and buried [A] horizons) made it possible to trace tendencies of changes in surface soils under different anthropogenic impacts and in the buried and sealed soils. The microtomographic study demonstrated differences in the bulk density and aggregation of urban soils from different functional zones. The A horizon in the forest-park zone is characterized by good aggregation and high porosity, whereas buried humus-accumulative horizons of anthropogenically transformed soils are characterized by poor aggregation and low porosity. The traditional parameters of soil structure and texture also proved to be informative for the identification of urban pedogenesis.

  13. Gravitational Agglomeration of Post-HCDA LMFBR Nonspherical Aerosols.

    DTIC Science & Technology

    1980-12-01

    AD-AIO6 766 AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH F/B 13/7 GRAVITATIONAL AGGLOMERATION OF POST- HCDA LMF8R NONSPHFRICAL AER--ETC(U) DEC 80 R...OF REPORT & PERIOD COVERED i Gravitational Agglomeration of Post- HCDA TfIfM/DISSERTATION LMFBR Nonspherical Aerosols . ________O____O______________ S...it to: AFIT/NR Wright-Patterson AFB OH 45433 RESEARCH TITLE: Gravitational Agglomeration of Post- HCDA LMFBR Nonspherical Aerosols AUTHOR: Ronald

  14. Leukocyte Agglomeration Reaction in Diagnosis of Allergy Reactions from Antibiotics,

    DTIC Science & Technology

    tested in a clinic on 80 patients with serious allergic anamnesis . The results of the studies indicate that the leukocyte agglomeration reaction is a highly sensitive immunological indicator of hypersensitivity to antibiotics.

  15. Acoustic agglomeration of power plant fly ash. Final report

    SciTech Connect

    Reethof, G.; McDaniel, O.H.

    1982-01-01

    The work has shown that acoustic agglomeration at practical acoustic intensities and frequencies is technically and most likely economically viable. The following studies were performed with the listed results: The physics of acoustic agglomeration is complex particularly at the needed high acoustic intensities in the range of 150 to 160 dB and frequencies in the 2500 Hz range. The analytical model which we developed, although not including nonlinear acoustic efforts, agreed with the trends observed. We concentrated our efforts on clarifying the impact of high acoustic intensities on the generation of turbulence. Results from a special set of tests show that although some acoustically generated turbulence of sorts exists in the 150 to 170 dB range with acoustic streaming present, such turbulence will not be a significant factor in acoustic agglomeration compared to the dominant effect of the acoustic velocities at the fundamental frequency and its harmonics. Studies of the robustness of the agglomerated particles using the Anderson Mark III impactor as the source of the shear stresses on the particles show that the agglomerates should be able to withstand the rigors of flow through commercial cyclones without significant break-up. We designed and developed a 700/sup 0/F tubular agglomerator of 8'' internal diameter. The electrically heated system functioned well and provided very encouraging agglomeration results at acoustic levels in the 150 to 160 dB and 2000 to 3000 Hz ranges. We confirmed earlier results that an optimum frequency exists at about 2500 Hz and that larger dust loadings will give better results. Studies of the absorption of acoustic energy by various common gases as a function of temperature and humidity showed the need to pursue such an investigation for flue gas constituents in order to provide necessary data for the design of agglomerators. 65 references, 56 figures, 4 tables.

  16. Novel Binders and Methods for Agglomeration of Ore

    SciTech Connect

    S. K. Kawatra; T. C. Eisele; J. A. Gurtler

    2004-03-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. A primary example of this is copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process. As a result, operators of acidic heap-leach facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of other agglomeration applications, particularly advanced primary ironmaking.

  17. Preparation of norfloxacin spherical agglomerates using the ammonia diffusion system.

    PubMed

    Puechagut, H G; Bianchotti, J; Chiale, C A

    1998-04-01

    Agglomerated crystals of norfloxacin were prepared by a spherical crystallization technique using the ammonia diffusion system (ADS). This technique makes it possible to agglomerate amphoteric drugs like norfloxacin, which cannot be agglomerated by conventional procedures. When an ammonia-water solution of norfloxacin is poured into an acetone dichloromethane mixture under agitation, a small amount of ammonia is liberated in the system. The ammonia-water solution plays a role both as a good solvent for norfloxacin and as a bridging liquid, allowing the crystals' collection to take place in one step. It has been proven that the agglomeration mechanism follows three steps: first acetone enters into the droplets of ammonia-water (this emulsion is formed because of the system characteristics); dissolved norfloxacin is consequently precipitated while the droplets collect the crystals; simultaneously, a part of the ammonia contained in the agglomerates diffuses to the outer organic solvent phase, thereby forming the norfloxacin spherical agglomerates. The correct selection of solvents has enabled us to obtain a suitable stable crystalline shape.

  18. NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

    SciTech Connect

    S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski

    2004-04-01

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

  19. Dynamics of nanoparticle agglomeration in a magnetic fluid in a varying magnetic field

    NASA Astrophysics Data System (ADS)

    Usanov, D. A.; Postel'ga, A. E.; Bochkova, T. S.; Gavrilin, V. N.

    2016-03-01

    It is found that the dependence of the magnetic nanoparticle agglomerate length in a magnetic fluid on the applied magnetic field has three characteristic segments: a substantial increase in the agglomerate length with the magnetic field in the range of weak fields, a segment with an insignificant increase in the average length of agglomerates upon an increase in the field, and a sharp increase in the agglomerate length with a further increase in the field. It is shown that the agglomerate length increases in the range of strong magnetic fields due to a decrease in the spacing between adjacent agglomerates down to their complete coalescence. The total number of agglomerates decreases thereby.

  20. Colloidal stability of coal-simulated suspensions in selective agglomeration

    SciTech Connect

    Schurger, M.L.

    1989-01-01

    A coal suspension was simulated by using graphite to simulate the carbonaceous fraction and kaolinite clay to simulate the ash fraction. Separate studies on each material established their response to additions of oxidized pyrite (ferrous sulfate) and a humic acid simulate (salicylic acid) in terms of zeta potentials profiles with pH and Ionic strength. Concentrations of iron and salicylic acid evaluated were 4.5 {times} 10{sup {minus}3} M and 2.0 {times} 10{sup {minus}4} M, respectively. The zeta potentials profiles of graphite, clay and hexadecane were negative throughout the pH ranges studied. The addition of iron lowered the zeta potentials all of the suspensions under all pH and ionic strength conditions. Salicylic acid decreased the graphite and hexadecane zeta potentials but had no effect on the clay zeta potential profiles. Agglomeration of graphite with bridging liquid shows distinct time dependent rate mechanisms, a initial growth of graphite agglomerates followed by consolidation phase. Graphite agglomeration was rapid with the maximum amount of agglomerate volume growth occurring in under 2-4 minutes. Agglomeration in the first two minutes was characterized by a 1st order rate mechanism. The presence of either Iron and salicylic acid generally improved the first order rates. The addition of clay also improved the first order rates except in the presence of salicylic acid. Heteroagglomeration of graphite with clay was found by hydrodynamic arguments to be unfavored. A multicomponent population balance model which had been developed for evaluating collision efficiencies of coal, ash and pyrite selective agglomeration was evaluated to explain these results. The growth and consolidation characteristics of graphite agglomeration for the experimental conditions examined herein revealed the limitations of such as model for this application.

  1. Novel Binders and Methods for Agglomeration of Ore

    SciTech Connect

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-12-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore processing which are intended to improve the

  2. A Critical Study of Agglomerated Multigrid Methods for Diffusion

    NASA Technical Reports Server (NTRS)

    Nishikawa, Hiroaki; Diskin, Boris; Thomas, James L.

    2011-01-01

    Agglomerated multigrid techniques used in unstructured-grid methods are studied critically for a model problem representative of laminar diffusion in the incompressible limit. The studied target-grid discretizations and discretizations used on agglomerated grids are typical of current node-centered formulations. Agglomerated multigrid convergence rates are presented using a range of two- and three-dimensional randomly perturbed unstructured grids for simple geometries with isotropic and stretched grids. Two agglomeration techniques are used within an overall topology-preserving agglomeration framework. The results show that multigrid with an inconsistent coarse-grid scheme using only the edge terms (also referred to in the literature as a thin-layer formulation) provides considerable speedup over single-grid methods but its convergence deteriorates on finer grids. Multigrid with a Galerkin coarse-grid discretization using piecewise-constant prolongation and a heuristic correction factor is slower and also grid-dependent. In contrast, grid-independent convergence rates are demonstrated for multigrid with consistent coarse-grid discretizations. Convergence rates of multigrid cycles are verified with quantitative analysis methods in which parts of the two-grid cycle are replaced by their idealized counterparts.

  3. A Critical Study of Agglomerated Multigrid Methods for Diffusion

    NASA Technical Reports Server (NTRS)

    Thomas, James L.; Nishikawa, Hiroaki; Diskin, Boris

    2009-01-01

    Agglomerated multigrid techniques used in unstructured-grid methods are studied critically for a model problem representative of laminar diffusion in the incompressible limit. The studied target-grid discretizations and discretizations used on agglomerated grids are typical of current node-centered formulations. Agglomerated multigrid convergence rates are presented using a range of two- and three-dimensional randomly perturbed unstructured grids for simple geometries with isotropic and highly stretched grids. Two agglomeration techniques are used within an overall topology-preserving agglomeration framework. The results show that multigrid with an inconsistent coarse-grid scheme using only the edge terms (also referred to in the literature as a thin-layer formulation) provides considerable speedup over single-grid methods but its convergence deteriorates on finer grids. Multigrid with a Galerkin coarse-grid discretization using piecewise-constant prolongation and a heuristic correction factor is slower and also grid-dependent. In contrast, grid-independent convergence rates are demonstrated for multigrid with consistent coarse-grid discretizations. Actual cycle results are verified using quantitative analysis methods in which parts of the cycle are replaced by their idealized counterparts.

  4. Advanced physical fine coal cleaning spherical agglomeration. Final report

    SciTech Connect

    Not Available

    1990-09-01

    The project included process development, engineering, construction, and operation of a 1/3 tph proof-of-concept (POC) spherical agglomeration test module. The POC tests demonstrated that physical cleaning of ultrafine coal by agglomeration using heptane can achieve: (1) Pyritic sulfur reductions beyond that possible with conventional coal cleaning methods; (2) coal ash contents below those which can be obtained by conventional coal cleaning methods at comparable energy recoveries; (3) energy recoveries of 80 percent or greater measured against the raw coal energy content; (4) complete recovery of the heptane bridging liquid from the agglomerates; and (5) production of agglomerates with 3/8-inch size and less than 30 percent moisture. Test results met or exceeded all of the program objectives. Nominal 3/8-inch size agglomerates with less than 20 percent moisture were produced. The clean coal ash content varied between 1.5 to 5.5 percent by weight (dry basis) depending on feed coal type. Ash reductions of the run-of-mine (ROM) coal were 77 to 83 percent. ROM pyritic sulfur reductions varied from 86 to 90 percent for the three test coals, equating to total sulfur reductions of 47 to 72 percent.

  5. Effects of crossover hydrogen on platinum dissolution and agglomeration

    NASA Astrophysics Data System (ADS)

    Cheng, Tommy T. H.; Rogers, Erin; Young, Alan P.; Ye, Siyu; Colbow, Vesna; Wessel, Silvia

    2011-10-01

    The durability of catalysts in the polymer-electrolyte membrane fuel cell (PEMFC) is identified as a critical limiting factor for wide commercialization of fuel cells. Even though much progress has been made in understanding the degradation mechanisms, the phenomena of Pt dissolution and agglomeration and their contributing factors are not fully understood. In the present investigation, the effects of crossover hydrogen on Pt degradation are studied using an accelerated stress test (AST). The end-of-test (EOT) membrane-electrode-assemblies (MEAs) were characterized by X-ray diffraction (XRD), scanning-electron microscopy (SEM), and energy-dispersive X-ray (EDX). The results provided mechanistic understanding of Pt dissolution and agglomeration: Pt growth and agglomeration were found to be less severe with more crossover hydrogen due likely to the chemical reduction of Pt oxides by crossover hydrogen and the subsequently decrease in the amount of Pt ions formed via the oxide pathway.

  6. Hierarchical agglomerates of carbon nanotubes as high-pressure cushions.

    PubMed

    Liu, Yi; Qian, Weizhong; Zhang, Qiang; Cao, Anyuan; Li, Zhifei; Zhou, Weiping; Ma, Yang; Wei, Fei

    2008-05-01

    We report the cushioning behavior of highly agglomerated carbon nanotubes. The nanotube agglomerates can be repeatedly compacted to achieve large volume reduction (>50%) and expanded to nearly original volume without structural failure, like a robust porous cushion. At a higher pressure range (10-125 MPa), the energy absorbed per unit volume is 1 order of magnitude higher than conventional cushion materials such as foamy polystyrene. The structure of hierarchical agglomerates can be controlled for tailoring the cushioning properties and obtaining a lower cushioning coefficient (higher energy absorption) over a wide range of pressures (1-100 MPa). The mechanism was studied in terms of morphology evolution of the nanotube aggregates and pore size distribution during compression.

  7. The Physics of Protoplanetesimal Dust Agglomerates. VIII. Microgravity Collisions between Porous SiO_2 Aggregates and Loosely Bound Agglomerates

    NASA Astrophysics Data System (ADS)

    Whizin, Akbar D.; Blum, Jürgen; Colwell, Joshua E.

    2017-02-01

    We performed laboratory experiments colliding 0.8–1.0 mm and 1.0–1.6 mm SiO2 dust aggregates with loosely bound centimeter-sized agglomerates of those aggregates in microgravity. This work builds on previous microgravity laboratory experiments examining the collisional properties of porous loosely bound dust aggregates. In centimeter-sized aggregates, surface forces dominate self-gravity and may play a large role in aggregate growth beyond this size range. We characterize the properties of protoplanetary aggregate analogs to help place constraints on initial formation mechanisms and environments. We determined several important physical characteristics of these aggregates in a large number of low-velocity collisions. We observed low coefficients of restitution and fragmentation thresholds near 1 m s‑1 for 1–2 cm agglomerates, which are in good agreement with previous findings in the literature. We find the accretion efficiency for agglomerates of loosely bound aggregates to be higher than that for just aggregates themselves. We find sticking thresholds of 6.6 ± 2 cm s‑1, somewhat higher than those in similar studies, which have observed few aggregates stick at speeds of under 3 cm s‑1. Even with highly dissipative collisions, loosely bound agglomerates have difficulty accreting beyond centimeter-sized bodies at typical collision speeds in the disk. Our results indicate agglomerates of porous aggregates have slightly higher sticking thresholds than previously thought, allowing possible growth to decimeter-sized bodies if velocities are low enough.

  8. Ice slurry cooling research: Storage tank ice agglomeration and extraction

    SciTech Connect

    Kasza, K.; Hayashi, Kanetoshi

    1999-08-01

    A new facility has been built to conduct research and development on important issues related to implementing ice slurry cooling technology. Ongoing studies are generating important information on the factors that influence ice particle agglomeration in ice slurry storage tanks. The studies are also addressing the development of methods to minimize and monitor agglomeration and improve the efficiency and controllability of tank extraction of slurry for distribution to cooling loads. These engineering issues impede the utilization of the ice slurry cooling concept that has been under development by various groups.

  9. Continuous air agglomeration method for high carbon fly ash beneficiation

    DOEpatents

    Gray, McMahon L.; Champagne, Kenneth J.; Finseth, Dennis H.

    2000-01-01

    The carbon and mineral components of fly ash are effectively separated by a continuous air agglomeration method, resulting in a substantially carboree mineral stream and a highly concentrated carbon product. The method involves mixing the fly ash comprised of carbon and inorganic mineral matter with a liquid hydrocarbon to form a slurry, contacting the slurry with an aqueous solution, dispersing the hydrocarbon slurry into small droplets within the aqueous solution by mechanical mixing and/or aeration, concentrating the inorganic mineral matter in the aqueous solution, agglomerating the carbon and hydrocarbon in the form of droplets, collecting the droplets, separating the hydrocarbon from the concentrated carbon product, and recycling the hydrocarbon.

  10. Universities' Entrepreneurial Performance: The Role of Agglomeration Economies

    ERIC Educational Resources Information Center

    Chen, Ping Penny

    2011-01-01

    In spite of the extensive research on universities' entrepreneurship, whether research strength fosters or dampens their entrepreneurial performance remains controversial. Much research claims an influential role of research universities in regional economy, however, little has been said about what a part that the agglomeration economies may play…

  11. Spherical agglomerates of lactose with enhanced mechanical properties.

    PubMed

    Lamešić, Dejan; Planinšek, Odon; Lavrič, Zoran; Ilić, Ilija

    2017-01-10

    The aim of this study was to prepare spherical agglomerates of lactose and to evaluate their physicochemical properties, flow properties, particle friability and compaction properties, and to compare them to commercially available types of lactose for direct compression (spray-dried, granulated and anhydrous β-lactose). Porous spherical agglomerates of α-lactose monohydrate with radially arranged prism-like primary particles were prepared exhibiting a high specific surface area. All types of lactose analysed had passable or better flow properties, except for anhydrous β-lactose, which had poor flowability. Particle friability was more pronounced in larger granulated lactose particles; however, particle structure was retained in all samples analysed. The mechanical properties of spherical agglomerates of lactose, in terms of compressibility, established with Walker analysis, and compactibility, established with a compactibility profile, were found to be superior to any commercially available types of lactose. Higher compactibility of spherical agglomerates of lactose is ascribed to significantly higher particle surface area due to a unique internal structure with higher susceptibility to fragmentation.

  12. Engineering development of selective agglomeration. Site closeout report

    SciTech Connect

    Not Available

    1993-04-01

    The Selective Agglomeration POC facility consisted of a coal crushing and grinding circuit, followed by an agglomeration circuit and product dewatering. (A plot plan of the facility is shown in Figure 1-2.) The coal crushing and grinding system consisted of a hammermill coal crusher, weigh-belt feeder, two ball mills (primary and secondary), and necessary hoppers, pumps, and conveyors. The mills were capable of providing coal over a range of grinds from a d{sub 50} of 125 to 25 microns. Slurry discharged from the ball mills was pumped to the agglomeration circuit. The agglomeration circuit began with a high-shear mixer, where diesel was added to the slurry to begin the formation of microagglomerates. The high-shear mixer was followed by two stages of conventional flotation cells for microagglomerate recovery. The second-stage-flotation-cell product was pumped to either a rotary-drum vacuum filter or a high-G centrifuge for dewatering. The dewatered product was then convoyed to the product pad from which dump trucks were used to transfer it to the utility plant located next to the facility. Plant tailings were pumped to the water clarifier for thickening and then dewatered in plate-and-frame filter presses. These dewatered tailings were also removed to the utility via dump truck. Clarified water (thickener overflow) was recycled to the process via a head tank.

  13. Frequency comparative study of coal-fired fly ash acoustic agglomeration.

    PubMed

    Liu, Jianzhong; Wang, Jie; Zhang, Guangxue; Zhou, Junhu; Cen, Kefa

    2011-01-01

    Particulate pollution is main kind of atmospheric pollution. The fine particles are seriously harmful to human health and environment. Acoustic agglomeration is considered as a promising pretreatment technology for fine particle agglomeration. The mechanisms of acoustic agglomeration are very complex and the agglomeration efficiency is affected by many factors. The most important and controversial factor is frequency. Comparative studies between high-frequency and low-frequency sound source to agglomerate coal-fired fly ash were carried out to investigate the influence of frequency on agglomeration efficiency. Acoustic agglomeration theoretical analysis, experimental particle size distributions (PSDs) and orthogonal design were examined. The results showed that the 20 kHz high-frequency sound source was not suitable to agglomerate coal-fired fly ash. Only within the size ranging from 0.2 to 0.25 microm the particles agglomerated to adhere together, and the agglomerated particles were smaller than 2.5 microm. The application of low-frequency (1000-1800 Hz) sound source was proved as an advisable pretreatment with the highest agglomeration efficiency of 75.3%, and all the number concentrations within the measuring range decreased. Orthogonal design L16 (4)3 was introduced to determine the optimum frequency and optimize acoustic agglomeration condition. According to the results of orthogonal analysis, frequency was the dominant factor of coal-fired fly ash acoustic agglomeration and the optimum frequency was 1400 Hz.

  14. Phosphate-enhanced cytotoxicity of zinc oxide nanoparticles and agglomerates.

    PubMed

    Everett, W Neil; Chern, Christina; Sun, Dazhi; McMahon, Rebecca E; Zhang, Xi; Chen, Wei-Jung A; Hahn, Mariah S; Sue, H-J

    2014-02-10

    Zinc oxide (ZnO) nanoparticles (NPs) have been found to readily react with phosphate ions to form zinc phosphate (Zn3(PO4)2) crystallites. Because phosphates are ubiquitous in physiological fluids as well as waste water streams, it is important to examine the potential effects that the formation of Zn3(PO4)2 crystallites may have on cell viability. Thus, the cytotoxic response of NIH/3T3 fibroblast cells was assessed following 24h of exposure to ZnO NPs suspended in media with and without the standard phosphate salt supplement. Both particle dosage and size have been shown to impact the cytotoxic effects of ZnO NPs, so doses ranging from 5 to 50 μg/mL were examined and agglomerate size effects were investigated by using the bioinert amphiphilic polymer polyvinylpyrrolidone (PVP) to generate water-soluble ZnO ranging from individually dispersed 4 nm NPs up to micron-sized agglomerates. Cell metabolic activity measures indicated that the presence of phosphate in the suspension media can led to significantly reduced cell viability at all agglomerate sizes and at lower ZnO dosages. In addition, a reduction in cell viability was observed when agglomerate size was decreased, but only in the phosphate-containing media. These metabolic activity results were reflected in separate measures of cell death via the lactate dehydrogenase assay. Our results suggest that, while higher doses of water-soluble ZnO NPs are cytotoxic, the presence of phosphates in the surrounding fluid can lead to significantly elevated levels of cell death at lower ZnO NP doses. Moreover, the extent of this death can potentially be modulated or offset by tuning the agglomerate size. These findings underscore the importance of understanding how nanoscale materials can interact with the components of surrounding fluids so that potential adverse effects of such interactions can be controlled.

  15. Improving the de-agglomeration and dissolution of a poorly water soluble drug by decreasing the agglomerate strength of the cohesive powder.

    PubMed

    Allahham, Ayman; Stewart, Peter J; Das, Shyamal C

    2013-11-30

    Influence of ternary, poorly water-soluble components on the agglomerate strength of cohesive indomethacin mixtures during dissolution was studied to explore the relationship between agglomerate strength and extent of de-agglomeration and dissolution of indomethacin (Ind). Dissolution profiles of Ind from 20% Ind-lactose binary mixtures, and ternary mixtures containing additional dibasic calcium phosphate (1% or 10%; DCP), calcium sulphate (10%) and talc (10%) were determined. Agglomerate strength distributions were estimated by Monte Carlo simulation of particle size, work of cohesion and packing fraction distributions. The agglomerate strength of Ind decreased from 1.19 MPa for the binary Ind mixture to 0.84 MPa for 1DCP:20Ind mixture and to 0.42 MPa for 1DCP:2Ind mixture. Both extent of de-agglomeration, demonstrated by the concentration of the dispersed indomethacin distribution, and extent of dispersion, demonstrated by the particle size of the dispersed indomethacin, were in descending order of 1DCP:2Ind>1DCP:20Ind>binary Ind. The addition of calcium sulphate dihydrate and talc also reduced the agglomerate strength and improved de-agglomeration and dispersion of indomethacin. While not definitively causal, the improved de-agglomeration and dispersion of a poorly water soluble drug by poorly water soluble components was related to the agglomerate strength of the cohesive matrix during dissolution.

  16. Oscillatory Dynamics of Single Bubbles and Agglomeration in a Sound Field in Microgravity

    NASA Technical Reports Server (NTRS)

    Marston, Philip L.; Trinh, Eugene H.; Depew, Jon; Asaki, Thomas J.

    1994-01-01

    A dual-frequency acoustic levitator containing water was developed for studying bubble and drop dynamics in low gravity. It was flown on USML-1 where it was used in the Glovebox facility. High frequency (21 or 63 kHz) ultrasonic waves were modulated by low frequencies to excite shape oscillations on bubbles and oil drops ultrasonically trapped in the water. Bubble diameters were typically close to 1 cm or larger. When such large bubbles are acoustically trapped on the Earth, the acoustic radiation pressure needed to overcome buoyancy tends to shift the natural frequency for quadrupole (n = 2) oscillations above the prediction of Lamb's equation. In low gravity, a much weaker trapping force was used and measurements of n = 2 and 3 mode frequencies were closer to the ideal case. Other video observations in low gravity include: (i) the transient reappearance of a bulge where a small bubble has coalesced with a large one, (ii) observations of the dynamics of bubbles coated by oil indicating that shape oscillations can shift a coated bubble away from the oil-water interface of the coating giving a centering of the core, and (iii) the agglomeration of bubbles induced by the sound field.

  17. The impact of agglomeration economies on hospital input prices.

    PubMed

    Friedson, Andrew I; Li, Jing

    2015-12-01

    This paper examines the extent to which agglomeration of the hospital service industry enhances the productivity of producing health care. Specifically, we use a large set of private insurance claims from the FAIR Health database to show that an increasing spatial concentration of hospital services results in a decreased cost of obtaining intermediate medical services. We explicitly test whether the reduced cost at concentrated locations arises from the ability to share intermediate service providers. The identification relies on state variation in medical lab technician licensure requirements, which influence the cost of intermediate services only through the cost of running a lab. Our findings suggest that agglomeration of the hospital service industry attracts specialized medical labs, which in turn help to reduce the cost of producing laboratory tests.

  18. Engineering development of selective agglomeration: Trace element removal study

    SciTech Connect

    Not Available

    1993-09-01

    Southern Company Services, Inc., (SCS) was contracted in 1989 by the US Department of Energy (DOE) to develop a commercially acceptable selective agglomeration technology to enhance the use of high-sulfur coals by 1993. The project scope involved development of a bench-scale process and components, as well as the design, testing, and evaluation of a proof-of-concept (POC) facility. To that end, a two-ton-per-hour facility was constructed and tested near Wilsonville, Alabama. Although it was not the primary focus of the test program, SCS also measured the ability of selective agglomeration to remove trace elements from coal. This document describes the results of that program.

  19. Development of methods to predict agglomeration and disposition in FBCs

    SciTech Connect

    Mann, M.D.; Henderson, A.K.; Swanson, M.K.; Erickson, T.A.

    1995-11-01

    This 3-year, multiclient program is providing the information needed to determine the behavior of inorganic components in FBC units using advanced methods of analysis coupled with bench-scale combustion experiments. The major objectives of the program are as follows: (1) To develop further our advanced ash and deposit characterization techniques to quantify the effects of the liquid-phase components in terms of agglomerate formation and ash deposits, (2) To determine the mechanisms of inorganic transformations that lead to bed agglomeration and ash deposition in FBC systems, and (3) To develop a better means to predict the behavior of inorganic components as a function of coal composition, bed material characteristics, and combustion conditions.

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

    SciTech Connect

    Robert S. Dahlin; Johnny R. Dorminey; WanWang Peng; Roxann F. Leonard; Pannalal Vimalchand

    2009-01-15

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

  1. Parallel Element Agglomeration Algebraic Multigrid and Upscaling Library

    SciTech Connect

    2015-02-19

    ParFELAG is a parallel distributed memory C++ library for numerical upscaling of finite element discretizations. It provides optimal complesity algorithms ro build multilevel hierarchies and solvers that can be used for solving a wide class of partial differential equations (elliptic, hyperbolic, saddle point problems) on general unstructured mesh (under the assumption that the topology of the agglomerated entities is correct). Additionally, a novel multilevel solver for saddle point problems with divergence constraint is implemented.

  2. Aluminum Agglomeration and Trajectory in Solid Rocket Motors

    DTIC Science & Technology

    2007-08-30

    cinematography data from China Lake. Task 2.2, Aluminum Agglomeration Model Selection (SEA/BYU/ATK Task) Part of the model selection task has already been... Manual . Software and Engineering Associates, Inc. 1802 N. Carson Street, Suite 200, Carson City, NV 89701. 2005. [DCF-2005b] S. S. Dunn, D. E. Coats, and J...C. French, SPP󈧈 Standard Stability Prediction Method for Solid Rocket Motors; Axial Mode Computer Program User’s Manual . Software and Engineering

  3. Contact mechanics of highly porous oxide nanoparticle agglomerates

    NASA Astrophysics Data System (ADS)

    Fabre, Andrea; Salameh, Samir; Ciacchi, Lucio Colombi; Kreutzer, Michiel T.; van Ommen, J. Ruud

    2016-07-01

    Efficient nanopowder processing requires knowledge of the powder's mechanical properties. Due to the large surface area to volume ratio, nanoparticles experience relatively strong attractive interactions, leading to the formation of micron-size porous structures called agglomerates. Significant effort has been directed towards the development of models and experimental procedures to estimate the elasticity of porous objects such as nanoparticle agglomerates; however, none of the existing models has been validated for solid fractions below 0.1. Here, we measure the elasticity of titania (TiO_2, 22 nm), alumina (Al_2O_3, 8 nm), and silica (SiO_2, 16 nm) nanopowder agglomerates by Atomic Force Microscopy, using a 3.75 μm glass colloid for the stress-strain experiments. Three sample preparations with varying degree of powder manipulation are assessed. The measured Young's moduli are in the same order of magnitude as those predicted by the model of Kendall et al., thus validating it for the estimation of the Young's modulus of structures with porosity above 90 %.

  4. The role of agglomeration in the conductivity of carbon nanotube composites near percolation

    NASA Astrophysics Data System (ADS)

    Tarlton, Taylor; Sullivan, Ethan; Brown, Joshua; Derosa, Pedro A.

    2017-02-01

    A detailed study of agglomeration in composite materials containing carbon nanotubes (CNT) is presented. Three dimensional samples with different degrees of agglomeration were created in three different ways, leading to a wider range of geometries available to study. Virtual charges are injected into the computer-generated samples and move through these samples according to a Monte Carlo hopping algorithm. Results show that there is an optimal level of agglomeration that is actually beneficial for charge transport at low volume concentrations, lowering the percolation threshold. It is found that near percolation, a more uniform CNT distribution (less agglomeration) leads to more conductive paths, but with a lower mobility. The optimum level of agglomeration comes from a trade off between these two properties. Beyond this optimum agglomeration state, it is observed that conductivity tends to decrease as dispersion increases at all concentrations studied here. At high concentration (percolated samples), where CNT clumps merge, conductivity seems to be less sensitive to agglomeration.

  5. Process for converting heavy oil deposited on coal to distillable oil in a low severity process

    DOEpatents

    Ignasiak, Teresa; Strausz, Otto; Ignasiak, Boleslaw; Janiak, Jerzy; Pawlak, Wanda; Szymocha, Kazimierz; Turak, Ali A.

    1994-01-01

    A process for removing oil from coal fines that have been agglomerated or blended with heavy oil comprises the steps of heating the coal fines to temperatures over 350.degree. C. up to 450.degree. C. in an inert atmosphere, such as steam or nitrogen, to convert some of the heavy oil to lighter, and distilling and collecting the lighter oils. The pressure at which the process is carried out can be from atmospheric to 100 atmospheres. A hydrogen donor can be added to the oil prior to deposition on the coal surface to increase the yield of distillable oil.

  6. Operation of dry-cleaned and agglomerated precompaction system (DAPS)

    SciTech Connect

    Tanaka, Shigemi; Okanishi, Kazuya; Kikuchi, Akio; Yamamura, Yuichi

    1997-12-31

    In order to reduce the manufacturing cost of coke, it is necessary to reduce mainly (1) the material cost and (2) operating cost. Both of these costs can be reduced by lowering the moisture of charging coal. Because dust generation increases with decreasing moisture of charging coal, however, the lower limit of charging coal moisture in the existing coke-oven equipment was about 5%, which yielded good results in coal moisture control (CMC) equipment. Nippon Steel has furthered the development of techniques for lowering the moisture of charging coal as far as possible in the existing coke ovens and has recently succeeded in developing a dry-cleaned and agglomerated precompaction system (DAPS) and incorporating this system in commercial production equipment. In this system, a coal preparation process is undertaken that involves separating coal fines, which cause dust generation, from dried charging coal and agglomerating them. The equipment incorporating this system was installed in the No. 3 and No. 4 coke batteries at Oita Works and brought into full-scale operation in September 1992. The equipment has since been operating smoothly.

  7. Agglomeration of Luminescent Porous Silicon Nanoparticles in Colloidal Solutions

    NASA Astrophysics Data System (ADS)

    Herynková, Kateřina; Šlechta, Miroslav; Šimáková, Petra; Fučíková, Anna; Cibulka, Ondřej

    2016-08-01

    We have prepared colloidal solutions of clusters composed from porous silicon nanoparticles in methanol, water and phosphate-buffered saline (PBS). Even if the size of the nanoclusters is between 60 and 500 nm, due to their highly porous "cauliflower"-like structure, the porous silicon nanoparticles are composed of interconnected nanocrystals having around 2.5 nm in size and showing strong visible luminescence in the orange-red spectral region (centred at 600-700 nm). Hydrophilic behaviour and good solubility of the nanoclusters in water and water-based solutions were obtained by adding hydrogen peroxide into the etching solution during preparation and 16 min long after-bath in hydrogen peroxide. By simple filtration of the solutions with syringe filters, we have extracted smaller nanoclusters with sizes of approx. 60-70 nm; however, these nanoclusters in water and PBS solution (pH neutral) are prone to agglomeration, as was confirmed by zeta potential measurements. When the samples were left at ambient conditions for several weeks, the typical nanocluster size increased to approx. 330-400 nm and then remained stable. However, both freshly filtered and aged samples (with agglomerated porous silicon nanoparticles) of porous silicon in water and PBS solutions can be further used for biological studies or as luminescent markers in living cells.

  8. Synthesis and agglomeration of gold nanoparticles in reverse micelles

    NASA Astrophysics Data System (ADS)

    Herrera, Adriana P.; Resto, Oscar; Briano, Julio G.; Rinaldi, Carlos

    2005-07-01

    Reverse micelles prepared in the system water, sodium bis-(2-ethylhexyl) sulfoccinate (AOT), and isooctane were investigated as a templating system for the production of gold nanoparticles from Au(III) and the reducing agent sulfite. A core-shell Mie model was used to describe the optical properties of gold nanoparticles in the reverse micelles. Dynamic light scattering of gold colloids in aqueous media and in reverse micelle solution indicated agglomeration of micelles containing particles. This was verified theoretically with an analysis of the total interaction energy between pairs of particles as a function of particle size. The analysis indicated that particles larger than about 8 nm in diameter should reversibly flocculate. Transmission electron microscopy measurements of gold nanoparticles produced in our reverse micelles showed diameters of 8-10 nm. Evidence of cluster formation was also observed. Time-correlated UV-vis absorption measurements showed a red shift for the peak wavelength. This was interpreted as the result of multiple scattering and plasmon interaction between particles due to agglomeration of micelles with particles larger than 8 nm.

  9. On minimal energy dipole moment distributions in regular polygonal agglomerates

    NASA Astrophysics Data System (ADS)

    Rosa, Adriano Possebon; Cunha, Francisco Ricardo; Ceniceros, Hector Daniel

    2017-01-01

    Static, regular polygonal and close-packed clusters of spherical magnetic particles and their energy-minimizing magnetic moments are investigated in a two-dimensional setting. This study focuses on a simple particle system which is solely described by the dipole-dipole interaction energy, both without and in the presence of an in-plane magnetic field. For a regular polygonal structure of n sides with n ≥ 3 , and in the absence of an external field, it is proved rigorously that the magnetic moments given by the roots of unity, i.e. tangential to the polygon, are a minimizer of the dipole-dipole interaction energy. Also, for zero external field, new multiple local minima are discovered for the regular polygonal agglomerates. The number of found local extrema is proportional to [ n / 2 ] and these critical points are characterized by the presence of a pair of magnetic moments with a large deviation from the tangential configuration and whose particles are at least three diameters apart. The changes induced by an in-plane external magnetic field on the minimal energy, tangential configurations are investigated numerically. The two critical fields, which correspond to a crossover with the linear chain minimal energy and with the break-up of the agglomerate, respectively are examined in detail. In particular, the numerical results are compared directly with the asymptotic formulas of Danilov et al. (2012) [23] and a remarkable agreement is found even for moderate to large fields. Finally, three examples of close-packed structures are investigated: a triangle, a centered hexagon, and a 19-particle close packed cluster. The numerical study reveals novel, illuminating characteristics of these compact clusters often seen in ferrofluids. The centered hexagon is energetically favorable to the regular hexagon and the minimal energy for the larger 19-particle cluster is even lower than that of the close packed hexagon. In addition, this larger close packed agglomerate has two

  10. Selection of feed coals for production of premium fuel using column flotation and selective agglomeration processes

    SciTech Connect

    Jha, M.C.; Smit, F.J.

    1995-10-01

    Column flotation and selective agglomeration are promising advanced physical cleaning processes that can be developed for preparing premium quality coal-water slurry fuel from coal fines. Such a fuel could either replace oil or natural gas in certain industrial and utility boilers or else could be burned in advanced combustors currently under development. These applications require coal cleaned to sulfur and ash contents below 258 g/GJ and 430--860 g/GJ (0.6 lb/million Btu and 1--2 lb/million Btu), respectively, to meet clean air emission requirements. A highly loaded slurry must be produced in order to avoid derating the boilers, and the total cost of the fuel must be below $2.37/GJ ($2.50/million Btu) in order to penetrate the market by the turn of the century. Achieving these technical and economic goals depend critically on the selection of suitable feed coals. This paper describes the identification and evaluation of 18 coals and final selection of six coals from different regions of the United States as potential feedstock for preparation of premium fuel. The work is being performed under a cost-shared DOE project.

  11. Intensive drying and the related microstructure features in agglomerate spheres

    NASA Astrophysics Data System (ADS)

    Kudlyk, Rostyslav

    Most metal ore concentrates are fine particulates with a wide particle-size distribution. Industrially they are pelletized by tumbling in balling discs or drums into spheres, an operation which requires the addition of typically up to 10% by weight of water. Further processing of these agglomerates involves first drying and then induration by heating up to 1250°C. The main objective of this thesis was the study of the interrelationship between the microstructure of the agglomerates with, on the one hand, the mechanical and physical properties of the pellets and their behaviour during intensive drying, on the other. The previously developed model of the drying process identified the loss of capillarity, resulting from the vapour lock, to be a critical component of the mechanism of intense as opposed to 'classical' drying. It was shown that the absence of the constant-rate drying period is a natural consequence of this effect. Several significant shortcomings of the previous model have been identified. This model treats the period of transition between surface- and shrinking-core drying as an instantaneous event. The new extended model, which overcomes the original model limitations, was developed in this project. In its formalism, the new model includes the pore-size distribution and thus simulates a gradual surface/shrinking-core transition. It was shown that the nature of the transition between the surface- and shrinking-core drying regimes during intensive drying is fundamentally different from that of classical drying, i.e. carried out at mild temperatures. In the latter case, liquid is being delivered to the surface through the network of interconnected small pores reaching the surface. The transition occurs when the larger pores, also reaching the surface, are being drained. On the other hand, under intense-drying conditions, the rate-limiting factor is the vapour lock. The latter phenomenon will occur in the smaller pores first, as they have smaller liquid

  12. Agglomerating combustor-gasifier method and apparatus for coal gasification

    DOEpatents

    Chen, Joseph L. P.; Archer, David H.

    1976-09-21

    A method and apparatus for gasifying coal wherein the gasification takes place in a spout fluid bed at a pressure of about 10 to 30 atmospheres and a temperature of about 1800.degree. to 2200.degree.F and wherein the configuration of the apparatus and the manner of introduction of gases for combustion and fluidization is such that agglomerated ash can be withdrawn from the bottom of the apparatus and gas containing very low dust loading is produced. The gasification reaction is self-sustaining through the burning of a stoichiometric amount of coal with air in the lower part of the apparatus to form the spout within the fluid bed. The method and apparatus are particularly suitable for gasifying coarse coal particles.

  13. Innovations in thermoelectric materials research: Compound agglomeration, testing and preselection

    NASA Astrophysics Data System (ADS)

    Lopez de Cardenas, Hugo Francisco Lopez

    Thermoelectric materials have the capacity to convert a temperature differential into electrical power and vice versa. They will represent the next revolution in alternative energies once their efficiencies are enhanced so they can complement other forms of green energies that depend on sources other than a temperature differential. Progress in materials science depends on the ability to discover new materials to eventually understand them and to finally improve their properties. The work presented here is aimed at dynamizing the screening of materials of thermoelectric interest. The results of this project will enable: theoretical preselection of thermoelectric compounds based on their bandgap and a rapid agglomeration method that does not require melting or sintering. A special interest will be given to Iodine-doped TiSe2 that generated extraordinary results and a new set of equations are proposed to accurately describe the dependence of the power factor and the figure of merit on the intrinsic properties of the materials.

  14. Molecular mechanisms responsible for hydrate anti-agglomerant performance.

    PubMed

    Phan, Anh; Bui, Tai; Acosta, Erick; Krishnamurthy, Pushkala; Striolo, Alberto

    2016-09-28

    Steered and equilibrium molecular dynamics simulations were employed to study the coalescence of a sI hydrate particle and a water droplet within a hydrocarbon mixture. The size of both the hydrate particle and the water droplet is comparable to that of the aqueous core in reverse micelles. The simulations were repeated in the presence of various quaternary ammonium chloride surfactants. We investigated the effects due to different groups on the quaternary head group (e.g. methyl vs. butyl groups), as well as different hydrophobic tail lengths (e.g. n-hexadecyl vs. n-dodecyl tails) on the surfactants' ability to prevent coalescence. Visual inspection of sequences of simulation snapshots indicates that when the water droplet is not covered by surfactants it is more likely to approach the hydrate particle, penetrate the protective surfactant film, reach the hydrate surface, and coalesce with the hydrate than when surfactants are present on both surfaces. Force-distance profiles obtained from steered molecular dynamics simulations and free energy profiles obtained from umbrella sampling suggest that surfactants with butyl tripods on the quaternary head group and hydrophobic tails with size similar to the solvent molecules can act as effective anti-agglomerants. These results qualitatively agree with macroscopic experimental observations. The simulation results provide additional insights, which could be useful in flow assurance applications: the butyl tripod provides adhesion between surfactants and hydrates; when the length of the surfactant tail is compatible with that of the hydrocarbon in the liquid phase a protective film can form on the hydrate; however, once a molecularly thin chain of water molecules forms through the anti-agglomerant film, connecting the water droplet and the hydrate, water flows to the hydrate and coalescence is inevitable.

  15. A MODEL FOR FINE PARTICLE AGGLOMERATION IN CIRCULATING FLUIDIZED BED ABSORBERS

    EPA Science Inventory

    A model for fine particle agglomeration in circulating fluidized bed absorbers (CFBAS) has been developed. It can model the influence of different factors on agglomeration, such as the geometry of CFBAs, superficial gas velocity, initial particle size distribution, and type of ag...

  16. Influence of the pan pelletizer rotational velocity and the particles size on the agglomeration of alumina oxide granules

    NASA Astrophysics Data System (ADS)

    Radeva, Zheni; Müller, Peter; Tomas, Juergen

    2013-06-01

    High fraction of agglomerates and better agglomerate strength are main purpose for every agglomeration process. For optimizing the agglomeration process of industrial produced granules, using liquid binders, it is necessary to understand the microinteractions between primary particles and binder and the marcointeractions between the agglomerates themselves. In order to investigate the influence of the rotational velocity of the pan pelletizer and the primary particle size on the fraction of agglomerates and the mechanical properties of the produced agglomerates, the obtained structures have to be basically analyzed. Agglomeration of industrial produced Alumina Oxide (γ-Al2O3) granules is carried out in a rotating pan pelletizer. A 6 mass-% solution of viscoelastic polymer - hydroxypropyl methylcellulose (HPMC) is used as binder. The rotational velocity of the pelletizer pan is previously measured and calibrated. By changing the rotational velocity of the process chamber it was found that there are critical speed limits for the pan. The minimum critical velocity of the pelletizer plate does not provide enough contact collisions between the particles and the necessary kinetic level for agglomeration cannot be reached. The maximum critical velocity leads to higher rotational kinetic energy and this causes breakages of the agglomerates. It was also proven that the breakage strength of the agglomerates decreases with the reduction of the agglomerate size. The conclusions from the experimental work help us to understand the basics of agglomeration process and tend to develop and facilitate the operating with particle collectives in science and industry.

  17. Morphological characterization of diesel soot agglomerates based on the Beer-Lambert law

    NASA Astrophysics Data System (ADS)

    Lapuerta, Magín; Martos, Francisco J.; José Expósito, Juan

    2013-03-01

    A new method is proposed for the determination of the number of primary particles composing soot agglomerates emitted from diesel engines as well as their individual fractal dimension. The method is based on the Beer-Lambert law and it is applied to micro-photographs taken in high resolution transmission electron microscopy. Differences in the grey levels of the images lead to a more accurate estimation of the geometry of the agglomerate (in this case radius of gyration) than other methods based exclusively on the planar projections of the agglomerates. The method was validated by applying it to different images of the same agglomerate observed from different angles of incidence, and proving that the effect of the angle of incidence is minor, contrary to other methods. Finally, the comparisons with other methods showed that the size, number of primary particles and fractal dimension (the latter depending on the particle size) are usually underestimated when only planar projections of the agglomerates are considered.

  18. Acoustic agglomeration of power-plant fly ash. A comprehensive semi-annual progress report

    SciTech Connect

    Reethof, G.

    1980-02-01

    Results obtained during the reporting period are presented. The agglomeration of submicron fly ash particles has been studied as a function of sound pressure level, sound frequency, loading, and exposure time. A second generation model of the agglomeration process is being developed. A high-frequency, high-intensity variable speed siren delivering at least 600 W at frequencies up to 4000 Hz has been developed and tested. Details on the design and operation are presented. The agglomeration chamber has been completely cleaned and the aerosol generating system has been rebuilt. A mathematical model of the acoustics of agglomeration is being developed. Preliminary results of computerized electron microscopic scanning of fly ash particles during agglomeration are presented. (DMC)

  19. Evaluation of physico-mechanical properties of drug-excipients agglomerates obtained by crystallization.

    PubMed

    Maghsoodi, M; Tajalli Bakhsh, A S

    2011-06-01

    Spherical crystallization (SC) of carbamazepine (CBZ) was carried out for preparation of the agglomerates using the solvent change method. The potential of the intraagglomerate addition of sodium starch glycolate (SSG) as a disintegrant agent and povidone (PVP) as a hydrophilic polymer was also evaluated. The process of SC involved recrystallization of CBZ and its simultaneous agglomeration with additives. An ethanol:isopropyl acetate:water system was used where isopropyl acetate acted as a bridging liquid and ethanol and water as good and bad solvents, respectively. The agglomerates were characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (XRPD), and Scanning electron microscopy and were evaluated for yield, flowability, disintegration time and drug release. CBZ agglomerates exhibited significantly improved micromeritic properties as well as dissolution behavior in comparison to conventional drug crystals. The dissolution rate of drug from agglomerates was enhanced by inclusion of SSG, while addition of PVP to CBZ/SSG agglomerates led to reduction in the release rate of CBZ even below that of the conventional drug crystals. SC process can be considered as a suitable alternative to conventional granulation process to obtain agglomerates of CBZ with excipients with improved micromeritic properties and modified dissolution rate.

  20. Modifying drug release and tablet properties of starch acetate tablets by dry powder agglomeration.

    PubMed

    Mäki, Riikka; Suihko, Eero; Rost, Susanne; Heiskanen, Minna; Murtomaa, Matti; Lehto, Vesa-Pekka; Ketolainen, Jarkko

    2007-02-01

    In this study three model drugs (N-acetyl-D-glucosamine (NAG), anhydrous caffeine, and propranolol hydrochloride) were agglomerated with starch acetate (SA) by mixing the binary powders on a stainless steel (SS) plate. Agglomeration was induced by triboelectrification of the particles during mixing, and it was evaluated as a method to achieve controlled drug release rate. These agglomerates, mixed with different amounts of a disintegrant, were compressed into tablets whose dissolution characteristics were determined. Triboelectric measurements showed that when the drugs were in contact with SS, charges of the opposite polarity were generated to SA (+) and caffeine and NAG (-) promoting adhesion. Instead, propranolol HCl was charged with the same polarity as SA. SEM micrographs showed that smaller caffeine particles, in spite of their larger negative charge, agglomerated less efficiently with SA than larger NAG particles. This emphasizes the importance of particle size in the agglomeration process. Propranolol HCl did not form agglomerates with SA since their particle sizes and charges were identical. As a result, agglomeration of powders prior to tablet compression allows for modification and control of the release rate of the drugs from the SA matrix tablets as well as the tensile strength of the tablets.

  1. Reducing adhesion and agglomeration within a cloud of combustible particles

    NASA Technical Reports Server (NTRS)

    Ross, Howard D.

    1988-01-01

    The study of combustible particle clouds inside flame tubes is of fundamental scientific interest as well as a practical concern. Only the suspended concentration is important to the combustion process, so that assurances must be provided that a minimum of particles adheres to the tube wall. This paper demonstrates experimentally the ability to minimize adhesion and agglomeration of acoustically-mixed lycopodium particles within a 5-cm diameter lexan flame tube. The area density of particles (ADP) adhering to the wall of bare lexan tubes was measured at greater than 100 particles/sq mm. The nature of adhesion was found to be clearly electrostatic, with the ADP level aggravated by increased mixing time, vigor, and the concentration of particles. Increases in the conductivity of the air and the tube wall did not affect ADP levels substantially. However, the observed adhesion was reduced to less than 10 p/sq mm when the air was ionized by use of an alpha emitter mounted on the inner walls of the flame tube.

  2. Noise action plan of agglomerations: sustainable hypothesis or utopy?

    PubMed

    Magri, S L; Masera, S; Fogola, J

    2009-12-01

    European and Italian laws establish that agglomerations of more than 100 000 inhabitants must adopt an action plan in order to manage noise issues and effects. The plan aim is to reduce population exposure to environmental noise, which is defined as the outdoor sound created by human activities, including noise emitted by road traffic, rail traffic and air traffic, and noise from sites of industrial activity. Although acoustic pollution represents one of the main causes of annoyance for inhabitants of urban areas, the political agenda does not acknowledge it among the main environmental issues. Thus, acoustic reclamation is often considered a duty to be accomplished rather than a way to improve quality of life for citizens. Furthermore, financial resources are generally very poor while the acoustic critical situations are numerous and serious in terms of exceeding the limit. In this situation, what is the meaning of an urban area noise action plan? What are the concrete actions that municipalities can realise to reduce urban noise pollution? This study tries to answer these questions, starting from the analysis carried out for the action plan of the city of Turin.

  3. Agglomeration Multigrid for an Unstructured-Grid Flow Solver

    NASA Technical Reports Server (NTRS)

    Frink, Neal; Pandya, Mohagna J.

    2004-01-01

    An agglomeration multigrid scheme has been implemented into the sequential version of the NASA code USM3Dns, tetrahedral cell-centered finite volume Euler/Navier-Stokes flow solver. Efficiency and robustness of the multigrid-enhanced flow solver have been assessed for three configurations assuming an inviscid flow and one configuration assuming a viscous fully turbulent flow. The inviscid studies include a transonic flow over the ONERA M6 wing and a generic business jet with flow-through nacelles and a low subsonic flow over a high-lift trapezoidal wing. The viscous case includes a fully turbulent flow over the RAE 2822 rectangular wing. The multigrid solutions converged with 12%-33% of the Central Processing Unit (CPU) time required by the solutions obtained without multigrid. For all of the inviscid cases, multigrid in conjunction with an explicit time-stepping scheme performed the best with regard to the run time memory and CPU time requirements. However, for the viscous case multigrid had to be used with an implicit backward Euler time-stepping scheme that increased the run time memory requirement by 22% as compared to the run made without multigrid.

  4. Assessment of Traffic Noise on Highway Passing from Urban Agglomeration

    NASA Astrophysics Data System (ADS)

    Vijay, Ritesh; Kori, Chandan; Kumar, Manoj; Chakrabarti, T.; Gupta, Rajesh

    2014-09-01

    Assessment of traffic noise pollution in developing countries is complex due to heterogeneity in traffic conditions like traffic volume, road width, honking, etc. To analyze the impact of such variables, a research study was carried out on a national highway passing from an urban agglomeration. Traffic volume and noise levels (L10, Lmin, Lmax, Leq and L90) were measured during morning and evening peak hours. Contribution of noise by individual vehicle was estimated using passenger car noise unit. Extent of noise pollution and impact of noisy vehicles were estimated using noise pollution level and traffic noise index, respectively. Noise levels were observed to be above the prescribed Indian and International standards. As per audio spectrum analysis of traffic noise, honking contributed an additional 3-4 dB(A) noise. Based on data analysis, a positive relationship was observed between noise levels and honking while negative correlation was observed between noise levels and road width. The study suggests that proper monitoring and analysis of traffic data is required for better planning of noise abatement measures.

  5. Gravitational agglomeration of post-HCDA LMFBR nonspherical aerosols

    NASA Astrophysics Data System (ADS)

    Tuttle, R. F.

    1980-12-01

    A theoretical investigation of collisional dynamics of two particle interactions in a gravitational field is reported. This research is unique in that it is the first attempt at modeling the hydrodynamic interactions between a nonspherical particle and a spherical particle undergoing gravitational collisions in an LMFBR environment. Basic definitions and expressions are developed for nonspherical particles and related to spherical particles by means of shape factors. Using volume equivalent diameter as the defining length in the gravitational collision kernel, the aerodynamic shape factor, k, the density correction factor, alpha, and the gravitational collision shape factor, beta, are used to correct the collision kernel for the case of collisions between aerosol agglomerates. The Navier-Stokes equation in oblate spheroidal coordinates is solved to model a nonspherical particle and then the dynamic equations for two particle motions are developed. A computer program NGCEFF is constructed, the Navier-Stokes equation is solved by the finite difference method, and the dynamical equations are solved by Gear's method. It is concluded that the aerosol gravitational collision shape factor can be determined by further theoretical work based on the concepts and methods developed in this dissertation.

  6. Monitoring of odor nuisance in the tri-city agglomeration

    NASA Astrophysics Data System (ADS)

    Gebicki, Jacek; Dymerski, Tomasz; Namieśnik, Jacek

    2016-11-01

    The paper describes a principle of operation of odor nuisance monitoring network, which is being designed in the tri-city agglomeration. Moreover, it presents the preliminary results of an investigation on ambient air quality with respect to odour nuisance in a vicinity of the municipal landfill. The investigation was performed during spring-winter season using a prototype of electronic nose and the Nasal Ranger field olfactometers. The prototype was equipped with a set of six semiconductor sensors by FIGARO Co. and one PID-type sensor. The field olfactometers were used to determine mean concentration of odorants, which amounted from 2.2 to 30.2 ou/m3 depending on the place of measurement. In case of the investigation with the electronic nose prototype a classification of the ambient air samples with respect to the place of sampling was performed utilizing kNN algorithm supported with a cross-validation method. Correct classification of the ambient air samples was at the level of 66.7%. Performed investigation revealed that discrimination of the ambient air samples differing in concentration of odorants and place of origin was possible.

  7. Engineering development of selective agglomeration: Task 5, Bench- scale process testing

    SciTech Connect

    Not Available

    1991-09-01

    Under the overall objectives of DOE Contract ``Engineering Development of Selective Agglomeration,`` there were a number of specific objectives in the Task 5 program. The prime objectives of Task 5 are highlighted below: (1) Maximize process performance in pyritic sulfur rejection and BTU recovery, (2) Produce a low ash product, (3) Compare the performance of the heavy agglomerant process based on diesel and the light agglomerant process using heptane, (4) Define optimum processing conditions for engineering design, (5) Provide first-level evaluation of product handleability, and (6) Explore and investigate process options/ideas which may enhance process performance and/or product handleability.

  8. Engineering development of selective agglomeration: Task 5, Bench- scale process testing

    SciTech Connect

    Not Available

    1991-09-01

    Under the overall objectives of DOE Contract Engineering Development of Selective Agglomeration,'' there were a number of specific objectives in the Task 5 program. The prime objectives of Task 5 are highlighted below: (1) Maximize process performance in pyritic sulfur rejection and BTU recovery, (2) Produce a low ash product, (3) Compare the performance of the heavy agglomerant process based on diesel and the light agglomerant process using heptane, (4) Define optimum processing conditions for engineering design, (5) Provide first-level evaluation of product handleability, and (6) Explore and investigate process options/ideas which may enhance process performance and/or product handleability.

  9. Magnetic agglomeration method for size control in the synthesis of magnetic nanoparticles

    DOEpatents

    Huber, Dale L.

    2011-07-05

    A method for controlling the size of chemically synthesized magnetic nanoparticles that employs magnetic interaction between particles to control particle size and does not rely on conventional kinetic control of the reaction to control particle size. The particles are caused to reversibly agglomerate and precipitate from solution; the size at which this occurs can be well controlled to provide a very narrow particle size distribution. The size of particles is controllable by the size of the surfactant employed in the process; controlling the size of the surfactant allows magnetic control of the agglomeration and precipitation processes. Agglomeration is used to effectively stop particle growth to provide a very narrow range of particle sizes.

  10. The Physics of Protoplanetesimal Dust Agglomerates. V. Multiple Impacts of Dusty Agglomerates at Velocities Above the Fragmentation Threshold

    NASA Astrophysics Data System (ADS)

    Kothe, Stefan; Güttler, Carsten; Blum, Jürgen

    2010-12-01

    In recent years, a number of new experiments have advanced our knowledge on the early growth phases of protoplanetary dust aggregates. Some of these experiments have shown that collisions between porous and compacted agglomerates at velocities above the fragmentation threshold velocity can lead to growth of the compact body, when the porous collision partner fragments upon impact and transfers mass to the compact agglomerate. To obtain a deeper understanding of this potentially important growth process, we performed laboratory and drop tower experiments to study multiple impacts of small, highly porous dust-aggregate projectiles onto sintered dust targets. The projectile and target consisted of 1.5 μm monodisperse, spherical SiO2 monomers with volume filling factors of 0.15 ± 0.01 and 0.45 ± 0.05, respectively. The fragile projectiles were accelerated by a solenoid magnet and combined with a projectile magazine with which 25 impacts onto the same spot on the target could be performed in vacuum. We measured the mass-accretion efficiency and the volume filling factor for different impact velocities between 1.5 and 6.0 m s^{-1}. The experiments at the lowest impact speeds were performed in the Bremen drop tower under microgravity conditions to allow partial mass transfer also for the lowest adhesion case. Within this velocity range, we found a linear increase of the accretion efficiency with increasing velocity. In the laboratory experiments, the accretion efficiency increases from 0.12 to 0.21 in units of the projectile mass. The recorded images of the impacts showed that the mass transfer from the projectile to the target leads to the growth of a conical structure on the target after less than 100 impacts. From the images, we also measured the volume filling factors of the grown structures, which ranged from 0.15 (uncompacted) to 0.40 (significantly compacted) with increasing impact speed. The velocity dependency of the mass-transfer efficiency and the packing

  11. THE PHYSICS OF PROTOPLANETESIMAL DUST AGGLOMERATES. VII. THE LOW-VELOCITY COLLISION BEHAVIOR OF LARGE DUST AGGLOMERATES

    SciTech Connect

    Schraepler, Rainer; Blum, Juergen; Seizinger, Alexander; Kley, Wilhelm

    2012-10-10

    We performed micro-gravity collision experiments in our laboratory drop tower using 5 cm sized dust agglomerates with volume filling factors of 0.3 and 0.4, respectively. This work is an extension of our previous experiments reported in Beitz et al. to aggregates of more than one order of magnitude higher masses. The dust aggregates consisted of micrometer-sized silica particles and were macroscopically homogeneous. We measured the coefficient of restitution for collision velocities ranging from 1 cm s{sup -1} to 0.5 m s{sup -1}, and determined the fragmentation velocity. For low velocities, the coefficient of restitution decreases with increasing impact velocity, in contrast to findings by Beitz et al. At higher velocities, the value of the coefficient of restitution becomes constant, before the aggregates break at the onset of fragmentation. We interpret the qualitative change in the coefficient of restitution as the transition from a solid-body-dominated to a granular-medium-dominated behavior. We complement our experiments by molecular-dynamics simulations of porous aggregates and obtain a reasonable match to the experimental data. We discuss the importance of our experiments for protoplanetary disks, debris disks, and planetary rings. This work is an extension to the previous work of our group and gives new insight into the velocity dependency of the coefficient of restitution due to improved measurements, better statistics, and a theoretical approach.

  12. Remediation technologies for oil-contaminated sediments.

    PubMed

    Agarwal, Ashutosh; Liu, Yu

    2015-12-30

    Oil-contaminated sediments pose serious environmental hazards for both aquatic and terrestrial ecosystems. Innovative and environmentally compatible technologies are urgently required to remove oil-contaminated sediments. In this paper, various physical, chemical and biological technologies are investigated for the remediation of oil-contaminated sediments such as flotation and washing, coal agglomeration, thermal desorption, ultrasonic desorption, bioremediation, chemical oxidation and extraction using ionic liquids. The basic principles of these technologies as well as their advantages and disadvantages for practical application have been discussed. A combination of two or more technologies is expected to provide an innovative solution that is economical, eco-friendly and adaptable.

  13. Zirconia nanoceramic via redispersion of highly agglomerated nanopowder and spark plasma sintering.

    PubMed

    Suárez, Gustavo; Borodianska, Hanna; Sakka, Yoshio; Aglietti, Esteban F; Vasylkiv, Oleg

    2010-10-01

    A 2.7 mol% yttria stabilizing tetragonal zirconia (2.7Y-TZP) nanopowder was synthesized and stored for five years. Humidity and unsatisfactory storage conditions gradually caused heavy agglomeration. Within a few months, 2.7Y-TZP nanopowder became useless for any technological application. A bead-milling deagglomeration technique was applied to recover the heavily agglomerated yttria-stabilized zirconia nanopowder. Low-temperature sintering and spark plasma sintering (SPS) were performed, resulting in fully dense nanostructured ceramics. Compacts formed with heavily agglomerated powder present low sinterability and poor mechanical properties. Bead-milling suspension formed compacts exhibit mechanical properties in the range of the values reported for nanostructured zirconia. This observation confirms the effectiveness of bead-milling in the deagglomeration of highly agglomerated nanopowders. The high value of Vickers hardness of 13.6 GPa demonstrates the success of the processing technique for recovering long-time-stored oxide nanopowders.

  14. Bed material agglomeration during fluidized bed combustion. Technical progress report, September 30, 1992--December 31, 1992

    SciTech Connect

    Brown, R.C.; Dawson, M.R.; Noble, S.

    1993-02-01

    The purpose of this project is to determine the physical and chemical reactions which led to the undesired agglomeration of bed material during fluidized bed combustion and to relate these reactions to specific causes. Survey of industrial-scale fluidized bed combustors is being conducted to determine the occurrence of bed agglomeration and the circumstances under which agglomeration took place. This task should be finished by the end of February. Samples of bed material, agglomerate material, and boiler deposits are being requested from boiler operators as part of the survey. Once received, these sample will be analyzed to determine chemical and mineralogic composition. The bulk chemical determination will be performed using x-ray fluorescence and inductively coupled plasma-optical emission (ICP). Mineralogy will be detected by x-ray diffraction (XRD). Chemical and mineral reactions will be determined by scanning electron microscopy, optical microscopy, and electron microprobe.

  15. Dynamic forces on agglomerated particles caused by high-intensity ultrasound.

    PubMed

    Knoop, Claas; Fritsching, Udo

    2014-03-01

    In this paper the acoustic forces on particles and agglomerates caused by high-intensity ultrasound in gaseous atmosphere are derived by means of computational fluid dynamics (CFD). Sound induced forces cause an oscillating stress scenario where the primary particles of an agglomerate are alternatingly pressed together and torn apart with the frequency of the applied wave. A comparison of the calculated acoustic forces with respect to the inter particle adhesion forces from Van-der-Waals and liquid bridge interactions reveals that the separation forces may reach the same order of magnitude for 80 μm sized SiO2-particles. Hence, with finite probability acoustically agitated gases may de-agglomerate/disperse solid agglomerate structures. This effect is confirmed by dispersion experiments in an acoustic particle levitation setup.

  16. A uHPLC-MS mathematical modeling approach to dry powder inhaler single agglomerate analysis.

    PubMed

    Pennington, Justin; Lena, John; Medendorp, Joseph; Ewing, Gary

    2011-10-01

    Demonstration of content uniformity (CU) is critical toward the successful development of dry powder inhalers (DPIs). Methods for unit dose CU determination for DPI products are well-established within the field of respiratory science. Recent advances in the area include a uHPLC-MS method for high-throughput uniformity analysis, which allows for a greater understanding of blending operations as the industry transitions to a quality-by-design approach to development. Further enhancements to this uHPLC-MS method now enable it to determine CU and sample weight at the single agglomerate level, which is roughly 50× smaller than a unit dose. When coupled with optical microscopy-based agglomerate sizing, the enhanced uHPLC-MS method can also predict the density and porosity of individual agglomerates. Expanding analytical capabilities to the single agglomerate level provides greater insights and confidence in the DPI manufacturing process.

  17. Sonic enhanced ash agglomeration and sulfur capture. Technical progress report, January 1992--March 1992

    SciTech Connect

    Not Available

    1992-12-31

    This program will demonstrate the effectiveness of a unique approach which uses a bimodal distribution composed of large sorbent particles and fine fly ash particles to enhance ash agglomeration and sulfur capture at conditions found in direct coal-fired turbines. Under the impact of high-intensity sound waves, sorbent reactivity and utilization, it is theorized, will increase while agglomerates of fly ash and sorbents are formed which are readily collected in commercial cyclones.

  18. Reduced bed agglomeration by co-combustion biomass with peat fuels in a fluidized bed

    SciTech Connect

    Karin Lundholm; Anders Nordin; Marcus Oehman; Dan Bostroem

    2005-12-01

    Fluidized bed combustion is an energy conversion technology that is very suitable for biomass combustion because of its fuel flexibility and low process temperatures. However, agglomeration of bed material may cause severe operating problems. To prevent or at least reduce this, peat has been suggested as an additive to the main fuels. Nevertheless, the characteristics of peat fuels vary and there is limited information of the effect of different peat fuels and of the mechanisms behind the agglomeration prevention. The objectives of the present work were therefore to: (I) quantify the potential positive effect by co-combustion peat with forest fuels in terms of initial agglomeration temperatures; (ii) determine the amount of peat fuel that is needed to significantly reduce the agglomeration tendencies; and, if possible, (iii) elucidate the governing mechanisms. The results showed that all peat fuels prevented agglomeration in the studied interval of 760-1020{sup o}C and even as little as 5% peat fuel was found to have significant effects. The results also indicated that the mechanism of the agglomeration prevention varies between different peat fuels. Possible mechanisms are the minerals in the peat fuel retain alkali, which then is either elutriated up from the bed or captured in the bed; calcium and other refractory elements increase the melting temperature and thereby counteract the melting of alkali; and sulfur reacts with alkali metals and the alkali sulfates is either elutriated up from the bed or prevents agglomeration by increased melting temperature and lowered viscosity. Results from elemental analysis of the coating on bed particles showed that all mixtures with peat fuel resulted in a decreased or unchanged fraction of potassium and an increased fraction of aluminum in the coatings. The results also indicated a complex relationship between the fuel inorganic contents and the agglomeration process. 21 refs., 6 figs., 5 tabs.

  19. Cell agglomeration in the wells of a 24-well plate using acoustic streaming.

    PubMed

    Kurashina, Yuta; Takemura, Kenjiro; Friend, James

    2017-02-28

    Cell agglomeration is essential both to the success of drug testing and to the development of tissue engineering. Here, a MHz-order acoustic wave is used to generate acoustic streaming in the wells of a 24-well plate to drive particle and cell agglomeration. Acoustic streaming is known to manipulate particles in microfluidic devices, and even provide concentration in sessile droplets, but concentration of particles or cells in individual wells has never been shown, principally due to the drag present along the periphery of the fluid in such a well. The agglomeration time for a range of particle sizes suggests that shear-induced migration plays an important role in the agglomeration process. Particles with a diameter of 45 μm agglomerated into a suspended pellet under exposure to 2.134 MHz acoustic waves at 1.5 W in 30 s. Additionally, BT-474 cells also agglomerated as adherent masses at the center bottom of the wells of tissue-culture treated 24-well plates. By switching to low cell binding 24-well plates, the BT-474 cells formed suspended agglomerations that appeared to be spheroids, fully fifteen times larger than any cell agglomerates without the acoustic streaming. In either case, the viability and proliferation of the cells were maintained despite acoustic irradiation and streaming. Intermittent excitation was effective in avoiding temperature excursions, consuming only 75 mW per well on average, presenting a convenient means to form fully three-dimensional cellular masses potentially useful for tissue, cancer, and drug research.

  20. Combined deterministic-stochastic framework for modeling the agglomeration of colloidal particles

    NASA Astrophysics Data System (ADS)

    Mortuza, S. M.; Kariyawasam, Lahiru K.; Banerjee, Soumik

    2015-07-01

    We present a multiscale model, based on molecular dynamics (MD) and kinetic Monte Carlo (kMC), to study the aggregation driven growth of colloidal particles. Coarse-grained molecular dynamics (CGMD) simulations are employed to detect key agglomeration events and calculate the corresponding rate constants. The kMC simulations employ these rate constants in a stochastic framework to track the growth of the agglomerates over longer time scales and length scales. One of the hallmarks of the model is a unique methodology to detect and characterize agglomeration events. The model accounts for individual cluster-scale effects such as change in size due to aggregation as well as local molecular-scale effects such as changes in the number of neighbors of each molecule in a colloidal cluster. Such definition of agglomeration events allows us to grow the cluster to sizes that are inaccessible to molecular simulations as well as track the shape of the growing cluster. A well-studied system, comprising fullerenes in NaCl electrolyte solution, was simulated to validate the model. Under the simulated conditions, the agglomeration process evolves from a diffusion limited cluster aggregation (DLCA) regime to percolating cluster in transition and finally to a gelation regime. Overall the data from the multiscale numerical model shows good agreement with existing theory of colloidal particle growth. Although in the present study we validated our model by specifically simulating fullerene agglomeration in electrolyte solution, the model is versatile and can be applied to a wide range of colloidal systems.

  1. Preparation of submicron-sized gold particles using laser-induced agglomeration-fusion process

    NASA Astrophysics Data System (ADS)

    Tsuji, T.; Higashi, Y.; Tsuji, M.; Ishikawa, Y.; Koshizaki, N.

    2014-03-01

    Recently, laser irradiation (LI) of colloidal nanoparticles (NPs) using a non-focused laser beam at moderate fluence attracts much attention as a novel and simple technique to obtain submicron-sized spherical particles. In the present study, we applied this technique to prepare gold SMPs. It was revealed that agglomeration of the source nanoparticles prior to laser irradiation is necessary to produce SMPs. However, when the agglomeration occurred in too much extent, significant amount of the source particles remained as the sediment after LI, leading to the lowering of the formation efficiency of SMPs. Therefore, the control of the agglomeration conditions of the source NPs is necessary to obtain SMPs efficiently. In the present study, we tried to adjust the agglomeration conditions of the source NPs by adjusting the concentration of citrate that was used as the stabilizing reagent of the source NPs. It was revealed that SMPs were obtained efficiently while the sedimentation of the source NPs were suppressed when the concentration of citrate was adjusted around 0.01-0.005 mM. In addition, observation of the temporal change in the shape of the colloidal particles during LI revealed that there is an induction period in which no formation of SMPs is brought about by LI. This finding suggested that LI removes the citrate ligands from the source NPs and induces the agglomeration of the source NPs, i.e. the agglomeration condition of the source NPs is also controlled by LI.

  2. Quantitative characterization of agglomerate abrasion in a tumbling blender by using the Stokes number approach.

    PubMed

    Willemsz, Tofan A; Nguyen, Tien Thanh; Hooijmaijers, Ricardo; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

    2013-03-01

    Removal of microcrystalline cellulose agglomerates in a dry-mixing system (lactose, 100 M) predominantly occurs via abrasion. The agglomerate abrasion rate potential is estimated by the Stokes abrasion (StAbr) number of the system. The StAbr number equals the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. Basically, the StAbr number concept describes the blending condition of the dry-mixing system. The concept has been applied to investigate the relevance of process parameters on agglomerate abrasion in tumbling blenders. Here, process parameters such as blender rotational speed and relative fill volumes were investigated. In this study, the StAbr approach revealed a transition point between abrasion rate behaviors. Below this transition point, a blending condition exists where agglomerate abrasion is dominated by the kinetic energy density of the powder blend. Above this transition point, a blending condition exists where agglomerates show (undesirable) slow abrasion rates. In this situation, the blending condition is mainly determined by the high fill volume of the filler.

  3. Effect of the Additives on the Desulphurization Rate of Flash Hydrated and Agglomerated CFB Fly Ash

    NASA Astrophysics Data System (ADS)

    Li, D. X.; Li, H. L.; Xu, M.; Lu, J. F.; Liu, Q.; Zhang, J. S.; Yue, G. X.

    CFB fly ash from separators was mixed with water or the mixture of water and additives under the temperature of 363K by use of a blender. Then, this compound of fly ash and water or additives was pumped into a CFB combustion chamber by a sludge pump. Because the temperature of flue gas was high in CFB, the fly ash was hydrated fast and agglomerated in the same time. Through this process, the size of agglomerating fly ash is larger than the original particle and the relative residence time of agglomerated fly ash in CFB becomes longer. Therefore, the rate of utility of calcium in fly ash improves and the content of carbon in fly ash decreases. This results in a low Ca/S and low operational cost for CFB boiler. The additive is one key factor, which affects the rate of desulfurization of agglomerated fly ash. Effect of different additives on rate of desulfurization is not same. Cement and limestone are beneficiated to sulfur removal of agglomerated fly ash, but sodium silicate does not devote to the rate of sulfur removal of agglomerated fly ash.

  4. Centrifugal air-assisted melt agglomeration for fast-release "granulet" design.

    PubMed

    Wong, Tin Wui; Musa, Nafisah

    2012-07-01

    Conventional melt pelletization and granulation processes produce round and dense, and irregularly shaped but porous agglomerates respectively. This study aimed to design centrifugal air-assisted melt agglomeration technology for manufacture of spherical and yet porous "granulets" for ease of downstream manufacturing and enhancing drug release. A bladeless agglomerator, which utilized shear-free air stream to mass the powder mixture of lactose filler, polyethylene glycol binder and poorly water-soluble tolbutamide drug into "granulets", was developed. The inclination angle and number of vane, air-impermeable surface area of air guide, processing temperature, binder content and molecular weight were investigated with reference to "granulet" size, shape, texture and drug release properties. Unlike fluid-bed melt agglomeration with vertical processing air flow, the air stream in the present technology moved centrifugally to roll the processing mass into spherical but porous "granulets" with a drug release propensity higher than physical powder mixture, unprocessed drug and dense pellets prepared using high shear mixer. The fast-release attribute of "granulets" was ascribed to porous matrix formed with a high level of polyethylene glycol as solubilizer. The agglomeration and drug release outcomes of centrifugal air-assisted technology are unmet by the existing high shear and fluid-bed melt agglomeration techniques.

  5. Experimental validation of light scattering and absorption theories of fractal-like carbonaceous aerosol agglomerates

    NASA Astrophysics Data System (ADS)

    Chakrabarty, R.; Moosmuller, H.; Arnott, W. P.; Garro, M.; Slowik, J.; Cross, E.; Han, J.; Davidovits, P.; Onasch, T.; Worsnop, D.

    2007-12-01

    The optical coefficients of size-selected carbonaceous aerosol agglomerates measured at a wavelength of 870 nm are compared with those predicted by three theories, namely Rayleigh-Debye-Gans (RDG) approximation, volume-equivalent Mie theory, and integral equation formulation for scattering (IEFS). Carbonaceous agglomerates, produced via flame synthesis, were size-selected using two differential mobility analyzers (DMAs) in series, and their scattering and absorption coefficients were measured with nephelometry and photoacoustic spectroscopy. Scanning electron microscopy, along with image processing techniques, were used for the parameterization of the structural properties of the fractal-like agglomerates. The agglomerate structural parameters were used to evaluate the predictions of the optical coefficients based on the three light scattering and absorption theories. The results indicate that the RDG approximation agrees within 10% of the experimental results and the exact electromagnetic calculations of the IEFS theory. The experimental scattering coefficient is over predicted by the volume-equivalent Mie theory by a factor of ~3.2. Also, the RDG approximation-predicted optical coefficients showed pronounced sensitivity to changes in monomer mean diameter, the count median diameter of the agglomerates, and the geometric standard deviation of the agglomerate number size distribution.

  6. A kinetic study of the mechanism of radiation induced agglomeration of ovalbumin in aqueous solution

    NASA Astrophysics Data System (ADS)

    Tuce, Zorana; Janata, Eberhard; Radojcic, Marija; Milosavljevic, Bratoljub H.

    2001-10-01

    The effect of concentration on the protein radiolytic damage resulting in a change in molecular mass was measured in the concentration range from 0.2 to 2 mmol×dm -3 ovalbumin in phosphate buffered solutions saturated with N 2O. The electrophoretic analysis of samples on discontinuous SDS-polyacrylamide gels in the presence or absence of 5% β-mercaptoethanol showed an expected result, i.e. that the protein scission did not take place in the absence of oxygen. Only ovalbumin agglomerates, bonded by covalent bonds other than S-S bridges, were observed. The G-value for the formation of ovalbumin agglomerates increased linearly from 1.1 to 2.4 by increasing the ovalbumin concentration from 0.2 to 2 mmol×dm -3. The result is interpreted as to be owing to the competition between ovalbumin agglomeration and some intramolecular reactions which did not lead to the change in the molecular mass. It was also found that the G-value is independent of irradiation dose rate. The result was rationalized as a kinetic evidence that the agglomeration is not a cross-linking process, i.e. it does not occur via recombination of the protein radicals produced in the interaction of ovalbumin and rad OH radical. The result suggested that the agglomeration takes place via the process of grafting, i.e. it occurs in the reaction of ovalbumin radical and an intact ovalbumin molecule. The time-resolved light scattering experiments provided an additional proof, supporting the reaction scheme of radiation-induced protein agglomeration. The biological consequences of the proposed mechanism of protein agglomeration are also discussed.

  7. Combustion of single and agglomerated aluminum particles in solid rocket motor flows

    NASA Astrophysics Data System (ADS)

    Melcher, John Charles, IV

    2001-07-01

    Single and agglomerated aluminum droplets were studied in a solid rocket motor (SRM) test chamber with optical access to the internal flow at 6--22 atm and 2300 K. The chamber was pressurized by burning a main grain AP/HTPB propellant, and the burning aluminum droplets were generated by a smaller aluminized solid propellant sample, center-mounted in the flow. A 35 mm camera was used with a chopper wheel to give droplet flame diameter vs. time measurements of the burning droplets in flight, from which bum-rate laws were developed. A high-speed video CCD was used with high-magnification optics in order to image the flame/smoke cloud surrounding the burning liquid droplets. The intensity profiles of the droplet images were de-convoluted using an Abel inversion to give true intensity profiles. Both single and agglomerated droplets were studied, where agglomerates are comprised of hundreds of parent particles or more. The Abel inversion results show that the relative smoke cloud size is not constant with diameter, but instead grows as the droplet shrinks, by ˜D -0.5, for both the single and agglomerated droplets. Measured diameter trajectories show that for single droplets, the diameter law is D 0.75 = DO0.75 = 8·t [mu m, msec], and for agglomerated droplets, D 1.0 = Do1.0 - 20·t, such that the single droplets burn faster than the agglomerates. For both single and agglomerated droplets, the burning rate slope k did not change significantly over the chamber pressure studied. Lastly, a model was developed to describe the oxide cap accumulation on the droplet surface from the oxide smoke cloud surrounding the droplet. Results suggest that less oxide accumulates in high-pressure SRMs when considering mass burning rates for different relative cap sizes. The thermophoretic force, which can control oxide transport only over the cap, decreases with pressure.

  8. Transport and Deposition of Welding Fume Agglomerates in a Realistic Human Nasal Airway.

    PubMed

    Tian, Lin; Inthavong, Kiao; Lidén, Göran; Shang, Yidan; Tu, Jiyuan

    2016-07-01

    Welding fume is a complex mixture containing ultra-fine particles in the nanometer range. Rather than being in the form of a singular sphere, due to the high particle concentration, welding fume particles agglomerate into long straight chains, branches, or other forms of compact shapes. Understanding the transport and deposition of these nano-agglomerates in human respiratory systems is of great interest as welding fumes are a known health hazard. The neurotoxin manganese (Mn) is a common element in welding fumes. Particulate Mn, either as soluble salts or oxides, that has deposited on the olfactory mucosa in human nasal airway is transported along the olfactory nerve to the olfactory bulb within the brain. If this Mn is further transported to the basal ganglia of the brain, it could accumulate at the part of the brain that is the focal point of its neurotoxicity. Accounting for various dynamic shape factors due to particle agglomeration, the current computational study is focused on the exposure route, the deposition pattern, and the deposition efficiency of the inhaled welding fume particles in a realistic human nasal cavity. Particular attention is given to the deposition pattern and deposition efficiency of inhaled welding fume agglomerates in the nasal olfactory region. For particles in the nanoscale, molecular diffusion is the dominant transport mechanism. Therefore, Brownian diffusion, hydrodynamic drag, Saffman lift force, and gravitational force are included in the model study. The deposition efficiencies for single spherical particles, two kinds of agglomerates of primary particles, two-dimensional planar and straight chains, are investigated for a range of primary particle sizes and a range of number of primary particles per agglomerate. A small fraction of the inhaled welding fume agglomerates is deposited on the olfactory mucosa, approximately in the range 0.1-1%, and depends on particle size and morphology. The strong size dependence of the deposition

  9. Agglomeration and defluidization in fluidized beds due to thermally induced sintering

    SciTech Connect

    Compo, P.; Pfeffer, R.; Tardos, G.I.

    1987-01-01

    The surfaces of fluidizable particles often soften at temperatures well below the material's bulk solid melting point. When particles come into contact at elevated temperatures, there is a tendency for material bridges to form resulting in an interparticle adhesive force. This phenomenon, known as sintering, is driven by the reduction of excess surface energy and for each material is dependent on factors such as particle size and morphology, the interparticle compression force and most importantly, temperature. High temperature fluidization of cohesive powders results in agglomeration, thereby increasing the effective diameter and changing the hydrodynamic properties of the particles. If interparticle forces become significantly greater than forces generated by particle motion, defluidization will occur. In industrial practice, agglomeration is usually undesirable and must be avoided, although there are cases where controlled agglomeration is useful as in fluid-bed coal gasification where the mineral matter agglomerates and is removed from the reactor. The experimental work reported here consists of dilatometry to determine the sintering behavior of a powder as a function of temperature and high temperature fluidization in a pilot size unit to measure the minimum fluidization velocity (defluidization limit) and the voidage at minimum fluidization in the cohesive temperature range of the material. A wide variety of particles have been studied ranging from pure substances including polymers, salts and glass beads to ores and cracking catalysts obtained from industrial reactors where problematic agglomeration at high temperature fluidization was encountered.

  10. Experimental development of a two-stage fluidized-bed/cyclonic agglomerating incinerator

    SciTech Connect

    Mensinger, M.C.; Rehmat, A.; Bryan, B.G.; Lau, F.S. ); Shearer, T.L. ); Duggan, P.A. )

    1991-01-01

    The Institute of Gas Technology (IGT) is conducting an experimental program to develop and test through pilot-plant scale of operation, IGT's two-stage fluidized-bed/cyclonic agglomerating incinerator (TSI). The TSI is based on combining the fluidized-bed agglomeration/gasification technology and the cyclonic combustion/incineration technology, which have been developed at IGT over many years. The TSI is a unique and extremely flexible combustor that can operate over a wide range of conditions in the fluidized-bed first stage from low temperature (desorption) to high temperature (agglomeration) including gasification of high-Btu wastes. The TSI can easily and efficiently destroy solid, liquid and gaseous organic wastes, while containing solid inorganic contaminants within an essentially non-leachable glassy matrix, suitable for disposal in an ordinary landfill. This paper presents the results of tests conducted in a batch, fluidized-bed bench-scale unit (BSU) with commercially available clean'' top soil and the same soil spiked with lead and chromium compounds. The objectives of these tests were to determine the operating conditions necessary to achieve soil agglomeration and to evaluate the leaching characteristics of the soil agglomerates formed. 7 refs., 7 figs., 6 tabs.

  11. Acoustic agglomeration of power plant fly ash: Quarterly technical report, November 5, 1986--February 5, 1987

    SciTech Connect

    Reethof, G.

    1987-03-20

    The objective of this project is to complete the investigations on the use of high intensity acoustic energy to agglomerate micron and submicron sized particulates in fly ash aerosols in order to provide the necessary scientific knowledge and design criteria for the specification of technically and economically viable intermediate flue gas treatment of coal fired power plants. The results of the project are to provide technical and economic information for the better development and evaluation of potential fine particulate control systems. The goals of the proposed work are to further the understanding of certain fundamental processes by means of theoretical and experimental investigations, to include this knowledge in an advanced computerized model of the agglomeration processes. Tests with the two acoustic agglomerators available in Penn State's new High Intensity Acoustics Laboratory will be used to verify the results from the agglomeration simulation. Research work will continue on high power, high efficiency sirens with special emphasis on the nonlinear acoustic phenomena and novel means of significantly increasing siren efficiency. A study will be carried out to evaluate the economics of conventional coal fired power plant clean-up systems using acoustic agglomerators as intermediate flue gas treatment.

  12. Acoustic agglomeration of power plant fly ash for environmental and hot gas cleanup

    SciTech Connect

    Reethof, G.; Koopmann, G.H.

    1989-12-01

    This two year research program has the objectives of completing the several investigations associated with the use of high intensity acoustic energy to agglomerate micron and submicron sized particles in fly ash aerosols in order to provide the necessary scientific knowledge and design criteria for the specification of technically and economically viable intermediate flue gas treatment of coal fired power plants. Goals are to further the understanding of certain fundamental processes by means of theoretical and experimental investigations to include this knowledge in an advanced computerized model of the agglomeration processes. Tests with the acoustic agglomeration facilities available in Penn State's new High Intensity Acoustic Laboratory were to be used to verify the results from the acoustic agglomeration simulations. Research work continued on high power, high efficiency sirens with special emphasis on the nonlinear acoustic phenomena and novel means of significantly increasing siren efficiency. A study was carried out to evaluate the economics of conventional coal fired power plant clean-up systems using acoustic agglomeration as an intermediate flue gas treatment. 154 refs., 152 figs., 30 tabs.

  13. Hydrodynamic chromatography coupled with single particle-inductively coupled plasma mass spectrometry for investigating nanoparticles agglomerates.

    PubMed

    Rakcheev, Denis; Philippe, Allan; Schaumann, Gabriele E

    2013-11-19

    Studying the environmental fate of engineered or natural colloids requires efficient methods for measuring their size and quantifying them in the environment. For example, an ideal method should maintain its correctness, accuracy, reproducibility, and robustness when applied to samples contained in complex matrixes and distinguish the target particles from the natural colloidal background signals. Since it is expected that a large portion of nanoparticles will form homo- or heteroagglomerates when released into environmental media, it is necessary to differentiate agglomerates from primary particles. At present, most sizing techniques do not fulfill these requirements. In this study, we used online coupling of two promising complementary sizing techniques: hydrodynamic chromatography (HDC) and single-particle ICPMS analysis to analyze gold nanoparticles agglomerated under controlled conditions. We used the single-particle mode of the ICPMS detector to detect single particles eluted from an HDC-column and determine a mass and an effective diameter for each particle using a double calibration approach. The average agglomerate relative density and fractal dimension were calculated using these data and used to follow the morphological evolution of agglomerates over time during the agglomeration process. The results demonstrate the ability of HDC coupled to single-particle analysis to identify and characterize nanoparticle homoagglomerates and is a very promising technique for the analysis of colloids in complex media.

  14. Thermal conductivity and particle agglomeration in alumina nanofluids: Experiment and theory

    NASA Astrophysics Data System (ADS)

    Timofeeva, Elena V.; Gavrilov, Alexei N.; McCloskey, James M.; Tolmachev, Yuriy V.; Sprunt, Samuel; Lopatina, Lena M.; Selinger, Jonathan V.

    2007-12-01

    In recent years many experimentalists have reported an anomalously enhanced thermal conductivity in liquid suspensions of nanoparticles. Despite the importance of this effect for heat transfer applications, no agreement has emerged about the mechanism of this phenomenon, or even about the experimentally observed magnitude of the enhancement. To address these issues, this paper presents a combined experimental and theoretical study of heat conduction and particle agglomeration in nanofluids. On the experimental side, nanofluids of alumina particles in water and ethylene glycol are characterized using thermal conductivity measurements, viscosity measurements, dynamic light scattering, and other techniques. The results show that the particles are agglomerated, with an agglomeration state that evolves in time. The data also show that the thermal conductivity enhancement is within the range predicted by effective medium theory. On the theoretical side, a model is developed for heat conduction through a fluid containing nanoparticles and agglomerates of various geometries. The calculations show that elongated and dendritic structures are more efficient in enhancing the thermal conductivity than compact spherical structures of the same volume fraction, and that surface (Kapitza) resistance is the major factor resulting in the lower than effective medium conductivities measured in our experiments. Together, these results imply that the geometry, agglomeration state, and surface resistance of nanoparticles are the main variables controlling thermal conductivity enhancement in nanofluids.

  15. On the Mechanism of Ultrasound-Driven Deagglomeration of Nanoparticle Agglomerates in Aluminum Melt

    NASA Astrophysics Data System (ADS)

    Kudryashova, Olga; Vorozhtsov, Sergey

    2016-05-01

    One of the promising directions in the technology of composite alloys with improved mechanical properties is reinforcement of the metallic matrix with nanopowders introduced in the liquid metal. Ultrasonic processing is known to significantly improve the introduction of submicrone particles to the metallic melt. This study focuses on the mechanisms of deagglomeration and wettability of such particles by the melt under the action of ultrasound. The suggested mechanism involves the penetration of the liquid metal into the pores and cracks of the agglomerates under the excess pressure created by imploding cavitation bubbles and further destruction of the agglomerate by the sound wave. The main dependences connecting the acoustic parameters and processing time with the physical and chemical properties of particles and the melt are obtained through analytical modeling. The mathematical description of the ultrasonic deagglomeration in liquid metal is presented; a dependence of the threshold intensity of ultrasound for the break-up of agglomerates on their size is reported.

  16. Directional Agglomeration Multigrid Techniques for High-Reynolds Number Viscous Flows

    NASA Technical Reports Server (NTRS)

    Mavriplis, Dimitri J.

    1998-01-01

    A preconditioned directional-implicit agglomeration algorithm is developed for solving two- and three-dimensional viscous flows on highly anisotropic unstructured meshes of mixed-element types. The multigrid smoother consists of a pre-conditioned point- or line-implicit solver which operates on lines constructed in the unstructured mesh using a weighted graph algorithm. Directional coarsening or agglomeration is achieved using a similar weighted graph algorithm. A tight coupling of the line construction and directional agglomeration algorithms enables the use of aggressive coarsening ratios in the multigrid algorithm, which in turn reduces the cost of a multigrid cycle. Convergence rates which are independent of the degree of grid stretching are demonstrated in both two and three dimensions. Further improvement of the three-dimensional convergence rates through a GMRES technique is also demonstrated.

  17. Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers.

    PubMed

    Atif, Rasheed; Inam, Fawad

    2016-01-01

    One of the main issues in the production of polymer nanocomposites is the dispersion state of filler as multilayered graphene (MLG) and carbon nanotubes (CNTs) tend to agglomerate due to van der Waals forces. The agglomeration can be avoided by using organic solvents, selecting suitable dispersion and production methods, and functionalizing the fillers. Another proposed method is the use of hybrid fillers as synergistic effects can cause an improvement in the dispersion state of the fillers. In this review article, various aspects of each process that can help avoid filler agglomeration and improve dispersion state are discussed in detail. This review article would be helpful for both current and prospective researchers in the field of MLG- and CNT-based polymer nanocomposites to achieve maximum enhancement in mechanical, thermal, and electrical properties of produced polymer nanocomposites.

  18. A Novel Equivalent Agglomeration Model for Heat Conduction Enhancement in Nanofluids

    NASA Astrophysics Data System (ADS)

    Sui, Jize; Zheng, Liancun; Zhang, Xinxin; Chen, Ying; Cheng, Zhengdong

    2016-01-01

    We propose a multilevel equivalent agglomeration (MEA) model in which all particles in an irregular cluster are treated as a new particle with equivalent volume, the liquid molecules wrapping the cluster and in the gaps are considered to assemble on the surface of new particle as mixing nanolayer (MNL), the thermal conductivity in MNL is assumed to satisfy exponential distribution. Theoretical predictions for thermal conductivity enhancement are highly in agreement with the classical experimental data. Also, we first try to employ TEM information quantitatively to offer probable reference agglomeration ratio (not necessary a very precise value) to just test rational estimations range by present model. The comparison results indicate the satisfactory priori agglomeration ratio estimations range from renovated model.

  19. Bed material agglomeration during fluidized bed combustion. Technical progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Brown, R.C.; Dawson, M.R.; Smeenk, J.L.

    1995-04-01

    Experiments performed support the hypothesis that a reducing atmosphere during fluidized bed coal combustion contributes to the formation of agglomerates. Reducing conditions are imposed by controlling the amount of combustion air supplied to the combustor, 50% of theoretical in these experiments. These localized reducing conditions may arise from either poor lateral bed mixing or oxygen-starved conditions due to the coal feed locations. Deviations from steady-state operating conditions in bed pressure drop may be used to detect agglomerate formation. Interpretation of the bed pressure drop was made more straightforward by employing a moving average difference method. During steady-state operation, the difference between the moving point averages should be close to zero, within {plus_minus}0.03 inches of water. Instability within the combustor, experienced once agglomerates begin to form, can be recognized as larger deviations from zero, on the magnitude of {plus_minus}0.15 inches of water.

  20. Effect of whey protein agglomeration on spray dried microcapsules containing Saccharomyces boulardii.

    PubMed

    Duongthingoc, Diep; George, Paul; Katopo, Lita; Gorczyca, Elizabeth; Kasapis, Stefan

    2013-12-01

    This work investigates the effect of whey protein agglomeration on the survivability of Saccharomyces boulardii within spray dried microcapsules. It attempts to go beyond phenomenological observations by establishing a relationship between physicochemical characteristics of the polymeric matrix and its effect on probiotic endurance upon spray drying. It is well known that this type of thermal shock has lethal consequences on the yeast cells. To avoid such undesirable outcome, we take advantage of the early agglomeration phenomenon observed for whey protein by adjusting the pH value of preparations close to isoelectric point (pH 4-5). During the subsequent process of spray drying, development of whey protein agglomerates induces formation of an early crust, and the protein in this molten globular state creates a cohesive network encapsulating the yeast cells. It appears that the early crust formation at a given sample pH and temperature regime during spray drying benefits the survivability of S. boulardii within microcapsules.

  1. Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

    PubMed Central

    Atif, Rasheed

    2016-01-01

    Summary One of the main issues in the production of polymer nanocomposites is the dispersion state of filler as multilayered graphene (MLG) and carbon nanotubes (CNTs) tend to agglomerate due to van der Waals forces. The agglomeration can be avoided by using organic solvents, selecting suitable dispersion and production methods, and functionalizing the fillers. Another proposed method is the use of hybrid fillers as synergistic effects can cause an improvement in the dispersion state of the fillers. In this review article, various aspects of each process that can help avoid filler agglomeration and improve dispersion state are discussed in detail. This review article would be helpful for both current and prospective researchers in the field of MLG- and CNT-based polymer nanocomposites to achieve maximum enhancement in mechanical, thermal, and electrical properties of produced polymer nanocomposites. PMID:27826492

  2. A Novel Equivalent Agglomeration Model for Heat Conduction Enhancement in Nanofluids

    PubMed Central

    Sui, Jize; Zheng, Liancun; Zhang, Xinxin; Chen, Ying; Cheng, Zhengdong

    2016-01-01

    We propose a multilevel equivalent agglomeration (MEA) model in which all particles in an irregular cluster are treated as a new particle with equivalent volume, the liquid molecules wrapping the cluster and in the gaps are considered to assemble on the surface of new particle as mixing nanolayer (MNL), the thermal conductivity in MNL is assumed to satisfy exponential distribution. Theoretical predictions for thermal conductivity enhancement are highly in agreement with the classical experimental data. Also, we first try to employ TEM information quantitatively to offer probable reference agglomeration ratio (not necessary a very precise value) to just test rational estimations range by present model. The comparison results indicate the satisfactory priori agglomeration ratio estimations range from renovated model. PMID:26777389

  3. Agglomeration in Stripper Ash Coolers and Its Possible Remedial Solutions: a Case Study

    NASA Astrophysics Data System (ADS)

    Singh, Ravi Inder

    2016-04-01

    The bottom ash of circulating fluidized bed (CFB) boiler contains large amounts of physical heat. When low quality coals are used in these types of boilers, the ash content is normally more than 40 % and the physical heat loss is approximately 3 % if the bottom ash is discharged without cooling. Bottom ash cooler (BAC) is often used to treat the high temperature bottom ash to reclaim heat, and to facilitate the easily handling and transportation of ash. The CFB boiler at BLA Power, Newari, MP (India) is facing problems of clinker formation in strip ash coolers of plant since the installation of unit. These clinkers are basically agglomerates, which leads to defluidization of stripper ash cooler (BAC) units. There are two strip ash coolers in unit. Each strip ash cooler is capable of working independently. The proper functioning of both strip coolers is very important as it is going to increase the combustion efficiency of boiler by stripping of fine unburnt coal particles from ash, which are injected into the furnace. In this paper causes, characterization of agglomerates, thermo gravimetric analysis of fuel used, particular size distribution of coal and sand and possible remedial solution to overcome these agglomerates in strip ash coolers has also been presented. High temperature in compact separators, non uniform supply of coal and not removing small agglomerates from stripper ash cooler are among main causes of agglomeration in stripper ash cooler. Control of compact separator temperature, replacing 10-12 % of bed material and cleaning stripper ash cooler periodically will decrease agglomeration in stripper ash cooler of unit.

  4. Characterization of size, surface charge, and agglomeration state of nanoparticle dispersions for toxicological studies

    NASA Astrophysics Data System (ADS)

    Jiang, Jingkun; Oberdörster, Günter; Biswas, Pratim

    2009-01-01

    Characterizing the state of nanoparticles (such as size, surface charge, and degree of agglomeration) in aqueous suspensions and understanding the parameters that affect this state are imperative for toxicity investigations. In this study, the role of important factors such as solution ionic strength, pH, and particle surface chemistry that control nanoparticle dispersion was examined. The size and zeta potential of four TiO2 and three quantum dot samples dispersed in different solutions (including one physiological medium) were characterized. For 15 nm TiO2 dispersions, the increase of ionic strength from 0.001 M to 0.1 M led to a 50-fold increase in the hydrodynamic diameter, and the variation of pH resulted in significant change of particle surface charge and the hydrodynamic size. It was shown that both adsorbing multiply charged ions (e.g., pyrophosphate ions) onto the TiO2 nanoparticle surface and coating quantum dot nanocrystals with polymers (e.g., polyethylene glycol) suppressed agglomeration and stabilized the dispersions. DLVO theory was used to qualitatively understand nanoparticle dispersion stability. A methodology using different ultrasonication techniques (bath and probe) was developed to distinguish agglomerates from aggregates (strong bonds), and to estimate the extent of particle agglomeration. Probe ultrasonication performed better than bath ultrasonication in dispersing TiO2 agglomerates when the stabilizing agent sodium pyrophosphate was used. Commercially available Degussa P25 and in-house synthesized TiO2 nanoparticles were used to demonstrate identification of aggregated and agglomerated samples.

  5. In-Situ Agglomeration and De-agglomeration by Milling of Nano-Engineered Lubricant Particulate Composites for Cold Spray Deposition

    NASA Astrophysics Data System (ADS)

    Neshastehriz, M.; Smid, I.; Segall, A. E.

    2014-10-01

    Nano-engineered self-lubricating particles comprised of hexagonal-boron-nitride powder (hBN) encapsulated in nickel have been developed for cold spray coating of aluminum components. The nickel encapsulant consists of several nano-sized layers, which are deposited on the hBN particles by electroless plating. In the cold spray deposition, the nickel becomes the matrix in which hBN acts as the lubricant. The coating demonstrated a very promising performance by reducing the coefficient of friction by almost 50% and increasing the wear resistance more than tenfold. The coatings also exhibited higher bond strength, which was directly related to the hardenability of the particles. During the encapsulation process, the hBN particles agglomerate and form large clusters. De-agglomeration has been studied through low- and high-energy ball milling to create more uniform and consistent particle sizes and to improve the cold spray deposition efficiency. The unmilled and milled particles were characterized with Scanning Electron Microscopy, Energy-Dispersive X-Ray Spectroscopy, BET, and hardness tests. It was found that in low-energy ball milling, the clusters were compacted to a noticeable extent. However, the high-energy ball milling resulted in breakup of agglomerations and destroyed the nickel encapsulant.

  6. Detailed analysis of a quench bomb for the study of aluminum agglomeration in solid propellants

    NASA Astrophysics Data System (ADS)

    Gallier, S.; Kratz, J.-G.; Quaglia, N.; Fouin, G.

    2016-07-01

    A standard quench bomb (QB) - widely used to characterize condensed phase from metalized solid propellant combustion - is studied in detail. Experimental and numerical investigations proved that collected particles are mostly unburned aluminum (Al) agglomerates despite large quenching distances. Particles are actually found to quench early as propellant surface is swept by inert pressurant. Further improvements of the QB are proposed which allow measuring both Al agglomerates and alumina residue with the same setup. Finally, the results obtained on a typical aluminized ammonium perchlorate (AP) / hydroxyl-terminated polybutadiene (HTPB) propellant are briefly discussed.

  7. Two-stage fluidized-bed/cyclonic agglomerating incinerator. Technology spotlight report

    SciTech Connect

    1995-08-01

    The two-stage fluidized-bed/cyclonic agglomerating incinerator combines and improves upon the fluidized-bed, agglomeration/ incineration-technology and the cyclonic-combustion technology developed at Institute of Gas Technolgy (IGT) over many years. The result is a unique and extremely flexible incinerator for solid, liquid, and gaseous wastes. The system can operate over a wide range of conditions and has a destruction and removal efficiency (DRE) greater than 99.99%. Solid inorganic contaminants are contained within aglassy matrix, rendering them benign and suitable for disposal in an ordinary landfill.

  8. Application of Dynamic Light Scattering to Characterize Nanoparticle Agglomeration in Alumina Nanofluids and its Effect on Thermal Conductivity

    DTIC Science & Technology

    2012-07-11

    Application of Dynamic Light Scattering to Characterize Nanoparticle Agglomeration in Alumina Nanofluids and its Effect on Thermal Conductivity Bridget...increased thermal conductivity and increased heat transfer potential. In practical applications, these particles agglomerate in nanofluid to form...aggregates, as opposed to completely dispersing in the base fluid. The resulting nanofluid has a size distribution of aggregated nanoparticles at different

  9. Agglomeration of Celecoxib by Quasi Emulsion Solvent Diffusion Method: Effect of Stabilizer

    PubMed Central

    Maghsoodi, Maryam; Nokhodchi, Ali

    2016-01-01

    Purpose: The quasi-emulsion solvent diffusion (QESD) has evolved into an effective technique to manufacture agglomerates of API crystals. Although, the proposed technique showed benefits, such as cost effectiveness, that is considerably sensitive to the choice of a stabilizer, which agonizes from a absence of systemic understanding in this field. In the present study, the combination of different solvents and stabilizers were compared to investigate any connections between the solvents and stabilizers. Methods: Agglomerates of celecoxib were prepared by QESD method using four different stabilizers (Tween 80, HPMC, PVP and SLS) and three different solvents (methyl acetate, ethyl acetate and isopropyl acetate). The solid state of obtained particles was investigated by differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. The agglomerated were also evaluated in term of production yield, distribution of particles and dissolution behavior. Results: The results showed that the effectiveness of stabilizer in terms of particle size and particle size distribution is specific to each solvent candidate. A stabilizer with a lower HLB value is preferred which actually increased its effectiveness with the solvent candidates with higher lipophilicity. HPMC appeared to be the most versatile stabilizer because it showed a better stabilizing effect compared to other stabilizers in all solvents used. Conclusion: This study demonstrated that the efficiency of stabilizers in forming the celecoxib agglomerates by QESD was influenced by the HLB of the stabilizer and lipophilicity of the solvents. PMID:28101468

  10. Direct numerical simulations of agglomeration of circular colloidal particles in two-dimensional shear flow

    SciTech Connect

    Choi, Young Joon Djilali, Ned

    2016-01-15

    Colloidal agglomeration of nanoparticles in shear flow is investigated by solving the fluid-particle and particle-particle interactions in a 2D system. We use an extended finite element method in which the dynamics of the particles is solved in a fully coupled manner with the flow, allowing an accurate description of the fluid-particle interfaces without the need of boundary-fitted meshes or of empirical correlations to account for the hydrodynamic interactions between the particles. Adaptive local mesh refinement using a grid deformation method is incorporated with the fluid-structure interaction algorithm, and the particle-particle interaction at the microscopic level is modeled using the Lennard-Jones potential. Motivated by the process used in fabricating fuel cell catalysts from a colloidal ink, the model is applied to investigate agglomeration of colloidal particles under external shear flow in a sliding bi-periodic Lees-Edwards frame with varying shear rates and particle fraction ratios. Both external shear and particle fraction are found to have a crucial impact on the structure formation of colloidal particles in a suspension. Segregation intensity and graph theory are used to analyze the underlying agglomeration patterns and structures, and three agglomeration regimes are identified.

  11. Agglomeration of Celecoxib by Quasi Emulsion Solvent Diffusion Method: Effect of Stabilizer.

    PubMed

    Maghsoodi, Maryam; Nokhodchi, Ali

    2016-12-01

    Purpose: The quasi-emulsion solvent diffusion (QESD) has evolved into an effective technique to manufacture agglomerates of API crystals. Although, the proposed technique showed benefits, such as cost effectiveness, that is considerably sensitive to the choice of a stabilizer, which agonizes from a absence of systemic understanding in this field. In the present study, the combination of different solvents and stabilizers were compared to investigate any connections between the solvents and stabilizers. Methods: Agglomerates of celecoxib were prepared by QESD method using four different stabilizers (Tween 80, HPMC, PVP and SLS) and three different solvents (methyl acetate, ethyl acetate and isopropyl acetate). The solid state of obtained particles was investigated by differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. The agglomerated were also evaluated in term of production yield, distribution of particles and dissolution behavior. Results: The results showed that the effectiveness of stabilizer in terms of particle size and particle size distribution is specific to each solvent candidate. A stabilizer with a lower HLB value is preferred which actually increased its effectiveness with the solvent candidates with higher lipophilicity. HPMC appeared to be the most versatile stabilizer because it showed a better stabilizing effect compared to other stabilizers in all solvents used. Conclusion: This study demonstrated that the efficiency of stabilizers in forming the celecoxib agglomerates by QESD was influenced by the HLB of the stabilizer and lipophilicity of the solvents.

  12. A complex network approach for nanoparticle agglomeration analysis in nanoscale images

    NASA Astrophysics Data System (ADS)

    Machado, Bruno Brandoli; Scabini, Leonardo Felipe; Margarido Orue, Jonatan Patrick; de Arruda, Mauro Santos; Goncalves, Diogo Nunes; Goncalves, Wesley Nunes; Moreira, Raphaell; Rodrigues-Jr, Jose F.

    2017-02-01

    Complex networks have been widely used in science and technology because of their ability to represent several systems. One of these systems is found in Biochemistry, in which the synthesis of new nanoparticles is a hot topic. However, the interpretation of experimental results in the search of new nanoparticles poses several challenges. This is due to the characteristics of nanoparticle images and due to their multiple intricate properties; one property of recurrent interest is the agglomeration of particles. Addressing this issue, this paper introduces an approach that uses complex networks to detect and describe nanoparticle agglomerates so to foster easier and more insightful analyses. In this approach, each detected particle in an image corresponds to a vertice and the distances between the particles define a criterion for creating edges. Edges are created if the distance is smaller than a radius of interest. Once this network is set, we calculate several discrete measures able to reveal the most outstanding agglomerates in a nanoparticle image. Experimental results using images of scanning tunneling microscopy (STM) of gold nanoparticles demonstrated the effectiveness of the proposed approach over several samples, as reflected by the separability between particles in three usual settings. The results also demonstrated efficacy for both convex and non-convex agglomerates.

  13. Sonic enhanced ash agglomeration and sulfur capture. Quarterly report, January 1996--March 1996

    SciTech Connect

    1996-04-01

    A major concern with the utilization of coal in directly fired gas turbines is the control of particulate emissions and reduction of sulfur dioxide, and alkali vapor from combustion of coal, upstream of the gas turbine. Much research and development has been sponsored on methods for particulate emissions control and the direct injection of calcium-based sorbents to reduce SO{sub 2} emission levels. The results of this research and development indicate that both acoustic agglomeration of particulates and direct injection of sorbents have the potential to become a significant emissions control strategy. The Sonic Enhanced Ash Agglomeration and Sulfur Capture program focuses upon the application of an MTCI proprietary invention (Patent No. 5,197,399) for simultaneously enhancing sulfur capture and particulate agglomeration of the combustor effluent. This application can be adapted as either a {open_quotes}hot flue gas cleanup{close_quotes} subsystem for the current concepts for combustor islands or as an alternative primary pulse combustor island in which stagging, sulfur capture, particulate agglomeration and control, and alkali gettering as well as NO{sub x} control processes become an integral part of the pulse combustion process.

  14. Prediction of Agglomeration, Fouling, and Corrosion Tendency of Fuels in CFB Co-Combustion

    NASA Astrophysics Data System (ADS)

    Barišć, Vesna; Zabetta, Edgardo Coda; Sarkki, Juha

    Prediction of agglomeration, fouling, and corrosion tendency of fuels is essential to the design of any CFB boiler. During the years, tools have been successfully developed at Foster Wheeler to help with such predictions for the most commercial fuels. However, changes in fuel market and the ever-growing demand for co-combustion capabilities pose a continuous need for development. This paper presents results from recently upgraded models used at Foster Wheeler to predict agglomeration, fouling, and corrosion tendency of a variety of fuels and mixtures. The models, subject of this paper, are semi-empirical computer tools that combine the theoretical basics of agglomeration/fouling/corrosion phenomena with empirical correlations. Correlations are derived from Foster Wheeler's experience in fluidized beds, including nearly 10,000 fuel samples and over 1,000 tests in about 150 CFB units. In these models, fuels are evaluated based on their classification, their chemical and physical properties by standard analyses (proximate, ultimate, fuel ash composition, etc.;.) alongside with Foster Wheeler own characterization methods. Mixtures are then evaluated taking into account the component fuels. This paper presents the predictive capabilities of the agglomeration/fouling/corrosion probability models for selected fuels and mixtures fired in full-scale. The selected fuels include coals and different types of biomass. The models are capable to predict the behavior of most fuels and mixtures, but also offer possibilities for further improvements.

  15. Do Universities Generate Agglomeration Spillovers? Evidence from Endowment Value Shocks. NBER Working Paper No. 15299

    ERIC Educational Resources Information Center

    Kantor, Shawn; Whalley, Alexander

    2009-01-01

    In this paper we quantify the extent and magnitude of agglomeration spillovers from a formal institution whose sole mission is the creation and dissemination of knowledge--the research university. We use the fact that universities follow a fixed endowment spending policy based on the market value of their endowments to identify the causal effect…

  16. Effects of baffle configuration and tank size on spherical agglomerates of dimethyl fumarate in a common stirred tank.

    PubMed

    Lin, Po Yen; Lee, Hung Lin; Chen, Chih Wei; Lee, Tu

    2015-11-30

    To pave the way for technology transfer and scale up of the spherical agglomeration (SA) process for dimethyl fumarate, effects of the US, European and Kawashima type baffles and 0.5, 2.0 and 10 L-sized common stirred tank were studied. It was found that the particle size distribution varied significantly. However, the size-related properties such as dissolution profile and flowability of agglomerates from the same size cut after sieving could remain unchanged. The interior structure-related properties such as particle density and mechanical property of agglomerates upon baffle change and scale up from the same size cut were decayed and the agglomerates could become denser and stronger by prolonged maturation time. To maintain the same size distribution, agglomerates from any batch could have been separated and classified by sieving and then blended back together artificially by the desired weight% of each cut.

  17. Nucleocapsid Protein from Fig Mosaic Virus Forms Cytoplasmic Agglomerates That Are Hauled by Endoplasmic Reticulum Streaming

    PubMed Central

    Ishikawa, Kazuya; Miura, Chihiro; Maejima, Kensaku; Komatsu, Ken; Hashimoto, Masayoshi; Tomomitsu, Tatsuya; Fukuoka, Misato; Yusa, Akira; Yamaji, Yasuyuki

    2014-01-01

    ABSTRACT Although many studies have demonstrated intracellular movement of viral proteins or viral replication complexes, little is known about the mechanisms of their motility. In this study, we analyzed the localization and motility of the nucleocapsid protein (NP) of Fig mosaic virus (FMV), a negative-strand RNA virus belonging to the recently established genus Emaravirus. Electron microscopy of FMV-infected cells using immunogold labeling showed that NPs formed cytoplasmic agglomerates that were predominantly enveloped by the endoplasmic reticulum (ER) membrane, while nonenveloped NP agglomerates also localized along the ER. Likewise, transiently expressed NPs formed agglomerates, designated NP bodies (NBs), in close proximity to the ER, as was the case in FMV-infected cells. Subcellular fractionation and electron microscopic analyses of NP-expressing cells revealed that NBs localized in the cytoplasm. Furthermore, we found that NBs moved rapidly with the streaming of the ER in an actomyosin-dependent manner. Brefeldin A treatment at a high concentration to disturb the ER network configuration induced aberrant accumulation of NBs in the perinuclear region, indicating that the ER network configuration is related to NB localization. Dominant negative inhibition of the class XI myosins, XI-1, XI-2, and XI-K, affected both ER streaming and NB movement in a similar pattern. Taken together, these results showed that NBs localize in the cytoplasm but in close proximity to the ER membrane to form enveloped particles and that this causes passive movements of cytoplasmic NBs by ER streaming. IMPORTANCE Intracellular trafficking is a primary and essential step for the cell-to-cell movement of viruses. To date, many studies have demonstrated the rapid intracellular movement of viral factors but have failed to provide evidence for the mechanism or biological significance of this motility. Here, we observed that agglomerates of nucleocapsid protein (NP) moved rapidly

  18. Iron Oxide Nanoparticle Agglomeration Influences Dose-Rates and Modulates Oxidative Stress Mediated Dose-Response Profiles In Vitro

    SciTech Connect

    Sharma, Gaurav; Kodali, Vamsi K.; Gaffrey, Matthew J.; Wang, Wei; Minard, Kevin R.; Karin, Norman J.; Teeguarden, Justin G.; Thrall, Brian D.

    2013-07-31

    Spontaneous agglomeration of engineered nanoparticles (ENPs) is a common problem in cell culture media which can confound interpretation of in vitro nanotoxicity studies. The authors created stable agglomerates of iron oxide nanoparticles (IONPs) in conventional culture medium, which varied in hydrodynamic size (276 nm-1.5 μm) but were composed of identical primary particles with similar surface potentials and protein coatings. Studies using C10 lung epithelial cells show that the dose rate effects of agglomeration can be substantial, varying by over an order of magnitude difference in cellular dose in some cases. Quantification by magnetic particle detection showed that small agglomerates of carboxylated IONPs induced greater cytotoxicity and redox-regulated gene expression when compared with large agglomerates on an equivalent total cellular IONP mass dose basis, whereas agglomerates of amine-modified IONPs failed to induce cytotoxicity or redox-regulated gene expression despite delivery of similar cellular doses. Dosimetry modelling and experimental measurements reveal that on a delivered surface area basis, large and small agglomerates of carboxylated IONPs have similar inherent potency for the generation of ROS, induction of stress-related genes and eventual cytotoxicity. The results suggest that reactive moieties on the agglomerate surface are more efficient in catalysing cellular ROS production than molecules buried within the agglomerate core. Because of the dynamic, size and density-dependent nature of ENP delivery to cells in vitro, the biological consequences of agglomeration are not discernible from static measures of exposure concentration (μg/ml) alone, highlighting the central importance of integrated physical characterisation and quantitative dosimetry for in vitro studies. The combined experimental and computational approach provides a quantitative framework for evaluating relationships between the biocompatibility of nanoparticles and their

  19. Bed material agglomeration during fluidized bed combustion. Technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Brown, R.C.; Dawson, M.R.; Noble, S.D.

    1993-04-01

    The purpose of this project is to determine the physical and chemical reactions which lead to the undesired agglomeration of bed material during fluidized bed combustion and to relate these reactions to specific causes. A survey of agglomeration and deposit formation in industrial fluidized bed boilers is in progress. Preliminary results indicate that at least five boilers were experiencing some form of bed material agglomeration. In these instances it was observed that large particles were forming within the bed which were larger that the feed. Four operators could confirm that the larger bed particles had formed due to bed particles sticking together or agglomerating. Deposit formation was reported at nine sites with these deposits being found most commonly at coal feed locations and in cyclones. Other deposit locations included side walls and return loops. Examples of these agglomerates and deposits have been received from five of the surveyed facilities. Also during this quarter, a bulk sample of Illinois No. 6 coal was obtained from the Fossil Energy Program at Ames Laboratory here at Iowa State University and prepared for combustion tests. This sample was first ground to a top-size of 3/8`` using a jaw crusher then a size fraction of 3/8`` {times} 8 (US mesh) was then obtained by sieving using a Gilson Test-Master. This size fraction was selected for the preliminary laboratory-scale experiments designed to simulate the dense bed conditions that exist in the bottom of CFB combustors. To ensure uniformity of fuel composition among combustion runs, the sized coal was riffled using, a cone and long row method and stored in bags for each experiment. During this quarter additional modifications were made to achieve better control of fluidization regimes and to aid in monitoring the hydrodynamic and chemical conditions within the reactor.

  20. Pilot plant testing of IGT`s two-stage fluidized-bed/cyclonic agglomerating combustor

    SciTech Connect

    Rehmat, A.; Mensinger, M.C.; Richardson, T.L.

    1993-12-31

    The Institute of Gas Technology (IGT) is conducting a multi-year experimental program to develop and test, through pilot-scale operation, IGT`s two-stage fluidized-bed/cyclonic agglomerating combustor (AGGCOM). The AGGCOM process is based on combining the fluidized-bed agglomeration and gasification technology with the cyclonic combustion technology, both of which have been developed at IGT over many years. AGGCOM is a unique and extremely flexible combustor that can operate over a wide range of conditions in the fluidized-bed first stage from low temperature (desorption) to high temperature (agglomeration), including gasification of high-energy-content wastes. The ACCCOM combustor can easily and efficiently destroy solid, liquid, and gaseous organic wastes, while isolating solid inorganic contaminants within an essentially non-leachable glassy matrix, suitable for disposal in ordinary landfills. Fines elutriated from the first stage are captured by a high-efficiency cyclone and returned to the fluidized bed for ultimate incorporation into the agglomerates. Intense mixing in the second-stage cyclonic combustor ensures high destruction and removal efficiencies (DRE) for organic compounds that may be present in the feed material. This paper presents an overview of the experimental development of the AGGCOM process and progress made to date in designing, constructing, and operating the 6-ton/day AGGCOM pilot plant. Results of the bench-scale tests conducted to determine the operating conditions necessary to agglomerate a soil were presented at the 1991 Incineration Conference. On-site construction of the AGGCOM pilot plant was initiated in August 1992 and completed at the end of March 1993, with shakedown testing following immediately thereafter. The initial tests in the AGGCOM pilot plant will focus on the integrated operation of both stages of the combustor and will be conducted with ``clean`` topsoil.

  1. Sonic enhanced ash agglomeration and sulfur capture. Quarterly technical progress report, April--June 1995

    SciTech Connect

    1995-08-01

    A major concern with the utilization of coal in directly fired gas turbines is the control of particulate emissions and reduction of sulfur dioxide, and alkali vapor from combustion of coal, upstream of the gas turbine. Much research and development has been sponsored on methods for particulate emissions control and the direct injection of calcium-based sorbents to reduce SO{sub 2} emission levels. The results of this research and development indicate that both acoustic agglomeration of particulates and direct injection of sorbents have the potential to become a significant emissions control strategy. The Sonic Enhanced Ash Agglomeration and Sulfur Capture program focuses upon the application of an MTCI proprietary invention (Patent No. 5,197,399) for simultaneously enhancing sulfur capture and particulate agglomeration of the combustor effluent. This application can be adapted as either a {open_quotes}hot flue gas cleanup{close_quotes} subsystem for the current concepts for combustor islands or as an alternative primary pulse combustor island in which slagging, sulfur capture, particulate agglomeration and control, and alkali gettering as well as NO{sub x} control processes become an integral part of the pulse combustion process. The goal of the program is to support the DOE mission in developing coal-fired combustion gas turbines. In particular, the MTCI proprietary process for bimodal ash agglomeration and simultaneous sulfur capture will be evaluated and developed. The technology embodiment of the invention provides for the use of standard grind, moderately beneficiated coal and WEM for firing the gas turbine with efficient sulfur capture and particulate emission control upstream of the turbine. The process also accommodates injection of alkali gettering material if necessary. The proposed technology provides for practical, reliable, and capital (and O&M) cost-effective means of protection for the gas turbine from impurities in the coal combustor effluent.

  2. A discrete element and ray framework for rapid simulation of acoustical dispersion of microscale particulate agglomerations

    NASA Astrophysics Data System (ADS)

    Zohdi, T. I.

    2016-03-01

    In industry, particle-laden fluids, such as particle-functionalized inks, are constructed by adding fine-scale particles to a liquid solution, in order to achieve desired overall properties in both liquid and (cured) solid states. However, oftentimes undesirable particulate agglomerations arise due to some form of mutual-attraction stemming from near-field forces, stray electrostatic charges, process ionization and mechanical adhesion. For proper operation of industrial processes involving particle-laden fluids, it is important to carefully breakup and disperse these agglomerations. One approach is to target high-frequency acoustical pressure-pulses to breakup such agglomerations. The objective of this paper is to develop a computational model and corresponding solution algorithm to enable rapid simulation of the effect of acoustical pulses on an agglomeration composed of a collection of discrete particles. Because of the complex agglomeration microstructure, containing gaps and interfaces, this type of system is extremely difficult to mesh and simulate using continuum-based methods, such as the finite difference time domain or the finite element method. Accordingly, a computationally-amenable discrete element/discrete ray model is developed which captures the primary physical events in this process, such as the reflection and absorption of acoustical energy, and the induced forces on the particulate microstructure. The approach utilizes a staggered, iterative solution scheme to calculate the power transfer from the acoustical pulse to the particles and the subsequent changes (breakup) of the pulse due to the particles. Three-dimensional examples are provided to illustrate the approach.

  3. CONSOLIDATION OF K BASIN SLUDGE DATA AND EXPERIENCES ON AGGLOMERATE FORMATION

    SciTech Connect

    HILL SR

    2010-06-10

    The formation of high sludge strength agglomerates is a key concern to the Sludge Treatment Project (STP) to ensure the sludge can be retrieved after planned storage for up to 10 years in Sludge Transport and Storage Containers (STSC) at T Plant. This report addresses observations of agglomerate formation, conditions that the data shows lead to agglomeration, the frequency of agglomerate formation and postulated physiochemical mechanisms that may lead to agglomeration. Although the exact underlying chemistry of K Basin sludge agglomerate formation is not known, the factors that lead to agglomeration formation, based on observations, are as follows: (1) High Total Uranium Content (i.e., sample homogeneity and influence from other constituents); (2) Distribution of Uranium Phases (i.e., extent of conversion from uraninite to uranium oxide hydroxide compounds); (3) Sample Dry-out (loss of cover water); (4) Elevated temperature; (5) Solubility ofU(IV) phases vs. U(VI) phases; and (6) Long storage times. Agglomerated sludge has occurred infrequently and has only been observed in four laboratory samples, five samples subjected to hydrothermal testing (performed for 7 to 10 hours at {approx}185 C and 225 psig), and indirectly during six sampling events in the KE Basin. In the four laboratory samples where agglomerates were observed, the agglomerates exhibited high shear strength and the sample container typically had to be broken to remove the solids. The total uranium content (dry basis) for the four samples (KE Pit, KC-2/3 SS, KC-2/3 M250 and 96-13) were {approx}8 wt%, {approx}59.0 wt%, 68.3 wt% and 82 wt%. The agglomerates that were present during the six sampling events were undoubtedly disturbed and easily broken apart during sample collection, thus no agglomerates were observed in subsequent laboratory analyses. The highest shear strengths measured for K Basin sludge samples were obtained after hydrothermal treatment (7 to 10 hr at 185 C) of high-uranium-content KE

  4. Agglomerates, smoke oxide particles, and carbon inclusions in condensed combustion products of an aluminized GAP-based propellant

    NASA Astrophysics Data System (ADS)

    Ao, Wen; Liu, Peijin; Yang, Wenjing

    2016-12-01

    In solid propellants, aluminum is widely used to improve the performance, however the condensed combustion products especially the large agglomerates generated from aluminum combustion significantly affect the combustion and internal flow inside the solid rocket motor. To clarify the properties of the condensed combustion products of aluminized propellants, a constant-pressure quench vessel was adopted to collect the combustion products. The morphology and chemical compositions of the collected products, were then studied by using scanning electron microscopy coupled with energy dispersive (SEM-EDS) method. Various structures have been observed in the condensed combustion products. Apart from the typical agglomerates or smoke oxide particles observed before, new structures including the smoke oxide clusters, irregular agglomerates and carbon-inclusions are discovered and investigated. Smoke oxide particles have the highest amount in the products. The highly dispersed oxide particle is spherical with very smooth surface and is on the order of 1-2 μm, but due to the high temperature and long residence time, these small particles will aggregate into smoke oxide clusters which are much larger than the initial particles. Three types of spherical agglomerates have been found. As the ambient gas temperature is much higher than the boiling point of Al2O3, the condensation layer inside which the aluminum drop is burning would evaporate quickly, which result in the fact that few "hollow agglomerates" has been found compared to "cap agglomerates" and "solid agglomerates". Irregular agglomerates usually larger than spherical agglomerates. The formation of irregular agglomerates likely happens by three stages: deformation of spherical aluminum drops; combination of particles with various shape; finally production of irregular agglomerates. EDS results show the ratio of O to Al on the surface of agglomerates is lower in comparison to smoke oxide particles. C and O account for

  5. Stable nanoparticle aggregates/agglomerates of different sizes and the effect of their size on hemolytic cytotoxicity.

    PubMed

    Zook, Justin M; Maccuspie, Robert I; Locascio, Laurie E; Halter, Melissa D; Elliott, John T

    2011-12-01

    To study the toxicity of nanoparticles under relevant conditions, it is critical to disperse nanoparticles reproducibly in different agglomeration states in aqueous solutions compatible with cell-based assays. Here, we disperse gold, silver, cerium oxide, and positively-charged polystyrene nanoparticles in cell culture media, using the timing between mixing steps to control agglomerate size in otherwise identical media. These protein-stabilized dispersions are generally stable for at least two days, with mean agglomerate sizes of ∼23 nm silver nanoparticles ranging from 43-1400 nm and average relative standard deviations of less than 10%. Mixing rate, timing between mixing steps and nanoparticle concentration are shown to be critical for achieving reproducible dispersions. We characterize the size distributions of agglomerated nanoparticles by further developing dynamic light scattering theory and diffusion limited colloidal aggregation theory. These theories frequently affect the estimated size by a factor of two or more. Finally, we demonstrate the importance of controlling agglomeration by showing that large agglomerates of silver nanoparticles cause significantly less hemolytic toxicity than small agglomerates.

  6. The impact of agglomeration and storage on flavor and flavor stability of whey protein concentrate 80% and whey protein isolate.

    PubMed

    Wright, B J; Zevchak, S E; Wright, J M; Drake, M A

    2009-01-01

    The impact of agglomeration on flavor and flavor stability of whey protein concentrates 80% (WPC80) and whey protein isolates (WPI) has not been widely addressed. This study examined the impact of agglomeration on the flavor and flavor stability of commercial WPC80 and WPI across 18 mo of storage. Duplicate agglomerated and nonagglomerated WPC80 and WPI were collected from 4 facilities and stored at 21 degrees C, 50% relative humidity. Volatile analysis using solid phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) and descriptive sensory analysis were conducted every 2 mo. Solubility index, bulk volume, dispersibility, moisture, and color (L, a, b) were tested every 3 or 6 mo. Consumer acceptance testing with protein beverages was conducted with fresh and stored whey proteins. Higher intensities and more rapid development of lipid oxidation flavors (cardboard, raisin/brothy, cucumber, and fatty) were noted in agglomerated powders compared to nonagglomerated powders (P < 0.05). Volatile analysis results confirmed sensory results, which indicated increased formation of aldehydes and ketones in agglomerated products compared to nonagglomerated powders (P < 0.05). Consumer acceptance scores for protein beverages were lower for beverages made with agglomerated WPC80 stored for 12 mo and agglomerated or nonagglomerated WPI stored for 18 mo compared to fresh products while trained panelists detected differences among beverages and rehydrated proteins earlier. Agglomeration with or without lecithin decreased the storage stability of whey proteins. These results indicate that the optimum shelf life at 21 degrees C for nonagglomerated whey proteins is 12 to 15 mo and 8 to 12 mo for agglomerated whey proteins.

  7. Disentangling the effects of polymer coatings on silver nanoparticle agglomeration, dissolution, and toxicity to determine mechanisms of nanotoxicity

    NASA Astrophysics Data System (ADS)

    Zook, Justin M.; Halter, Melissa D.; Cleveland, Danielle; Long, Stephen E.

    2012-10-01

    Silver nanoparticles (AgNPs) are frequently coated with a variety of polymers, which may affect various interdependent mechanisms of toxicity or antimicrobial action, including agglomeration and dissolution rates. Here, we systematically measure how citrate, dextran, 5 and 20 kDa poly(ethylene glycol) (PEG), and poly(vinyl pyrrolidone) coatings affect AgNP agglomeration, dissolution, and toxicity. In addition, to disentangle the coatings' effects on agglomeration from their other effects, we produce multiple stable agglomerate sizes of several of the coated 23 nm AgNPs ranging from singly-dispersed to mean agglomerate sizes of several hundred nanometers. These dispersions allow us to independently study the effects of agglomeration and polymer coating on dissolution rate and hemolytic toxicity. We find that both hemolytic toxicity and dissolution rate are highest for the 5 kDa PEG coating, and toxicity and dissolution rate decrease significantly with increasing agglomerate size independent of coating. This correlation between toxicity and dissolution rate suggests that both polymer coating and agglomeration may affect hemolytic toxicity largely through their effects on dissolution. Because both the AgNP dissolution rate and hemolysis decrease only moderately compared to the large increases in agglomerate size, AgNPs' hemolytic toxicity may be caused by their large surface area and consequently high dissolution rate, rather than from other size-specific effects. At the silver concentrations used in this work, silver dissolved from AgNPs is expected to be primarily in the form of AgCl NPs, which are therefore more likely than Ag+ ions to be the primary drivers of hemolytic toxicity. In addition, all AgNPs we tested are much more toxic to horse red blood cells than sheep red blood cells, highlighting the complexity of toxic responses and the need to test toxicity in multiple biological systems.

  8. In Situ Observations of Interaction Between Particulate Agglomerates and an Advancing Planar Solid/Liquid Interface: Microgravity Experiments

    NASA Technical Reports Server (NTRS)

    Sen, S.; Juretzko, F.; Stafanescu, D. M.; Dhindaw, B. K.; Curreri, P. A.

    1999-01-01

    Results are reported of directional solidification experiments on particulate agglomerate pushing and engulfment by a planar solid/liquid (s/l) interface. These experiments were conducted on the Space Shuttle Columbia during the United States Microgravity Payload 4 (USMP-4) Mission. It was found that the pushing to engulfment transition velocity, V(sub cr) for agglomerates depends not only on their effective size but also their orientation with respect to the s,1 interface. The analytical model for predicting V(sub cr) of a single particle was subsequently enhanced to predict V(sub cr) of the agglomerates by considering their shape factor and orientation.

  9. In-Situ Observations of Interaction Between Particulate Agglomerates and an Advancing Planar Solid/Liquid Interface: Microgravity Experiments

    NASA Technical Reports Server (NTRS)

    Sen, S.; Juretzko, F.; Stefanescu, D. M.; Dhindaw, B. K.; Curreri, P. A.

    1999-01-01

    Results are reported of directional solidification experiments on particulate agglomerate pushing and engulfment by a planar solid/liquid (s/1) interface. These experiments were conducted on the Space Shuttle Columbia during the United States Microgravity Payload 4 (USMP-4) Mission. It was found that the pushing to engulfment transition velocity, V(sub ct),, for agglomerates depends not only on their effective size but also their orientation with respect to the s/l interface. The analytical model for predicting V(sub cr) of a single particle was subsequently enhanced to predict V(sub cr) of the agglomerates by considering their shape factor and orientation.

  10. Substructure of Titanium Dioxide Agglomerates from Dry Ball-milling Experiments

    NASA Astrophysics Data System (ADS)

    Gesenhues, Ulrich

    1999-06-01

    The calciner discharge of TiO2 white pigments from the sulphate process is ground batchwise in a planetary ball mill, varying the energy of comminution between 0 and 5.1 times the earth's gravitational constant. Particle sizes and specific surfaces of the ground products reveal that the calciner discharge consists of aggregates of 430 nm diameter built from 160-210 nm TiO2 crystals. The contact area of a primary particle in an aggregate is about 15% of its surface. The success in comminution of aggregates as a function of grinding energy follows Kick's law. The theory by Rose and Weichert is used to quantify the mechanical strength of the aggregates. Ca. 20% of the aggregates are further agglomerated to granules of ca. 35 µm. At all energy levels above a certain threshold, agglomerates break directly into aggregates.

  11. Evaluation of water security: an integrated approach applied in Wuhan urban agglomeration, China.

    PubMed

    Shao, Dongguo; Yang, Fengshun; Xiao, Chun; Tan, Xuezhi

    2012-01-01

    To evaluate water security, the Water Resources Sustainability Evaluation Model has been developed. The model employs four criteria (economic development, flood control security, water supply security, and water environment security) and has 22 indicators, integrating them using their relative weights. The model is applied to evaluate the water security of Wuhan urban agglomeration, China. The values of the indicators are normalized using the exponential efficacy functions based on the law of diminishing marginal utility. The evaluation results show that, overall, the state of water security in Wuhan urban agglomeration is good, which is in good agreement with the true situation. The comparison between the results of the model and other three evaluation methods by the Spearman coefficient of rank correlation verifies the science and reliability of the developed model. Consequently, it is concluded that the model can be an effective tool for evaluating the states of water security and provide a basis on which to create policies for improving inadequacies in water security.

  12. On Two Numerical Techniques for Light Scattering by Dielectric Agglomerated Structures

    PubMed Central

    Lakhtakia, Akhlesh; Mulholland, George W.

    1993-01-01

    Smoke agglomerates are made of many soot sphcres, and their light scattering response is of interest in fire research. The numerical techniques chiefly used for theoretical scattering studies are the method of moments and the coupled dipole moment. The two methods have been obtained in this tutorial paper directly from the monochromatic Maxwell curl equations and shown to be equivalent. The effects of the finite size of the primary spheres have been numerically delineated. PMID:28053494

  13. Sonic enhanced ash agglomeration and sulfur capture. Quarterly report, July--September 1995

    SciTech Connect

    1995-10-01

    The major objective of the Phase I test program is to confirm the feasibility of the MTCI bimodal particle size approach to enhance particulate control by acoustic ash agglomeration. An ancillary objective of the Phase I effort is to demonstrate and confirm the feasibility of an acoustic field to enhance sulfur capture by increasing sorbent reactivity. Phase I tests are designed to cover the frequency range between 50 and 1400 Hz, establish monomodal baseline performance as a benchmark from which to measure the degree of enhancement expected from the bimodal approach, and, finally, to confirm the effectiveness of low-frequency fields over high-frequency fields for realistic particulate streams. The program will demonstrate the effectiveness of a unique approach which uses a bimodal distribution composed of large sorbent particles and fine fly ash particles to enhance ash agglomeration and sulfur capture at conditions found in direct coal-fired turbines. Under the impact of high-intensity sound waves, sorbent reactivity and utilization, it is theorized, will increase while agglomerates of fly ash and sorbents are formed which are readily collected in commercial cyclones. The work will extend the concept from the demonstration of feasibility (Phase I), through proof-of-concept (Phase II) to the construction (Phase III) of a coal-fired pulsed combustor with in-furnace sorbent injection. For Phase 1, Pennsylvania State University will conduct studies for enhanced sulfur capture in The Combustion Laboratory and agglomeration tests in the High Intensity Acoustic Laboratory. During this reporting period, design, design analysis and procurement proceeded as scheduled. An independent analysis of the structure was completed and the concrete pad was found to be inadequate so it will be re-designed.

  14. Development of clean coal and clean soil technologies using advanced agglomeration technologies

    SciTech Connect

    Ignasiak, B.; Pawlak, W.; Szymocha, K.; Marr, J.

    1990-04-01

    The specific objectives of the bituminous coal program were to explore and evaluate the application of advanced agglomeration technology for: (1)desulphurization of bituminous coals to sulphur content acceptable within the current EPA SO{sub 2} emission guidelines; (2) deashing of bituminous coals to ash content of less than 10 percent; and (3)increasing the calorific value of bituminous coals to above 13,000 Btu/lb. (VC)

  15. Spherical agglomerates of pure drug nanoparticles for improved pulmonary delivery in dry powder inhalers

    NASA Astrophysics Data System (ADS)

    Hu, Jun; Dong, Yuancai; Pastorin, Giorgia; Ng, Wai Kiong; Tan, Reginald B. H.

    2013-04-01

    The aim of this study was to produce micron-sized spherical agglomerates of pure drug nanoparticles to achieve improved aerosol performance in dry powder inhalers (DPIs). Sodium cromoglicate was chosen as the model drug. Pure drug nanoparticles were prepared through a bottom-up particle formation process, liquid antisolvent precipitation, and then rapidly agglomerated into porous spherical microparticles by immediate (on-line) spray drying. Nonporous spherical drug microparticles with similar geometric size distribution were prepared by conventional spray drying of the aqueous drug solution, which together with the mechanically micronized drug particles were used as the control samples. The three samples were characterized by field emission scanning electron microscopy, laser diffraction, Brunauer-Emmett-Teller analysis, density measurement, powder X-ray diffraction, and in vitro aerosol deposition measurement with a multistage liquid impinger. It was found that drug nanoparticles with a diameter of 100 nm were precipitated and agglomerated into highly porous spherical microparticles with a volume median diameter ( D 50 %) of 2.25 ± 0.08 μm and a specific surface area of 158.63 ± 3.27 m2/g. In vitro aerosol deposition studies showed the fine particle fraction of such spherical agglomerates of drug nanoparticles was increased by more than 50 % in comparison with the control samples, demonstrating significant improvements in aerosol performance. The results of this study indicated the potential of the combined particle engineering process of liquid antisolvent precipitation followed by immediate (on-line) spray drying in the development of novel DPI drug products with improved aerosol performance.

  16. Quantum dot agglomerates in biological media and their characterization by asymmetrical flow field-flow fractionation.

    PubMed

    Moquin, Alexandre; Neibert, Kevin D; Maysinger, Dusica; Winnik, Françoise M

    2015-01-01

    The molecular composition of the biological environment of nanoparticles influences their physical properties and changes their pristine physicochemical identity. In order to understand, or predict, the interactions of cells with specific nanoparticles, it is critical to know their size, shape, and agglomeration state not only in their nascent state but also in biological media. Here, we use asymmetrical flow field-flow fractionation (AF4) with on-line multiangle light scattering (MALS), dynamic light scattering (DLS) and UV-Visible absorption detections to determine the relative concentration of isolated nanoparticles and agglomerates in the case of three types of semi-conductor quantum dots (QDs) dispersed in Dulbecco's Modified Eagle Media (DMEM) containing 10% of fetal bovine serum (DMEM-FBS). AF4 analysis also yielded the size and size distribution of the agglomerates as a function of the time of QDs incubation in DMEM-FBS. The preferred modes of internalization of the QDs are assessed for three cell-types, N9 microglia, human hepatocellular carcinoma cells (HepG2) and human embryonic kidney cells (Hek293), by confocal fluorescence imaging of live cells, quantitative determination of the intracellular QD concentration, and flow cytometry. There is an excellent correlation between the agglomeration status of the three types of QDs in DMEM-FBS determined by AF4 analysis and their preferred mode of uptake by the three cell lines, which suggests that AF4 yields an accurate description of the nanoparticles as they encounter cells and advocates its use as a means to characterize particles under evaluation.

  17. Recent satellite-based trends of tropospheric nitrogen dioxide over large urban agglomerations worldwide

    NASA Astrophysics Data System (ADS)

    Schneider, P.; Lahoz, W. A.; van der A, R.

    2015-02-01

    Trends in tropospheric nitrogen dioxide (NO2) columns over 66 large urban agglomerations worldwide have been computed using data from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument onboard the Envisat platform for the period August 2002 to March 2012. A seasonal model including a~linear trend was fitted to the satellite-based time series over each site. The results indicate distinct spatial patterns in trends. While agglomerations in Europe, North America, and some locations in East Asia/Oceania show decreasing tropospheric NO2 levels on the order of -5% yr-1, rapidly increasing levels of tropospheric NO2 are found for agglomerations in large parts of Asia, Africa, and South America. The site with the most rapidly increasing absolute levels of tropospheric NO2 was found to be Tianjin in China with a trend of 3.04 (±0.47) × 1015 molecules cm-2yr-1, whereas the site with the most rapidly increasing relative trend was Kabul in Afghanistan with 14.3 (±2.2) % yr-1. In total, 34 sites exhibited increasing trends of tropospheric NO2 throughout the study period, 24 of which were found to be statistically significant. A total of 32 sites showed decreasing levels of tropospheric NO2 during the study period, of which 20 sites did so at statistically significant magnitudes. Overall, going beyond the relatively small set of megacities investigated previously, this study provides the first consistent analysis of recent changes in tropospheric NO2 levels over most large urban agglomerations worldwide, and indicates that changes in urban NO2 levels are subject to substantial regional differences as well as influenced by economic and demographic factors.

  18. Recent satellite-based trends of tropospheric nitrogen dioxide over large urban agglomerations worldwide

    NASA Astrophysics Data System (ADS)

    Schneider, P.; Lahoz, W. A.; van der A, R.

    2014-09-01

    Trends in tropospheric nitrogen dioxide (NO2) concentrations over 66 large urban agglomerations worldwide have been computed using data from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument onboard the Envisat platform for the period August 2002 to March 2012. A seasonal model including a linear trend was fitted to the satellite-based time series over each site. The results indicate distinct spatial patterns in trends. While agglomerations in Europe, North America, and some locations in East Asia/Oceania show decreasing tropospheric NO2 levels on the order of -5 % yr-1, rapidly increasing levels of tropospheric NO2 are found for agglomerations in large parts of Asia, Africa, and South America. The site with the most rapidly increasing absolute levels of tropospheric NO2 was found to be Tianjin in China with a trend value of 3.04 (±0.47) × 1015 molecules cm-2 yr-1, whereas the site with the most rapidly increasing relative trend was Kabul in Afghanistan with 14.3 (±2.2) % yr-1. In total, 34 sites exhibited increasing trends of tropospheric NO2 throughout the study period, 24 of which were found to be statistically significant. A total of 32 sites showed decreasing levels of tropospheric NO2 during the study period, of which 20 sites did so at statistically significant magnitudes. Overall, going beyond the relatively small set of megacities investigated previously, this study provides the first consistent analysis of recent changes in tropospheric NO2 levels over most large urban agglomerations worldwide.

  19. Nanostructured natural-based polyelectrolyte multilayers to agglomerate chitosan particles into scaffolds for tissue engineering.

    PubMed

    Miranda, Emanuel Sá; Silva, Tiago H; Reis, Rui L; Mano, João F

    2011-11-01

    The layer-by-layer (LbL) deposition technique is a self-assembly process that allows the coating of material's surface with nanostructured layers of polyelectrolytes, allowing to control several surface properties. This technique presents some advantages when compared with other thin film assembly techniques, like having the possibility to coat surfaces with complex geometries in mild conditions or to incorporate active compounds. Tissue engineering (TE) involves typically the use of porous biodegradable scaffolds for the temporary support of cells. Such structures can be produced by agglomeration of microspheres that needs to be fixed into a three-dimensional (3D) structure. In this work we suggest the use of LbL to promote such mechanical fixation in free-formed microspheres assemblies and simultaneously to control the properties of its surface. For the proof of concept the biological performance of chitosan/alginate multilayers is first investigated in two-dimensional (2D) models in which the attachment and proliferation of L929 and ATDC5 cells are studied in function of the number of layers and the nature of the final layer. Scaffolds prepared by agglomeration of chitosan particles using the same multilayered system were processed and characterized; it was found that they could support the attachment and proliferation of ATDC5 cells. This study suggests that LbL can be used as a versatile methodology to prepare scaffolds by particle agglomeration that could be suitable for TE applications.

  20. [Spatio-temporal dynamics of ecosystem service value in Wuhan Urban Agglomeration].

    PubMed

    Zeng, Jie; Li, Jiang-Feng; Yao, Xiao-Wei

    2014-03-01

    Based on the land use vector data of Wuhan Urban Agglomeration in the years 1990, 2000 and 2009, this paper used Costanza' s evaluation formula to estimate the ecosystem service value (ESV) of the study area according to "equivalent value per unit area of ecosystem services in China" and analyze its spatio-temporal characteristics. Then the correlation analysis was applied to explore the association between the ESV evolution and the land use changes. The results showed that due to the substantial growth of water area, the ESV of Wuhan Urban Agglomeration increased by 9.5% during the study period, which showed an overall rising trend. The ESV of water regulation and waste treatment increased obviously. Furthermore, the ESV changes showed obvious regional differences, which were most significant in Xiantao, Xinzhou and Yunmeng. The ESV was higher in the southeast and lower in the northwest. Over time, a Wuhan-centered "low-high-low" hierarchically distributed structure of ESV was formed in the eastern, western and northern parts. The ecologic dominance of the northern mountainous and hilly region was gradually abated, while a structural expansion with a high-ESV cluster had taken place in the southern part of the region in 2009. During the research period, the temporal change of ESV in Wuhan Urban Agglomeration was positively correlated with the area changes of forestland, water, grassland and cultivated land. However, the spatially balanced distribution of ESV was negatively correlated with the dispersion degrees of the cultivated land and unused land.

  1. Final report on agglomerate column flotation for cleaning and desulfurization of Ohio coal fines

    SciTech Connect

    Attia, Y.A.; El Zeky, M.; Yu, Mulong . Dept. of Materials Science and Engineering)

    1990-08-30

    The objective of this research program was investigate the feasibility of cleaning and desulfurization of Ohio coal by an agglomerate column flotation process, which integrates selective flocculation with conventional column flotation. It was concluded earlier on in the program that the conventional design of flotation column was not particularly efficient for pyrite rejection. A novel design for flotation column system was conceived and a prototype unit was manufactured and tested in the laboratory. Several design and operational parameters for the column and the agglomerate flotation process were briefly investigated to define proper design and working conditions for a satisfactory performance. The novel design was compared with conventional design of flotation column through laboratory tests and through published results. The role of selective flocculation of coal including selective depression of pyrite has been identified and tested with both novel and conventional design of flotation columns. The results of these brief investigations, which are summarized in this report, suggest that: (1) excellent performance ca n be obtained with agglomerate column flotation using the new design. For example, a raw coal containing 3.16% total sulfur, 2.11% pyritic sulfur, and 17% ash can be cleaned to 1.91 % ash, 0.42% pyritic sulfur, 1.32% total sulfur, while maintaining a projected Btu/coal recovery of 86% (mmmf basis). This is equivalent to 89% ash removal and 81% pyritic sulfur (58% total sulfur) rejection. (2) The novel design of flotation column is superior to conventional design particularly for pyrite rejection.

  2. Integrated low emission cleanup system for direct coal-fueled turbines (electrostatic agglomeration)

    SciTech Connect

    Quimby, J.M.; Kumar, K.S.

    1992-01-01

    The objective of this contract was to investigate the removal of SO[sub x] and particulate matter from direct coal fired combustion gas streams at high temperature and high pressure conditions. This investigation was to be accomplished through a bench scale testing and evaluation program for SO[sub x] removal and the innovative particulate collection concept of particulate growth through electrostatic agglomeration followed by high efficiency mechanical collection. The process goal was to achieve control better than that required by 1979 New Source Performance Standards. During Phase I, the designs of the combustor and gas cleanup apparatus were successfully completed. Hot gas cleanup was designed to be accomplished at temperature levels between 1800[degrees] and 2500[degrees]F at pressures up to 15 atmospheres. The combustor gas flow rate could be varied between 0.2--0.5 pounds per second. The electrostatic agglomerator residence time could be varied between 0.25 to 3 seconds. In Phase II, all components were fabricated, and erected successfully. Test data from shakedown testing was obtained. Unpredictable difficulties in pilot plant erection and shakedown consumed more budget resources than was estimated and as a consequence DOE, METC, decided ft was best to complete the contract at the end of Phase II. Parameters studied in shakedown testing revealed that high-temperature high pressure electrostatics offers an alternative to barrier filtration in hot gas cleanup but more research is needed in successful system integration between the combustor and electrostatic agglomerator.

  3. The impact of solution agglomeration on the deposition of self-assembled monolayers

    SciTech Connect

    BUNKER,BRUCE C.; CARPICK,ROBERT W.; ASSINK,ROGER A.; THOMAS,MICHAEL L.; HANKINS,MATTHEW G.; VOIGT,JAMES A.; SIPOLA,DIANA L.; DE BOER,MAARTEN P.; GULLEY,GERALD L.

    2000-04-17

    Self-assembled monolayers (SAMS) are commonly produced by immersing substrates in organic solutions containing trichlorosilane coupling agents. Unfortunately, such deposition solutions can also form alternate structures including inverse micelles and lamellar phases. The formation of alternate phases is one reason for the sensitivity of SAM depositions to factors such as the water content of the deposition solvent. If such phases are present, the performance of thin films used for applications such as minimization of friction and stiction in micromachines can be seriously compromised. Inverse micelle formation has been studied in detail for depositions involve 1H-, 1H-, 2H-, 2H-perfluorodecyltrichlorosilane (FDTS) in isooctane. Nuclear magnetic resonance experiments have been used to monitor the kinetics of hydrolysis and condensation reactions between water and FDTS. Light scattering experiments show that when hydrolyzed FDTS concentrations reach a critical concentration, there is a burst of nucleation to form high concentrations of spherical agglomerates. Atomic force microscopy results show that the agglomerates then deposit on substrate surfaces. Deposition conditions leading to monolayer formation involve using deposition times that are short relative to the induction time for agglomeration. After deposition, inverse micelles can be converted into lamellar or monolayer structures with appropriate heat treatments if surface concentrations are relatively low.

  4. Investigations on Agglomeration and Haemocompatibility of Vitamin E TPGS Surface Modified Berberine Chloride Nanoparticles

    PubMed Central

    Vuddanda, Parameswara Rao; Rajamanickam, Vijayakumar Mahalingam; Yaspal, Madhu; Singh, Sanjay

    2014-01-01

    The objective of the present study is to investigate the influence of surface modification on systemic stability of NPs. Vitamin E TPGS (1% w/v) was used for surface modification of berberine chloride nanoparticles. Naked and surface modified NPs were incubated in different SBFs (pH 6.8 and 7.4) with or without bile salts and human plasma. NPs were observed for particle agglomeration and morphology by particle size analyzer and TEM, respectively. The haemocompatibility studies were conducted on developed NPs to evaluate their safety profile. The surface modified NPs were stable compared to naked NPs in different SBFs due to the steric stabilization property of vitamin E TPGS. Particle agglomeration was not seen when NPs were incubated in SBF (pH 6.8) with bile salts. No agglomeration was observed in NPs after their incubation in plasma but particle size of the naked NPs increased due to adhesion of plasma proteins. The TEM images confirmed the particle size results. DSC and FT-IR studies confirmed the coexistence of TPGS in surface modified NPs. The permissible haemolysis, LDH release, and platelet aggregation revealed that NPs were compatible for systemic administration. Thus, the study illustrated that the surface modification is helpful in the maintenance of stability of NPs in systemic conditions. PMID:25162037

  5. Sonic Enhanced Ash Agglomeration and Sulfur Capture. Technical progress report, April--June 1993

    SciTech Connect

    Not Available

    1993-12-31

    The shakedown testing of the system proceeded on schedule. Some of the preliminary results were ambiguous in that they indicated a higher carbon concentration in the baghouse than in the cyclone. Apparently this was due to the use of the baghouse for tests on an integrated coal-fired boiler. This was remedied by installing a separate baghouse for the bimodal agglomeration testing. The testing with coal/dolomite mixture indicated that the sulfur is captured effectively with the present system configuration and that combustion efficiencies were greater than 99 percent. The coal/dolomite test was on-line for approximately 7 hours during which it achieved steady-state operation at 3 atmospheres for about 5 1/2 hours. The agglomeration chamber catch contained agglomerates ranging in size from 1/4 to 3/4 inches. West Virginia University developed some new aerovalve designs including a vortex design for the vitiated air pulse combustor. A set of modifications resulting from the initial shakedown tests were also completed.

  6. Agglomeration of alumina submicronparticles by silica nanoparticles: application to processing spheres by colloidal route.

    PubMed

    Garcia-Perez, P; Pagnoux, C; Pringuet, A; Videcoq, A; Baumard, J F

    2007-09-15

    In aqueous media, heterocoagulation between submicronic alumina (400 nm) and nanometric silica (25 nm) leads to the adsorption of silica on the alumina surface. By controlling the coverage rate of alumina particles, this adsorption destabilizes the suspension that leads to a very porous network of agglomerated particles. This work shows that the structure is all the more open as the density of charge carried by the two oxides is high and the ionic strength in the suspension low. From such a flocculated suspension, a new colloidal process to fabricate ceramic spheres is proposed which is based on a size increase of agglomerates. Under a controlled rotation of the vessel, electrostatic attraction between the surface charges of opposite polarity induces a size increase of agglomerates until the formation of spheres occurs. It has been shown that the mechanism of growth is poisoned by species adsorbed such as ions. Nevertheless, this new process proves very promising because it leads to a narrow size distribution of spheres by colloidal way, which can be subsequently consolidated by sintering, with a smooth surface.

  7. Gasification of palm empty fruit bunch in a bubbling fluidized bed: a performance and agglomeration study.

    PubMed

    Lahijani, Pooya; Zainal, Zainal Alimuddin

    2011-01-01

    Gasification of palm empty fruit bunch (EFB) was investigated in a pilot-scale air-blown fluidized bed. The effect of bed temperature (650-1050 °C) on gasification performance was studied. To explore the potential of EFB, the gasification results were compared to that of sawdust. Results showed that maximum heating values (HHV) of 5.37 and 5.88 (MJ/Nm3), dry gas yield of 2.04 and 2.0 (Nm3/kg), carbon conversion of 93% and 85 % and cold gas efficiency of 72% and 71 % were obtained for EFB and sawdust at the temperature of 1050 °C and ER of 0.25. However, it was realized that agglomeration was the major issue in EFB gasification at high temperatures. To prevent the bed agglomeration, EFB gasification was performed at temperature of 770±20 °C while the ER was varied from 0.17 to 0.32. Maximum HHV of 4.53 was obtained at ER of 0.21 where no agglomeration was observed.

  8. Control of nanoparticle agglomeration through variation of the time-temperature profile in chemical vapor synthesis

    NASA Astrophysics Data System (ADS)

    Djenadic, Ruzica; Winterer, Markus

    2017-02-01

    The influence of the time-temperature history on the characteristics of nanoparticles such as size, degree of agglomeration, or crystallinity is investigated for chemical vapor synthesis (CVS). A simple reaction-coagulation-sintering model is used to describe the CVS process, and the results of the model are compared to experimental data. Nanocrystalline titania is used as model material. Titania nanoparticles are generated from titanium-tetraisopropoxide (TTIP) in a hot-wall reactor. Pure anatase particles and mixtures of anatase, rutile (up to 11 vol.%), and brookite (up to 29 vol.%) with primary particle sizes from 1.7 nm to 10.5 nm and agglomerate particle sizes from 24.3 nm to 55.6 nm are formed depending on the particle time-temperature history. An inductively heated furnace with variable inductor geometry is used as a novel system to control the time-temperature profile in the reactor externally covering a large wall temperature range from 873 K to 2023 K. An appropriate choice of inductor geometry, i.e. time-temperature profile, can significantly reduce the degree of agglomeration. Other particle characteristics such as crystallinity are also substantially influenced by the time-temperature profile.

  9. A Rational Analysis of Uniformity Risk for Agglomerated Drug Substance Using NIR Chemical Imaging.

    PubMed

    Scherholz, Megerle L; Wan, Boyong; McGeorge, Gary

    2017-02-01

    Early risk detection and quick diagnosis of manufacturing challenges are necessary to support the accelerated development pace of drug product in the current competitive environment. Analytical tools, such as near-infrared (NIR) chemical imaging (CI), can be employed for alerting drug substance uniformity risks in intermediates and the final product of solid dosage forms. In this particular study, the ability to characterize the behavior of agglomerated drug substance throughout process development was enabled by NIR CI to identify uniformity risks with small sample sizes and short turnaround time. Using NIR chemical imaging, the drug substance distribution and cluster size in all intermediates were visualized throughout the drug product process. NIR CI enabled rapid identification of the key unit operations that produced the greatest reduction in cluster size for enhanced distribution of the drug substance. The comil acted as a high shear mixing step to disperse soft lumps prior to roller compaction. Shear forces or pressure during roller compaction was sufficient to break down and disperse the agglomerates further. Ultimately, the process was robust against a range of drug substance input properties such that the uniformity of the final blend was consistently achieved and the agglomerated drug substance had no risks to the drug product process.

  10. Phloem ultrastructure and pressure flow: Sieve-Element-Occlusion-Related agglomerations do not affect translocation.

    PubMed

    Froelich, Daniel R; Mullendore, Daniel L; Jensen, Kåre H; Ross-Elliott, Tim J; Anstead, James A; Thompson, Gary A; Pélissier, Hélène C; Knoblauch, Michael

    2011-12-01

    Since the first ultrastructural investigations of sieve tubes in the early 1960s, their structure has been a matter of debate. Because sieve tube structure defines frictional interactions in the tube system, the presence of P protein obstructions shown in many transmission electron micrographs led to a discussion about the mode of phloem transport. At present, it is generally agreed that P protein agglomerations are preparation artifacts due to injury, the lumen of sieve tubes is free of obstructions, and phloem flow is driven by an osmotically generated pressure differential according to Münch's classical hypothesis. Here, we show that the phloem contains a distinctive network of protein filaments. Stable transgenic lines expressing Arabidopsis thaliana Sieve-Element-Occlusion-Related1 (SEOR1)-yellow fluorescent protein fusions show that At SEOR1 meshworks at the margins and clots in the lumen are a general feature of living sieve tubes. Live imaging of phloem flow and flow velocity measurements in individual tubes indicate that At SEOR1 agglomerations do not markedly affect or alter flow. A transmission electron microscopy preparation protocol has been generated showing sieve tube ultrastructure of unprecedented quality. A reconstruction of sieve tube ultrastructure served as basis for tube resistance calculations. The impact of agglomerations on phloem flow is discussed.

  11. Experimental and numerical study on the optical properties and agglomeration of nanoparticle suspensions

    NASA Astrophysics Data System (ADS)

    Otanicar, Todd; Hoyt, Jordan; Fahar, Maryam; Jiang, Xuchuan; Taylor, Robert A.

    2013-11-01

    Nanoparticles have garnered significant interest because of their ability to enhance greatly the optical properties of the base fluid in which they are suspended. The optical properties of nanoparticles are sensitive to the materials used, as well as to the host medium. Most fluids exhibit refractive indices that are highly temperature-dependent, resulting in nanoparticle suspensions which also exhibit temperature-dependent optical properties. Previous work has shown that temperature increases result in decreased absorption in nanoparticle suspensions. Here, we expand previous work to include core-shell particles due to the potential spectral shifts in optical properties that will arise from the base fluid with temperature changes and the role of agglomeration under temperature cycling through both experimental and numerical efforts. Thermal cycling tests for silica and gold, the constituents of the core-shell nanoparticles used in this study, were tested to determine the extent of particle agglomeration resulting from up to 200 accelerated heating cycles. Optical properties were recorded after heating two base fluids (water and ethylene glycol) with multiple surfactants for silver nanospheres and silica-gold core-shell nanoparticles. It was found that the temperature results in a small increase in the transmittance for both particle types and a blue shift in the spectral transmittance for core-shell nanoparticles. Further, the coupling effect of temperature and agglomeration played a significant role in determining both the spectral properties—particularly the resulting transmittance—of the silver nanoparticle suspensions.

  12. Gas-diffusion microextraction coupled with spectrophotometry for the determination of formaldehyde in cork agglomerates.

    PubMed

    Brandão, Pedro F; Ramos, Rui M; Valente, Inês M; Almeida, Paulo J; Carro, Antonia M; Lorenzo, Rosa A; Rodrigues, José A

    2017-04-01

    In this work, a simple methodology was developed for the extraction and determination of free formaldehyde content in cork agglomerate samples. For the first time, gas-diffusion microextraction was used for the extraction of volatile formaldehyde directly from samples, with simultaneous derivatization with acetylacetone (Hantzsch reaction). The absorbance of the coloured solution was read in a spectrophotometer at 412 nm. Different extraction parameters were studied and optimized (extraction temperature, sample mass, volume of acceptor solution, extraction time and concentration of derivatization reagent) by means of an asymmetric screening. The developed methodology proved to be a reliable tool for the determination of formaldehyde in cork agglomerates with the following suitable method features: low LOD (0.14 mg kg(-1)) and LOQ (0.47 mg kg(-1)), r (2) = 0.9994, and intraday and interday precision of 3.5 and 4.9%, respectively. The developed methodology was applied to the determination of formaldehyde in different cork agglomerate samples, and contents between 1.9 and 9.4 mg kg(-1) were found. Furthermore, formaldehyde was also determined by the standard method EN 717-3 for comparison purposes; no significant differences between the results of both methods were observed. Graphical abstract Representation of the GDME system and its main components.

  13. Visualizing powder de-agglomeration upon impact with simultaneous flowing charge behaviour

    NASA Astrophysics Data System (ADS)

    Kwek, Jin Wang; Heng, Desmond; Lee, Sie Huey; Ng, Wai Kiong; Chan, Hak-Kim; Heng, Jerry; Tan, Reginald

    2013-06-01

    The effectiveness of the dry powder inhaler (DPI) in treating respiratory diseases lies in its ability to deliver consistent and reliable drug dosage with each actuation. From aerosolization upon actuation to throat impaction, the deagglomeration with subsequent detachment of the drug from the carrier particles depend on the interaction forces, including electrostatic contributions, between the particles themselves or with the inhaler wall and the extent of which could depend on the surface roughness of the carrier particles. In this study, we have simultaneously investigated the contributions of the electrostatic forces while visualizing the de-agglomeration and impaction behaviours of carrier powders in an impaction throat model using a non-contact vibrating capacitive probe and a high speed camera respectively. Rough and smooth carrier particles were obtained by spray drying and then aerosolized at 60 L/min in the model. Higher flowing charges were observed for the rough aerosolized carrier particles while experiencing rebound or limited agglomerate fracture upon impaction. On the other hand, smooth particles were broken up upon impaction resulting in a 'plume-like' re-entrainment. Further analyses revealed that the increased moisture sorption on the larger specific surface area of the rough particles would have facilitated the accumulation of surface charges that could in turn contribute to the cohesiveness of the rough particles. Combined high speed imaging with electrostatic monitoring has proved to be useful in investigating the mechanisms of powder de-agglomeration upon impaction.

  14. Get More Out of Your Data: A New Approach to Agglomeration and Aggregation Studies Using Nanoparticle Impact Experiments

    PubMed Central

    Ellison, Joanna; Tschulik, Kristina; Stuart, Emma J E; Jurkschat, Kerstin; Omanović, Dario; Uhlemann, Margitta; Crossley, Alison; Compton, Richard G

    2013-01-01

    Anodic particle coloumetry is used to size silver nanoparticles impacting a carbon microelectrode in a potassium chloride/citrate solution. Besides their size, their agglomeration state in solution is also investigated solely by electrochemical means and subsequent data analysis. Validation of this new approach to nanoparticle agglomeration studies is performed by comparison with the results of a commercially available nanoparticle tracking analysis system, which shows excellent agreement. Moreover, it is demonstrated that the electrochemical technique has the advantage of directly yielding the number of atoms per impacting nanoparticle irrespective of its shape. This is not true for the optical nanoparticle tracking system, which requires a correction for the nonspherical shape of agglomerated nanoparticles to derive reasonable information on the agglomeration state. PMID:24551537

  15. A protocol for assessing the effectiveness of oil spill dispersants in stimulating the biodegradation of oil.

    PubMed

    Prince, Roger C; Butler, Josh D

    2014-01-01

    Dispersants are important tools in oil spill response. Taking advantage of the energy in even small waves, they disperse floating oil slicks into tiny droplets (<70 μm) that entrain in the water column and drift apart so that they do not re-agglomerate to re-form a floating slick. The dramatically increased surface area allows microbial access to much more of the oil, and diffusion and dilution lead to oil concentrations where natural background levels of biologically available oxygen, nitrogen, and phosphorus are sufficient for microbial growth and oil consumption. Dispersants are only used on substantial spills in relatively deep water (usually >10 m), conditions that are impossible to replicate in the laboratory. To date, laboratory experiments aimed at following the biodegradation of dispersed oil usually show only minimal stimulation of the rate of biodegradation, but principally because the oil in these experiments disperses fairly effectively without dispersant. What is needed is a test protocol that allows comparison between an untreated slick that remains on the water surface during the entire biodegradation study and dispersant-treated oil that remains in the water column as small dispersed oil droplets. We show here that when this is accomplished, the rate of biodegradation is dramatically stimulated by an effective dispersant, Corexit 9500. Further development of this approach might result in a useful tool for comparing the full benefits of different dispersants.

  16. Agglomerated oral dosage forms of artemisinin/β-cyclodextrin spray-dried primary microparticles showing increased dissolution rate and bioavailability.

    PubMed

    Balducci, Anna Giulia; Magosso, Enrico; Colombo, Gaia; Sonvico, Fabio; Khan, Nurzalina Abdul Karim; Yuen, Kah Hay; Bettini, Ruggero; Colombo, Paolo; Rossi, Alessandra

    2013-09-01

    Artemisinin, a poorly water-soluble antimalarial drug, presents a low and erratic bioavailability upon oral administration. The aim of this work was to study an agglomerated powder dosage form for oral administration of artemisinin based on the artemisinin/β-cyclodextrin primary microparticles. These primary microparticles were prepared by spray-drying a water-methanol solution of artemisinin/β-cyclodextrin. β-Cyclodextrin in spray-dried microparticles increased artemisinin water apparent solubility approximately sixfold. The thermal analysis evidenced a reduction in the enthalpy value associated with drug melting, due to the decrease in drug crystallinity. The latter was also evidenced by powder X-ray diffraction analysis, while (13)C-NMR analysis indicated the partial complexation with β-cyclodextrin. Agglomerates obtained by sieve vibration of spray-dried artemisinin/β-cyclodextrin primary microparticles exhibited free flowing and close packing properties compared with the non-flowing microparticulate powder. The in vitro dissolution rate determination of artemisinin from the agglomerates showed that in 10 min about 70% of drug was released from the agglomerates, whereas less than 10% of artemisinin was dissolved from raw material powder. Oral administration of agglomerates in rats yielded higher artemisinin plasma levels compared to those of pure drug. In the case of the agglomerated powder, a 3.2-fold increase in drug fraction absorbed was obtained.

  17. The self-preserving size distribution theory. I. Effects of the Knudsen number on aerosol agglomerate growth.

    PubMed

    Dekkers, Petrus J; Friedlander, Sheldon K

    2002-04-15

    Gas-phase synthesis of fine solid particles leads to fractal-like structures whose transport and light scattering properties differ from those of their spherical counterparts. Self-preserving size distribution theory provides a useful methodology for analyzing the asymptotic behavior of such systems. Apparent inconsistencies in previous treatments of the self-preserving size distributions in the free molecule regime are resolved. Integro-differential equations for fractal-like particles in the continuum and near continuum regimes are derived and used to calculate the self-preserving and quasi-self-preserving size distributions for agglomerates formed by Brownian coagulation. The results for the limiting case (the continuum regime) were compared with the results of other authors. For these cases the finite difference method was in good in agreement with previous calculations in the continuum regime. A new analysis of aerosol agglomeration for the entire Knudsen number range was developed and compared with a monodisperse model; Higher agglomeration rates were found for lower fractal dimensions, as expected from previous studies. Effects of fractal dimension, pressure, volume loading and temperature on agglomerate growth were investigated. The agglomeration rate can be reduced by decreasing volumetric loading or by increasing the pressure. In laminar flow, an increase in pressure can be used to control particle growth and polydispersity. For D(f)=2, an increase in pressure from 1 to 4 bar reduces the collision radius by about 30%. Varying the temperature has a much smaller effect on agglomerate coagulation.

  18. High efficiency shale oil recovery

    SciTech Connect

    Adams, D.C.

    1993-04-22

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical conditions (heating, mixing, pyrolysis, oxidation) exist in both systems.The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed this quarter. (1) Twelve pyrolysis runs were made on five different oil shales. All of the runs exhibited a complete absence of any plugging, tendency. Heat transfer for Green River oil shale in the rotary kiln was 84.6 Btu/hr/ft[sup 2]/[degrees]F, and this will provide for ample heat exchange in the Adams kiln. (2) One retorted residue sample was oxidized at 1000[degrees]F. Preliminary indications are that the ash of this run appears to have been completely oxidized. (3) Further minor equipment repairs and improvements were required during the course of the several runs.

  19. Dust agglomeration

    NASA Technical Reports Server (NTRS)

    2000-01-01

    John Marshall, an investigator at Ames Research Center and a principal investigator in the microgravity fluid physics program, is studying the adhesion and cohesion of particles in order to shed light on how granular systems behave. These systems include everything from giant dust clouds that form planets to tiny compressed pellets, such as the ones you swallow as tablets. This knowledge should help us control the grains, dust, and powders that we encounter or use on a daily basis. Marshall investigated electrostatic charge in microgravity on the first and second U.S. Microgravity Laboratory shuttle missions to see how grains aggregate, or stick together. With gravity's effects eliminated on orbit, Marshall found that the grains of sand that behaved ever so freely on Earth now behaved like flour. They would just glom together in clumps and were quite difficult to disperse. That led to an understanding of the prevalence of the electrostatic forces. The granules wanted to aggregate as little chains, like little hairs, and stack end to end. Some of the chains had 20 or 30 grains. This phenomenon indicated that another force, what Marshall believes to be an electrostatic dipole, was at work.(The diagram on the right emphasizes the aggregating particles in the photo on the left, taken during the USML-2 mission in 1995.)

  20. Oil Spills

    MedlinePlus

    Oil spills often happen because of accidents, when people make mistakes or equipment breaks down. Other causes include natural disasters or deliberate acts. Oil spills have major environmental and economic effects. Oil spills ...

  1. Oil Spills

    MedlinePlus

    ... the Deepwater Horizon/BP oil spill in 2010. (NOAA) Oil Spills During an oil spill in coastal ... Shoreline Assessment Manual , and the FOSC 's Guide to NOAA Scientific Support . Response Tools To better prepare response ...

  2. Population amalgamation and genetic variation: observations on artificially agglomerated tribal populations of Central and South America.

    PubMed Central

    Chakraborty, R; Smouse, P E; Neel, J V

    1988-01-01

    The interpretation of data on genetic variation with regard to the relative roles of different evolutionary factors that produce and maintain genetic variation depends critically on our assumptions concerning effective population size and the level of migration between neighboring populations. In humans, recent population growth and movements of specific ethnic groups across wide geographic areas mean that any theory based on assumptions of constant population size and absence of substructure is generally untenable. We examine the effects of population subdivision on the pattern of protein genetic variation in a total sample drawn from an artificial agglomerate of 12 tribal populations of Central and South America, analyzing the pooled sample as though it were a single population. Several striking findings emerge. (1) Mean heterozygosity is not sensitive to agglomeration, but the number of different alleles (allele count) is inflated, relative to neutral mutation/drift/equilibrium expectation. (2) The inflation is most serious for rare alleles, especially those which originally occurred as tribally restricted "private" polymorphisms. (3) The degree of inflation is an increasing function of both the number of populations encompassed by the sample and of the genetic divergence among them. (4) Treating an agglomerated population as though it were a panmictic unit of long standing can lead to serious biases in estimates of mutation rates, selection pressures, and effective population sizes. Current DNA studies indicate the presence of numerous genetic variants in human populations. The findings and conclusions of this paper are all fully applicable to the study of genetic variation at the DNA level as well. PMID:3189334

  3. Diffusion mediated agglomeration of CdS nanoparticles via Langmuir–Blodgett technique

    SciTech Connect

    Das, Nayan Mani Roy, Dhrubojyoti; Gupta, P.S.

    2013-10-15

    Graphical abstract: - Highlights: • Diffusion mediated agglomeration of CdS nanoparticles are discussed. • Formation of CdS nanoparticles are confirmed by the change of chain length in XRD. • AFM shows the agglomeration of particles with a film swelling of about 5 Å. • UV–vis absorbance suggests that the grown particles show quantum confinement. • Hexagonal form of particle was confirmed by UV–vis reflectivity. - Abstract: We have reported a diffusion mediated agglomeration of cadmium sulphide (CdS) nanoparticles within cadmium arachidate (CdA{sub 2}) film matrix. The structural morphology and formation of CdS nanoparticles are characterized by X-ray diffraction (XRD), X-ray reflectivity (XRR), atomic force microscopy (AFM) and ultraviolet-visible spectroscopy techniques. X-ray diffraction (XRD) results show a change in bilayer difference from 53.04 Å to 43 Å after the sulphidation. An epitaxial growth of the films by ∼5 Å after sulphidation is confirmed from atomic force microscopy studies. The particle size calculated form UV–vis absorption edges are found to be varying from 2.6 nm to 3.3 nm for the different layers. A lateral dimension of 72–80 nm from AFM measurements and a size of 2.6–3.3 nm have confirmed one side flat pseudo two-dimensional disk-like nanoparticles. UV–vis reflectivity peak at E{sub 1} (A) confirms the formation of hexagonal CdS nanoparticles along the c-axis.

  4. Reverse micelle synthesis of oxide nanopowders: mechanisms of precipitate formation and agglomeration effects.

    PubMed

    Graeve, Olivia A; Fathi, Hoorshad; Kelly, James P; Saterlie, Michael S; Sinha, Kaustav; Rojas-George, Gabriel; Kanakala, Raghunath; Brown, David R; Lopez, Enrique A

    2013-10-01

    We present an analysis of reverse micelle stability in four model systems. The first two systems, composed of unstable microemulsions of isooctane, water, and Na-AOT with additions of either iron sulfate or yttrium nitrate, were used for the synthesis of iron oxide or yttrium oxide powders. These oxide powders were of nanocrystalline character, but with some level of agglomeration that was dependent on calcination temperature and cleaning procedures. Results show that even though the reverse micellar solutions were unstable, nanocrystalline powders with very low levels of agglomeration could be obtained. This effect can be attributed to the protective action of the surfactant on the surfaces of the powders that prevents neck formation until after all the surfactant has volatilized. A striking feature of the IR spectra collected on the iron oxide powders is the absence of peaks in the ~1715 cm(-1) to 1750 cm(-1) region, where absorption due to the symmetric C=O (carbonyl) stretching occurs. The lack of such peaks strongly suggests the carbonyl group is no longer free, but is actively participating in the surfactant-precipitate interaction. The final two microemulsion systems, containing CTAB as the surfactant, showed that loss of control of the reverse micelle synthesis process can easily occur when the amount of salt in the water domains exceeds a critical concentration. Both model systems eventually resulted in agglomerated powders of broad size distributions or particles that were large compared to the sizes of the reverse micelles, consistent with the notion that the microemulsions were not stable and the powders were precipitated in an uncontrolled fashion. This has implications for the synthesis of nanopowders by reverse micelle synthesis and provides a benchmark for process control if powders of the highest quality are desired.

  5. Microstructural evolution and macroscopic shrinkage in the presence of density gradients and agglomeration

    NASA Astrophysics Data System (ADS)

    Lu, Peizhen

    X-ray computed tomography (CT) can characterize internal density gradients. An in-situ laser dilatometry has been constructed to track dimensional change at different positions of a sample during binder removal and sintering. This combination of tools not only allows us to better understand how microscopic change affects macroscopic dimensions, but also provides guidance for a variety of ceramic processes. Non-uniform agglomerate packing and deformation provide density gradients which drive binder migration during binder removal. Simultaneously, density undergoes a slight decrease accompanied by a 1.0% loss in dimensional tolerance. This and CT difference images suggest that capillary forces generated during binder melting can change the density distribution. During sintering, nonuniformities present in the green state persist into the fired state and become exaggerated. Regions of different initial density can occupy different stages sintering. At ˜88% sintered density, CT clearly showed that open porosity follows the distribution of low density areas. Mercury porosimetry detected three distinct levels of porosity. Microstructural examination correlated the porosity level with the coordination of (i) two to three or (ii) multiple grains around pores. Microstructural packing controls both the observed macroscopic expansion at T ≤ 1000°C and the onset of shrinkage. Neck formation initiates during expansion and not exclusively during shrinkage. Inter- and intra-agglomerate expansion/shrinkage proceed simultaneously but the effective 'transmission' of particle-level behavior to the macroscopic level appears to be controlled by the initial agglomerate bonding and internal agglomerate densities. Discrete element modeling provides corroborating evidence regarding the importance of compact continuity. Following the expansion-shrinkage transition, the higher the zone density the faster the initial shrinkage. The 25% RH sample shrank more rapidly than the same zone in

  6. Nucleation, wetting and agglomeration of copper and copper-alloy thin films on metal liner surfaces

    NASA Astrophysics Data System (ADS)

    LaBarbera, Stephanie Florence

    One of the key challenges in fabricating narrower and higher aspect ratio interconnects using damascene technology has been achieving an ultra-thin (˜2 nm) and continuous Cu seed coverage on trench sidewalls. The thin seed is prone to agglomeration because of poor Cu wetting on the Ta liner. Using in-situ conductance measurements, the effect of lowering the substrate temperature during Cu seed deposition has been studied on tantalum (Ta) and ruthenium (Ru) liner surfaces. On a Ta surface, it was found that lowering the deposition temperature to --65°C increases the nucleation rate of the Cu thin film, and reduces the minimum coalescing thickness for Cu on Ta liner from ˜4.5 nm (at room temperature) to ˜2 nm. On a Ru surface, Cu coalesces at < 1 nm at room temperature, and no further reduction in initial coalescing thickness was found at low temperature. For the Cu seed deposited at --65°C on a Ta liner on trench sidewalls, extensive thermal stress-induced grain growth was observed during warming up to room temperature. No grain growth was observed in the seed layer deposited at low temperatures on a Ru liner. Small feature size and high current densities make electromigration an important concern for on-chip Cu interconnects. Cu-alloy seeds or Cu-alloy interconnects are therefore needed for future technology. The wetting angle, coalescing thickness, and agglomeration resistance of thin Cu-3% Au, Cu-3% Mn, and Cu-3% Al layers on a Ta liner surface have been studied. It was found that the alloying increases the wetting angle of Cu on Ta at high temperature, as a result of either reduction in Cu alloy surface energy, solute surface segregation, or solute-liner interactions. In addition, the Cu alloys were found to be less agglomeration resistive as compared to pure Cu; their smaller grain size, interaction with the liner surface, and tendency to oxidize were found to accelerate their agglomeration. The coalescing thickness of the Cu alloys was found to be reduced

  7. Agglomeration response of nanoparticles in magnetic fluid via monitoring of light transmission.

    PubMed

    Zou, Yun; Di, Ziyun; Chen, Xianfeng

    2011-03-10

    We systemically investigate the chain formation speed in magnetic fluid (MF) at various volume fractions, temperatures, and magnetic fields. Experiments are carried out on a water-based Fe(3)O(4) MF to investigate the agglomeration response of the nanoparticles under an applied magnetic field. The transmission of light is monitored to determine the response time undergoing a squared pulsed external magnetic field. The results reveal that enhancement of the response performance of photonic devices based on MF can be realized by properly adjusting the physical parameters, which are essential for both the physics of chain formation and practical applications.

  8. The effect of particle agglomeration on the formation of a surface-connected compartment induced by hydroxyapatite nanoparticles in human monocyte-derived macrophages☆

    PubMed Central

    Müller, Karin H.; Motskin, Michael; Philpott, Alistair J.; Routh, Alexander F.; Shanahan, Catherine M.; Duer, Melinda J.; Skepper, Jeremy N.

    2014-01-01

    Agglomeration dramatically affects many aspects of nanoparticle–cell interactions. Here we show that hydroxyapatite nanoparticles formed large agglomerates in biological medium resulting in extensive particle uptake and dose-dependent cytotoxicity in human macrophages. Particle citration and/or the addition of the dispersant Darvan 7 dramatically reduced mean agglomerate sizes, the amount of particle uptake and concomitantly cytotoxicity. More surprisingly, agglomeration governed the mode of particle uptake. Agglomerates were sequestered within an extensive, interconnected membrane labyrinth open to the extracellular space. In spite of not being truly intracellular, imaging studies suggest particle degradation occurred within this surface-connected compartment (SCC). Agglomerate dispersion prevented the SCC from forming, but did not completely inhibit nanoparticle uptake by other mechanisms. The results of this study could be relevant to understanding particle–cell interactions during developmental mineral deposition, in ectopic calcification in disease, and during application of hydroxyapatite nanoparticle vectors in biomedicine. PMID:24183166

  9. Appendix D: Use of wave scenarios to assess potential submerged oil mat (SOM) formation along the coast of Florida and Alabama

    USGS Publications Warehouse

    Dalyander, P. Soupy; Long, Joseph W.; Plant, Nathaniel G.; Thompson, David M.

    2013-01-01

    During the Deepwater Horizon oil spill, oil in the surf zone mixed with sediment in the surf zone to form heavier-than-water sediment oil agglomerates of various size, ranging from small (cm-scale) pieces (surface residual balls, SRBs) to large mats (100-m scale, surface residue mats, SR mats). Once SR mats formed in the nearshore or in the intertidal zone, they may have become buried by sand moving onshore or alongshore. To assist in locating possible sites of buried oil, wave scenarios previously developed by the U.S. Geological Survey (USGS) were used to determine the depths at which surface oil had the potential to mix with suspended sediment. For sediment to mix with floating oil and form an agglomerate of sufficient density to sink to the seafloor, either the water must be very shallow (e.g., within the swash zone) or sediment must be suspended to the water surface in sufficient concentrations to create a denser-than-sea water agglomerate. The focus of this study is to analyze suspended sediment mixing with surface oil in depths beyond the swash zone, in order to define the seaward limit of mat formation. A theoretical investigation of sediment dynamics in the nearshore zone revealed that non-breaking waves do not suspend enough sediment to the surface to form sinking sand/oil agglomerates. For this study, it was assumed that the cross-shore distribution of potential agglomerate formation is associated with the primary breaker line, and the presence of plunging breakers, over the time frame of oiling. The potential locations of submerged oil mats (SOMs) are sites where (1) possible agglomerate formation occurred, where (2) sediment accreted post-oiling and buried the SOM, and where (3) the bathymetry has not subsequently eroded to re-expose any mat that may have formed at that site. To facilitate identification of these locations, the range of water level variation over the time frame of oiling was also prescribed, which combined with the wave-breaking depth

  10. Water-extractable and water-unextractable arabinoxylans affect gluten agglomeration behavior during wheat flour gluten-starch separation.

    PubMed

    Frederix, Sofie A; Van Hoeymissen, Klaartje E; Courtin, Christophe M; Delcour, Jan A

    2004-12-29

    Water-extractable arabinoxylan (WE-AX) of variable molecular weight (MW) and water-unextractable arabinoxylan (WU-AX) were added to wheat flour to study their effect on gluten agglomeration in a dough and batter gluten-starch separation process with recovery of gluten from the batter with a set of vibrating sieves (400, 250, and 125 microm). Low MW WE-AX had almost no impact on the distribution of the gluten on the different sieves. High MW WE-AX decreased yields of the largest (400 microm sieve) gluten aggregates, more than their medium MW counterparts, indicating the importance of AX MW for their effect on gluten interactions. Correlations between the total level of gluten protein recovered on the three sieves and the batter extract viscosity as well as between the proportion of gluten protein recovered on the 400 microm sieve to that on the three sieves and the batter extract viscosity pointed to the importance of viscosity as an indicator for gluten agglomeration, as did the fact that another viscosity increasing plant polysaccharide (guar gum) also negatively influenced gluten agglomeration. However, the obtained data cannot rule out that AX and guar gum also exert steric effects on gluten agglomeration. WU-AX, present as discrete cell wall fragments, had a negative impact on the level of large gluten aggregates. Taken together, the results show that both native WE-AX and WU-AX detrimentally impact gluten agglomeration.

  11. Physical simulation of precipitation of radioactive element oxalates by using the harmless neodymium oxalate for studying the agglomeration phenomena

    NASA Astrophysics Data System (ADS)

    Lalleman, Sophie; Bertrand, Murielle; Plasari, Edouard

    2012-03-01

    Oxalic precipitation is usually applied in nuclear industry to process radioactive wastes or to recover actinides from a multicomponent solution. This paper deals with the development of methods adapted to a nuclear environment in order to study the agglomeration phenomena during actinide oxalic precipitation. These methods are previously setup with harmless elements that simulate the actinide behaviour: the lanthanides. A parametric study is carried out to quantify the influence of operating parameters on the agglomeration kernel and to determine a kinetic law for this mechanism. The experimental study is performed in a continuous-MSMPR precipitator at steady-state. The method is based on the resolution of two population balances using the moment approach, one for elementary crystals and the other for agglomerates. Provided that the kinetic rates of nucleation and growth are known, the agglomeration kernel can be obtained from a mathematical treatment of the experimental particle size distributions. Results point out that experimental crystal sizes are consistent with an independent kernel. It appears that the agglomeration kernel is directly proportional to supersaturation, increases with temperature but is limited by ionic strength and shear rate.

  12. Effects of temperature and pressure on asphaltene particle size distributions in crude oils diluted with n-pentane

    SciTech Connect

    Nielsen, B.B.; Svrcek, W.Y.; Mehrotra, A.K. . Dept. of Chemical and Petroleum Engineering)

    1994-05-01

    The effects of temperature (0--150 C) and pressure (0--5.6 MPa) on the size distribution of asphaltene particles (or agglomerates), formed as a result of diluting the crude oils with n-pentane, were studied using a modified laser particle analyzer. Four crude oils, ranging from an asphaltic condensate to a heavy oil-sand bitumen, were tested in this investigation. The average size of asphaltene agglomerates ranged from 266 to 495 Am. The results suggest that the mean asphaltene particle size increases with pressure and decreases slightly with temperature; however, no trends were evident with the molar mass of crude oils. Although the particle size distributions in most cases were unimodal and described adequately by the log-normal distribution function, bimodal distributions were also identified in certain cases.

  13. Oil Spill!

    ERIC Educational Resources Information Center

    Ansberry, Karen Rohrich; Morgan, Emily

    2005-01-01

    An oil spill occurs somewhere in the world almost every day of the year, and the consequences can be devastating. In this month's column, students explore the effects of oil spills on plants, animals, and the environment and investigate oil spill clean-up methods through a simulated oil spill. The activities described in this article give students…

  14. Study of ink paper sensor based on aluminum/carbon nanotubes agglomerated nanocomposites.

    PubMed

    dos Reis, Marcos A L; Saraiva, Augusto F; Vieira, Manuel F G; Del Nero, Jordan

    2012-09-01

    Agglomerated nanocomposites based on Aluminum/Carbon Nanotubes (AI/CNT) were produced by an arc discharge technique under argon/acetone atmosphere and ultrasonically dispersed in distilled water to form an ink-like composite. This ink was spread onto commercial paper to produce a conductive thick film. Experimental results show that the electrical resistance of Al/CNT nanocomposite on paper changes when a mechanical stress and/or heat is applied. The multi-sensory properties obtained are the following: (i) piezoresistive effect, electrical resistance shows linear dependence with pressure intensity at room temperature; (ii) polynomial relationship between electrical resistance and temperature; and (iii) high accuracy thermal sensor compared to a K type thermocouple at 25 degrees C. The nanocomposite and paper morphology was analyzed by Scanning Electron Microscopy with Energy Dispersive Spectrometry (SEM/EDS) and a favorable surface for physisorption was observed. Transmission Electron Microscopy (TEM) was utilized for Al/CNT agglomerated indicating that the ink paper based on nanocomposite shows good performance as a thermo-piezoresistive sensor.

  15. Application of acoustic agglomeration to reduce fine particle emissions from coal combustion plants

    SciTech Connect

    Gallego-Juarez, J.A.; Riera-Franco De Sarabia, E.; Rodriguez-Corral, G.

    1999-11-01

    Removal of fine particles (smaller than 2.5 {micro}m) from industrial flue gases is, at present, one of the most important problems in air pollution abatement. These particles which are hazardous because of their ability to penetrate deeply into the lungs, are difficult to remove by conventional separation technology. Sonic energy offers a means to solve this problem. The application of a high-intensity acoustic field to an aerosol induces agglomeration processes which changes the size distribution in favor of larger particles, which are then easier to precipitate with a conventional separator. In this work, the authors present a semiindustrial pilot plant in which this process is applied for reduction of particle emissions in coal combustion fumes. This installation basically consists of an acoustic agglomeration chamber with a rectangular cross-section, driven by four high-power and highly directional acoustic transducers of 10 and/or 20 kHz, and an electrostatic precipitator (ESP). In the experiments, a fluidized bed coal combustor was used as fume generator, and a sophisticated air sampling station was set up to carry out measurements with fume flow rates up to about 2,000 m{sup 3}/h, gas temperatures of about 150 C, and mass concentrations in the range 1--5 g/m{sup 3}. The fine particle reduction produced by the acoustic filter was about 40% of the number concentration.

  16. An accelerated stochastic vortex structure method for particle collision and agglomeration in homogeneous turbulence

    NASA Astrophysics Data System (ADS)

    Dizaji, Farzad F.; Marshall, Jeffrey S.

    2016-11-01

    Modeling the response of interacting particles, droplets, or bubbles to subgrid-scale fluctuations in turbulent flows is a long-standing challenge in multiphase flow simulations using the Reynolds-Averaged Navier-Stokes approach. The problem also arises for large-eddy simulation for sufficiently small values of the Kolmogorov-scale particle Stokes number. This paper expands on a recently proposed stochastic vortex structure (SVS) method for modeling of turbulence fluctuations for colliding or otherwise interacting particles. An accelerated version of the SVS method was developed using the fast multipole expansion and local Taylor expansion approach, which reduces computation speed by two orders of magnitude compared to the original SVS method. Detailed comparisons are presented showing close agreement of the energy spectrum and probability density functions of various fields between the SVS computational model, direct numerical simulation (DNS) results, and various theoretical and experimental results found in the literature. Results of the SVS method for particle collision rate and related measures of particle interaction exhibit excellent agreement with DNS predictions for homogeneous turbulent flows. The SVS method was also used with adhesive particles to simulate formation of particle agglomerates with different values of the particle Stokes and adhesion numbers, and various measures of the agglomerate structure are compared to the DNS results.

  17. Environmental influence of Wuhan urban agglomeration development and strategies of environmental protection.

    PubMed

    Gao, Qun; Liu, Ying-Tao; Mao, Han-Ying

    2006-01-01

    In Wuhan urban agglomeration (WUA), the population growth and concentration, the industrial development and urban sprawl have been affecting the environment fundamentally. Comparing with Yangtze delta metropolitan region, the level of urbanization and industrialization of WUA has lagged behind for about 10 years; but the problems in environmental protection and rehabilitation are commonly serious. In the future, WUA should avoid unnecessary mistakes and seek a win-win strategy for economy and environment in its large-scale development stage. Based on the analysis of the changing of main environmental pollutants and the coupled curves in past decades, the paper discussed the important links among the urban environmental pollutions, industry growth and urban sprawl in WUA. It is concluded that the integration of economic and environmental policies in urban development is more required and significant at the large urban agglomeration region. Four proactive and long-term strategies need to be adopted to provide prior guidance and better protection for the development of WUA.

  18. A micromanipulation particle tester for agglomeration contact mechanism studies in a controlled environment

    NASA Astrophysics Data System (ADS)

    Haider, C. I.; Althaus, T.; Niederreiter, G.; Hounslow, M. J.; Palzer, S.; Salman, A. D.

    2012-10-01

    Pressure agglomeration of powders is widely applied in various industries and an increasing interest lies in the identification and description of contact mechanisms between particles, which are responsible for the compaction product properties. In this paper, the design and development of a novel micromanipulation particle tester (MPT) is presented. This device makes it possible to measure the deformation kinetics and resulting adhesion of two individual particles in contact under load, which are strongly influenced by the applied process conditions. The MPT set-up is, therefore, designed to offer a unique control over the process conditions most relevant to the compaction of powders: external stress, dwell or holding time at constant deformation, compression velocity as well as relative humidity and temperature determining the physical state and mechanical characteristics of hygrosensitive amorphous particles. The latter are often part of powder formulations, e.g. in the food industry, and have been used for force and contact-zone development studies with the MPT. The experimental results on the microscale level will deliver valuable quantitative information for an improved tailoring of pressure agglomeration process conditions of bulk solids.

  19. Sonic enhanced ash agglomeration and sulfur capture: Quarterly report, October--December 1994

    SciTech Connect

    1995-01-01

    The major objective of the Phase 1 test program is to confirm the feasibility of the MTCI bimodal particle size approach to enhance particulate control by acoustic ash agglomeration. An ancillary objective of the Phase 1 effort is to demonstrate and confirm the feasibility of an acoustic field to enhance sulfur capture by increasing sorbent reactivity. The program will demonstrate the effectiveness of a unique approach which uses a bimodal distribution composed of large sorbent particles and fine fly ash particles to enhance ash agglomeration and sulfur capture at conditions found in direct coal-fired turbines. The work will extend the concept from the demonstration of feasibility (Phase 1), through proof-of-concept (Phase 2) to the construction (Phase 3) of a coal-fired pulsed combustor with in-furnace sorbent injection. In view of the potentially large repowering market in the US, several possible configurations were formulated and evaluated for application to the repowering market. Based on discussions between the DOE/METC team members and MTCI staff; seven different configuration were proposed for further evaluation. The technical and market issues associated with each of these configurations were identified and summarized. An initial system simulation test for the system operating at inlet air temperatures of 700--800 F as for a gas turbine application was conducted, indicating that acoustic performance can be further improved by modifying gas injectors. Development of the advanced vortex aerovalve continued.

  20. Calcium Oxalate Stone Agglomeration Inhibition [tm] Reflects Renal Stone-Forming Activity.

    PubMed

    Lindberg, J S; Cole, F E; Romani, W; Husserl, F E; Fuselier, H A; Kok, D J; Erwin, D T

    2000-04-01

    Louisiana and other Gulf South states comprise a "Stone Belt" where calcium oxalate stone formers (CaOx SFs) are found at a high rate of approximately 5%. In these patients, the agglomeration of small stone crystals, which are visible in nearly all morning urine collections, forms stones that can become trapped in the renal parenchyma and the renal pelvis. Without therapy, about half of CaOx SFs repeatedly form kidney stones, which can cause excruciating pain that can be relieved by passage, fragmentation (lithotripsy), or surgical removal. The absence of stones in "normal" patients suggests that there are stone inhibitors in "normal" urines.At the Ochsner Renal Stone Clinic, 24-hour urine samples are collected by the patient and sent to the Ochsner Renal Stone Research Program where calcium oxalate stone agglomeration inhibition [tm] measurements are performed. Urine from healthy subjects and inactive stone formers has demonstrated strongly inhibited stone growth [tm] in contrast to urine from recurrent CaOx SFs. [tm] data from 1500 visits of 700 kidney stone patients have been used to evaluate the risk of recurrence in Ochsner's CaOx SF patients. These data have also been used to demonstrate the interactive roles of certain identified urinary stone-growth inhibitors, citrate and Tamm-Horsfall protein (THP), which can be manipulated with medication to diminish recurrent stone formation. Our goal is to offer patients both financial and pain relief by reducing their stones with optimized medication, using medical management to avoid costly treatments.

  1. Nano-sized Mn oxide/agglomerated silsesquioxane composite as a good catalyst for water oxidation.

    PubMed

    Najafpour, Mohammad Mahdi; Madadkhani, Sepideh

    2016-12-01

    Water splitting to hydrogen and oxygen is an important reaction to store sustainable energies, and water oxidation is identified as the bottleneck for water splitting because it requires the high activation energy to perform. Herein a nano-sized Mn oxide/agglomerated silsesquioxane composite was used to synthesize an efficient catalyst for water oxidation. The composite was synthesized by a straightforward and simple procedure and characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, dynamic light scattering, X-ray diffraction spectrometry, and electrochemical methods. Silsesquioxane causes good dispersion of Mn in the composite. The water-oxidizing activity of this composite was studied in the presence of cerium(IV) ammonium nitrate. The composite at the best calcination temperature (300 °C) shows a turnover frequency 0.3 (mmol O2/mol Mn.s). Regarding the low-cost, environmentally friendly precursors, simple synthesis, and efficiency for water oxidation, the composite is a promising catalyst that can be used in artificial photosynthetic systems for water splitting. We used Agglomerated silsesquioxane as a support for nano-sized Mn oxide to synthesize a good water-oxidizing catalyst.

  2. The role of nanoparticulate agglomerates in TiO2 photocatalysis: degradation of oxalic acid

    NASA Astrophysics Data System (ADS)

    Ivanova, Irina; Mendive, Cecilia B.; Bahnemann, Detlef

    2016-07-01

    The simultaneous bimodal study of the photocatalytic oxalic acid degradation by aqueous TiO2 suspensions revealed that particular systems possess the capacity to protect a certain amount of oxalic acid from oxidation, thus hindering, to some extent, the photocatalytic reaction. While measurements of the oxalic acid concentration in the bulk liquid phase indicated full photocatalytic degradation; in situ pH-stat measurements allowed the quantification of the amount of oxalic acid remaining in the part of the nanoparticulate agglomerates where light could apparently not access. An explanation for this phenomenon takes into account the possibility of the formation of TiO2 agglomerates in which these molecules are hidden from the effect of the light, thus being protected from photocatalytic degradation. Studies of different TiO2 materials with different particle sizes allowed a deeper exploration of this phenomenon. In addition, because this property of encapsulating pollutant molecules by photocatalytic systems is found to be a reversible phenomenon, P25 appears to be more convenient and advantageous as compared to the use of large surface area photocatalysts.

  3. Agglomeration multigrid methods with implicit Runge-Kutta smoothers applied to aerodynamic simulations on unstructured grids

    NASA Astrophysics Data System (ADS)

    Langer, Stefan

    2014-11-01

    For unstructured finite volume methods an agglomeration multigrid with an implicit multistage Runge-Kutta method as a smoother is developed for solving the compressible Reynolds averaged Navier-Stokes (RANS) equations. The implicit Runge-Kutta method is interpreted as a preconditioned explicit Runge-Kutta method. The construction of the preconditioner is based on an approximate derivative. The linear systems are solved approximately with a symmetric Gauss-Seidel method. To significantly improve this solution method grid anisotropy is treated within the Gauss-Seidel iteration in such a way that the strong couplings in the linear system are resolved by tridiagonal systems constructed along these directions of strong coupling. The agglomeration strategy is adapted to this procedure by taking into account exactly these anisotropies in such a way that a directional coarsening is applied along these directions of strong coupling. Turbulence effects are included by a Spalart-Allmaras model, and the additional transport-type equation is approximately solved in a loosely coupled manner with the same method. For two-dimensional and three-dimensional numerical examples and a variety of differently generated meshes we show the wide range of applicability of the solution method. Finally, we exploit the GMRES method to determine approximate spectral information of the linearized RANS equations. This approximate spectral information is used to discuss and compare characteristics of multistage Runge-Kutta methods.

  4. Unraveling the Agglomeration Mechanism in Charged Block Copolymer and Surfactant Complexes

    DOE PAGES

    Borreguero, Jose M.; Pincus, Philip A.; Sumpter, Bobby G.; ...

    2017-01-27

    Here, we report a molecular dynamics simulation investigation of self-assembly and complex formation of charged-neutral double hydrophilic and hydrophobic-hydrophilic block copolymers (BCP) with oppositely charged surfactants. Furthermore, the structure of the surfactant micelles and the BCP aggregation on the micelle surface is systematically studied for five different BCP volume fractions that also mimics a reduction of the surfactant concentration. The local electrostatic interactions between the oppositely charged species encourage the formation of core-shell structures between the surfactant micelles where the surfactants form the cores and the charged blocks of the BCP form the corona. The emergent morphologies of these aggregatesmore » are contingent upon the nature of the BCP neutral blocks. The hydrophilic neutral blocks agglomerate with the micelles as hairy colloidal structures while the hydrophobic neutrals agglomerate in lamellar structures with the surfactant micelles. The distribution of counterion charges along the simulation box show a close-to-normal density distribution for the hydrophilic neutral blocks and a binodal distribution for hydrophobic neutral blocks. No specific surfactant concentration dependent scaling relation is observed as opposed to the simpler case of homo-polyelectrolytes.« less

  5. All About Oils

    MedlinePlus

    ... corn oil, cottonseed oil, olive oil, safflower oil, soybean oil, and sunflower oil. Some oils are used ... such as canola, corn, cottonseed, olive, peanut, safflower, soybean, and sunflower) 1 Tbsp 3 tsp/14 g ...

  6. Development of a fluidized bed agglomeration modeling methodology to include particle-level heterogeneities in ash chemistry and granular physics

    NASA Astrophysics Data System (ADS)

    Khadilkar, Aditi B.

    The utility of fluidized bed reactors for combustion and gasification can be enhanced if operational issues such as agglomeration are mitigated. The monetary and efficiency losses could be avoided through a mechanistic understanding of the agglomeration process and prediction of operational conditions that promote agglomeration. Pilot-scale experimentation prior to operation for each specific condition can be cumbersome and expensive. So the development of a mathematical model would aid predictions. With this motivation, the study comprised of the following model development stages- 1) development of an agglomeration modeling methodology based on binary particle collisions, 2) study of heterogeneities in ash chemical composition and gaseous atmosphere, 3) computation of a distribution of particle collision frequencies based on granular physics for a poly-disperse particle size distribution, 4) combining the ash chemistry and granular physics inputs to obtain agglomerate growth probabilities and 5) validation of the modeling methodology. The modeling methodology comprised of testing every binary particle collision in the system for sticking, based on the extent of dissipation of the particles' kinetic energy through viscous dissipation by slag-liquid (molten ash) covering the particles. In the modeling methodology developed in this study, thermodynamic equilibrium calculations are used to estimate the amount of slag-liquid in the system, and the changes in particle collision frequencies are accounted for by continuously tracking the number density of the various particle sizes. In this study, the heterogeneities in chemical composition of fuel ash were studied by separating the bulk fuel into particle classes that are rich in specific minerals. FactSage simulations were performed on two bituminous coals and an anthracite to understand the effect of particle-level heterogeneities on agglomeration. The mineral matter behavior of these constituent classes was studied

  7. Megacities and large urban agglomerations in the coastal zone: interactions between atmosphere, land, and marine ecosystems.

    PubMed

    von Glasow, Roland; Jickells, Tim D; Baklanov, Alexander; Carmichael, Gregory R; Church, Tom M; Gallardo, Laura; Hughes, Claire; Kanakidou, Maria; Liss, Peter S; Mee, Laurence; Raine, Robin; Ramachandran, Purvaja; Ramesh, R; Sundseth, Kyrre; Tsunogai, Urumu; Uematsu, Mitsuo; Zhu, Tong

    2013-02-01

    Megacities are not only important drivers for socio-economic development but also sources of environmental challenges. Many megacities and large urban agglomerations are located in the coastal zone where land, atmosphere, and ocean meet, posing multiple environmental challenges which we consider here. The atmospheric flow around megacities is complicated by urban heat island effects and topographic flows and sea breezes and influences air pollution and human health. The outflow of polluted air over the ocean perturbs biogeochemical processes. Contaminant inputs can damage downstream coastal zone ecosystem function and resources including fisheries, induce harmful algal blooms and feedback to the atmosphere via marine emissions. The scale of influence of megacities in the coastal zone is hundreds to thousands of kilometers in the atmosphere and tens to hundreds of kilometers in the ocean. We list research needs to further our understanding of coastal megacities with the ultimate aim to improve their environmental management.

  8. Agglomeration, isolation and dissolution of commercially manufactured silver nanoparticles in aqueous environments

    NASA Astrophysics Data System (ADS)

    Elzey, Sherrie; Grassian, Vicki H.

    2010-06-01

    The increasing use of manufactured nanoparticles ensures these materials will make their way into the environment. Silver nanoparticles in particular, due to use in a wide range of applications, have the potential to get into water systems, e.g., drinking water systems, ground water systems, estuaries, and/or lakes. One important question is what is the chemical and physical state of these nanoparticles in water? Are they present as isolated particles, agglomerates or dissolved ions, as this will dictate their fate and transport. Furthermore, does the chemical and physical state of the nanoparticles change as a function of size or differ from micron-sized particles of similar composition? In this study, an electrospray atomizer coupled to a scanning mobility particle sizer (ES-SMPS) is used to investigate the state of silver nanoparticles in water and aqueous nitric acid environments. Over the range of pH values investigated, 0.5-6.5, silver nanoparticles with a bimodal primary particle size distribution with the most intense peak at 5.0 ± 7.4 nm, as determined from transmission electron microscopy (TEM), show distinct size distributions indicating agglomeration between pH 6.5 and 3 and isolated nanoparticles at pH values from 2.5 to 1. At the lowest pH investigated, pH 0.5, there are no peaks detected by the SMPS, indicating complete nanoparticle dissolution. Further analysis of the solution shows dissolved Ag ions at a pH of 0.5. Interestingly, silver nanoparticle dissolution shows size dependent behavior as larger, micron-sized silver particles show no dissolution at this pH. Environmental implications of these results are discussed.

  9. Coconut Oil

    MedlinePlus

    ... oil comes from the nut (fruit) of the coconut palm. The oil of the nut is used to ... Gras de Noix de Coco, Coconut Fatty Acid, Coconut Palm, Coco Palm, Coconut, Cocos nucifera, Cocotier, Cold Pressed ...

  10. SYNTHETIC OIL,

    DTIC Science & Technology

    The patent concerns a dicarboxylate-base synthetic oil with antiwear and antioxidation additives. The oil is prepared from the esterification of 2- or 3-methylcyclohexanol and 2-ethylhexanol with adipic acid. (Author)

  11. Petroleum Oils

    EPA Pesticide Factsheets

    Different types of crude oil and refined product, of all different chemical compositions, have distinct physical properties. These properties affect the way oil spreads and breaks down, its hazard to marine and human life, and the likelihood of threat.

  12. Steric stabilization of nonaqueous silicon slips. I - Control of particle agglomeration and packing. II - Pressure casting of powder compacts

    NASA Technical Reports Server (NTRS)

    Kerkar, Awdhoot V.; Henderson, Robert J. M.; Feke, Donald L.

    1990-01-01

    The application of steric stabilization to control particle agglomeration and packing of silicon powder in benzene and trichloroethylene is reported. The results provide useful guidelines for controlling unfavorable particle-particle interactions during nonaqueous processing of silicon-based ceramic materials. The application of steric stabilization to the control and improvement of green processing of nonaqueous silicon slips in pressure consolidation is also demonstrated.

  13. THE PHYSICS OF PROTOPLANETESIMAL DUST AGGLOMERATES. VI. EROSION OF LARGE AGGREGATES AS A SOURCE OF MICROMETER-SIZED PARTICLES

    SciTech Connect

    Schraepler, Rainer; Blum, Juergen

    2011-06-20

    Observed protoplanetary disks consist of a large amount of micrometer-sized particles. Dullemond and Dominik pointed out for the first time the difficulty in explaining the strong mid-infrared excess of classical T Tauri stars without any dust-retention mechanisms. Because high relative velocities in between micrometer-sized and macroscopic particles exist in protoplanetary disks, we present experimental results on the erosion of macroscopic agglomerates consisting of micrometer-sized spherical particles via the impact of micrometer-sized particles. We find that after an initial phase, in which an impacting particle erodes up to 10 particles of an agglomerate, the impacting particles compress the agglomerate's surface, which partly passivates the agglomerates against erosion. Due to this effect, the erosion halts for impact velocities up to {approx}30 m s{sup -1} within our error bars. For higher velocities, the erosion is reduced by an order of magnitude. This outcome is explained and confirmed by a numerical model. In a next step, we build an analytical disk model and implement the experimentally found erosive effect. The model shows that erosion is a strong source of micrometer-sized particles in a protoplanetary disk. Finally, we use the stationary solution of this model to explain the amount of micrometer-sized particles in the observational infrared data of Furlan et al.

  14. World Urbanization Prospects: The 1994 Revision. Estimates and Projections of Urban and Rural Populations and of Urban Agglomerations.

    ERIC Educational Resources Information Center

    United Nations New York, NY. Dept. of Economic and Social Information and Policy Analysis.

    This publication presents data from the current revision of estimates and projections of the size and growth of urban and rural populations for all countries of the world. The publication also contains revised estimates and projections for all urban agglomerations of at least 750,000 inhabitants in 1994. The revisions are part of a series of…

  15. World Urbanization Prospects: The 1992 Revision. Estimates and Projections of Urban and Rural Populations and of Urban Agglomerations.

    ERIC Educational Resources Information Center

    United Nations New York, NY. Dept. of Economic and Social Information and Policy Analysis.

    This United Nation's publication presents data on the size and growth of urban and rural populations for all countries of the world and contains revised estimates and projections for all urban agglomerations that had at least one million inhabitants in 1990. Chapter 1 presents levels of urbanization and future trends for urban and rural…

  16. [Sonic Enhanced Ash Agglomeration and Sulfur Capture]. [Quarterly technical progress report, September 27, 1993--January 2, 1994

    SciTech Connect

    Not Available

    1993-12-31

    A major concern with the utilization of coal in directly fired gas turbines is the control of particulate emissions and reduction of sulfur dioxide, and alkali vapor from combustion of coal, upstream of the gas turbine. The Sonic Enhanced Ash Agglomeration and Sulfur Capture program focuses upon the application of an MTCI proprietary invention (Patent No. 5,197,399) for simultaneously enhancing sulfur capture and particulate agglomeration of the combustor effluent. This application can be adapted as either a ``hot flue gas cleanup`` subsystem for the current concepts for combustor islands or as an alternative primary pulse combustor island in which slagging, sulfur capture, particulate agglomeration and control, and alkali gettering as well as NO{sub x} control processes become an integral part of the pulse combustion process. The goal of the program is to support the DOE mission in developing coal-fired combustion gas turbines. In particular, the MTCI proprietary process for bimodal ash agglomeration and simultaneous sulfur capture will be evaluated and developed. The technology embodiment of the invention provides for the use of standard grind, moderately beneficiated coal and WEM for firing the gas turbine with efficient sulfur capture and particulate emission control upstream of the turbine. The process also accommodates injection of alkali gettering material if necessary. This is aimed at utilization of relatively inexpensive coal fuels, thus realizing the primary benefit being sought by direct firing of coal in such gas turbine systems.

  17. Mineral oils

    NASA Technical Reports Server (NTRS)

    Furby, N. W.

    1973-01-01

    The characteristics of lubricants made from mineral oils are discussed. Types and compositions of base stocks are reviewed and the product demands and compositions of typical products are outlined. Processes for commercial production of mineral oils are examined. Tables of data are included to show examples of product types and requirements. A chemical analysis of three types of mineral oils is reported.

  18. Research approach and first results on agglomerate compaction in protoplanetary dust simulation in the Cloud Manipulation System

    NASA Astrophysics Data System (ADS)

    Vedernikov, Andrei; Blum, Jurgen; Ingo Von Borstel, Olaf; Schraepler, Rainer; Balapanov, Daniyar; Cecere, Anselmo

    2016-07-01

    Nanometre and micrometre-sized solid particles are ubiquitous in space and on Earth - from galaxies, interstellar space, protoplanetary and debris disks to planetary rings and atmospheres, planetary surfaces, comets, interplanetary space, Earth's atmosphere. Apparently, the most intriguing problem in the picture of the formation of planets is the transition from individual microscopic dust grains to kilometre-sized planetesimals. Revealing the mechanisms of this transition is one of the main tasks of the European Space Agency's project Interaction in Cosmic and Atmospheric Particle Systems (ICAPS). It was found that Brownian motion driven agglomeration could not provide the transition within reasonable time scale. As a result, at this stage top scientific goals shifted towards forced agglomeration and concentration of particles, targeting revealing the onset of compaction, experimental study of the evolution of fractal dimensions, size and mass distribution, occurrence of bouncing. The main tasks comprise 1) development of the rapid agglomeration model 2) development of the experimental facilities creating big fractal-type agglomerates from 10 to 1000 μm from a cloud of micrometre-size grains; 3) experimental realization of the rapid agglomeration in microgravity and ground conditions; and 4) in situ investigation of the morphology, mobility, mechanical and optical properties of the free-floating agglomerates, including investigation of thermophoresis, photophoresis of the agglomerates and of the two-phase flow phenomena. To solve the experimental part of the tasks we developed a Cloud Manipulation System, realized as a breadboard (CMS BB) for long duration microgravity platforms and a simplified laboratory version (CMS LV) mostly oriented on short duration microgravity and ground tests. The new system is based on the use of thermophoresis, most favourable for cloud manipulation without creating additional particle-particle forces in the cloud with a possibility

  19. Computational imaging analysis of fibrin matrices with the inclusion of erythrocytes from homozygous SS blood reveals agglomerated and amorphous structures.

    PubMed

    Averett, Rodney D; Norton, David G; Fan, Natalie K; Platt, Manu O

    2017-01-01

    Sickle cell disease is a single point mutation disease that is known to alter the coagulation system, leading to hypercoagulable plasma conditions. These hypercoagulable conditions can lead to complications in the vasculature, caused by fibrin clots that form undesirably. There is a need to understand the morphology and structure of fibrin clots from patients with sickle cell disease, as this could lead to further discovery of treatments and life-saving therapies. In this work, a computational imaging analysis method is presented to evaluate fibrin agglomeration in the presence of erythrocytes (RBCs) homozygous for the sickle cell mutation (SS). Numerical algorithms were used to determine agglomeration of fibrin fibers within a matrix with SS RBCs to test the hypothesis that fibrin matrices with the inclusion of SS RBCs possess a more agglomerated structure than native fibrin matrices with AA RBCs. The numerical results showed that fibrin structures with SS RBCs displayed an overall higher degree of agglomeration as compared to native fibrin structures. The computational algorithm was also used to evaluate fibrin fiber overlap (aggregation) and anisotropy (orientation) in normal fibrin matrices compared to fibrin matrices polymerized around SS RBCs; however, there was no statistical difference. Ultrasound measurements of stiffness revealed rigid RBCs in the case of samples derived from homozygous SS blood, and densely evolving matrices, when compared to normal fibrin with the inclusion of AA RBCs. An agglomeration model is suggested to quantify the fibrin aggregation/clustering near RBCs for both normal fibrin matrices and for the altered structures. The results of this work are important in the sense that the understanding of aggregation and morphology in fibrin clots with incorporation of RBCs from persons living with sickle cell anemia may elucidate the complexities of comorbidities and other disease complications.

  20. Surfactant protein A (SP-A) inhibits agglomeration and macrophage uptake of toxic amine modified nanoparticles

    PubMed Central

    McKenzie, Zofi; Kendall, Michaela; Mackay, Rose-Marie; Whitwell, Harry; Elgy, Christine; Ding, Ping; Mahajan, Sumeet; Morgan, Cliff; Griffiths, Mark; Clark, Howard; Madsen, Jens

    2015-01-01

    Abstract The lung provides the main route for nanomaterial exposure. Surfactant protein A (SP-A) is an important respiratory innate immune molecule with the ability to bind or opsonise pathogens to enhance phagocytic removal from the airways. We hypothesised that SP-A, like surfactant protein D, may interact with inhaled nanoparticulates, and that this interaction will be affected by nanoparticle (NP) surface characteristics. In this study, we characterise the interaction of SP-A with unmodified (U-PS) and amine-modified (A-PS) polystyrene particles of varying size and zeta potential using dynamic light scatter analysis. SP-A associated with both 100 nm U-PS and A-PS in a calcium-independent manner. SP-A induced significant calcium-dependent agglomeration of 100 nm U-PS NPs but resulted in calcium-independent inhibition of A-PS self agglomeration. SP-A enhanced uptake of 100 nm U-PS into macrophage-like RAW264.7 cells in a dose-dependent manner but in contrast inhibited A-PS uptake. Reduced association of A-PS particles in RAW264.7 cells following pre-incubation of SP-A was also observed with coherent anti-Stokes Raman spectroscopy. Consistent with these findings, alveolar macrophages (AMs) from SP-A−/− mice were more efficient at uptake of 100 nm A-PS compared with wild type C57Bl/6 macrophages. No difference in uptake was observed with 500 nm U-PS or A-PS particles. Pre-incubation with SP-A resulted in a significant decrease in uptake of 100 nm A-PS in macrophages isolated from both groups of mice. In contrast, increased uptake by AMs of U-PS was observed after pre-incubation with SP-A. Thus we have demonstrated that SP-A promotes uptake of non-toxic U-PS particles but inhibits the clearance of potentially toxic A-PS particles by blocking uptake into macrophages. PMID:25676620

  1. A variational approach to environmental and climatic problems of urban agglomerations

    NASA Astrophysics Data System (ADS)

    Penenko, V. V.; Tsvetova, E. A.

    2016-11-01

    We discuss some aspects of the development of a variational approach to study the dynamics of climatic and ecological systems under intensive actions of natural and anthropogenic origin. The variational principle essentially represents a versatile tool to create a consistent modeling technology based on models of processes coupled with available observational data. The basic entities included in the formulation of the variational principle are models of processes; data and models of observations; target criteria for forecasting; a priori information about all the required elements of the system. We develop a set of mathematical models combined within the framework of the variational principle. They describe the dynamics of the atmosphere and water bodies in conjunction with a thermally and dynamically heterogeneous surface of the Earth; the hydrological cycle, moisture in the atmosphere and the soil; radiation transfer in the system of the atmosphere and the underlying surface; and transport and transformation of various substances in gaseous and aerosol states in the atmosphere. As an example, we demonstrate the results of calculations performed with a set of numerical models adapted to the conditions of a Novosibirsk city agglomeration. The results of scenario calculations on the formation of mesoclimates and quality of the atmosphere for the typical conditions of Siberian cities are presented.

  2. Elasticity and electrical properties of porous bodies described as an agglomerate-of-spheres

    NASA Astrophysics Data System (ADS)

    Höpfinger, H.; Winsel, A.

    The phenomenological characterization of a sintered, pressed or electrolytically produced porous body as an 'agglomerate-of-spheres' (AOS), estimated by the properties of their connections — the so-called necks—, was used to predict its break-force, elasticity and resistance. To this, the previous theoretical description of the AOS could be expanded by the definition of an ideal AOS. Furthermore, it could be shown, that the behaviour of the AOS is re-inforced by the relation of the radii of the sphere and neck. The description of the mechanical properties correlates well in the case of elasticity and breaktension with data of experiments at the University of Kassel with PbO 2-electrodes. The theoretically predicted values of the electrical properties are about a hundred times smaller than the experimental ones. This may be caused by the material-specific circuit capacity used for the PbO 2, since there are no data concerning the stoichiometric variance of the oxygen phase width in the neck region. An attempt to approach to real electrodes is only a trial, which, for the first time, takes experimental data into consideration. The lack of dependable material-specific sizes of lead dioxide is still the greatest inaccuracy in comparison with experimental data.

  3. An agglomeration induced glassy magnetic state in a carbon nanotube/NiO nanocomposite system.

    PubMed

    Chattopadhyay, S; Jana, S; Giri, S; Majumdar, S

    2012-10-31

    A series of nanocomposite materials were synthesized using multi-walled carbon nanotubes (MWCNTs) and NiO nanoparticles by varying the concentration of NiO in the MWCNT host matrix. Such an increment in the NiO particle density actually tunes the degree of isolation among the magnetic nanoparticles. Careful investigation by transmission electron microscopy shows that particle agglomeration increases substantially with NiO particle density. Field dependence of magnetization measurements depict a gradual enhancement of coercivity with increasing NiO concentration, signifying the enhancement of magnetic anisotropy in this nanocomposite system. Furthermore, field cooled and zero field cooled memory effect as well as magnetization relaxation measurements show that a glassy magnetic state gradually develops when the concentration increases. Analysis based on the result of high resolution transmission electron microscopy along with the magnetization data reveals that interparticle magnetic exchange interaction in the presence of interfacial disorders plays the major role in the emergence of the glassy magnetic state in this nanocomposite system.

  4. Gold, silver, and palladium nanoparticle/nano-agglomerate generation, collection, and characterization

    NASA Astrophysics Data System (ADS)

    Boddu, Sunita R.; Gutti, Veera R.; Ghosh, Tushar K.; Tompson, Robert V.; Loyalka, Sudarshan K.

    2011-12-01

    Generation, collection, and characterization of gold, silver, and palladium nanoparticles and nano-agglomerates (collectively "nanoparticles") have been explored. The nanoparticles were generated with a spark aerosol generator (Palas GFG-1000). They were collected using a deposition cell under diffusion and thermophoresis. The shapes and sizes of the deposited particles were measured using transmission electron microscopy (TEM). TEM images showed that the particles were in the range of 8-100 nm in diameter, and their shapes varied from nearly spherical to highly non-spherical. Thermophoresis enhanced the deposition of nanoparticles (over the diffusive or the isothermal deposition) in all cases. Further, the size distributions of the nanoparticles generated in the gas phase (aerosol) were measured using a scanning mobility particle sizer (SMPS 3080, TSI) spectrometer. The SMPS results show that an increase in the spark frequency of the generator shifted the size distributions of the nanoparticles to larger diameters, and the total particle mass production rate increased linearly with increase in the spark frequency. The computational fluid dynamics code Fluent (Ansys) was used to model the flow in the deposition cell, and the computed results conform to the observations.

  5. Coal-gold agglomeration: an alternative separation process in gold recovery

    SciTech Connect

    Akcil, A.; Wu, X.Q.; Aksay, E.K.

    2009-07-01

    Considering the increasing environmental concerns and the potential for small gold deposits to be exploited in the future, the uses of environmentally friendly processes are essential. Recent developments point to the potential for greatly increased plant performance through a separation process that combines the cyanide and flotation processes. In addition, this kind of alternative treatment processes to the traditional gold recovery processes may reduce the environmental risks of present small-scale gold mining. Gold recovery processes that applied to different types of gold bearing ore deposits show that the type of deposits plays an important role for the selection of mineral processing technologies in the production of gold and other precious metals. In the last 25 years, different alternative processes have been investigated on gold deposits located in areas where environmental issues are a great concern. In 1988, gold particles were first recovered by successful pilot trial of coal-gold agglomeration (CGA) process in Australia. The current paper reviews the importance of CGA in the production of gold ore and identifies areas for further development work.

  6. Numerical study of the cathode electrode in the Microfluidic Fuel Cell using agglomerate model

    NASA Astrophysics Data System (ADS)

    Moein-Jahromi, M.; Movahed, S.; Kermani, M. J.

    2015-03-01

    Simulation of the cathode electrode of a Microfluidic Fuel Cell (hereafter MFC) is performed with focus on the electrochemical reaction. Oxygen transport phenomena are modeled from the microchannel inlet to the reaction sites surface (on the platinum particles) in the catalyst layer. The dissolved oxygen in sulfuric acid and the formic acid are considered as the oxidant and the fuel, respectively. The cathode catalyst layer is modeled using the agglomerate model versus the homogenous model which is incapable of predicting concentration loss at high current densities. The results are validated versus the experiments of Choban et al. published in 2004. A set of parametric study is performed to investigate the influence of operating and structural parameters on the cell performance; at the end, a sensitivity analysis is implemented to rank the studied parameters with rank 1 for the most influential parameters. The results indicate that oxygen concentration at the inlet of microchannel within the range 0.1 M-0.7 M is the most influential parameter, and the cell performance can enhance by 2.615 W m-2 at the studied range. The results could be used by the microfluidic fuel cell manufacturers to overcome the current drawbacks of the MFCs.

  7. Assessment of ecological status in small urban streams of Prague agglomeration.

    PubMed

    Nábelková, J; Komínková, D; St'astná, G

    2004-01-01

    The purpose of this research was to compare ecological status of a few small urban watersheds in Prague agglomeration (the Botic creek, the Zátisský creek and the Komoranský creek) with different sources of pollution, different sewer systems and with different hydraulic regimes of the recipient. Concentrations of selected heavy metals (Cd, Cu, Ni, Pb, Zn) were measured in water and sediment samples and in different species of benthic organisms. The biological assessment of macrozoobenthos has also been carried out using two biotic indexes: the saprobic index and the ASPT. The assessment of the environmental risk in an aquatic environment has been based on three different coefficients: the Distribution coefficient (Kd), the Hazard Quotient (HQ) and the Metal Pollution Index (MPI). In the Botic creek there was found out chronic load of bottom sediment by heavy metals. There is higher ecological risk of sediment toxicity in this creek. Outlets of combined sewer system in the Botic creek degrade water quality and consequently deteriorate biological indicators. In the Zátisský creek the main problem is connected with storm sewer outlets. The comparison of the Zátisský creek with the reference stream, the Komoranský creek demonstrates strong hydraulic impact, which induces frequent changes of watercourse morphology reflecting on the composition and representation of benthic macroorganisms.

  8. HVOF and HVAF Coatings of Agglomerated Tungsten Carbide-Cobalt Powders for Water Droplet Erosion Application

    NASA Astrophysics Data System (ADS)

    Tarasi, F.; Mahdipoor, M. S.; Dolatabadi, A.; Medraj, M.; Moreau, C.

    2016-12-01

    Water droplet erosion (WDE) is a phenomenon caused by impingement of water droplets of several hundred microns to a few millimeters diameter at velocities of hundreds of meters per second on the edges and surfaces of the parts used in such services. The solution to this problem is sought especially for the moving compressor blades in gas turbines and those operating at the low-pressure end of steam turbines. Thermal-sprayed tungsten carbide-based coatings have been the focus of many studies and are industrially accepted for a multitude of wear and erosion resistance applications. In the present work, the microstructure, phase analysis and mechanical properties (micro-hardness and fracture toughness) of WC-Co coatings are studied in relation with their influence on the WDE resistance of such coatings. The coatings are deposited by high-velocity oxygen fuel (HVOF) and high-velocity air fuel (HVAF) processes. The agglomerated tungsten carbide-cobalt powders were in either sintered or non-sintered conditions. The WDE tests were performed using 0.4 mm water droplets at 300 m/s impact velocity. The study shows promising results for this cermet as WDE-resistant coating when the coating can reach its optimum quality using the right thermal spray process and parameters.

  9. Impact Of Particle Agglomeration On Accumulation Rates In The Glass Discharge Riser Of HLW Melter

    SciTech Connect

    Kruger, A. A.; Rodriguez, C. A.; Matyas, J.; Owen, A. T.; Jansik, D. P.; Lang, J. B.

    2012-11-12

    The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with x-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, and on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185+-155 {mu}m, and produced >3 mm thick layer after 120 h at 850 deg C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.

  10. How much drinking water can be saved by using rainwater harvesting on a large urban area? application to Paris agglomeration.

    PubMed

    Belmeziti, Ali; Coutard, Olivier; de Gouvello, Bernard

    2014-01-01

    This paper is based on a prospective scenario of development of rainwater harvesting (RWH) on a given large urban area (such as metropolitan area or region). In such a perspective, a new method is proposed to quantify the related potential of potable water savings (PPWS) indicator on this type of area by adapting the reference model usually used on the building level. The method is based on four setting-up principles: gathering (definition of buildings-types and municipalities-types), progressing (use of an intermediate level), increasing (choice of an upper estimation) and prioritizing (ranking the stakes of RWH). Its application to the Paris agglomeration shows that is possible to save up to 11% of the total current potable water through the use of RWH. It also shows that the residential sector offers the most important part because it holds two-thirds of the agglomeration PPWS.

  11. Particle aerosolisation and break-up in dry powder inhalers: evaluation and modelling of impaction effects for agglomerated systems.

    PubMed

    Wong, William; Fletcher, David F; Traini, Daniela; Chan, Hak-kim; Crapper, John; Young, Paul M

    2011-07-01

    This study utilised a combination of computational fluid dynamics (CFD) and standardised entrainment tubes to investigate the influence of impaction on the break-up and aerosol performance of a model inhalation formulation. A series of entrainment tubes, with different impaction plate angles were designed in silico and the flow characteristics, and particle tracks, were simulated using CFD. The apparatuses were constructed using three-dimensional printing. The deposition and aerosol performance of a model agglomerate system (496.3-789.2 μm agglomerates containing 3.91 μm median diameter mannitol particles) were evaluated by chemical analysis and laser diffraction, respectively. Analysis of the mannitol recovery from the assembly and CFD simulations indicated that mass deposition on the plate was dependent on the impactor angle (45°-90°) but independent of the airflow rate (60-140 L·min(-1)). In comparison, wall losses, perpendicular to the impactor plate were dependent on both the impactor angle and flow rate. Analysis of the particle size distribution exiting the impactor assembly suggested mannitol aerosolisation to be independent of impactor angle but dependent on the air velocity directly above the impactor plate. It is proposed that particle-wall impaction results in initial agglomerate fragmentation followed by reentrainment in the airstream above the impaction plate. Such observations have significant implications in the design of dry powder inhaler devices.

  12. Evaluation of optical and electronic properties of silicon nano-agglomerates embedded in SRO: applying density functional theory

    PubMed Central

    2014-01-01

    In systems in atomic scale and nanoscale such as clusters or agglomerates constituted by particles from a few to less than 100 atoms, quantum confinement effects are very important. Their optical and electronic properties are often dependent on the size of the systems and the way in which the atoms in these clusters are bonded. Generally, these nanostructures display optical and electronic properties significantly different to those found in corresponding bulk materials. Silicon agglomerates embedded in silicon rich oxide (SRO) films have optical properties, which have been reported to be directly dependent on silicon nanocrystal size. Furthermore, the room temperature photoluminescence (PL) of SRO has repeatedly generated a huge interest due to its possible applications in optoelectronic devices. However, a plausible emission mechanism has not been widely accepted in the scientific community. In this work, we present a short review about the experimental results on silicon nanoclusters in SRO considering different techniques of growth. We focus mainly on their size, Raman spectra, and photoluminescence spectra. With this as background, we employed the density functional theory with a functional B3LYP and a basis set 6-31G* to calculate the optical and electronic properties of clusters of silicon (constituted by 15 to 20 silicon atoms). With the theoretical calculation of the structural and optical properties of silicon clusters, it is possible to evaluate the contribution of silicon agglomerates in the luminescent emission mechanism, experimentally found in thin SRO films. PMID:25276105

  13. Integrated low emission cleanup system for direct coal-fueled turbines (electrostatic agglomeration). Draft final technical report

    SciTech Connect

    Quimby, J.M.; Kumar, K.S.

    1992-12-31

    The objective of this contract was to investigate the removal of SO{sub x} and particulate matter from direct coal fired combustion gas streams at high temperature and high pressure conditions. This investigation was to be accomplished through a bench scale testing and evaluation program for SO{sub x} removal and the innovative particulate collection concept of particulate growth through electrostatic agglomeration followed by high efficiency mechanical collection. The process goal was to achieve control better than that required by 1979 New Source Performance Standards. During Phase I, the designs of the combustor and gas cleanup apparatus were successfully completed. Hot gas cleanup was designed to be accomplished at temperature levels between 1800{degrees} and 2500{degrees}F at pressures up to 15 atmospheres. The combustor gas flow rate could be varied between 0.2--0.5 pounds per second. The electrostatic agglomerator residence time could be varied between 0.25 to 3 seconds. In Phase II, all components were fabricated, and erected successfully. Test data from shakedown testing was obtained. Unpredictable difficulties in pilot plant erection and shakedown consumed more budget resources than was estimated and as a consequence DOE, METC, decided ft was best to complete the contract at the end of Phase II. Parameters studied in shakedown testing revealed that high-temperature high pressure electrostatics offers an alternative to barrier filtration in hot gas cleanup but more research is needed in successful system integration between the combustor and electrostatic agglomerator.

  14. Development of Impregnated Agglomerate Pelletization (IAP) process for fabrication of (Th,U)O 2 mixed oxide pellets

    NASA Astrophysics Data System (ADS)

    Khot, P. M.; Nehete, Y. G.; Fulzele, A. K.; Baghra, Chetan; Mishra, A. K.; Afzal, Mohd.; Panakkal, J. P.; Kamath, H. S.

    2012-01-01

    Impregnated Agglomerate Pelletization (IAP) technique has been developed at Advanced Fuel Fabrication Facility (AFFF), BARC, Tarapur, for manufacturing (Th, 233U)O 2 mixed oxide fuel pellets, which are remotely fabricated in hot cell or shielded glove box facilities to reduce man-rem problem associated with 232U daughter radionuclides. This technique is being investigated to fabricate the fuel for Indian Advanced Heavy Water Reactor (AHWR). In the IAP process, ThO 2 is converted to free flowing spheroids by powder extrusion route in an unshielded facility which are then coated with uranyl nitrate solution in a shielded facility. The dried coated agglomerate is finally compacted and then sintered in oxidizing/reducing atmosphere to obtain high density (Th,U)O 2 pellets. In this study, fabrication of (Th,U)O 2 mixed oxide pellets containing 3-5 wt.% UO 2 was carried out by IAP process. The pellets obtained were characterized using optical microscopy, XRD and alpha autoradiography. The results obtained were compared with the results for the pellets fabricated by other routes such as Coated Agglomerate Pelletization (CAP) and Powder Oxide Pelletization (POP) route.

  15. Study on GIS Visualization in Evaluation of the Human Living Environment in Shenyang-Dalian Urban Agglomeration

    PubMed Central

    Hou, Kang; Zhou, Jieting; Li, Xuxiang; Ge, Shengbin

    2016-01-01

    Analysis of human living environmental quality of Shenyang-Dalian urban agglomerations has important theoretical and practical significance in rapid development region. A lot of investigations have been carried for Shenyang-Dalian urban agglomerations, including 38 counties. Based on the carrying capacity of resources, natural and socioeconomic environmental factors and regional changes of human living environmental evaluation are analyzed with the application of geographic information systems (GIS) software. By using principal component analysis (PCA) model and natural breaks classification (NBC) method, the evaluation results are divided into five categories. The results show that the human living environmental evaluation (HLEE) indexes of Dalian, Shenyang, and Liaoyang are higher than other counties. Among these counties, the human living environmental evaluation (HLEE) indexes of coastal counties are significantly higher than inland counties. The range of the human living environmental evaluation index in most of the study area is at III, IV, and V levels, accounting for 80.01%. Based on these results, it could illustrate the human living environment is in relatively suitable condition in Shenyang-Dalian urban agglomeration. PMID:27200212

  16. Towards a better understanding on agglomeration mechanisms and thermodynamic properties of TiO₂ nanoparticles interacting with natural organic matter.

    PubMed

    Loosli, Frédéric; Vitorazi, Letícia; Berret, Jean-François; Stoll, Serge

    2015-09-01

    Interaction between engineered nanoparticles and natural organic matter is investigated by measuring the exchanged heat during binding process with isothermal titration calorimetry. TiO2 anatase nanoparticles and alginate are used as engineered nanoparticles and natural organic matter to get an insight into the thermodynamic association properties and mechanisms of adsorption and agglomeration. Changes of enthalpy, entropy and total free energy, reaction stoichiometry and affinity binding constant are determined or calculated at a pH value where the TiO2 nanoparticles surface charge is positive and the alginate exhibits a negative structural charge. Our results indicate that strong TiO2-alginate interactions are essentially entropy driven and enthalpically favorable with exothermic binding reactions. The reaction stoichiometry and entropy gain are also found dependent on the mixing order. Finally correlation is established between the binding enthalpy, the reaction stoichiometry and the zeta potential values determined by electrophoretic mobility measurements. From these results two types of agglomeration mechanisms are proposed depending on the mixing order. Addition of alginate in TiO2 dispersions is found to form agglomerates due to polymer bridging whereas addition of TiO2 in alginate promotes a more individually coating of the nanoparticles.

  17. AC impedance modelling study on porous electrodes of proton exchange membrane fuel cells using an agglomerate model

    NASA Astrophysics Data System (ADS)

    Gerteisen, Dietmar; Hakenjos, Alex; Schumacher, Jürgen O.

    A one-dimensional model of the PEM fuel cell cathode is developed to analyse ac impedance spectra and polarisation curves. The porous gas diffusion electrode is assumed to consist of a network of dispersed catalyst (Pt/C) forming spherically shaped agglomerated zones that are filled with electrolyte. The coupled differential equation system describes: ternary gas diffusion in the backing (O2 , N2 , water vapour), Fickian diffusion and Tafel kinetics for the oxygen reduction reaction (ORR) inside the agglomerates, proton migration with ohmic losses and double-layer charging in the electrode. Measurements are made of a temperature-controlled fuel cell with a geometric area of 1.4 cm × 1.4 cm. Lateral homogeneity is ensured by using a high stoichiometry of λmin . The model predicts the behaviour of measured polarisation curves and impedance spectra. It is found that a better humidification of the electrode leads to a higher volumetric double-layer capacity. The catalyst layer resistance shows the same behaviour depending on the humidification as the membrane resistance. Model parameters, e.g. Tafel slope, ionic resistance and agglomerate radius are varied. A sensitivity analysis of the model parameters is conducted.

  18. Assessment of Morphological and Functional Changes in Organs of Rats after Intramuscular Introduction of Iron Nanoparticles and Their Agglomerates

    PubMed Central

    Sizova, Elena; Miroshnikov, Sergey; Yausheva, Elena; Polyakova, Valentina

    2015-01-01

    The research was performed on male Wistar rats based on assumptions that new microelement preparations containing metal nanoparticles and their agglomerates had potential. Morphological and functional changes in tissues in the injection site and dynamics of chemical element metabolism (25 indicators) in body were assessed after repeated intramuscular injections (total, 7) with preparation containing agglomerate of iron nanoparticles. As a result, iron depot was formed in myosymplasts of injection sites. The quantity of muscle fibers having positive Perls' stain increased with increasing number of injections. However, the concentration of the most chemical elements and iron significantly decreased in the whole skeletal muscle system (injection sites are not included). Consequently, it increased up to the control level after the sixth and the seventh injections. Among the studied organs (liver, kidneys, and spleen), Caspase-3 expression was revealed only in spleen. The expression had a direct dependence on the number of injections. Processes of iron elimination from preparation containing nanoparticles and their agglomerates had different intensity. PMID:25789310

  19. Phloem Ultrastructure and Pressure Flow: Sieve-Element-Occlusion-Related Agglomerations Do Not Affect Translocation[W

    PubMed Central

    Froelich, Daniel R.; Mullendore, Daniel L.; Jensen, Kåre H.; Ross-Elliott, Tim J.; Anstead, James A.; Thompson, Gary A.; Pélissier, Hélène C.; Knoblauch, Michael

    2011-01-01

    Since the first ultrastructural investigations of sieve tubes in the early 1960s, their structure has been a matter of debate. Because sieve tube structure defines frictional interactions in the tube system, the presence of P protein obstructions shown in many transmission electron micrographs led to a discussion about the mode of phloem transport. At present, it is generally agreed that P protein agglomerations are preparation artifacts due to injury, the lumen of sieve tubes is free of obstructions, and phloem flow is driven by an osmotically generated pressure differential according to Münch’s classical hypothesis. Here, we show that the phloem contains a distinctive network of protein filaments. Stable transgenic lines expressing Arabidopsis thaliana Sieve-Element-Occlusion-Related1 (SEOR1)–yellow fluorescent protein fusions show that At SEOR1 meshworks at the margins and clots in the lumen are a general feature of living sieve tubes. Live imaging of phloem flow and flow velocity measurements in individual tubes indicate that At SEOR1 agglomerations do not markedly affect or alter flow. A transmission electron microscopy preparation protocol has been generated showing sieve tube ultrastructure of unprecedented quality. A reconstruction of sieve tube ultrastructure served as basis for tube resistance calculations. The impact of agglomerations on phloem flow is discussed. PMID:22198148

  20. IMPACT OF PARTICLE SIZE AND AGGLOMERATION ON SETTLING OF SOLIDS IN CONTINUOUS MELTERS PROCESSING RADIOACTIVE WASTE GLASS

    SciTech Connect

    HRMA PR

    2008-12-18

    The major factor limiting waste loading for many waste compositions in continuous waste glass melters is the settling of crystalline materials. The currently used constraints, i.e., the minimum liquidus temperature or the maximum fraction of equilibrium crystallinity at a given temperature, are based on thennodynamic equilibria. Because of the rapid circular convection in the melter, these constraints are probably irrelevant and cannot prevent large crystals from settling. The main factor that detennines the rate of settling ofindividual crystals, such as those ofspinel, is their size. The tiny crystals of RU02 are too small to settle, but they readily fonn large agglomerates that accelerate their rate ofsettling by severalorders ofmagnitude. The RU02 agglomerates originate early in the melting process and then grow by the shear-flocculation mechanism. It is estimated that these agglomerates must either be ofhundreds micrometers in size or have an elongated shape to match the observed rates ofthe sludge-layer fonnation. PACS: 47.57.ef, 81.05.Kj, 81.10.Fg

  1. Evaluation of optical and electronic properties of silicon nano-agglomerates embedded in SRO: applying density functional theory.

    PubMed

    Espinosa-Torres, Néstor D; la Luz, David Hernández-de; Flores-Gracia, José Francisco J; Luna-López, José A; Martínez-Juárez, Javier; Vázquez-Valerdi, Diana E

    2014-01-01

    In systems in atomic scale and nanoscale such as clusters or agglomerates constituted by particles from a few to less than 100 atoms, quantum confinement effects are very important. Their optical and electronic properties are often dependent on the size of the systems and the way in which the atoms in these clusters are bonded. Generally, these nanostructures display optical and electronic properties significantly different to those found in corresponding bulk materials. Silicon agglomerates embedded in silicon rich oxide (SRO) films have optical properties, which have been reported to be directly dependent on silicon nanocrystal size. Furthermore, the room temperature photoluminescence (PL) of SRO has repeatedly generated a huge interest due to its possible applications in optoelectronic devices. However, a plausible emission mechanism has not been widely accepted in the scientific community. In this work, we present a short review about the experimental results on silicon nanoclusters in SRO considering different techniques of growth. We focus mainly on their size, Raman spectra, and photoluminescence spectra. With this as background, we employed the density functional theory with a functional B3LYP and a basis set 6-31G* to calculate the optical and electronic properties of clusters of silicon (constituted by 15 to 20 silicon atoms). With the theoretical calculation of the structural and optical properties of silicon clusters, it is possible to evaluate the contribution of silicon agglomerates in the luminescent emission mechanism, experimentally found in thin SRO films.

  2. Effect of treatment media on the agglomeration of titanium dioxide nanoparticles: impact on genotoxicity, cellular interaction, and cell cycle.

    PubMed

    Prasad, Raju Y; Wallace, Kathleen; Daniel, Kaitlin M; Tennant, Alan H; Zucker, Robert M; Strickland, Jenna; Dreher, Kevin; Kligerman, Andrew D; Blackman, Carl F; Demarini, David M

    2013-03-26

    The widespread use of titanium dioxide (TiO2) nanoparticles in consumer products increases the probability of exposure to humans and the environment. Although TiO2 nanoparticles have been shown to induce DNA damage (comet assay) and chromosome damage (micronucleus assay, MN) in vitro, no study has systematically assessed the influence of medium composition on the physicochemical characteristics and genotoxicity of TiO2 nanoparticles. We assessed TiO2 nanoparticle agglomeration, cellular interaction, induction of genotoxicity, and influence on cell cycle in human lung epithelial cells using three different nanoparticle-treatment media: keratinocyte growth medium (KGM) plus 0.1% bovine serum albumin (KB); a synthetic broncheoalveolar lavage fluid containing PBS, 0.6% bovine serum albumin and 0.001% surfactant (DM); or KGM with 10% fetal bovine serum (KF). The comet assay showed that TiO2 nanoparticles induced similar amounts of DNA damage in all three media, independent of the amount of agglomeration, cellular interaction, or cell-cycle changes measured by flow cytometry. In contrast, TiO2 nanoparticles induced MN only in KF, which is the medium that facilitated the lowest amount of agglomeration, the greatest amount of nanoparticle cellular interaction, and the highest population of cells accumulating in S phase. These results with TiO2 nanoparticles in KF demonstrate an association between medium composition, particle uptake, and nanoparticle interaction with cells, leading to chromosomal damage as measured by the MN assay.

  3. Barley Oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Barley (Hordeum vulgare) is an ancient grain that has was domesticated for use as a food. Currently only about 2% is used for food, about two thirds is used for animal feed and one third for malting. Because the oil content of most barley cultivars is low (<2%), obtaining oil from whole barley gra...

  4. Investigation into the impact of sub-populations of agglomerates on the particle size distribution and flow properties of conventional microcrystalline cellulose grades.

    PubMed

    Gamble, John F; Chiu, Wing-Sin; Tobyn, Mike

    2011-10-01

    Microcrystalline cellulose (MCC) is regarded as one of the most versatile tablet filler binders, finding a wide use in both granulation and direct compression operations. It has been shown that MCC particle populations consist of a mixture of 'rod like' primary particles, and agglomerates, and that the proportion of these primary particles and agglomerates differs within the different grades of materials, contributing to the different bulk properties of these materials. However, the proportion of primary particles and agglomerates has not previously been fully elucidated, and their contribution to the performance factors such as flow explained. In this paper we use a novel microscopy-based characterization technique to demonstrate that the proportion of 'agglomerates' in the series of MCC grades between PH101 and PH200 is, by number, very low, but sufficient to perturb a volume-based particle size method by significant amounts.

  5. Composite propellant aluminum agglomeration reduction using tailored Al/PTFE particles

    NASA Astrophysics Data System (ADS)

    Sippel, Travis R.

    can be ignited via optical flash. Propellant aluminum agglomeration is assessed through replacement of reference aluminum powders (spherical, flake, or nanoscale) with Al/PTFE (90/10 or 70/30 wt.%) particles. The effects on burning rate, pressure dependence, and aluminum ignition, combustion, and agglomeration are quantified. Microscopic imaging shows tailored particles promptly ignite at the burning surface and appear to breakup into smaller particles. Replacement of spherical aluminum with Al/PTFE 70/30 wt.% also increases the pressure exponent from 0.36 to 0.58, which results in a 50% increase in propellant burning rate at 13.8 MPa. Combustion products were quench collected using a liquid-free technique at 2.1 and 6.9 MPa. Sizing of products indicates that composite particles result in nominally 25 μm coarse products, which are smaller than the original, average particle size and are also 66% smaller in diameter (96% by volume) than the 76 μm products collected from reference spherical aluminized propellant. Smaller diameter condensed phase products and more gaseous products will likely decrease two-phase flow loss and reduce slag accumulation in solid rocket motors.

  6. Climatic effects of urban expansion over the three largest urban agglomerations of China

    NASA Astrophysics Data System (ADS)

    Cao, Qian; Yu, Deyong; Georgescu, Matei; Wu, Jianguo

    2016-04-01

    Urbanization has long been known to affect local, regional, and global climate. China is urbanizing at an unprecedented rate, and modification of land surface to urban areas has raised climate concerns for its citizens. Using the Weather Research and Forecasting (WRF) model, we examine how urbanization under different intensities and climate regimes affects regional climate of the three largest urban agglomerations across China - the Beijing-Tianjin-Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD). We simulated three urban expansion scenarios corresponding to 1988, 2000, and 2010 conditions into the WRF model, with each scenario simulated by three separate summers (i.e., 2001, 2003, and 2005). Urban extent of the three regions indicates stable growth during 1988 - 2000, followed by a phase of rapid expansion during 2000 - 2010. Our simulations show that urban environment-induced near-surface warming, mainly rising temperatures during nighttime, is greatest over the BTH with local maximum warming approaching 1.5 °C, followed by the YRD with peak warming reaching 1 °C and the PRD 0.8 °C. Due to the initial moisture conditions, the YRD and the PRD suffer more humidity deficit, particularly during daytime, with maximum reductions in water vapor mixing ratio reaching 0.8 g/kg. Our findings demonstrate that urban expansion has warmed and dried the urbanized regions in eastern China. The spatial pattern and magnitude of temperature and humidity differences quantified by our simulations provide useful information for understanding the impacts of urbanization on regional climate and for developing mitigation and adaptation strategies that can alleviate the deleterious impacts induced by urban expansion.

  7. A PROTOSOLAR NEBULA ORIGIN FOR THE ICES AGGLOMERATED BY COMET 67P/CHURYUMOV–GERASIMENKO

    SciTech Connect

    Mousis, O.; Vernazza, P.; Lunine, J. I.; Luspay-Kuti, A.; Hässig, M.; Waite, J. H.; Guillot, T.; Marty, B.; Ali-Dib, M.

    2016-03-10

    The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula (PSN) is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the PSN. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the PSN. On the basis of existing laboratory and modeling data, we find that the N{sub 2}/CO and Ar/CO ratios measured in the coma of the Jupiter-family comet 67P/Churyumov–Gerasimenko by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument on board the European Space Agency’s Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N{sub 2}/CO and Ar/CO ratios in 67P/Churyumov–Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov–Gerasimenko is impoverished in Ar and N{sub 2}, the volatile enrichments observed in Jupiter’s atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.

  8. Urban influence on increasing ozone concentrations in a characteristic Mediterranean agglomeration

    NASA Astrophysics Data System (ADS)

    Escudero, M.; Lozano, A.; Hierro, J.; Valle, J. del; Mantilla, E.

    2014-12-01

    Air quality in cities has been extensively studied due to the high population density potentially exposed to high levels of pollutants. The main problems in urban areas have been related to particulate matter (PM) and NO2. Less attention has been directed towards O3 because urban levels are generally lower than those recorded in rural areas. The implementation of air quality plans, together with technological improvements, have resulted in reductions of PM and NO2 levels in many European cities. In contrast, urban O3 levels have experimented increases which may respond to declining NOx emission trends. It is therefore necessary to intensify the study of urban O3 and its potential relation with NOx variations. In the agglomeration of Zaragoza (NE Spain), traffic circulation through the centre has dropped by 28.3% since 2008 due to several factors such as the implementation of a mobility plan, the completion of major construction projects and the economic crisis in Spain. The study of this case offers a unique opportunity to evaluate the impact of reductions in NOx emissions on the levels of O3 in a characteristic Mediterranean city. This work analyses the variability and trends of ambient air levels of O3 and NOx in Zaragoza and the Ebro valley from 2007 to 2012. Results demonstrate that, although the main factor explaining O3 variability is still linked to meteorology, changes in NOx emissions strongly influence O3 variability and trends, mainly due to interaction with fresh NO. Specific analysis of the O3 "weekend effect" show a significant correlation (r2 = 0.81) between the drop of NO concentrations (associated to emissions) and the increment of O3 levels during weekends. Moreover, trend analyses reveal that the decline in NOx emissions in Zaragoza from 2007 to 2012 can be associated with significant increments in O3 levels.

  9. A Protosolar Nebula Origin for the Ices Agglomerated by Comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Mousis, O.; Lunine, J. I.; Luspay-Kuti, A.; Guillot, T.; Marty, B.; Ali-Dib, M.; Wurz, P.; Altwegg, K.; Bieler, A.; Hässig, M.; Rubin, M.; Vernazza, P.; Waite, J. H.

    2016-03-01

    The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula (PSN) is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the PSN. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the PSN. On the basis of existing laboratory and modeling data, we find that the N2/CO and Ar/CO ratios measured in the coma of the Jupiter-family comet 67P/Churyumov-Gerasimenko by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument on board the European Space Agency’s Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N2/CO and Ar/CO ratios in 67P/Churyumov-Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov-Gerasimenko is impoverished in Ar and N2, the volatile enrichments observed in Jupiter’s atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.

  10. Assessing PM10 source reduction in urban agglomerations for air quality compliance.

    PubMed

    Aleksandropoulou, Victoria; Eleftheriadis, Konstantinos; Diapouli, Evangelia; Torseth, Kjetil; Lazaridis, Mihalis

    2012-01-01

    The objective of this work was to study PM(10) and PM(2.5) concentration data available from monitoring stations in two large urban agglomerations in Greece and to estimate the emissions reduction required for compliance with the EU Air Quality Standards (AQS) for particulate matter. The cities studied are namely the Athens and Thessaloniki Metropolitan Areas (AMA and TMA, respectively). PM(10) concentrations during the period 2001-2010 have been evaluated for 15 air quality monitoring stations in the two urban areas. It was found that the concentrations of PM(10) during the period studied constantly exceeded the threshold values at the traffic and industrial stations in TMA and most of the traffic sites in AMA. Most of the occurrences of non-attainment to the daily AQSs were observed during the winter period at all stations (more pronounced for TMA stations). The reduction in current emission source strength to meet the air quality goal was calculated by the rollback equation using PM(10) day-averaged concentrations over the selected period at each station. Among the lognormal and Weibull distributions, the lognormal distribution was found to best fit the frequency distributions of PM(10) concentrations at the selected stations. The results showed that the minimum reduction required in order to meet the AQS in the AMA ranges from approximately 20 to 38% and up to 11% for traffic and background stations, respectively. Reductions in the range of 31% for traffic and 44% for industrial areas in TMA are also required. The same methodology was applied to PM(2.5) concentrations in the AMA and showed that emission reductions up to 31% are necessary in order to meet the 2020 EU AQS. Finally, continuous concentration data of organic (OC) and elementary carbon (EC) in PM(2.5) were used to study the possibility of achieving specific emission attenuation objectives in AMA.

  11. Determination of Uniaxial Compressive Strength of Ankara Agglomerate Considering Fractal Geometry of Blocks

    NASA Astrophysics Data System (ADS)

    Coskun, Aycan; Sonmez, Harun; Ercin Kasapoglu, K.; Ozge Dinc, S.; Celal Tunusluoglu, M.

    2010-05-01

    The uniaxial compressive strength (UCS) of rock material is a crucial parameter to be used for design stages of slopes, tunnels and foundations to be constructed in/on geological medium. However, preparation of high quality cores from geological mixtures or fragmented rocks such as melanges, fault rocks, coarse pyroclastic rocks, breccias and sheared serpentinites is often extremely difficult. According to the studies performed in literature, this type of geological materials may be grouped as welded and unwelded birmocks. Success of preparation of core samples from welded bimrocks is slightly better than unwelded ones. Therefore, some studies performed on the welded bimrocks to understand the mechanical behavior of geological mixture materials composed of stronger and weaker components (Gokceoglu, 2002; Sonmez et al., 2004; Sonmez et al., 2006; Kahraman, et al., 2008). The overall strength of bimrocks are generally depends on strength contrast between blocks and matrix; types and strength of matrix; type, size, strength, shape and orientation of blocks and volumetric block proportion. In previously proposed prediction models, while UCS of unwelded bimrocks may be determined by decreasing the UCS of matrix considering the volumetric block proportion, the welded ones can be predicted by considering both UCS of matrix and blocks together (Lindquist, 1994; Lindquist and Goodman, 1994; Sonmez et al., 2006 and Sonmez et al., 2009). However, there is a few attempts were performed about the effect of blocks shape and orientation on the strength of bimrock (Linqduist, 1994 and Kahraman, et al., 2008). In this study, Ankara agglomerate, which is composed of andesite blocks and surrounded weak tuff matrix, was selected as study material. Image analyses were performed on bottom, top and side faces of cores to identify volumetric block portions. In addition to the image analyses, andesite blocks on bottom, top and side faces were digitized for determination of fractal

  12. Formation of metal agglomerates during carbonisation of chromated copper arsenate (CCA) treated wood waste: Comparison between a lab scale and an industrial plant.

    PubMed

    Helsen, Lieve; Hacala, Amélie

    2006-10-11

    This paper compares the results obtained by scanning electron microscopy coupled to X-ray analysis (SEM-EDXA) of the solid product after carbonisation of treated wood waste in a lab scale and in an industrial installation. These setups (lab scale and industrial) are characterized by different operating conditions of the carbonisation process. Moreover, the wood waste input to the processes differs significantly. From this study, it is clear that some similarities but also some differences exist between the lab scale study and the study with the industrial Chartherm plant. In both reactors, a metal (and mineral) agglomeration process takes place, even in the case of untreated wood. The agglomerates initially present in the wood input may serve as a seed for the metal agglomeration process during "chartherisation". The industrial setup leads to a broader range of agglomerates' size (0.1-50 microm) and composition (all possible combinations of Cu, Cr, As and wood minerals). Some agglomerates contain the three metals but the major part is a combination of wood minerals and one or two of the three preservative metals, while all agglomerates analysed in the lab scale product contain the three metals. The separate influence of wood input characteristics and process conditions cannot be derived from these experiments, but the observations suggest that the higher the CCA retention in the wood input is, the easier is the metal agglomeration process during chartherisation of CCA treated wood waste. From the analyses performed in this study it seems that copper behaves differently in the sense that it agglomerates easily, but the resulting particles are small (<1 microm).

  13. Designing of the Information Advising System to Assess the Potential of Creation and Development of Cluster Agglomeration in the Industrial Complex of the Region

    NASA Astrophysics Data System (ADS)

    Averchenkova, E. E.; Averchenkov, A. V.; Kulagina, N. A.

    2017-01-01

    The theoretical aspects of creation of the information advising system to assess the potential of development of the cluster agglomeration are described in this article. The algorithm provided in the article estimates possibilities of creation and development of the regional industrial cluster agglomeration. This article describes the possible use of the information advising system of the evaluation and diagnostic type in making managerial decisions by the participants of the technology innovation cluster.

  14. Pretreatment of coal and recycle oil for direct liquefaction

    SciTech Connect

    Winschel, R.A.; Lancet, M.S.; Robbins, G.A.; Burke, F.P.; Kottenstette, R.J.; Stephens, H.P.

    1993-07-01

    A research and development program is being conducted by the University of Kentucky/Center for Applied Energy Research, Sandia National Laboratories, LDP Associates and CONSOL Inc. to improve current coal liquefaction technology by physical and chemical pretreatments of the coal and recycle oil. These pretreatment steps include: (1) agglomeration of the coal with ash-containing recycle oil to simultaneously reject coal ash and recycle-oil ash, (2) fluid coking of the distillation bottoms (ash-purge) stream and recycle of the coker overhead, (3) dewaxing of the distillate portion of the recycle oil, and (4) low-severity hydrotreatment of the coker overhead and dewaxed oil using hydrogen from an in-situ water-gas shift reaction. These pretreatment steps will remove the ash and unconverted coal, reducing the ash load in the system and simultaneously recovering the maximum amount of organics. Dewaxing and hydrotreatment will yield a high-quality recycle oil distillate. These pretreatment steps are being evaluated technically and economically to develop an improved conceptual liquefaction process. The baseline process to which the improved process will be compared is the Two-Stage Liquefaction Process as it was practiced at the Wilsonville, AL, USA Advanced Coal Liquefaction Test Facility.

  15. OIL BOND®

    EPA Pesticide Factsheets

    Technical product bulletin: this miscellaneous oil spill control agent is a solidifier used in cleanups. It absorbs and solidifies hydrocarbon spills on freshwater and saltwater or land applications. Ring spill with booms or pillows before treatment.

  16. Peanut Oil

    MedlinePlus

    ... are pregnant or breast-feeding. Allergy to peanuts, soybeans, and related plants: Peanut oil can cause serious ... reactions in people who are allergic to peanuts, soybeans, and other members of the Fabaceae plant family.

  17. Palm Oil

    MedlinePlus

    ... treating malaria, high blood pressure, high cholesterol, and cyanide poisoning. Palm oil is used for weight loss ... to decrease symptoms of malaria. High blood pressure. Cyanide poisoning. Weight loss agent. Cancer. Anti-aging. Brain ...

  18. Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue

    SciTech Connect

    Howe, Daniel T.; Taasevigen, Danny J.; Gerber, Mark A.; Gray, Michel J.; Fernandez, Carlos A.; Saraf, Laxmikant; Garcia-Perez, Manuel; Wolcott, Michael P.

    2015-11-13

    This research investigates the bed agglomeration phenomena during the steam gasification of a high lignin residue produced from the simultaneous saccharification and fermentation (SSF) of corn stover in a bubbling fluidized bed. The studies were conducted at 895°C using alumina as bed material. Biomass was fed at 1.5 kg/hr, while steam was fed to give a velocity equal to 2.5 times the minimum fluidization velocity, with a steam/carbon ratio of 0.9. The pelletized feedstock was co-fed with a cooling nitrogen stream to mitigate feed line plugging issues. Tar production was high at 50.3 g/Nm3, and the fraction of C10+ compounds was greater than that seen in the gasification of traditional lignocellulosic feedstocks. Carbon closures over 94 % were achieved for all experiments. Bed agglomeration was found to be problematic, indicated by pressure drop increases observed below the bed and upstream of the feed line. Two size categories of solids were recovered from the reactor, +60 mesh and -60 mesh. After a 2.75-hour experiment, 61.7 wt % was recovered as -60 mesh particles and 38.2 wt% of the recovered reactor solids were +60 mesh. A sizeable percentage, 31.8 wt%, was +20 mesh. The -60 mesh particles were mainly formed by the initial bed material (Al2O3). Almost 50 wt. % of the + 20 mesh particles was found to be formed by organics. The unreacted carbon remaining in the reactor resulted in a low conversion rate to product gas. ICP-AES, SEM, SEM-EDS, and XRD confirmed that the large agglomerates (+ 20 mesh) were not encapsulated bed material but rather un-gasified feedstock pellets with sand particles attached to it.

  19. Recent Advances in the Development and Application of Power Plate Transducers in Dense Gas Extraction and Aerosol Agglomeration Processes

    NASA Astrophysics Data System (ADS)

    Riera, E.; Cardoni, A.; Gallego-Juárez, J. A.; Acosta, V. M.; Blanco, A.; Rodríguez, G.; Blasco, M.; Herranz, L. E.

    Power ultrasound (PU) is an emerging, innovative, energy saving and environmental friendly technology that is generating a great interest in sectors such as food and pharmaceutical industries, green chemistry, environmental pollution, and other processes, where sustainable and energy efficient methods are required to improve and/or produce specific effects. Two typical effects of PU are the enhancement of mass transfer in gases and liquids, and the induction of particle agglomeration in aerosols. These effects are activated by a variety of mechanisms associated to the nonlinear propagation of high amplitude ultrasonic waves such as diffusion, agitation, entrainment, turbulence, etc. During the last years a great effort has been jointly made by the Spanish National Research Council (CSIC) and the company Pusonics towards introducing novel processes into the market based on airborne ultrasonic plate transducers. This technology was specifically developed for the treatment of gas and multiphasic media characterized by low specific acoustic impedance and high acoustic absorption. Different strategies have been developed to mitigate the effects of the nonlinear dynamic behavior of such ultrasonic piezoelectric transducers in order to enhance and stabilize their response at operational power conditions. This work deals with the latter advances in the mitigation of nonlinear problems found in power transducers; besides it describes two applications assisted by ultrasound developed at semi-industrial and laboratory scales and consisting in extraction via dense gases and particle agglomeration. Dense Gas Extraction (DGE) assisted by PU is a new process with a potential to enhance the extraction kinetics with supercritical CO2. Acoustic agglomeration of fine aerosol particles has a great potential for the treatment of air pollution problems generated by particulate materials. Experimental and numerical results in both processes will be shown and discussed.

  20. Bovine Serum Albumin Adsorption on TiO2 Colloids: The Effect of Particle Agglomeration and Surface Composition.

    PubMed

    Márquez, Augusto; Berger, Thomas; Feinle, Andrea; Hüsing, Nicola; Himly, Martin; Duschl, Albert; Diwald, Oliver

    2017-02-28

    Protein adsorption at nanostructured oxides strongly depends on the synthesis conditions and sample history of the material investigated. We measured the adsorption of bovine serum albumin (BSA) to commercial Aeroxide TiO2 P25 nanoparticles in aqueous dispersions. Significant changes in the adsorption capacity were induced by mild sample washing procedures and attributed to the structural modification of adsorbed water and surface hydroxyls. Motivated by the lack of information about the sample history of commercial TiO2 nanoparticle samples, we used vapor-phase-grown TiO2 nanoparticles, a well-established model system for adsorption and photocatalysis studies, and performed on this material for the first time a systematic and quantitative BSA adsorption study. After alternating vacuum and oxygen treatment of the nanoparticle powders at elevated temperatures for surface purification, we determined size distributions covering both the size of the individualized nanoparticles and nanoparticle agglomerates using transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) in an aqueous dispersion. Quantitative BSA adsorption measurements at different pH values and thus variable combinations of surface-charged proteins and TiO2 nanoparticles revealed a consistent picture: BSA adsorbs only at the outer agglomerate surfaces without penetrating the interior of the agglomerates. This process levels at coverages of single monolayers, which resist consecutive simple washing procedures. A detailed analysis of the protein-specific IR amide bands reveals that the adsorption-induced protein conformational change is associated with a decrease in the helical content. This study underlines that robust qualitative and quantitative statements about protein adsorption and corona formation require well-documented and controllable surface properties of the nanomaterials involved.

  1. Catalytic soot oxidation in microscale experiments: Simulation of interactions between co-deposited graphitic nanoparticle agglomerates and platinum nanoparticles

    NASA Astrophysics Data System (ADS)

    Seipenbusch, Martin; Friedlander, Sheldon K.

    2004-12-01

    Continuously regenerating catalytic soot traps are under development to reduce particulate emissions from diesel exhaust. A good understanding of the processes that take place during soot oxidation is needed to optimize diesel soot trap performance. To gain insight into these processes from the perspective of nanoparticle technology, the effects of catalyst particle size and the interparticle distance between soot and catalyst particles were measured. A model catalyst was prepared by depositing Pt nanoparticles on a SiO/SiO2-coated transmission electron microscope (TEM) grid. A soot surrogate composed of graphitic nanoparticle agglomerates generated by laser ablation was deposited on the same surface. This system simulates, morphologically, catalytic soot traps used in practice. The reaction was carried out in a tubular flow reactor in which the gas phase simulated diesel exhaust gas, composed of a mixture of 10% O2 and 1000 ppm NO with the remainder N2. The progress of the carbon nanoparticle oxidation was monitored off-line by analysis of electron microscopy images of the agglomerates before and after reaction. This experimental method permitted the correlation of reaction rate with particle sizes and separation distances as well as catalyst surface area in the direct environs of the soot particles. The experimental results revealed no effect of Pt catalyst particle size in the range 7-31 nm on the rate of reaction. Also observed were a decrease in the rate of reaction with increasing distance between carbon agglomerates and catalyst particles and a linear dependence of the reaction rate on the fractional catalyst surface area coverage.

  2. A satellite-based analysis of temporal dynamics in tropospheric nitrogen dioxide levels over large urban agglomerations worldwide

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; van der A, Ronald; Valdebenito, Alvaro

    2014-05-01

    Satellite observations allow for a consistent perspective on tropospheric nitrogen dioxide at a global scale and their operational status facilitates studies on multi-annual to decadal temporal dynamics. Utilizing close to a decade of data from the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) and the Ozone Monitoring Instrument (OMI) sensors, we present in this contribution a global analysis of the temporal dynamics in tropospheric nitrogen dioxide over the worlds' major urban agglomerations during the last 10 years. The results indicate that while levels of nitrogen dioxide have been slowly declining in most areas of the United States and Europe over the last decade, very rapid increases in tropospheric nitrogen dioxide can be observed over many megacities and other large urban agglomerations throughout most of Asia, often with highly significant trends. Particularly in Eastern China, increases of 10 to 20 percent per year are quite widespread. Some of the large urban agglomerations with the most rapid increase in nitrogen dioxide pollution are Dhaka in Bangladesh, Kabul in Afghanistan, and Tianjin in China, and these are investigated in more detail. An inter-comparison of trends derived separately from SCIAMACHY and OMI shows that in terms of spatial patterns the resulting trends agree quite well between the two instruments, particularly in the more polluted areas. However, at the individual grid cell level substantial differences can be found. In addition, the satellite-based trends in tropospheric nitrogen dioxide levels were compared to those obtained from the European Monitoring and Evaluation Programme (EMEP) chemical transport model over the same time period, and furthermore sampling the model at the same time of day as the satellite overpass, thus eliminating the impact of the distinct diurnal cycle of nitrogen dioxide. While generally a good correspondence in the trends has been found between the two data sources

  3. A 3D agglomeration multigrid solver for the Reynolds-averaged Navier-Stokes equations on unstructured meshes

    NASA Technical Reports Server (NTRS)

    Marvriplis, D. J.; Venkatakrishnan, V.

    1995-01-01

    An agglomeration multigrid strategy is developed and implemented for the solution of three-dimensional steady viscous flows. The method enables convergence acceleration with minimal additional memory overheads, and is completely automated, in that it can deal with grids of arbitrary construction. The multigrid technique is validated by comparing the delivered convergence rates with those obtained by a previously developed overset-mesh multigrid approach, and by demonstrating grid independent convergence rates for aerodynamic problems on very large grids. Prospects for further increases in multigrid efficiency for high-Reynolds number viscous flows on highly stretched meshes are discussed.

  4. Evaluation of the antifungal effects of bio-oil prepared with lignocellulosic biomass using fast pyrolysis technology.

    PubMed

    Kim, Kwang Ho; Jeong, Han Seob; Kim, Jae-Young; Han, Gyu Seong; Choi, In-Gyu; Choi, Joon Weon

    2012-10-01

    This study was performed to investigate the utility of bio-oil, produced via a fast pyrolysis process, as an antifungal agent against wood-rot fungi. Bio-oil solutions (25-100 wt.%) were prepared by diluting the bio-oil with EtOH. Wood block samples (yellow poplar and pitch pine) were treated with diluted bio-oil solutions and then subjected to a leaching process under hot water (70°C) for 72 h. After the wood block samples were thoroughly dried, they were subjected to a soil block test using Tyromyces palustris and Trametes versicolor. The antifungal effect of the 75% and 100% bio-oil solutions was the highest for both wood blocks. Scanning electron microscopy analysis indicated that some chemical components in the bio-oil solution could agglomerate together to form clusters in the inner part of the wood during the drying process, which could act as a wood preservative against fungal growth. According to GC/MS analysis, the components of the agglomerate were mainly phenolic compounds derived from lignin polymers.

  5. Development of clean coal and clean soil technologies using advanced agglomeration techniques

    SciTech Connect

    Ignasiak, B.; Ignasiak, T.; Szymocha, K.

    1990-01-01

    Three major topics are discussed in this report: (1) Upgrading of Low Rank Coals by the Agflotherm Process. Test data, procedures, equipment, etc., are described for co-upgrading of subbituminous coals and heavy oil; (2) Upgrading of Bituminous Coals by the Agflotherm Process. Experimental procedures and data, bench and pilot scale equipments, etc., for beneficiating bituminous coals are described; (3) Soil Clean-up and Hydrocarbon Waste Treatment Process. Batch and pilot plant tests are described for soil contaminated by tar refuse from manufactured gas plant sites. (VC)

  6. Myristica oil poisoning

    MedlinePlus

    Nutmeg oil; Myristicin ... Myristica oil ( Myristica fragrans ) can be harmful. It comes from the seed of a nutmeg. ... Myristica oil is found in: Aromatherapy products Mace Nutmeg Other products may also contain myristica oil.

  7. Anthropogenic heat fluxes over Moscow agglomeration and other Russian and world cities

    NASA Astrophysics Data System (ADS)

    Belova, Iya; Ginzburg, Alexander

    2010-05-01

    Urbanization, particularly with respect to its sustainability, remains to be a great challenge in all regions of the world. Urbanization has an influence on soils, hydrology, and climate, these changes have effect on global climate, pollution, increase of anthropogenic greenhouse gases in the earth's atmosphere and human health. Thus anthropogenic heat flux is an important factor for estimation of development of global climate. The simple formula for anthropogenic heat fluxes (AHF) was proposed in the EGU General Assembly 2008 presentation [1] AHF = k × PD × EC, were PD is urban population density and EC is total energy consumption per capita. It was estimated that two of the world megacities - Seoul and Moscow - have the highest AHF values - 83 and 56 W/m2 correspondently. In presented paper it was studied the reasons of such high anthropogenic heat fluxes within Moscow region as well as AHF over the major Russian cities. It was shown that main reason of this circumstance is the administrative divisions in Moscow region. Moscow is ringed by Moscow circle motor road. Accordingly the city has sharply defined boundaries and densely populated residential suburbs are cut off and don't included in Moscow city administrative area. It was constructed the special graph to illuminate why Moscow city has such a high anthropogenic heat factor and how much Moscow agglomeration AHF could be if consider not only Moscow city itself but also the nearest suburb towns. Using the data from World Bank [2] and Russian governmental statistic agency [3] anthropogenic heat fluxes for Russian cities with population more than 500 000 were estimated. Energy consumption data for different Russian regions were calculated by special routine using in the Web-atlas [4]. This research is supported by RAS Fundamental Research Project 'Influence of anthropogenic heat fluxes and aerosol pollution on heat balance and climate of urbanized areas'. Other results of this project is presented in paper [5

  8. Importance of agglomeration state and exposure conditions for uptake and pro-inflammatory responses to amorphous silica nanoparticles in bronchial epithelial cells.

    PubMed

    Gualtieri, Maurizio; Skuland, Tonje; Iversen, Tore-Geir; Låg, Marit; Schwarze, Per; Bilaničová, Dagmar; Pojana, Giulio; Refsnes, Magne

    2012-11-01

    Amorphous silica nanoparticles (SiNPs, 30 and 50 nm) and rhodamine-coated SiNPs (50 nm) were examined for their ability to induce pro-inflammatory responses and cytotoxicity in BEAS-2B cells under different experimental conditions. The SiNPs formed micrometre-sized agglomerates in the absence of bovine serum albumin (BSA) in the culture medium, whereas with BSA (0.1%) they were much less agglomerated. All the SiNPs induced IL-6 and IL-8 responses, as measured by ELISA and real-time PCR. The responses were more marked without BSA and higher for the rhodamine SiNPs than the plain ones. Rhodamine SiNPs were not taken up by cells during a 3-h exposure, even though cytokine mRNAs were up-regulated. In conclusion, agglomerated SiNPs induced more potent cytokine responses than the non-agglomerated ones; either due to the agglomeration state per se or more conceivably to a change in surface reactivity against cellular targets due to BSA. Furthermore, cytokine expression was up-regulated independently of SiNP uptake.

  9. Role of Interparticle Charge Transfers in Agglomerated Photocatalyst Nanoparticles: Demonstration in Aqueous Suspension of Dye-Sensitized TiO2.

    PubMed

    Park, Yiseul; Kim, Wooyul; Monllor-Satoca, Damián; Tachikawa, Takashi; Majima, Tetsuro; Choi, Wonyong

    2013-01-03

    The interparticle charge transfer within the agglomerates of TiO2 nanoparticles in slurries markedly enhanced the dye-sensitized production of H2 under visible light. By purposely decoupling the light absorbing part of Dye/TiO2 from the active catalytic center of Pt/TiO2, the role of bare TiO2 nanoparticles working as a mediator that connects the above two parts in the agglomerates was investigated systematically. The presence of mediator in the agglomerate facilitated the charge separation and the electron transfer from Dye/TiO2 to Pt/TiO2 through multiple grain boundaries and subsequently produced more hydrogen. The dye-sensitized reduction of Cr(VI) to Cr(III) was also enhanced when Dye/TiO2 nanoparticles were agglomerated with bare TiO2 nanoparticles. The charge recombination between the oxidized dye and the injected electron was retarded in the presence of bare TiO2 nanoparticles, and this retarded recombination on Dye/TiO2 was confirmed by using transient laser spectroscopy. This phenomenon can be rationalized in terms of an interparticle Fermi level gradient within the agglomerates, which drives the charge separation.

  10. Polystyrene-divinylbenzene stationary phases agglomerated with quaternized multi-walled carbon nanotubes for anion exchange chromatography.

    PubMed

    Huang, Zhongping; Wu, Hongwei; Wang, Fengli; Yan, Wenwu; Guo, Weiqiang; Zhu, Yan

    2013-06-14

    This work explores the potential of multi-walled carbon nanotubes as an agglomerated material for ion chromatography stationary phases for the separation of inorganic anions. Polyelectrolytes with quaternary ammonium groups were introduced onto the carbon nanotube surface, based on condensation polymerization of 1,4-butanediol diglycidyl ether (BDDE) and methylamine (MA). Quaternized multi-walled carbon nanotubes (Q-MWCNTs) were electrostatically adsorbed onto the surface of sulfonated polystyrene-divinylbenzene (PS-DVB) beads to generate the anion exchanger, which were confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). A 100mm×4.0mm i.d. column was packed with Q-MWCNTs agglomerated PS-DVB particles, with a capacity of 56μequiv./column. Separation of inorganic anions, such as F(-), Cl(-), NO2(-), Br(-), NO3(-), SO4(2-) and PO4(3-) were performed. The stationary phase was rigid, chemically stable and showed good ion-exchange characteristics.

  11. Non-agglomerated gold-PMMA nanocomposites by in situ-stabilized laser ablation in liquid monomer for optical applications

    NASA Astrophysics Data System (ADS)

    Schwenke, Andreas; Dalüge, Hauke; Kiyan, Roman; Sajti, C. Laszlo; Chichkov, Boris N.

    2013-05-01

    The main goal in the production of nanocomposites for optical applications is the uniform and non-agglomerated incorporation of nanoparticles into polymer matrices. Therefore, in this work gold nanoparticles have been generated by short-pulsed liquid phase laser ablation in methyl methacrylate (MMA) with or without dissolved poly(methyl methacrylate) (PMMA) followed by polymerization. The polymeric materials were then used in injection molding to form model nanocomposites for further analysis. It has been observed that the steric in situ-stabilization of nanoparticles by dissolved PMMA inhibits particle aggregation in MMA and due to particle quenching results in smaller nanoparticles than that achieved by working in pure MMA. Similar but even more pronounced stability issues have been highlighted on injection molded optical nanocomposites, revealing that the in situ-stabilization of nanoparticles with PMMA not only prevent an agglomeration in the colloidal state but could also prevent changes in particles dispersion along the entire processing chain ending in final 3D polymer samples. Besides the optical study of the characteristic plasmon peak of gold nanoparticles and the nonlinear absorption behavior for femtosecond laser pulses, XRD analysis revealed the appearance of atomic gold in a centrosymmetric Fm3m cubic structure.

  12. Influence of dispersive agent on nanomaterial agglomeration and implications for biological effects in vivo or in vitro.

    PubMed

    Sauer, Ursula G; Aumann, Alexandra; Ma-Hock, Lan; Landsiedel, Robert; Wohlleben, Wendel

    2015-02-01

    Comparing the dispersing properties of the porcine lung surfactant Curosurf(®) to bovine serum albumin (BSA), the present study investigated how a more close simulation of the in vivo situation influences nanomaterial dispersion and hence the proportion of the administered dose that will reach the in vitro test system, i.e. the ‘effective dose’. Dispersions of 16 OECD reference nanomaterials (ZnO, Ag, TiO(2), CeO(2), SiO(2), and multi-walled carbon nanotubes (MWCNTs) were assessed. Overall, the NMs were better dispersed in the BSA-supplemented medium. BSA-addition combined with ultrasonication proved most effective in deagglomerating MWCNTs, but also reduced agglomeration for most metal oxidenanomaterials as compared to the Curosurf(®) dispersions. However, all materials were at least partially agglomerated in either dispersing agent. For the different nanomaterials, the calculated effective dosage upon 12- or 24-h test substance incubation differed considerably (and to different extents) depending on the applied dispersing agent. When testing nanomaterial effects in vitro, selection of the type of cell culture medium and its additives should take into account what the system is intended to mimic. Study protocols should address whether they aim at best-possible dispersion of the nanomaterials or at simulating more realistically in vivo tissue uptake and distribution.

  13. Understanding the influence of powder flowability, fluidization and de-agglomeration characteristics on the aerosolization of pharmaceutical model powders.

    PubMed

    Zhou, Qi Tony; Armstrong, Brian; Larson, Ian; Stewart, Peter J; Morton, David A V

    2010-08-11

    The aim of this study was to investigate the influence of the intrinsic inter-particulate cohesion of model pharmaceutical powders on their aerosolization from a dry powder inhaler. Two cohesive poly-disperse lactose powders with median particle sizes of around 4 and 20 microm were examined. The results showed that after dry coating with magnesium stearate, their flowability, fluidization and de-agglomeration behaviours could be substantially improved, as indicated by powder rheometry, shear testing and laser diffraction aerosol testing. This was achieved by reducing their cohesiveness via surface modification. In contrast to some previous reports, this study demonstrated how powder aerosolization may be improved more significantly and consistently (for widely varying air flow rates) by substantially reducing their inter-particulate cohesive forces. This study contributes to the understanding of the relationship between intrinsic cohesive nature and bulk properties such as flowability, fluidization and de-agglomeration and its impact on their aerosolization, which is fundamental and critical in the optimal design of dry powder inhaler formulations. The intensive mechanical dry coating technique also demonstrated a promising potential to improve aerosolization efficiency of fine cohesive model powders.

  14. Science: Oil Slick.

    ERIC Educational Resources Information Center

    VanCleave, Janice

    2000-01-01

    Presents a science experiment about oil spills and oil pollution for 7th- and 8th-grade science students. This variation on a method used by pollution control experts to clean up oil spills shows students how oil is collected after an oil spill, explaining that with this method, much of the damage from an oil spill can be averted. (SM)

  15. Engineering Development of Advanced Physical Fine Coal Cleaning for Premium Fuel Applications: Task 9 - Selective agglomeration Module Testing and Evaluation.

    SciTech Connect

    Moro, N.` Jha, M.C.

    1997-09-29

    The primary goal of this project was the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and bench-scale testing of both processes on six coals to optimize the processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. This report summarizes the findings of all the selective agglomeration (SA) test work performed with emphasis on the results of the PDU SA Module testing. Two light hydrocarbons, heptane and pentane, were tested as agglomerants in the laboratory research program which investigated two reactor design concepts: a conventional two-stage agglomeration circuit and a unitized reactor that combined the high- and low-shear operations in one vessel. The results were used to design and build a 25 lb/hr bench-scale unit with two-stage agglomeration. The unit also included a steam stripping and condensation circuit for recovery and recycle of heptane. It was tested on six coals to determine the optimum grind and other process conditions that resulted in the recovery of about 99% of the energy while producing low ash (1-2 lb/MBtu) products. The fineness of the grind was the most important variable with the D80 (80% passing size) varying in the 12 to 68 micron range. All the clean coals could be formulated into coal-water-slurry-fuels with acceptable properties. The bench-scale results were used for the conceptual and detailed design of the PDU SA Module which was integrated with the existing grinding and dewatering circuits. The PDU was operated for about 9 months. During the first three months, the shakedown testing was performed to fine tune the operation and control of various equipment. This was followed by parametric testing, optimization/confirmatory testing, and finally a

  16. Diamond-like-carbon nanoparticle production and agglomeration following UV multi-photon excitation of static naphthalene/helium gas mixtures.

    PubMed

    Walsh, A J; Tielens, A G G M; Ruth, A A

    2016-07-14

    We report the formation of nanoparticles with significant diamond character after UV multi-photon laser excitation of gaseous naphthalene, buffered in static helium gas, at room temperature. The nanoparticles are identified in situ by their absorption and scattering spectra between 400 and 850 nm, which are modeled using Mie theory. Comparisons of the particles' spectroscopic and optical properties with those of carbonaceous materials indicate a sp(3)/sp(2) hybridization ratio of 8:1 of the particles formed. The particle extinction in the closed static (unstirred) gas-phase system exhibits a complex and quasi-oscillatory time dependence for the duration of up to several hours with periods ranging from seconds to many minutes. The extinction dynamics of the system is based on a combination of transport features and particle interaction, predominantly agglomeration. The relatively long period of agglomeration allows for a unique analysis of the agglomeration process of diamond-like carbon nanoparticles in situ.

  17. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Task 6 -- Selective agglomeration laboratory research and engineering development for premium fuels

    SciTech Connect

    Moro, N.; Jha, M.C.

    1997-06-27

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and benchscale testing on six coals to optimize these processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. This report represents the findings of Subtask 6.5 Selective Agglomeration Bench-Scale Testing and Process Scale-up. During this work, six project coals, namely Winifrede, Elkhorn No. 3, Sunnyside, Taggart, Indiana VII, and Hiawatha were processed in a 25 lb/hr continuous selective agglomeration bench-scale test unit.

  18. Vegetable oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is a technically competitive alternative to petroleum-derived diesel fuel. It can be obtained from commodity oils and fats such as soybean, sunflower, canola or tallow. However, the available amounts of these biodiesel feedstocks do not suffice to satisfy the long-term need for biodiesel...

  19. Size-dependent cytotoxicity of silver nanoparticles in human lung cells: the role of cellular uptake, agglomeration and Ag release

    PubMed Central

    2014-01-01

    Background Silver nanoparticles (AgNPs) are currently one of the most manufactured nanomaterials. A wide range of toxicity studies have been performed on various AgNPs, but these studies report a high variation in toxicity and often lack proper particle characterization. The aim of this study was to investigate size- and coating-dependent toxicity of thoroughly characterized AgNPs following exposure of human lung cells and to explore the mechanisms of toxicity. Methods BEAS-2B cells were exposed to citrate coated AgNPs of different primary particle sizes (10, 40 and 75 nm) as well as to 10 nm PVP coated and 50 nm uncoated AgNPs. The particle agglomeration in cell medium was investigated by photon cross correlation spectroscopy (PCCS); cell viability by LDH and Alamar Blue assay; ROS induction by DCFH-DA assay; genotoxicity by alkaline comet assay and γH2AX foci formation; uptake and intracellular localization by transmission electron microscopy (TEM); and cellular dose as well as Ag release by atomic absorption spectroscopy (AAS). Results The results showed cytotoxicity only of the 10 nm particles independent of surface coating. In contrast, all AgNPs tested caused an increase in overall DNA damage after 24 h assessed by the comet assay, suggesting independent mechanisms for cytotoxicity and DNA damage. However, there was no γH2AX foci formation and no increased production of intracellular reactive oxygen species (ROS). The reasons for the higher toxicity of the 10 nm particles were explored by investigating particle agglomeration in cell medium, cellular uptake, intracellular localization and Ag release. Despite different agglomeration patterns, there was no evident difference in the uptake or intracellular localization of the citrate and PVP coated AgNPs. However, the 10 nm particles released significantly more Ag compared with all other AgNPs (approx. 24 wt% vs. 4–7 wt%) following 24 h in cell medium. The released fraction in cell medium did not induce any

  20. Effect of mechanical vibration on platinum particle agglomeration and growth in Polymer Electrolyte Membrane Fuel Cell catalyst layers

    NASA Astrophysics Data System (ADS)

    Diloyan, Georgiy; Sobel, Marcus; Das, Kiranmoy; Hutapea, Parsaoran

    2012-09-01

    The effect of mechanical vibration on Platinum (Pt) particle agglomeration and growth in the catalyst layer of a Membrane Electrode Assembly (MEA) for a Proton Exchange Membrane Fuel Cell (PEMFC) was investigated. A series of experiments were conducted using a 300-h accelerated test with potential cycling and transmission electron microscopy (TEM). Each of the 300-h accelerated tests used different constant mechanical vibration conditions (frequency and acceleration). It was observed that the average diameter of Pt particles under vibration is 10% smaller than the ones that were under no vibration conditions. The Pt particles in the order of 2-2.5 nm in the pristine state have grown to approximately 6 nm (after 300-h accelerated test without vibration condition) and to approximately 5.47 nm (after 300 h accelerated test under 1 g 20 Hz vibration condition).

  1. [Optimization of ecological footprint model based on environmental pollution accounts: a case study in Pearl River Delta urban agglomeration].

    PubMed

    Bai, Yu; Zeng, Hui; Wei, Jian-bing; Zhang, Wen-juan; Zhao, Hong-wei

    2008-08-01

    To solve the problem of ignoring the calculation of environment pollution in traditional ecological footprint model accounts, this paper put forward an optimized ecological footprint (EF) model, taking the pollution footprint into account. In the meantime, the environmental capacity's calculation was also added into the system of ecological capacity, and further used to do ecological assessment of Pearl River Delta urban agglomeration in 2005. The results showed a perfect inosculation between the ecological footprint and the development characteristics and spatial pattern, and illustrated that the optimized EF model could make a better orientation for the environmental pollution in the system, and also, could roundly explain the environmental effects of human activity. The optimization of ecological footprint model had better integrality and objectivity than traditional models.

  2. Acoustic agglomeration of power plant fly ash: Quarterly technical report, 5 November 1986--5 February 1987

    SciTech Connect

    Reethof, G.

    1987-03-20

    High-intensity, high-efficiency sound sources are needed for acoustic agglomeration of particle-laden aerosols in power plant flues and for combustion enhancement. The theory of the linear model is reviewed and show to be in strong disagreement with experimental results. A theoretical study of the sound generation mechanism in sirens is then presented. The various sound attenuation mechanisms are reviewed and a low frequency numerical solution for the frequency response is given which includes arbitrary attenuation, dispersion, horn shape, and mean flow. Next finite-amplitude sound propagation in a horn is studied. Results are presented that agree very well with experimental data. Important nonlinear phenomena such as shock formation, acoustic saturation, and distortion of initially non-sinusoidal finite- amplitude waves are discussed. Finally, a new siren design methodology is presented, including a step-by-step discussion on hot to minimize the acoustic losses. 8 figs.

  3. Manipulation and light-induced agglomeration of carbon nanotubes through optical trapping of attached silver nanoparticles.

    PubMed

    Shi, Chao; Zhang, Yi; Gu, Claire; Seballos, Leo; Zhang, Jin Z

    2008-05-28

    A simple experimental method has been demonstrated for manipulating multi-walled carbon nanotube (MWCNT) bundles through the optical trapping of attached silver nanoparticles (SNPs). In our experiments, without the SNPs, the MWCNTs cannot be trapped due to their irregular shapes and large aspect ratio. However, when mixed with SNPs, the MWCNTs can be successfully trapped along with the SNPs using a TEM(00) mode laser at 532 nm. This is attributed to the optical trapping of the SNPs and attractive interaction or binding between the SNPs and MWCNTs due to electrostatic and van der Waals forces. Therefore, optical manipulation of MWCNT bundles is achieved through the manipulation of the attached silver nanoparticles/aggregates. In addition, we have observed the phenomenon of light-induced further agglomeration of SNPs/MWCNTs which could potentially be exploited for fabricating patterned MWCNT films for future nanoscale devices and other applications.

  4. Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Topical report, Process analysis, FY 1983

    SciTech Connect

    1987-07-31

    KRW Energy Systems, Inc., is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally-acceptable production of low- and medium-Btu fuel gas from a variety of fossilized carbonaceous feedstocks and industrial fuels. This report presents process analysis of the 24 ton-per-day Process Development Unit (PDU) operations and is a continuation of the process analysis work performed in 1980 and 1981. Included is work performed on PDU process data; gasification; char-ash separation; ash agglomeration; fines carryover, recycle, and consumption; deposit formation; materials; and environmental, health, and safety issues. 63 figs., 43 tabs.

  5. Oil damage

    SciTech Connect

    Helm, R.C.

    1995-03-31

    This book presents the results of a series of studies designed to determine the extent and magnitude of the effects of the Exxon Valdez oil spill on marine mammals, particularly sea otters. A third of the book focuses on studies that quantify population-level impacts, with much of the remainder focusing on behavioral, pathologic, or toxicologic studies designed to understand how petroleum hydrocarbons negatively affect free ranging marine animals.

  6. Water resources management in the urban agglomeration of the Lake Biwa region, Japan: An ecosystem services-based sustainability assessment.

    PubMed

    Chen, Xiaochen; Chen, Yuqing; Shimizu, Toshiyuki; Niu, Jia; Nakagami, Ken'ichi; Qian, Xuepeng; Jia, Baoju; Nakajima, Jun; Han, Ji; Li, Jianhua

    2017-05-15

    An innovative ecosystem services-based sustainability assessment was conducted in the important urban agglomeration of the Lake Biwa region, Japan, covering the time period from 1950 to 2014. A 22-indicator system was established that was based on the major ecosystem services of Lake Biwa and its water courses, i.e., provisioning services regarding aquatic products and water; regulating services regarding floods and water quality; cultural services regarding recreation and tourism, scientific research, and environmental education; and supporting services regarding biodiversity. First, changes in the eight ecosystem services were discussed together with the considerable experience and difficult lessons that can be drawn from the development trajectory. Next, with the indicators rearranged according to sustainability principles, the regional sustainability over the past six-plus decades was assessed. In general, this urban agglomeration has been progressing in terms of its sustainability, although economic and social development was achieved at the cost of environmental degradation in the past, and the current economic downturn is hurting the balanced development and integrated benefits. The results lead directly to recommendations for regional development, especially in terms of economic rejuvenation, from the perspective of improving management of Lake Biwa's water resources. Moreover, the relevant knowledge is educational and inspirational for other places in the world that are facing similar development issues. For example, the effective and even pioneering countermeasures that have been taken against environmental degradation, as well as the participation and collaboration of multiple stakeholders, could be useful as a model. Moreover, the study invites increased understanding of ecosystem vulnerability to anthropogenic devastation and emphasizes the priority of precautionary measures over countermeasures in the context of holistic urban planning and sustainable

  7. The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China.

    PubMed

    Huang, Qunfang; Lu, Yuqi

    2015-07-27

    The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957-2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming.

  8. Spatial-temporal characteristics and determinants of PM2.5 in the Bohai Rim Urban Agglomeration.

    PubMed

    Wang, Zhen-bo; Fang, Chuang-lin

    2016-04-01

    Ambient particulate matter (PM) pollution of China has become a global concern and has great impact on air quality and human health. This paper adopts the PM2.5 concentration data obtained from 241 newly located observation points in the Bohai Rim Urban Agglomeration (BRUA), as well as economic, urban and industrial working population data in the study area, revealing the spatio-temporal distribution of PM2.5 and its determinants with the help of a spatial data model. The results indicate that: 1) The BRUA was the core area of PM2.5 pollution in China in 2014, the average PM2.5 concentration of which reached 74 μg/m(3), which is 13 μg/m(3) higher than the country average (61 μg/m(3)); 2) The PM2.5 concentration distribution had a characteristic of high in winter and autumn but low in spring and summer, presenting a U-shaped monthly profile and a U-impulse type daily profile; 3) The urban PM2.5 concentrations showed obvious spatial variation and agglomeration. The highest hot-spot was observed in spring, while the lowest was in summer. High concentration cities were mainly located in southern Hebei and western Shandong, and low concentration cities were in the coastal area around the Bohai Sea and the mountainous areas in northern Hebei. High hot-spot areas demonstrated an M-shaped change, with two cycles of advance and retreat from west to east. 4) The Geographically weighted regression (GWR) model shows that the GDP per capita, urbanization rate and construction of the cities were closely related to PM2.5 concentrations in the BRUA.

  9. The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China

    PubMed Central

    Huang, Qunfang; Lu, Yuqi

    2015-01-01

    The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957–2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming. PMID:26225986

  10. Influence of agglomeration and specific lung lining lipid/protein interaction on short-term inhalation toxicity.

    PubMed

    Wohlleben, Wendel; Driessen, Marc D; Raesch, Simon; Schaefer, Ulrich F; Schulze, Christine; Vacano, Bernhard von; Vennemann, Antje; Wiemann, Martin; Ruge, Christian A; Platsch, Herbert; Mues, Sarah; Ossig, Rainer; Tomm, Janina M; Schnekenburger, Jürgen; Kuhlbusch, Thomas A J; Luch, Andreas; Lehr, Claus-Michael; Haase, Andrea

    2016-09-01

    Lung lining fluid is the first biological barrier nanoparticles (NPs) encounter during inhalation. As previous inhalation studies revealed considerable differences between surface functionalized NPs with respect to deposition and toxicity, our aim was to investigate the influence of lipid and/or protein binding on these processes. Thus, we analyzed a set of surface functionalized NPs including different SiO2 and ZrO2 in pure phospholipids, CuroSurf(TM) and purified native porcine pulmonary surfactant (nS). Lipid binding was surprisingly low for pure phospholipids and only few NPs attracted a minimal lipid corona. Additional presence of hydrophobic surfactant protein (SP) B in CuroSurf(TM) promoted lipid binding to NPs functionalized with Amino or PEG residues. The presence of the hydrophilic SP A in nS facilitated lipid binding to all NPs. In line with this the degree of lipid and protein affinities for different surface functionalized SiO2 NPs in nS followed the same order (SiO2 Phosphate ∼ unmodified SiO2 < SiO2 PEG < SiO2 Amino NPs). Agglomeration and biomolecule interaction of NPs in nS was mainly influenced by surface charge and hydrophobicity. Toxicological differences as observed in short-term inhalation studies (STIS) were mainly influenced by the core composition and/or surface reactivity of NPs. However, agglomeration in lipid media and lipid/protein affinity appeared to play a modulatory role on short-term inhalation toxicity. For instance, lipophilic NPs like ZrO2, which are interacting with nS to a higher extent, exhibited a far higher lung burden than their hydrophilic counterparts, which deserves further attention to predict or model effects of respirable NPs.

  11. Extrinsic lactose fines improve dry powder inhaler formulation performance of a cohesive batch of budesonide via agglomerate formation and consequential co-deposition.

    PubMed

    Kinnunen, Hanne; Hebbink, Gerald; Peters, Harry; Huck, Deborah; Makein, Lisa; Price, Robert

    2015-01-15

    The aim of the study was to investigate how the fine particle content of lactose carriers prepared with different types of lactose fines regulates dry powder inhaler (DPI) formulation performance of a cohesive batch of micronised budesonide. Budesonide formulations (0.8 wt%) were prepared with three different lactose carriers (Lactohale (LH) LH100, 20 wt% LH210 in LH100 and 20 wt% LH300 in LH100). Fine particle fraction of emitted dose (FPFED) and mean mass aerodynamic diameter (MMAD) of budesonide was assessed with a Next Generation Impactor (NGI) using a Cyclohaler at 90 l/min. Morphological and chemical characteristics of particles deposited on Stage 2 were determined using a Malvern Morphologi G3-ID. The results indicate that increasing concentration of lactose fines (<4.5 μm) not only increased the FPFED but also the MMAD of budesonide, suggesting drug deposition in agglomerates. Presence of agglomerates on Stage 2 was confirmed by morphological analysis of particles. Raman analysis of material collected on Stage 2 indicated that the more fine lactose particles were available the more agglomerates of budesonide and lactose were delivered to Stage 2. These results suggest drug-fines agglomerate formation is an important mechanism for how lactose fines improve and regulate DPI formulation performance.

  12. Design of sustained release fine particles using two-step mechanical powder processing: particle shape modification of drug crystals and dry particle coating with polymer nanoparticle agglomerate.

    PubMed

    Kondo, Keita; Ito, Natsuki; Niwa, Toshiyuki; Danjo, Kazumi

    2013-09-10

    We attempted to prepare sustained release fine particles using a two-step mechanical powder processing method; particle-shape modification and dry particle coating. First, particle shape of bulk drug was modified by mechanical treatment to yield drug crystals suitable for the coating process. Drug crystals became more rounded with increasing rotation speed, which demonstrates that powerful mechanical stress yields spherical drug crystals with narrow size distribution. This process is the result of destruction, granulation and refinement of drug crystals. Second, the modified drug particles and polymer coating powder were mechanically treated to prepare composite particles. Polymer nanoparticle agglomerate obtained by drying poly(meth)acrylate aqueous dispersion was used as a coating powder. The porous nanoparticle agglomerate has superior coating performance, because it is completely deagglomerated under mechanical stress to form fine fragments that act as guest particles. As a result, spherical drug crystals treated with porous agglomerate were effectively coated by poly(meth)acrylate powder, showing sustained release after curing. From these findings, particle-shape modification of drug crystals and dry particle coating with nanoparticle agglomerate using a mechanical powder processor is expected as an innovative technique for preparing controlled-release coated particles having high drug content and size smaller than 100 μm.

  13. Why Does the Spatial Agglomeration of Firms Benefit Workers? Examining the Role of Organizational Diversity in U.S. Industries and Labor Markets

    ERIC Educational Resources Information Center

    Fullerton, Andrew S.; Villemez, Wayne J.

    2011-01-01

    Several recent studies across the social sciences show that the spatial agglomeration of employment in a local labor market benefits both firms and workers in terms of better firm performance and higher wages. Drawing from the organizational ecology perspective, we argue that workers receive higher wages in large industrial clusters and urban…

  14. Turpentine oil poisoning

    MedlinePlus

    Turpentine oil comes from a substance in pine trees. Turpentine oil poisoning occurs when someone swallows turpentine oil or breathes in the fumes. Breathing these fumes on purpose is sometimes called " ...

  15. Exploring Oil Pollution

    ERIC Educational Resources Information Center

    Rillo, Thomas J.

    1974-01-01

    Discusses damages of oil tanker spillage to the marine organisms and scientists' research in oil pollution removal techniques. Included is a list of learning activities concerning the causes and effects of oil pollution and methods of solving the problem. (CC)

  16. FracMAP: A user-interactive package for performing simulation and orientation-specific morphology analysis of fractal-like solid nano-agglomerates

    NASA Astrophysics Data System (ADS)

    Chakrabarty, Rajan K.; Garro, Mark A.; Chancellor, Shammah; Herald, Christopher; Moosmüller, Hans

    2009-08-01

    Computer simulation techniques have found extensive use in establishing empirical relationships between three-dimensional (3d) and two-dimensional (2d) projected properties of particles produced by the process of growth through the agglomeration of smaller particles (monomers). In this paper, we describe a package, FracMAP, that has been written to simulate 3d quasi-fractal agglomerates and create their 2d pixelated projection images by restricting them to stable orientations as commonly encountered for quasi-fractal agglomerates collected on filter media for electron microscopy. Resulting 2d images are analyzed for their projected morphological properties. Program summaryProgram title: FracMAP Catalogue identifier: AEDD_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDD_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 4722 No. of bytes in distributed program, including test data, etc.: 27 229 Distribution format: tar.gz Programming language: C++ Computer: PC Operating system: Windows, Linux RAM: 2.0 Megabytes Classification: 7.7 Nature of problem: Solving for a suitable fractal agglomerate construction under constraints of typical morphological parameters. Solution method: Monte Carlo approximation. Restrictions: Problem complexity is not representative of run-time, since Monte Carlo iterations are of a constant complexity. Additional comments: The distribution file contains two versions of the FracMAP code, one for Windows and one for Linux. Running time: 1 hour for a fractal agglomerate of size 25 on a single processor.

  17. Process for retorting oil shale with fluidized retorting of shale fines

    SciTech Connect

    Deering, R. F.

    1985-05-07

    Hot particles removed from a retort, preferably retort-sized particles of oil shale removed from a retort operating at superatmospheric pressure, are crushed and fed to a fluidized surge zone maintained under non-oxidizing conditions at substantially the pressure of the retort to forestall escape of retort gases. Raw fines are introduced into the surge zone and retorted without agglomeration by heat transferred from the hot retorted particles and/or a heated fluidizing gas stream to educe hydrocarbonaceous vapors. Educed vapors are scrubbed, condensed and separated into liquid and gaseous product streams, a portion of the latter being recycled to provide fluidizing process gas streams.

  18. Synthesis of colloids based on gold nanoparticles dispersed in castor oil

    NASA Astrophysics Data System (ADS)

    da Silva, E. C.; da Silva, M. G. A.; Meneghetti, S. M. P.; Machado, G.; Alencar, M. A. R. C.; Hickmann, J. M.; Meneghetti, M. R.

    2008-12-01

    New colloidal solutions of gold nanoparticles (AuNP), using castor oil as a nontoxic organic dispersant agent, were prepared via three different methods. In all three cases, tetrachloroauric(III) acid was employed as the gold source. The colloids were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). The AuNP produced by the three methods were quasispherical in shape, however with different average sizes. The individual characteristics of the nanoparticles presented in each colloidal system were also confirmed by observation of absorption maxima at different wavelengths of visible light. Each method of synthesis leads to colloids with different grades of stability with respect to particle agglomeration.

  19. Biochemically enhanced oil recovery and oil treatment

    DOEpatents

    Premuzic, Eugene T.; Lin, Mow

    1994-01-01

    This invention relates to the preparation of new, modified organisms, through challenge growth processes, that are viable in the extreme temperature, pressure and pH conditions and salt concentrations of an oil reservoir and that are suitable for use in microbial enhanced oil recovery. The modified microorganisms of the present invention are used to enhance oil recovery and remove sulfur compounds and metals from the crude oil.

  20. Biochemically enhanced oil recovery and oil treatment

    DOEpatents

    Premuzic, E.T.; Lin, M.

    1994-03-29

    This invention relates to the preparation of new, modified organisms, through challenge growth processes, that are viable in the extreme temperature, pressure and pH conditions and salt concentrations of an oil reservoir and that are suitable for use in microbial enhanced oil recovery. The modified microorganisms of the present invention are used to enhance oil recovery and remove sulfur compounds and metals from the crude oil. 62 figures.

  1. [MICROBIAL DESTRUCTION MINERAL (OIL) MOTOR OIL].

    PubMed

    Homenko, L A; Nogina, T M

    2015-01-01

    In a review information is presented about composition of mineral motor oils and their negative impact on the environment and the ability of microorganisms, in particular actinobacteria, to assimilate hydrocarbon oil components. The role of bacteria is described in the process of cleaning up polluted environments motor oils and the prospect of their use in biotechnology, environmental clean-up of these pollutants.

  2. Non-Petroleum Oils

    EPA Pesticide Factsheets

    These include synthetics such as silicone fluids and tung oils, wood-derivative oils such as resin/rosin, animal fats/oil, and seed oils. Many have similar physical properties to petroleum-based, such as water insolubility and formation of slicks.

  3. [Spatiotemporal pattern of urban growth and its driving forces in urban agglomeration of central Liaoning Province, China].

    PubMed

    Xi, Feng-Ming; He, Hong-Shi; Hu, Yuan-Man; Wu, Xiao-Qing; Chang, Yu; Liu, Miao; Shi, Tie-Mao; Wang, Jin-Nian

    2010-03-01

    Based on the five temporal Landsat TM remote sensing data of 1988, 1992, 1997, 2000, and 2004, and by using GIS spatial analysis and landscape pattern analysis, this paper analyzed the spatiotemporal pattern of urban growth and its driving forces in the urban agglomeration of central Liaoning Province (UACLP). From 1988 to 2004, the urban area in the UACLP had being increased from 812.55 km2 to 1345.86 km2, with an average growth rate of 32.96 km2 per year. The urban growth rate increased rapidly after 1997, and the urban growth intensity was up to the peak in 1997-2000. The urban growth was mainly concentrated in the central dense belt of the UACLP. From 1988 to 1997, the urban growth was relatively slow, its spatial pattern was compact, and edge growth and filling were the main urban growth types. From 1997 to 2004, the urban growth became faster with diffused spatial pattern and complex patch shape, and "frog leap" and diffusion were the main urban growth types. Non-agricultural population growth, economic growth, urban spatial mutual attraction, industrial development, and development zones construction policies were the main driving forces of urban growth in the UACLP.

  4. Organic market gardening around the Paris agglomeration: agro-environmental performance and capacity to meet urban requirements.

    PubMed

    Anglade, Juliette; Medina, Michael Ramos; Billen, Gilles; Garnier, Josette

    2016-05-04

    Organic market gardening is often promoted by urban municipalities as a way to resource part of the food supply, creating new social links and protecting groundwater resources. The agronomical and environmental performance of six commercial organic market gardening farms supplying vegetables in Paris were evaluated and compared with other vegetable production systems. When expressed in terms of protein production, the yield of these systems appears rather low compared with the productive capacity of open-field organic cropping systems where vegetable production is inserted into rotation with other crops. Moreover, the requirement of producing infiltrated water meeting the drinking water standards seriously limits the allowable rate of fertilisation, thus limiting production. The data reported herein show that to supply the amount of vegetables required by the Paris agglomeration (12 million inhabitants) only by organic market gardening, 160,000-205,000 ha, i.e. 28-36 % of the agricultural area of the surrounding Ile-de-France region, would be required. We conclude that organic market gardening is only one of several other farming systems which can contribute to a re-localised supply of vegetables to large cities.

  5. Removal of oxide nanoparticles in a model wastewater treatment plant: influence of agglomeration and surfactants on clearing efficiency.

    PubMed

    Limbach, Ludwig K; Bereiter, Robert; Müller, Elisabeth; Krebs, Rolf; Galli, René; Stark, Wendelin J

    2008-08-01

    The rapidly increasing production of engineered nanoparticles has created a demand for particle removal from industrial and communal wastewater streams. Efficient removal is particularly important in view of increasing long-term persistence and evidence for considerable ecotoxicity of specific nanoparticles. The present work investigates the use of a model wastewater treatment plant for removal of oxide nanoparticles. While a majority of the nanoparticles could be captured through adhesion to clearing sludge, a significant fraction of the engineered nanoparticles escaped the wastewater plant's clearing system, and up to 6 wt % of the model compound cerium oxide was found in the exit stream of the model plant. Our study demonstrates a significant influence of surface charge and the addition of dispersion stabilizing surfactants as routinely used in the preparation of nanoparticle derived products. A detailed investigation on the agglomeration of oxide nanoparticles in wastewater streams revealed a high stabilization of the particles against clearance (adsorption on the bacteria from the sludge). This unexpected finding suggests a need to investigate nanoparticle clearance in more detail and demonstrates the complex interactions between dissolved species and the nanoparticles within the continuously changing environment of the clearing sludge.

  6. Formulation Development of Spherical Crystal Agglomerates of Itraconazole for Preparation of Directly Compressible Tablets with Enhanced Bioavailability.

    PubMed

    Fadke, Janki; Desai, Jagruti; Thakkar, Hetal

    2015-12-01

    The objective of the present work was to formulate tablet dosage form of itraconazole with enhanced bioavailability. Spherical crystal agglomerates (SCA) of itraconazole prepared by quasi emulsification solvent diffusion method using Soluplus and polyethylene glycol 4000 (PEG 4000) showed increased solubility (540 μg/ml) in 0.1 N hydrochloric acid as compared to pure drug (12 μg/ml). A Fourier transform infrared (FTIR) study indicated compatibility of drug with the excipients. The developed SCA were spherical with smooth surface having an average size of 412 μm. The significantly improved micromeritic properties compared to the plain drug suggested its suitability for direct compression. The antifungal activity of itraconazole was retained in the SCA form as evidenced from the results of the disc diffusion method. The optimized SCA formulation could be easily compressed into tablet with desirable characteristics of hardness (5 kg/cm(2)) and disintegration time (6.3 min). The in vitro dissolution studies showed significant difference in the dissolution profiles of pure drug (21%) and SCA formulation (85%) which was even greater than that of marketed preparation (75%). In vivo pharmacokinetic showed significant enhancement in C max and AUC0-t with relative bioavailability of 225%. The SCA formulation seems to be promising for enhancement of oral bioavailability of itraconazole.

  7. An adaptive extended finite element method for the analysis of agglomeration of colloidal particles in a flowing fluid

    SciTech Connect

    Choi, Young Joon; Jorshari, Razzi Movassaghi; Djilali, Ned

    2015-03-10

    Direct numerical simulations of the flow-nanoparticle interaction in a colloidal suspension are presented using an extended finite element method (XFEM) in which the dynamics of the nanoparticles is solved in a fully-coupled manner with the flow. The method is capable of accurately describing solid-fluid interfaces without the need of boundary-fitted meshes to investigate the dynamics of particles in complex flows. In order to accurately compute the high interparticle shear stresses and pressures while minimizing computing costs, an adaptive meshing technique is incorporated with the fluid-structure interaction algorithm. The particle-particle interaction at the microscopic level is modeled using the Lennard-Jones (LJ) potential and the corresponding potential parameters are determined by a scaling procedure. The study is relevant to the preparation of inks used in the fabrication of catalyst layers for fuel cells. In this paper, we are particularly interested in investigating agglomeration of the nanoparticles under external shear flow in a sliding bi-periodic Lees-Edwards frame. The results indicate that the external shear has a crucial impact on the structure formation of colloidal particles in a suspension.

  8. To prevent the occurrence of black water agglomerate through delaying decomposition of cyanobacterial bloom biomass by sediment microbial fuel cell.

    PubMed

    Zhou, Yan-Li; Jiang, He-Long; Cai, Hai-Yuan

    2015-04-28

    Settlement of cyanobacterial bloom biomass (CBB) into sediments in eutrophic lakes often induced the occurrence of black water agglomerate and then water quality deterioration. This study investigated the effect of sediment microbial fuel cell (SMFC) on CBB removal in sediments and related water pollution. Sediment bulking and subsequent black water from decomposition of settled CBB happened without SMFC, but were not observed over 100-day experiments with SMFC employment. While CBB in sediments improved power production from SMFC, the removal efficiency of organic matters in CBB-amended sediments with SMFC was significantly lower than that without SMFC. Pyrosequencing analysis showed higher abundances of the fermentative Clostridium and acetoclastic methanogen in CBB-amended bulk sediments without SMFC than with SMFC at the end of experiments. Obviously, SMFC operation changed the microbial community in CBB-amended sediments, and delayed the CBB degradation against sediment bulking. Thus, SMFC could be potentially applied as pollution prevention in CBB-settled and sensitive zones in shallow lakes.

  9. Graph-based active learning of agglomeration (GALA): a Python library to segment 2D and 3D neuroimages.

    PubMed

    Nunez-Iglesias, Juan; Kennedy, Ryan; Plaza, Stephen M; Chakraborty, Anirban; Katz, William T

    2014-01-01

    The aim in high-resolution connectomics is to reconstruct complete neuronal connectivity in a tissue. Currently, the only technology capable of resolving the smallest neuronal processes is electron microscopy (EM). Thus, a common approach to network reconstruction is to perform (error-prone) automatic segmentation of EM images, followed by manual proofreading by experts to fix errors. We have developed an algorithm and software library to not only improve the accuracy of the initial automatic segmentation, but also point out the image coordinates where it is likely to have made errors. Our software, called gala (graph-based active learning of agglomeration), improves the state of the art in agglomerative image segmentation. It is implemented in Python and makes extensive use of the scientific Python stack (numpy, scipy, networkx, scikit-learn, scikit-image, and others). We present here the software architecture of the gala library, and discuss several designs that we consider would be generally useful for other segmentation packages. We also discuss the current limitations of the gala library and how we intend to address them.

  10. Potential sensitivity of warm season precipitation to urbanization extents: Modeling study in Beijing-Tianjin-Hebei urban agglomeration in China

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Feng, Jinming; Yan, Zhongwei

    2015-09-01

    In this study, we investigated how different degrees of urbanization affect local and regional rainfall using high-resolution simulations based on the Weather Research and Forecasting Model. The extreme rainfall event of 21 July 2012 in Beijing was simulated for three representative urban land use distributions (no urbanization, early urbanization level of 1980, and recent urbanization level of 2009). Results suggest that urban modification of rainfall is potentially sensitive to urban land use condition. Rainfall was increased significantly over the downwind Beijing metropolis because of the effects of early urbanization; however, recent conditions of high urban development caused no significant increase. Further comparative analysis revealed that positive urban thermodynamical effects (i.e., urban warming, increased sensible heat transportation, and enhanced convergence and vertical motions) play major roles in urban modification of rainfall during the early urbanization stage. However, after cities expand to a certain extent (i.e., urban agglomeration), the regional moisture depression induced by the prevalence of impervious urban land has an effect on atmospheric instability energy, which might negate the city's positive impact on regional rainfall. Additional results from regional climate simulations for 10 Julys confirm this supposition. Given the explosive urban population growth and increasing demand for freshwater in cities, the potential negative effects of the urban environment on precipitation are worth investigation, particularly in rapidly developing countries and regions.

  11. Insights into the inner structure of high-nickel agglomerate as high-performance lithium-ion cathodes

    NASA Astrophysics Data System (ADS)

    Yang, Cheng-Kai; Qi, Li-Ya; Zuo, Zicheng; Wang, Ru-Na; Ye, Meng; Lu, Jing; Zhou, Heng-Hui

    2016-11-01

    In this paper, the intrinsic impact of inner structure features on the electrochemical performances of LiNi0.6Co0.2Mn0.2O2 cathodes is for the first time systematically investigated. Three different spherical Ni0.6Co0.2Mn0.2(OH)2 precursors are successfully synthesized by controlling pH values and ammonia concentrations. Interestingly, via a further lithiation process, the final cathodes can gradually inherit the structural features, showing distinct particle arrangement and genetic orientation characteristics in the inner structures. Such a hereditary property can be well reined for customizing the grain-orientation, helping the growth of the inert crystal direction, reducing cation mixing and exposing the high active (100) or (010) lattice planes for lithiation/delithiation processes via an intrinsical way. The degree of grain-orientation of the primary particles turns out to be a critical factor in determining the long-term stability and power performances. Due to the reduced cation mixing degree and favorable lithium diffusion pathways, the ordered agglomerates with the grain growth along with [003] direction exhibit superior rate capability and good cycle stability.

  12. Comparison of reduction disintegration characteristics of TiO2-rich burdens prepared with sintering process and composite agglomeration process

    NASA Astrophysics Data System (ADS)

    Yu, Zheng-wei; Li, Guang-hui; Liu, Chen; Zhou, Feng; Peng, Zhi-wei; Jiang, Tao

    2016-04-01

    To reveal the impact of the composite agglomeration process (CAP) on the reduction disintegration properties of TiO2-rich ironmaking burden for a blast furnace, the reduction disintegration indices (RDIs), mineral constituents, and microstructure of the products prepared by the CAP and the traditional sintering process (TSP) were investigated. The results showed that, compared to the sinter with a basicity of 2.0 prepared by the TSP, the RDI+6.3 and the RDI+3.15 of the CAP product with the same basicity increased by 28.2wt% and 13.7wt%, respectively, whereas the RDI-0.5 decreased by 2.7wt%. The analysis of the mineral constituents and microstructure of the products indicated that the decreasing titanohematite content decreased the volume expansion during reduction. Meanwhile, the decreasing perovskite content decreased its detrimental effect on the reduction disintegration properties. In addition, the higher silicoferrite of calcium and aluminum (SFCA) content improved the strength of the CAP product. Together, these factors result in an improvement of the RDI of the CAP products. In addition, compared to the sinter, the reduced CAP products clearly contained fewer cracks, which also led to mitigation of reduction disintegration.

  13. Vegetable oil fuel standards

    SciTech Connect

    Pryde, E.H.

    1982-01-01

    Suggested standards for vegetable oils and ester fuels, as well as ASTM specifications for No. 2 diesel oil are given. The following physical properties were discussed: cetane number, cloud point, distillation temperatures, flash point, pour point, turbidity, viscosity, free fatty acids, iodine value, phosphorus, and wax. It was apparent that vegetable oils and their esters cannot meet ASTM specifications D975 for No. 2 diesel oil for use in the diesel engine. Vegetable oil modification or engine design modification may make it possible eventually for vegetable oils to become suitable alternative fuels. Vegetable oils must be recognized as experimental fuels until modifications have been tested thoroughly and generally accepted. 1 table. (DP)

  14. Direct use of sunflower oil as a heating oil

    SciTech Connect

    Karaosmanoglu, F.; Kurt, G.

    1998-11-01

    Vegetable oils in particular have exceptional importance since they can be used as a fuel oil (heating oil type) alternative. In this research evaluation, the possibilities of sunflower oil as a heating oil candidate have been investigated. The fuel oil property tests of sunflower oil were performed according to standard methods. An overall evaluation of data indicates that sunflower oil can be proposed as a possible substitute for heating oil.

  15. Tea tree oil.

    PubMed

    Hartford, Orville; Zug, Kathryn A

    2005-09-01

    Tea tree oil is a popular ingredient in many over-the-counter healthcare and cosmetic products. With the explosion of the natural and alternative medicine industry, more and more people are using products containing tea tree oil. This article reviews basic information about tea tree oil and contact allergy, including sources of tea tree oil, chemical composition, potential cross reactions, reported cases of allergic contact dermatitis, allergenic compounds in tea tree oil, practical patch testing information, and preventive measures.

  16. A Single Step Lapping and Polishing Process for Achieving Surfaces of Compound Semiconductors with Atomic Flatness using a Sub-micron Agglomerate-free Alumina Slurry

    SciTech Connect

    P.S. Dutta; G. Rajagopalan; J.J. Gutmann; D. Keller; L. Sweet

    2002-08-29

    A novel approach for a single step lapping and final polishing of III-V and II-VI compounds using agglomerate-free alumina slurries has been developed. The agglomerate-free nature of the sub-micron slurry leads to removal rates comparable to conventional slurries (with larger particles of tens of microns) used for semiconductor lapping. Surfaces with minimal surface damage and extremely low surface roughness have been obtained using the sub-micron slurries and a soft pad. Strategies for post polishing surface cleaning have been discussed. The new methodology has been experimented on GaSb, InAs, GaAs, InP, InSb, CdTe, GaInSb, GaInAs, AlGaAsSb, GaInAsSb and HgCdTe. Selected results of surface analyses of GaSb and GaInSb using atomic force microscopy will be presented.

  17. Generation and agglomeration behaviour of size-selected sub-nm iron clusters as catalysts for the growth of carbon nanotubes

    PubMed Central

    Engstler, Jörg

    2011-01-01

    Summary Mass-selected, ligand-free FeN clusters with N = 10–30 atoms (cluster diameter: 0.6–0.9 nm) were implanted into [Al@SiOx] surfaces at a low surface coverage corresponding to a few thousandths up to a few hundredths of a monolayer in order to avoid initial cluster agglomeration. These studies are aimed towards gaining an insight into the lower limit of the size regime of carbon nanotube (CNT) growth by employing size-selected sub-nm iron clusters as catalyst or precatalyst precursors for CNT growth. Agglomeration of sub-nm iron clusters to iron nanoparticles with a median size range between three and six nanometres and the CNT formation hence can be observed at CVD growth temperatures of 750 °C. Below 600 °C, no CNT growth is observed. PMID:22259755

  18. Phase and sedimentation behavior of oil (octane) dispersions in the presence of model mineral aggregates.

    PubMed

    Gupta, Anju; Sender, Maximilian; Fields, Sarah; Bothun, Geoffrey D

    2014-10-15

    Adsorption of suspended particles to the interface of surfactant-dispersed oil droplets can alter emulsion phase and sedimentation behavior. This work examines the effects of model mineral aggregates (silica nanoparticle aggregates or SNAs) on the behavior of oil (octane)-water emulsions prepared using sodium bis(2-ethylhexyl) sulfosuccinate (DOSS). Experiments were conducted at different SNA hydrophobicities in deionized and synthetic seawater (SSW), and at 0.5mM and 2.5mM DOSS. SNAs were characterized by thermogravimetric analysis (TGA) and dynamic light scattering (DLS), and the emulsions were examined by optical and cryogenic scanning electron microscopy. In deionized water, oil-in-water emulsions were formed with DOSS and the SNAs did not adhere to the droplets or alter emulsion behavior. In SSW, water-in-oil emulsions were formed with DOSS and SNA-DOSS binding through cation bridging led to phase inversion to oil-in-water emulsions. Droplet oil-mineral aggregates (OMAs) were observed for hydrophilic SNAs, while hydrophobic SNAs yielded quickly sedimenting agglomerated OMAs.

  19. Modified MODFLOW-based model for simulating the agglomeration and transport of polymer-modified Fe(0) nanoparticles in saturated porous media.

    PubMed

    Babakhani, Peyman; Fagerlund, Fritjof; Shamsai, Abolfazl; Lowry, Gregory V; Phenrat, Tanapon

    2015-08-25

    The solute transport model MODFLOW has become a standard tool in risk assessment and remediation design. However, particle transport models that take into account both particle agglomeration and deposition phenomena are far less developed. The main objective of the present study was to evaluate the feasibility of adapting the standard code MODFLOW/MT3D to simulate the agglomeration and transport of three different types of polymer-modified nanoscale zerovalent iron (NZVI) in one-dimensional (1-D) and two-dimensional (2-D) saturated porous media. A first-order decay of the particle population was used to account for the agglomeration of particles. An iterative technique was used to optimize the model parameters. The model provided good matches to 1-D NZVI-breakthrough data sets, with R (2) values ranging from 0.96 to 0.99, and mass recovery differences between the experimental results and simulations ranged from 0.1 to 1.8 %. Similarly, simulations of NZVI transport in the heterogeneous 2-D model demonstrated that the model can be applied to more complicated heterogeneous domains. However, the fits were less good, with the R (2) values in the 2-D modeling cases ranging from 0.75 to 0.95, while the mass recovery differences ranged from 0.7 to 6.5 %. Nevertheless, the predicted NZVI concentration contours during transport were in good agreement with the 2-D experimental observations. The model provides insights into NZVI transport in porous media by mathematically decoupling agglomeration, attachment, and detachment, and it illustrates the importance of each phenomenon in various situations. Graphical Abstract ᅟ.

  20. 1D versus 3D quantum confinement in 1-5 nm ZnO nanoparticle agglomerations for application in charge-trapping memory devices

    NASA Astrophysics Data System (ADS)

    El-Atab, Nazek; Nayfeh, Ammar

    2016-07-01

    ZnO nanoparticles (NPs) have attracted considerable interest from industry and researchers due to their excellent properties with applications in optoelectronic devices, sunscreens, photocatalysts, sensors, biomedical sciences, etc. However, the agglomeration of NPs is considered to be a limiting factor since it can affect the desirable physical and electronic properties of the NPs. In this work, 1-5 nm ZnO NPs deposited by spin- and dip-coating techniques are studied. The electronic and physical properties of the resulting agglomerations of NPs are studied using UV-vis-NIR spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM), and their application in metal-oxide-semiconductor (MOS) memory devices is analyzed. The results show that both dip- and spin-coating techniques lead to agglomerations of the NPs mostly in the horizontal direction. However, the width of the ZnO clusters is larger with dip-coating which leads to 1D quantum confinement, while the smaller ZnO clusters obtained by spin-coating enable 3D quantum confinement in ZnO. The ZnO NPs are used as the charge-trapping layer of a MOS-memory structure and the analysis of the high-frequency C-V measurements allow further understanding of the electronic properties of the ZnO agglomerations. A large memory window is achieved in both devices which confirms that ZnO NPs provide large charge-trapping density. In addition, ZnO confined in 3D allows for a larger memory window at lower operating voltages due to the Poole-Frenkel charge-emission mechanism.

  1. Multiple-Locus Departures from Panmictic Equilibrium within and between Village Gene Pools of Amerindian Tribes at Different Stages of Agglomeration

    PubMed Central

    Smouse, Peter E.; Neel, James V.; Liu, Wanda

    1983-01-01

    A comparative analysis of departures from multiple-locus Hardy-Weinberg equilibrium is presented for a set of four tribal Indian groups (the Yanomama, Makiritare, Wapishana and Ticuna) from the lowlands of South America. These tribes span a range of agglomeration and acculturation from the most traditional, swidden horticulturalists to frontier townspeople. The small-group social organization typical of traditional horticulturalists leads to substantial departures from tribal panmixia, as manifested by the distribution of multiple-locus genotypes both within and between villages. Within villages, the departures from single-locus Hardy-Weinberg equilibrium are small and nonsignificant, but the departures from gametic equilibrium (independence of loci) are substantial, even for the unlinked loci we have used to characterize these populations. The departures from single-locus homogeneity across villages are also substantial. One of the normal concomitants of increasing acculturation in this setting is an increase in agglomeration. As agglomeration increases, the departures from multiple-locus panmixia decrease, a process that can be very rapid. We discuss both the shifting balance theory of evolution and punctuated evolutionary rates in light of the small group social organization that must have obtained throughout most of human evolution. PMID:6862182

  2. Effect of mechanical vibration on platinum particle agglomeration and growth in proton exchange membrane fuel cell catalyst layer

    NASA Astrophysics Data System (ADS)

    Diloyan, Georgiy

    The objective of the current research is to study the effect of mechanical vibration on catalyst layer degradation via Platinum (Pt) particle agglomeration and growth in the membrane electrode assembly (MEA) of a proton exchange membrane fuel cell (PEM Fuel Cell). This study is of great importance, since many PEM fuel cells operate under a vibrating environment, such as the case of vehicular applications, and this may influence the catalyst layer degradation and fuel cell performance. Through extensive literature review, there are only few researches that have been studied the effect of mechanical vibration on PEM fuel cells. These studies focused only on PEM fuel cell performance under vibration for less than 50 hours and none of them considered the degradation of the fuel cell components, such as MEA and its catalyst layer. To study the effect of the mechanical vibration on the catalyst layer an accelerated test with potential cycling was specially designed to simulate a typical vehicle driving condition. The length of the accelerated test was designed to be 300 hour with potential cycling comprised of idle running, constant load, triangle (variable) load and overload running at various mechanical vibration conditions. These mechanical vibration conditions were as follows: 1g 20 Hz, 1g 40 Hz, 4g 20 Hz and 4g 40 Hz. No vibration tests were also conducted to study the influence of operating time and were used as a baseline for comparison study. The series of accelerated tests were followed by microscopy and spectroscopy analyses using environmental scanning electron microscopy (ESEM), transmission electron microscopy (TEM) and X-Ray diffraction (XRD). An ESEM was used to qualitatively analyze pristine and degraded catalyst. TEM and XRD were used to quantitatively analyze catalyst layer degradation via Pt agglomeration and growth in pristine and degraded states. For each test condition, PEM fuel cell performance by means of Voltage - Current (VI) curves was

  3. Marine oil seeps

    SciTech Connect

    Meyer, R.F. )

    1991-03-01

    Petroleum hydrocarbons of both biogenic and thermogenic origin are common constituents of the marine water column and sediment of the continental shelves. Approximately 0.25 million metric tons of oil per year, constituting about 8% of the oil input into the sea, is derived from natural seeps, the rest being anthropogenic. Seepage has occurred world-wide for millions of years and must have been many times greater in the past, when enormous oil deposits, such as the Orinoco Oil Belt, were first exposed to erosion. Although the amount varies from site to site with time, seepage is pervasive in polar and temperate seas. Marine-seep oil is intensely weathered and thus can be distinguished chemically from recent biogenic or undegraded crude oil. The degraded oil from seeps appears to have little deleterious effect on many marine organisms, which ingest and discharge the oil mostly unmetabolized. Chemical analyses suggest that a very large oil-rich layer in the Sargasso Sea originated from a large and as yet undetected seep. Oil seeps have long been used as guides for oil exploration onshore but have been underutilized for this purpose offshore because of oil-plume drift from the site of the seep and because natural oil slicks may be masked by spilled oil. At least one marine seep, in the Santa Barbara Channel, California, is producing oil and natural gas into two hollow steel pyramids from which the oil is collected by work boats and the natural gas is transported to shore by pipeline. This facility effectively reduces atmospheric pollution, controls marine oil pollution from the largest seep in the area, provides emission credits, and yields a modest economic benefit, but the seep is not known to have been used directly in oil exploration.

  4. From environmental noise abatement to soundscape creation through strategic noise mapping in medium urban agglomerations in South Europe.

    PubMed

    Vogiatzis, Konstantinos; Remy, Nicolas

    2014-06-01

    In the framework of the European Directive 2002-49-EU, the medium sized cities of Volos and Larissa in central Greece recently completed (2012) their strategic noise maps and relevant action plans that define the main strategies to reduce noise exposure of residents and introduce and preserve "quite zones". For the first time in this framework, it has been decided to introduce, as well, a general study for five specific urban districts covering not only the measurement and modeling of environmental noise levels but also qualitative surveys on the sound perception by the residents and several analyses of the urban and architectural tissue. The districts (respectively four in Volos and one in Larissa with the two of them in the center of both agglomerations) were chosen as representatives of urban situations due to their proximity to transportation infrastructures (main road network, industrial harbor facilities and both regional and intercity train network) and also because they represent different urban typologies (residential district, downtown area with or without shops, more or less densely populated neighborhood, etc.…). Sociological surveys on sound and noise perception have been implemented on some 15% of the residents per district using opened questionnaires. Soundscape analysis was also conducted through qualitative criteria. A cross-analysis of these data explains in detail the physical reasons for the existence of sound qualities that contribute to the identity of each distinct neighborhood. This paper, in a strategic plan level, has introduced valuable recommendations in order not only to preserve the sound quality on the existing sites but also to authorize developers and decision makers (mayors, architects, town planners) to evolve them positively over time.

  5. Libyan oil industry

    SciTech Connect

    Waddams, F.C.

    1980-01-01

    Three aspects of the growth and progress of Libya's oil industry since the first crude oil discovery in 1961 are: (1) relations between the Libyan government and the concessionary oil companies; (2) the impact of Libyan oil and events in Libya on the petroleum markets of Europe and the world; and (3) the response of the Libyan economy to the development of its oil industry. The historical review begins with Libya's becoming a sovereign nation in 1951 and traces its subsequent development into a position as a leading world oil producer. 54 references, 10 figures, 55 tables.

  6. Chain-aggregate aerosols in smoke from the Kuwait oil fires

    NASA Astrophysics Data System (ADS)

    Weiss, Ray E.; Kapustin, Vladimir N.; Hobbs, Peter V.

    1992-09-01

    Electrooptical scattering was used to detect aggregated particle chains in the smoke from the Kuwait oil fires. Nonsphericity was detected by the change in light scattering brought about by induced alignment of particles when subjected to a pulsed, bipolar electric field. Measured parameters included the steady state enhancement of light scattering for complete orientation of the particles, and the rotational diffusion constant, calculated from the time required for the particles to relax to a random orientation after the electric field was removed. Chain aggregates of soot formed within seconds of combustion for those fires producing black smoke. These aggregates agglomerated to some extent in the smoke near the fires, but then remained relatively unchanged for several hours of travel downwind. Very little non sphericity was detected for particles in the plumes of white smoke, which consisted primarily of salt brine products emitted along with the oil.

  7. In Situ Formation and Evolution of Gas Hydrates in Water-in-Oil Emulsions Using Pressure Rheometry

    NASA Astrophysics Data System (ADS)

    Rensing, P. J.; Liberatore, M. W.; Tonmukayakul, N.; Koh, C. A.; Sloan, E. D.

    2008-07-01

    In oil and gas production and transportation a major concern is the formation of gas hydrates (crystalline gas-water inclusion compounds that are stable at high pressures and low temperatures). Gas hydrates have a tenacious ability to plug pipelines, and may lead to unscheduled shut downs. The successful operation of pipeline transport with gas hydrates particles will depend on the ability to control gas hydrate agglomerations and depositions. Gas hydrates can be thermodynamically inhibited but this is proving cost ineffective and environmentally unfriendly. For this reason the oil/gas industry is moving to hydrate management rather than traditional methods of thermodynamic inhibition. One intriguing possibility would be to convert the water in the pipelines to non-agglomerating gas hydrates and then flow the slurry. However, this cannot be reliably achieved until basic understanding of hydrate slurry rheology is gained. To develop this fundamental understanding, in situ pressurized gas hydrate formation and rheological measurements from a water-in-oil emulsion have been conducted. In this work, small amplitude oscillatory and steady shear techniques have been used to characterize the rheological properties of these systems. The results demonstrate that hydrate formation can be detected in steady shear and oscillatory measurements, where a large viscosity (and elastic modulus) increase coincides with hydrate formation. Since temperature and pressure affect the thermodynamic stability of hydrates these are particular key variables that need to be tuned for this system.

  8. Influence of agglomeration of cerium oxide nanoparticles and speciation of cerium(III) on short term effects to the green algae Chlamydomonas reinhardtii.

    PubMed

    Röhder, Lena A; Brandt, Tanja; Sigg, Laura; Behra, Renata

    2014-07-01

    Cerium oxide nanoparticles (CeO2 NP) are increasingly used in industrial applications and may be released to the aquatic environment. The fate of CeO2 NP and effects on algae are largely unknown. In this study, the short term effects of CeO2 NP in two different agglomeration states on the green algae Chlamydomonas reinhardtii were examined. The role of dissolved cerium(III) on toxicity, its speciation and the dissolution of CeO2 NP were considered. The role of cell wall of C. reinhardtii as a barrier and its influence on the sensitivity to CeO2 NP and cerium(III) was evaluated by testing both, the wild type and the cell wall free mutant of C. reinhardtii. Characterization showed that CeO2 NP had a surface charge of ∼0mV at physiological pH and agglomerated in exposure media. Phosphate stabilized CeO2 NP at pH 7.5 over 24h. This effect was exploited to test CeO2 NP dispersed in phosphate with a mean size of 140nm and agglomerated in absence of phosphate with a mean size of 2000nm. The level of dissolved cerium(III) in CeO2 NP suspensions was very low and between 0.1 and 27nM in all tested media. Exposure of C. reinhardtii to Ce(NO3)3 decreased the photosynthetic yield in a concentration dependent manner with EC50 of 7.5±0.84μM for wild type and EC50 of 6.3±0.53μM for the cell wall free mutant. The intracellular level of reactive oxygen species (ROS) increased upon exposure to Ce(NO3)3 with effective concentrations similar to those inhibiting photosynthesis. The agglomerated CeO2 NP caused a slight decrease of photosynthetic yield at the highest concentrations (100μM), while no effect was observed for dispersed CeO2 NP. The low toxicity of agglomerated CeO2 NP was attributed quantitatively to Ce(3+) ions co-occurring in the nanoparticle suspension whereas for dispersed CeO2 NP, dissolved Ce(3+) was precipitated with phosphate and not bioavailable. Furthermore CeO2 NP did not affect the intracellular ROS level. The cell wall free mutant and wild type of C

  9. Butter, margarine, and cooking oils

    MedlinePlus

    ... margarine are not the best choices. Choose liquid vegetable oils or margarines made from these oils when possible. ... over harder stick forms. Choose margarines with liquid vegetable oil, such as olive oil, as the first ingredient. ...

  10. EPA OIL FIELD SOLUTION

    EPA Pesticide Factsheets

    Technical product bulletin: aka HYDRO-CLEAN, GLOBAL ENVIRONMENTAL CLEANER, AWAN PRA, this surface washing agent for oil spill cleanups is sprayed full strength on oiled rocky surfaces at shorelines, mangroves, and seagrasses. Allow at least 30 minute soak.

  11. OIL SOLUTIONS POWDER

    EPA Pesticide Factsheets

    Technical product bulletin: aka OIL SOLUTIONS POWDER, SPILL GREEN LS, this miscellaneous oil spill control agent used in cleanups initially behaves like a synthetic sorbent, then as a solidifier as the molecular microencapsulating process occurs.

  12. Vegetable Oil-Biorefinery.

    PubMed

    Pudel, Frank; Wiesen, Sebastian

    2017-03-07

    Conventional vegetable oil mills are complex plants, processing oil, fruits, or seeds to vegetable fats and oils of high quality and predefined properties. Nearly all by-products are used. However, most of the high valuable plant substances occurring in oil fruits or seeds besides the oil are used only in low price applications (proteins as animal feeding material) or not at all (e.g., phenolics). This chapter describes the state-of-the-art of extraction and use of oilseed/oil fruit proteins and phyto-nutrients in order to move from a conventional vegetable oil processing plant to a proper vegetable oil-biorefinery producing a wide range of different high value bio-based products.

  13. Manitoba oil activity review, 1997

    SciTech Connect

    1998-12-01

    Annual review is presented of Manitoba Crown oil and gas dispositions, mineral owner leasing and revenue, geophysical and drilling activity, areas of activity, oil production and markets, oil prices, value of production, provincial revenue from oil production, surface owners, spills and reclamation, municipal taxes, the Manitoba Drilling Incentive Program, oil reserves, oil industry expenditures, and industry employment. Highlights of the current year are included.

  14. Automotive gear oil lubricant from soybean oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of lubricants that are based on renewable materials is rapidly increasing. Vegetable oils have good lubricity, wear protection and low volatility which are desired properties for automotive gear lubricant applications. Soybean oil is used widely in the lubricant industry due to its properti...

  15. Vegetable oils for tractors

    SciTech Connect

    Moroney, M.

    1981-11-14

    Preliminary tests by the Agricultural Institute, show that tractors can be run on a 50:50 rape oil-diesel mixture or on pure rape oil. In fact, engine power actually increased slightly with the 50:50 blend but decreased fractionally with pure rape oil. Research at the North Dakota State University on using sunflower oil as an alternative to diesel fuel is also noted.

  16. SRC Residual fuel oils

    DOEpatents

    Tewari, Krishna C.; Foster, Edward P.

    1985-01-01

    Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.

  17. Crude oil desulfurization

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Hsu, G. C.; Ernest, J. B. (Inventor)

    1982-01-01

    High sulfur crude oil is desulfurized by a low temperature (25-80 C.) chlorinolysis at ambient pressure in the absence of organic solvent or diluent but in the presence of water (water/oil=0.3) followed by a water and caustic wash to remove sulfur and chlorine containing reaction products. The process described can be practiced at a well site for the recovery of desulfurized oil used to generate steam for injection into the well for enhanced oil recovery.

  18. Biochemical upgrading of oils

    DOEpatents

    Premuzic, E.T.; Lin, M.S.

    1999-01-12

    A process for biochemical conversion of heavy crude oils is provided. The process includes contacting heavy crude oils with adapted biocatalysts. The resulting upgraded oil shows, a relative increase in saturated hydrocarbons, emulsions and oxygenates and a decrease in compounds containing organic sulfur, organic nitrogen and trace metals. Adapted microorganisms which have been modified under challenged growth processes are also disclosed. 121 figs.

  19. Biochemical upgrading of oils

    DOEpatents

    Premuzic, Eugene T.; Lin, Mow S.

    1999-01-12

    A process for biochemical conversion of heavy crude oils is provided. The process includes contacting heavy crude oils with adapted biocatalysts. The resulting upgraded oil shows, a relative increase in saturated hydrocarbons, emulsions and oxygenates and a decrease in compounds containing in organic sulfur, organic nitrogen and trace metals. Adapted microorganisms which have been modified under challenged growth processes are also disclosed.

  20. Sassafras oil overdose

    MedlinePlus

    Sassafras oil comes from the root bark of the sassafras tree. Sassafras oil overdose occurs when someone swallows more than ... Safrole is the poisonous ingredient in sassafras oil. It is a clear or ... yellow oily liquid. It can be dangerous in large amounts.

  1. Enhanced oil recovery update

    SciTech Connect

    Smith, R.V

    1989-03-01

    Technology continues to grow in the realm of enhanced oil recovery. Since 1950 several processes have proven economic for oil recovery. Others are still in their infancy and must be custom designed for each reservoir. This paper gives a general overview of these processes. The author focuses on the latest technology and the outlook for enhanced oil recovery operations.

  2. On experimental oil spills

    SciTech Connect

    Mackay, D.; Thornton, D. E.; Blackall, P. J.; Sergy, G. S.; Snow, N.; Hume, H.

    1980-09-01

    Experimental oil spills are an essential component of overall oil pollution research efforts. However, such experiments must be carefully designed and coordinated in order to cull the most information possible. Physical, biological, and ecological impacts must be examined simultaneously. Long-term monitoring of the multidisciplinary effects of experimental oil spills is recommended.

  3. Why Big Bad Oil?

    ERIC Educational Resources Information Center

    Olien, Diana Davids; Olien, Roger M.

    1996-01-01

    Investigates the negative and hostile public opinion towards the oil industry, in general, and Standard Oil, in particular. Discovers that those most responsible for criticizing Standard Oil had an economic interest in doing so. Defends the company's record and refutes its critics' charges. (MJP)

  4. Oil Spill Cleanup

    ERIC Educational Resources Information Center

    Kauble, Christena Ann

    2011-01-01

    Several classroom activities using a model of a seashore and an oil spill demonstrate the basic properties of oil spills in oceans. Students brainstorm about how to best clean up the mess. They work in teams, and after agreeing on how they will proceed, their method is tested by measuring the amount of oil removed and by rating the cleanliness of…

  5. Cod Liver Oil

    MedlinePlus

    Cod liver oil can be obtained from eating fresh cod liver or by taking supplements. Cod liver oil is used for high cholesterol, high triglycerides, ... ear infections (otitis media). Some people put cod liver oil on their skin to speed wound healing. ...

  6. Natural oils as lubricants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is currently an availability of vegetable oil lubricants, with the exception of engine oils. Vegetable oils are environmentally friendly, renewable, contribute to the reduction of our dependence on imported petroleum, and add value to the farmer. However, there are inherent weaknesses in veg...

  7. Positive and negative effects of dielectric breakdown in transformer oil based magnetic fluids

    SciTech Connect

    Lee, Jong-Chul; Lee, Won-Ho; Lee, Se-Hee; Lee, Sangyoup

    2012-10-15

    The transformer oil based magnetic fluids can be considered as the next-generation insulation fluids because they offer exciting new possibilities to enhance dielectric breakdown voltage as well as heat transfer performance compared to pure transformer oils. In this study, we have investigated the dielectric breakdown strength of the fluids with the various volume concentrations of nanoparticles in accordance with IEC 156 standard and have tried to find the reason for changing the dielectric breakdown voltage of the fluids from the magnetic field analysis. It was found that the dielectric breakdown voltage of pure transformer oil is around 12 kV with the gap distance of 1.5 mm. In the case of our transformer oil-based magnetic fluids with 0.08% < Φ < 0.6% (Φ means the volume concentration of magnetic nanoparticles), the dielectric breakdown voltage shows above 40 kV, which is 3.3 times higher positively than that of pure transformer oil. Negatively in the case when the volume concentration of magnetic nanoparticles is above 0.65%, the dielectric breakdown voltage decreases reversely. From the magnetic field analysis, the reason might be considered as two situations: the positive is for the conductive nanoparticles dispersed well near the electrodes, which play an important role in converting fast electrons to slow negatively charged particles, and the negative is for the agglomeration of the particles near the electrodes, which leads to the breakdown initiation.

  8. Utah Heavy Oil Program

    SciTech Connect

    J. Bauman; S. Burian; M. Deo; E. Eddings; R. Gani; R. Goel; C.K. Huang; M. Hogue; R. Keiter; L. Li; J. Ruple; T. Ring; P. Rose; M. Skliar; P.J. Smith; J.P. Spinti; P. Tiwari; J. Wilkey; K. Uchitel

    2009-10-20

    The Utah Heavy Oil Program (UHOP) was established in June 2006 to provide multidisciplinary research support to federal and state constituents for addressing the wide-ranging issues surrounding the creation of an industry for unconventional oil production in the United States. Additionally, UHOP was to serve as an on-going source of unbiased information to the nation surrounding technical, economic, legal and environmental aspects of developing heavy oil, oil sands, and oil shale resources. UHOP fulGilled its role by completing three tasks. First, in response to the Energy Policy Act of 2005 Section 369(p), UHOP published an update report to the 1987 technical and economic assessment of domestic heavy oil resources that was prepared by the Interstate Oil and Gas Compact Commission. The UHOP report, entitled 'A Technical, Economic, and Legal Assessment of North American Heavy Oil, Oil Sands, and Oil Shale Resources' was published in electronic and hard copy form in October 2007. Second, UHOP developed of a comprehensive, publicly accessible online repository of unconventional oil resources in North America based on the DSpace software platform. An interactive map was also developed as a source of geospatial information and as a means to interact with the repository from a geospatial setting. All documents uploaded to the repository are fully searchable by author, title, and keywords. Third, UHOP sponsored Give research projects related to unconventional fuels development. Two projects looked at issues associated with oil shale production, including oil shale pyrolysis kinetics, resource heterogeneity, and reservoir simulation. One project evaluated in situ production from Utah oil sands. Another project focused on water availability and produced water treatments. The last project considered commercial oil shale leasing from a policy, environmental, and economic perspective.

  9. Kinetic modeling of the retention and fate of inhaled cerium oxide nanoparticles in rats: The cumulative displacement volume of agglomerates determines the outcome.

    PubMed

    Pauluhn, Juergen

    2017-04-01

    This paper compares the pulmonary kinetics of inhaled nano-CeO2 from published repeated inhalation studies of 1-, 4-, 13-, and 52-week duration using a previously published kinetic model to simulate the pulmonary kinetics of inhaled micron-sized poorly soluble, low toxicity particles (PSPs) in rats. This comparative analysis demonstrates that the kinetic hallmarks characterizing lung overload-related pulmonary inflammation are indistinguishable for PSPs and agglomerated nano-CeO2. Unlike PSPs, nano-CeO2 appears to dissolve within the lung as long as tissue saturation has not been attained. When saturation is reached, the accumulated retained particle displacement volume becomes the prominent unifying factor interrelating the retained volumetric particle dose and pulmonary inflammogenicity observed in inhalation studies of 1- to 52-weeks duration. In summary, the pulmonary kinetics of nano-CeO2 inhaled as micron-sized agglomerates exhibit kinetic and toxicological profiles similar to micron-sized PSPs. The coherence of modeled and empirical outcomes supports the hypothesis that the leading metric of pulmonary toxicity is the displacement volume of accumulated aggregated particles. Whereas agglomerated nano-CeO2 particles follow the typical kinetic of lung overload, evidence of dissolution of nano-CeO2 demonstrates a much shorter elimination half-time of t1/2 = 17 days. Thus, kinetic modeling approaches appear to not only deliver the highest degree of integrated mechanistic information, it also provides a validating feed-back loop to verify/refute the starting hypothesis of inhalation studies.

  10. From Agglomerates of Spheres to Irregularly Shaped Particles: Determination of Dynamic Shape Factors from Measurements of Mobility and Vacuum Aerodynamic Diameters

    SciTech Connect

    Zelenyuk, Alla; Cai, Yong; Imre, Dan G.

    2006-03-01

    With the advert of aerosol instrumentation it has become possible to simultaneously measure individual particle mobility and vacuum aerodynamic diameters. For spherical particles these two diameters yield individual particle density. In contrast, assigning a physical meaning to the mobility or aerodynamic diameter of aspherical particles is not straightforward. This paper presents an experimental exploration of the effect of particle shape on the relationship between mobility and vacuum aerodynamic diameters. We make measurements on systems of three types: 1) Agglomerates of spheres, for which the density and the volume are known; 2) Ammonium sulfate, sodium chloride, succinic acid and lauric acid irregularly shaped particles of known density; and 3) Internally mixed particles, containing organics and ammonium sulfate, of unknown density and shape. For agglomerates of spheres we observed alignment effects in the DMA and report the first measurements of the dynamic shape factors (DSFs) in free molecular regime. We present here the first experimental determination of the DSF of ammonium sulfate particles. We find for ammonium sulfate particles a DSF that increases from 1.03 to 1.07 as particle mobility diameter increases from 160 nm to 500 nm. Three types of NaC1 particles were generated and characterized: nearly spherical particles with DSF of ~1.02; cubic with DSF that increases from 1.065 to 1.17 as particle mobility diameter increases from 200 nm to 900 nm; and compact agglomerates with DSF 1.3-1.4. Organic particles were found very nearly spherical. The data suggest that particles composed of binary mixtures of ammonium sulfate and succinic acid have lower dynamic shape factors than pure ammonium sulfate particles. However, for internally mixed ammonium sulfate and lauric acid particles we cannot distinguish between nearly spherical particles with low density and particles with DSF of 1.17.

  11. Oil shale commercialization study

    SciTech Connect

    Warner, M.M.

    1981-09-01

    Ninety four possible oil shale sections in southern Idaho were located and chemically analyzed. Sixty-two of these shales show good promise of possible oil and probable gas potential. Sixty of the potential oil and gas shales represent the Succor Creek Formation of Miocene age in southwestern Idaho. Two of the shales represent Cretaceous formations in eastern Idaho, which should be further investigated to determine their realistic value and areal extent. Samples of the older Mesozonic and paleozoic sections show promise but have not been chemically analyzed and will need greater attention to determine their potential. Geothermal resources are of high potential in Idaho and are important to oil shale prospects. Geothermal conditions raise the geothermal gradient and act as maturing agents to oil shale. They also might be used in the retorting and refining processes. Oil shales at the surface, which appear to have good oil or gas potential should have much higher potential at depth where the geothermal gradient is high. Samples from deep petroleum exploration wells indicate that the succor Creek shales have undergone considerable maturation with depth of burial and should produce gas and possibly oil. Most of Idaho's shales that have been analyzed have a greater potential for gas than for oil but some oil potential is indicated. The Miocene shales of the Succor Creek Formation should be considered as gas and possibly oil source material for the future when technology has been perfectes. 11 refs.

  12. Oil degradation in soil.

    PubMed

    Raymond, R L; Hudson, J O; Jamison, V W

    1976-04-01

    The environmental effects of adding certain selected petroleum products to field soils at widely separated geographical locations under optimum conditions for biodegradation were studied. The locations selected for study of soil biodegradation of six oils (used crankcase oil from cars, used crankcase oil from trucks, an Arabian Heavy crude oil, a Coastal Mix crude oil, a home heating oil no. 2, and a residual fuel oil no. 6) were Marcus Hook, Pennsylvania, Tulsa, Oklahoma, and Corpus Christi, Texas. The investigative process, covering a period of 1 year at each location, was conducted in 14 fields plots (1.7 by 3.0 m) to which the oils were added in a single application at a rate of 11.9 m3/4 X 10(3) m2. One-half of the plots at each location were fertilized, and the incorporation of the oils and fertilizers was accomplished with rototillers to a depth of 10 to 15 cm. Concentrations of all oils decreased significantly at all locations. The average reduction ranged from 48.5 to 90.0% depending upon the type of oil and location. Rates of degradation did not exceed 2.4 m3/4 X 10(3) m2 per month. Compositional changes in the oil with time were investigated using silica gel fractionation, gas chromatography, and ultraviolet absorbance. With the possible exception of the two fuel oils, the compositional changes were generally in the same direction for all of the oils. The silica gel fractionation and gravimetric data on residual oils show that all classes of compounds were degraded, but the more polar type degrade more slowly. Analysis of runoff water, leachate, and soils indicated that at the concentration applied no oil less was observed from these plots via water movement. No significant movement of lead compounds added to the soils in the used crankcase oils was observed. Significant increases in hydrocarbon-utilizing microorganisms were demonstrated in all treated plots using either the pure hydrocarbon, n-hexadecane, or the applied oils as the growth substrate

  13. 27 CFR 21.98 - Bone oil (Dipple's oil).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Bone oil (Dipple's oil....98 Bone oil (Dipple's oil). (a) Color. The color shall be a deep brown. (b) Distillation range. When... below 90 °C. (c) Pyrrol reaction. Prepare a 1.0 percent solution of bone oil in 95 percent...

  14. 27 CFR 21.98 - Bone oil (Dipple's oil).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Bone oil (Dipple's oil....98 Bone oil (Dipple's oil). (a) Color. The color shall be a deep brown. (b) Distillation range. When... below 90 °C. (c) Pyrrol reaction. Prepare a 1.0 percent solution of bone oil in 95 percent...

  15. 27 CFR 21.98 - Bone oil (Dipple's oil).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Bone oil (Dipple's oil....98 Bone oil (Dipple's oil). (a) Color. The color shall be a deep brown. (b) Distillation range. When... below 90 °C. (c) Pyrrol reaction. Prepare a 1.0 percent solution of bone oil in 95 percent...

  16. 27 CFR 21.98 - Bone oil (Dipple's oil).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Bone oil (Dipple's oil....98 Bone oil (Dipple's oil). (a) Color. The color shall be a deep brown. (b) Distillation range. When... below 90 °C. (c) Pyrrol reaction. Prepare a 1.0 percent solution of bone oil in 95 percent...

  17. Understanding oil spills and oil spill response

    SciTech Connect

    Not Available

    1993-10-01

    The volume contains individual sections that outline what oil spills are, their potential effects on the environment, how they are cleaned up, and how various agencies prepare for spills before they happen.

  18. Biodegradation of crude oils.

    PubMed

    Bosecker, K; Teschner, M; Wehner, H

    1989-01-01

    Petroleum from well sites in the Gifhorn Trough (Lower Saxony, NW-Germany) and the Maracaibo Basin (Venezuela) contained various types of microorganisms capable of degrading crude oils. Genetically related oils were inoculated with the isolated microorganisms and the degradation of the oils was followed by chromatographic techniques. Parameters important for the reactions (pH, supply of oxygen, nitrogen and phosphorus, reaction medium) were monitored and optimized. The degradation of n-alkanes was followed closely. Microorganisms active in degradation (yeast, bacteria) easily survived a period of inactivity due to missing nutrients and were reactivated within hours to degrade newly added crude oil. Under substrate-limiting conditions selectivity of degradation was found, destroying medium-chain n-alkanes (C20, C21) at a faster rate than long-chain n-alkanes (C30, C31). During degradation the physical parameters of the crude oils (e.g. density, viscosity, average molecular weight) were altered and shifted into the direction of heavy oil. In vitro degraded oil is very similar to oil degraded in nature. Aromatic hydrocarbons and biomarker molecules (steranes and triterpanes) were not degraded under the conditions used. Pyrolysis-GC analysis of asphaltenes revealed no significant changes in the composition of pyrolyzates during biodegradation. There is sufficient evidence that heavy oils - besides some other effects - are generated by the in situ-biodegradation of conventional oils.

  19. Crude Oil Analysis Database

    DOE Data Explorer

    Shay, Johanna Y.

    The composition and physical properties of crude oil vary widely from one reservoir to another within an oil field, as well as from one field or region to another. Although all oils consist of hydrocarbons and their derivatives, the proportions of various types of compounds differ greatly. This makes some oils more suitable than others for specific refining processes and uses. To take advantage of this diversity, one needs access to information in a large database of crude oil analyses. The Crude Oil Analysis Database (COADB) currently satisfies this need by offering 9,056 crude oil analyses. Of these, 8,500 are United States domestic oils. The database contains results of analysis of the general properties and chemical composition, as well as the field, formation, and geographic location of the crude oil sample. [Taken from the Introduction to COAMDATA_DESC.pdf, part of the zipped software and database file at http://www.netl.doe.gov/technologies/oil-gas/Software/database.html] Save the zipped file to your PC. When opened, it will contain PDF documents and a large Excel spreadsheet. It will also contain the database in Microsoft Access 2002.

  20. Spectroscopic study of Mentha oils

    NASA Astrophysics Data System (ADS)

    Rai, A. K.; Singh, A. K.

    The visible fluorescence and excitation spectra of Mentha oils (Japanese mint oil, peppermint oil and spearmint oil) have been recorded. Different physical constants which are characteristic of the fluorescent molecules have been calculated for all three oils. Results reveal that the same group of organic compounds dominate in the oils of peppermint and spearmint, whereas some different compound is present in Japanese mint oil. It is also found that the fluorescence intensity of these oils is comparable to that of Rhodamine 6G dye in methanol solution. Our studies suggest that Mentha oils may be a useful lasing material in the 450-600 nm wavelength range.

  1. A ∼32–70 K FORMATION TEMPERATURE RANGE FOR THE ICE GRAINS AGGLOMERATED BY COMET 67 P/CHURYUMOV–GERASIMENKO

    SciTech Connect

    Lectez, S.; Simon, J.-M.; Salazar, J. M.; Mousis, O.; Picaud, S.; Altwegg, K.; Rubin, M.

    2015-05-20

    Grand Canonical Monte Carlo simulations are used to reproduce the N{sub 2}/CO ratio ranging between 1.7 × 10{sup −3} and 1.6 × 10{sup −2} observed in situ in the Jupiter-family comet 67 P/Churyumov–Gerasimenko (67 P) by the ROSINA mass spectrometer on board the Rosetta spacecraft. By assuming that this body has been agglomerated from clathrates in the protosolar nebula (PSN), simulations are developed using elaborated interatomic potentials for investigating the temperature dependence of the trapping within a multiple-guest clathrate formed from a gas mixture of CO and N{sub 2} in proportions corresponding to those expected for the PSN. By assuming that 67 P agglomerated from clathrates, our calculations suggest the cometary grains must have been formed at temperatures ranging between ∼31.8 and 69.9 K in the PSN to match the N{sub 2}/CO ratio measured by the ROSINA mass spectrometer. The presence of clathrates in Jupiter-family comets could then explain the potential N{sub 2} depletion (factor of up to ∼87 compared to the protosolar value) measured in 67 P.

  2. Determination of Carbonyl Compounds in Cork Agglomerates by GDME-HPLC-UV: Identification of the Extracted Compounds by HPLC-MS/MS.

    PubMed

    Brandão, Pedro Francisco; Ramos, Rui Miguel; Almeida, Paulo Joaquim; Rodrigues, José António

    2017-02-08

    A new approach is proposed for the extraction and determination of carbonyl compounds in solid samples, such as wood or cork materials. Cork products are used as building materials due to their singular characteristics; however, little is known about its aldehyde emission potential and content. Sample preparation was done by using a gas-diffusion microextraction (GDME) device for the direct extraction of volatile aldehydes and derivatization with 2,4-dinitrophenylhydrazine. Analytical determination of the extracts was done by HPLC-UV, with detection at 360 nm. The developed methodology proved to be a reliable tool for aldehyde determination in cork agglomerate samples with suitable method features. Mass spectrometry studies were performed for each sample, which enabled the identification, in the extracts, of the derivatization products of a total of 13 aldehydes (formaldehyde, acetaldehyde, furfural, propanal, 5-methylfurfural, butanal, benzaldehyde, pentanal, hexanal, trans-2-heptenal, heptanal, octanal, and trans-2-nonenal) and 4 ketones (3-hydroxy-2-butanone, acetone, cyclohexanone, and acetophenone). This new analytical methodology simultaneously proved to be consistent for the identification and determination of aldehydes in cork agglomerates and a very simple and straightforward procedure.

  3. 3D RVE models able to capture and quantify the dispersion, agglomeration and orientation state of CNT in CNT/PP nanocomposites

    NASA Astrophysics Data System (ADS)

    Bhuiyan, Md; Pucha, Raghuram; Kalaitzidou, Kyriaki

    2016-02-01

    The focus of this study is to investigate the capabilities of 3D RVE models in predicting the tensile modulus of carbon nanotube polypropylene (CNT/PP) composites which differ slightly in the dispersion, agglomeration and orientation states of CNT within the PP matrix. The composites are made using melt mixing followed by either injection molding or melt spinning of fibers. The dispersion, agglomeration and orientation of CNT within the PP are experimentally altered by using a surfactant and by forcing the molten material to flow through a narrow orifice (melt spinning) that promotes alignment of CNT along the flow/drawing direction. An elaborate image analysis technique is used to quantify the CNT characteristics in terms of probability distribution functions (PDF). The PDF are then introduced to the 3D RVE models which also account for the CNT-PP interfacial interactions. It is concluded that the 3D RVE models can accurately distinguish among the different cases (dispersion, distribution, geometry and alignment of CNT) as the predicted tensile modulus is in good agreement with the experimentally determined one.

  4. Assessment of agglomeration, co-sedimentation and trophic transfer of titanium dioxide nanoparticles in a laboratory-scale predator-prey model system

    NASA Astrophysics Data System (ADS)

    Gupta, Govind Sharan; Kumar, Ashutosh; Shanker, Rishi; Dhawan, Alok

    2016-08-01

    Nano titanium dioxide (nTiO2) is the most abundantly released engineered nanomaterial (ENM) in aquatic environments. Therefore, it is prudent to assess its fate and its effects on lower trophic-level organisms in the aquatic food chain. A predator-and-prey-based laboratory microcosm was established using Paramecium caudatum and Escherichia coli to evaluate the effects of nTiO2. The surface interaction of nTiO2 with E. coli significantly increased after the addition of Paramecium into the microcosm. This interaction favoured the hetero-agglomeration and co-sedimentation of nTiO2. The extent of nTiO2 agglomeration under experimental conditions was as follows: combined E. coli and Paramecium > Paramecium only > E. coli only > without E. coli or Paramecium. An increase in nTiO2 internalisation in Paramecium cells was also observed in the presence or absence of E. coli cells. These interactions and nTiO2 internalisation in Paramecium cells induced statistically significant (p < 0.05) effects on growth and the bacterial ingestion rate at 24 h. These findings provide new insights into the fate of nTiO2 in the presence of bacterial-ciliate interactions in the aquatic environment.

  5. Larvae of Hydropsyche angustipennis (Trichoptera, Hydropsychidae) as indicators of stream contamination by heavy metals in Łódź agglomeration.

    PubMed

    Tszydel, Mariusz; Markowski, Marcin; Majecki, Janusz

    2016-07-14

    A biomonitoring technique was employed to assess metal contamination of several degraded urban streams in the Łódź agglomeration. Presence of heavy metals (Zn, Cu, Fe, Cd, Pb, Cr, was determined in whole bodies of Hydropsyche angustipennis larvae. Larvae of H. angustipennis were the only caddisflies living in most of  investigated streams. These metals as well as other environmental variables were investigated in sediments or free waters of urban streams and in a stretch of a similar size of the Grabia River (reference site), outside the city but still in the vicinity of the Łódź agglomeration. The results of our research demonstrated different levels of contamination of urban streams as well as a correlation between environmental and larval tissue concentrations of heavy metals. Significant differences among sites were observed for metal concentrations in H. angustipennis larval bodies and larval responses to metals were time specific. The highest concentration of heavy metals was observed during the spring months. Differences were evident among various heavy metal levels in the bodies of larvae collected from different streams and at different sampling stations in the same stream.

  6. Relationship between land use/cover and surface temperatures in the urban agglomeration of Cuiabá-Várzea Grande, Central Brazil

    NASA Astrophysics Data System (ADS)

    Callejas, Ivan Júlio Apolônio; de Oliveira, Angela Santana; de Moura Santos, Flávia Maria; Durante, Luciane Cleonice; de Jesus Albuquerque Nogueira, Marta Cristina; Zeilhofer, Peter

    2011-01-01

    We focus on the surface urban heat island (SUHI) and the spatiotemporal relationship between land use and surface temperatures (Ts) in Cuiabá-Várzea Grande, Mato Grosso, one of the major urban agglomerations of central-western Brazil, which has suffered intense urbanization processes since the 1960s. Supervised maximum likelihood classifications of optical bands of Landsat Thematic Mapper (Landsat TM) imagery from 1986 and 2007 are applied to generate land use/cover maps. Surface emissivity is determined using the logarithmic transformation of the normalized difference vegetation index. The Ts is retrieved from the thermal bands utilizing a radiative transfer equation. In both cities, urban expansion followed two main development axes, which are reflected in the spatial patterns of Ts. The highest values of Ts were found in bare soil and urbanized areas. Between 1986 and 2007, Ts increased 0.96°C on average and a maximum of 5.49°C in the urban agglomeration. The SUHI in Várzea Grande suffered intensification with an increase of 1.34°C in the downtown area. This tendency was stronger in the center of Cuiabá, where Ts increased 3.12°C. Slowing this rapid rate of temperature increase would demand decisive intervention by municipal authorities, such as restricting annual occupation taxes, reducing the occupation coefficient in new districts, preserving native vegetation, and designating new green areas.

  7. Assessment of agglomeration, co-sedimentation and trophic transfer of titanium dioxide nanoparticles in a laboratory-scale predator-prey model system.

    PubMed

    Gupta, Govind Sharan; Kumar, Ashutosh; Shanker, Rishi; Dhawan, Alok

    2016-08-17

    Nano titanium dioxide (nTiO2) is the most abundantly released engineered nanomaterial (ENM) in aquatic environments. Therefore, it is prudent to assess its fate and its effects on lower trophic-level organisms in the aquatic food chain. A predator-and-prey-based laboratory microcosm was established using Paramecium caudatum and Escherichia coli to evaluate the effects of nTiO2. The surface interaction of nTiO2 with E. coli significantly increased after the addition of Paramecium into the microcosm. This interaction favoured the hetero-agglomeration and co-sedimentation of nTiO2. The extent of nTiO2 agglomeration under experimental conditions was as follows: combined E. coli and Paramecium > Paramecium only > E. coli only > without E. coli or Paramecium. An increase in nTiO2 internalisation in Paramecium cells was also observed in the presence or absence of E. coli cells. These interactions and nTiO2 internalisation in Paramecium cells induced statistically significant (p < 0.05) effects on growth and the bacterial ingestion rate at 24 h. These findings provide new insights into the fate of nTiO2 in the presence of bacterial-ciliate interactions in the aquatic environment.

  8. Assessment of agglomeration, co-sedimentation and trophic transfer of titanium dioxide nanoparticles in a laboratory-scale predator-prey model system

    PubMed Central

    Gupta, Govind Sharan; Kumar, Ashutosh; Shanker, Rishi; Dhawan, Alok

    2016-01-01

    Nano titanium dioxide (nTiO2) is the most abundantly released engineered nanomaterial (ENM) in aquatic environments. Therefore, it is prudent to assess its fate and its effects on lower trophic-level organisms in the aquatic food chain. A predator-and-prey-based laboratory microcosm was established using Paramecium caudatum and Escherichia coli to evaluate the effects of nTiO2. The surface interaction of nTiO2 with E. coli significantly increased after the addition of Paramecium into the microcosm. This interaction favoured the hetero-agglomeration and co-sedimentation of nTiO2. The extent of nTiO2 agglomeration under experimental conditions was as follows: combined E. coli and Paramecium > Paramecium only > E. coli only > without E. coli or Paramecium. An increase in nTiO2 internalisation in Paramecium cells was also observed in the presence or absence of E. coli cells. These interactions and nTiO2 internalisation in Paramecium cells induced statistically significant (p < 0.05) effects on growth and the bacterial ingestion rate at 24 h. These findings provide new insights into the fate of nTiO2 in the presence of bacterial-ciliate interactions in the aquatic environment. PMID:27530102

  9. Agglomeration in core-shell structure of CuAg nanoparticles synthesized by the laser ablation of Cu target in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Petrović, S.; Salatić, B.; Milovanović, D.; Lazović, V.; Živković, Lj; Trtica, M.; Jelenković, B.

    2015-02-01

    Metallic copper Cu and bimetallic copper-silver CuAg nanoparticles (NPs) are generated by the ablation of copper bulk target in water and aqueous Ag colloidal solution, respectively. The experiments were performed using nanosecond Nd:YAG laser operating at 1064 nm. The generated NPs are characterized by UV-vis absorption spectroscopy, laser-induced breakdown spectroscopy, dynamic light scattering and scanning electron microscopy. The conducted investigations can be summarized as follows: (i) CuAg NPs colloidal solution possess the absorption in UV-vis spectral region, which can be attributed to the Cu-component; (ii) the primary bimetallic CuAg NPs have near uniform dimensions with diameter of about 15 nm, and as a rule, they are grouped into larger agglomerates without defined morphology; (iii) the obtained Cu NPs have mainly spherical form with average diameters up to 20 nm. Both types of NPs show a tendency towards the formation of large agglomerates with different morphology. Bimetallic NPs show the plasmon resonance in the vicinity of 640 nm with a good coincidence with formation of the colloidal solution of pure Cu NPs. The results also demonstrate that the core-shell structure (Ag-rich core/Cu-rich shell) is important for the formation of the bimetallic NPs, also agreeing very well with theory.

  10. Chemometric techniques in oil classification from oil spill fingerprinting.

    PubMed

    Ismail, Azimah; Toriman, Mohd Ekhwan; Juahir, Hafizan; Kassim, Azlina Md; Zain, Sharifuddin Md; Ahmad, Wan Kamaruzaman Wan; Wong, Kok Fah; Retnam, Ananthy; Zali, Munirah Abdul; Mokhtar, Mazlin; Yusri, Mohd Ayub

    2016-10-15

    Extended use of GC-FID and GC-MS in oil spill fingerprinting and matching is significantly important for oil classification from the oil spill sources collected from various areas of Peninsular Malaysia and Sabah (East Malaysia). Oil spill fingerprinting from GC-FID and GC-MS coupled with chemometric techniques (discriminant analysis and principal component analysis) is used as a diagnostic tool to classify the types of oil polluting the water. Clustering and discrimination of oil spill compounds in the water from the actual site of oil spill events are divided into four groups viz. diesel, Heavy Fuel Oil (HFO), Mixture Oil containing Light Fuel Oil (MOLFO) and Waste Oil (WO) according to the similarity of their intrinsic chemical properties. Principal component analysis (PCA) demonstrates that diesel, HFO, MOLFO and WO are types of oil or oil products from complex oil mixtures with a total variance of 85.34% and are identified with various anthropogenic activities related to either intentional releasing of oil or accidental discharge of oil into the environment. Our results show that the use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution in Malaysia. This, in consequence would result in cost and time saving in identification of the oil spill sources.

  11. Tea tree oil.

    PubMed

    Larson, David; Jacob, Sharon E

    2012-01-01

    Tea tree oil is an increasingly popular ingredient in a variety of household and cosmetic products, including shampoos, massage oils, skin and nail creams, and laundry detergents. Known for its potential antiseptic properties, it has been shown to be active against a variety of bacteria, fungi, viruses, and mites. The oil is extracted from the leaves of the tea tree via steam distillation. This essential oil possesses a sharp camphoraceous odor followed by a menthol-like cooling sensation. Most commonly an ingredient in topical products, it is used at a concentration of 5% to 10%. Even at this concentration, it has been reported to induce contact sensitization and allergic contact dermatitis reactions. In 1999, tea tree oil was added to the North American Contact Dermatitis Group screening panel. The latest prevalence rates suggest that 1.4% of patients referred for patch testing had a positive reaction to tea tree oil.

  12. Kinetics of oil dispersion in the absence and presence of block copolymers

    SciTech Connect

    Polat, H.; Polat, M.; Chander, S.

    1999-08-01

    Dispersion of oil into fine droplets is important in many applications, such as flotation, selective agglomeration, solvent extraction, wastewater treatment, and oil drilling. Size distribution of oil droplets determines the rate of mass transfer between the continuous and the disperse phase and the outcome of the process in these applications. A phenomenological model proposed describes droplet breakup in the turbulently agitated lean oil-in-water dispersions and provides a correlation between the median droplet size in an agitated vessel of standard geometry and the time of dispersion. It was assumed that the droplet breakup takes place in the dispersion-only region and coalescence is negligible. The model described the data from this study and the literature quite satisfactorily under these conditions. The effect of adding triblock PEO/PPO/PEO copolymeric surfactants on the dispersion kinetics of oil was also investigated. Addition of surfactant reduced the median oil droplet size significantly, and the extent of this reduction was a strong function of surfactant concentration. Application of the model on these data demonstrated that the change in the median droplet size could be divided into two distinct regions. The breakage rate was high initially, most probably due to continuous adsorption of surfactant molecules at the oil/water interface. A lower breakage rate was attained at longer times, as the surfactant molecules were depleted from the solution. The time of transition between the two was affected strongly by the concentration of the surfactant added. Furthermore, the time of addition of the surfactant did not affect the final droplet-size distribution in the system.

  13. High efficiency shale oil recovery. Fifth quarterly report, January 1, 1993--March 31, 1993

    SciTech Connect

    Adams, D.C.

    1993-04-22

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical conditions (heating, mixing, pyrolysis, oxidation) exist in both systems.The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed this quarter. (1) Twelve pyrolysis runs were made on five different oil shales. All of the runs exhibited a complete absence of any plugging, tendency. Heat transfer for Green River oil shale in the rotary kiln was 84.6 Btu/hr/ft{sup 2}/{degrees}F, and this will provide for ample heat exchange in the Adams kiln. (2) One retorted residue sample was oxidized at 1000{degrees}F. Preliminary indications are that the ash of this run appears to have been completely oxidized. (3) Further minor equipment repairs and improvements were required during the course of the several runs.

  14. 19. LOWER OIL ROOM DIABLO POWERHOUSE: SHARPLES OIL CENTRIFUGE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. LOWER OIL ROOM DIABLO POWERHOUSE: SHARPLES OIL CENTRIFUGE AND OIL TANK, 1989. - Skagit Power Development, Diablo Powerhouse, On Skagit River, 6.1 miles upstream from Newhalem, Newhalem, Whatcom County, WA

  15. The Obtaining of Oil from an Oil Reservoir.

    ERIC Educational Resources Information Center

    Dawe, R. A.

    1979-01-01

    Discusses the mechanics of how an actual oil reservoir works and provides some technical background in physics. An experiment which simulates an oil reservoir and demonstrates quantitatively all the basic concepts of oil reservoir rock properties is also presented. (HM)

  16. Kuwait Oil Fires, Kuwait

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Smoke from the burning oil fields to the north of Kuwait City, seen on the south shore of Kuwayt Bay, almost totally obscures the view of the tiny, but oil rich, nation of Kuwait (30.0N, 48.0E). During the brief war between Iraq and the Allied forces, many of the oil wells in Kuwait were destroyed and set afire. For several months, those fires burned out of control, spewing wind borne smoke and ash for hundreds of miles.

  17. Integrated palm oil processing

    SciTech Connect

    Compere, A.L.; Griffith, W.L.; Googin, J.M.

    1983-01-01

    Tree palms are a promising source of fuel extenders and substitutes. They are perennials which bear oil for a period of two to three decades after a roughly four year preliminary growth period. Tree palms are now one of the most efficient energy crops: the best modern varieties can provide up to 6 tonnes per hectare per year of mesocarp and kernal oils. Palms are particularly attractive in areas where more conventional farming would pose a significant threat of laterization of cause major ecological problems. Technology for palm oil production is can range between village level manual operations and highly industrialized mills. Process energy is often supplied by combustion of byproducts. Although palm oil is a good energy crop, its physical and combustion properties preclude most use in conventional diesel engines, although palm oil could be directly blended with residual fuel oils for use in some large engines. At present, two uses for palm oil as a diesel fuel extender or substitute appear attractive: microemulsion blends using palm soapstock and monoesters produced by exchanging small alcohols for the glycerol in triglycerides. The amount of alcohols required for conversion of a substantial fraction of palm oil or palm oil soapstock to fuel extenders or substitutes is proportionately small, and, to a major extent, can be supplied by palm processing waste materials. Fermentation and gasification produced alcohols in the one to four carbon range are suitable for use in formulating palm oil based fuels. On a stoichiometric basis, it appears that the value of the palm oil and alcohols are very close to their value as export items. Use of these palm oil fuels could help to decrease balance of payments problems for developing countries, as well as provide a secure market for agricultural products and improved rural employment.

  18. Vegetable oil fuels

    SciTech Connect

    Not Available

    1982-01-01

    Fifty contributions (presentations) involving more than one hundred people worldwide were given at the International Conference on Plant and Vegetable Oils as Fuels. The proceedings were in Fargo, North Dakota, from August 2-4, 1982. The conference helped to promote renewable fuels, bio-oils, from plant and vegetable oils. Separate abstracts were prepared for 44 items for inclusion in the Energy Data Base.

  19. Waste oil reduction: GKN

    SciTech Connect

    Hunt, G.

    1995-08-01

    This report details the steps required to establish a waste oil management program. Such a program can reduce operational costs, cut wastewater treatment costs and produce a better quality wastewater effluent through such means as: reducing the volume of oils used; segregating oils at the source of generation for recovery and reuse; and reducing the quality of oily wastewater generated. It discusses the metal-working fluid recovery options available for such a program, namely settling, filtration, hydrocyclone, and centrifugation. Included are source lists for vendors of oil skimmer equipment and coolant recovery systems.

  20. Melaleuca oil poisoning.

    PubMed

    Jacobs, M R; Hornfeldt, C S

    1994-01-01

    A 23-month-old boy became confused and was unable to walk thirty minutes after ingesting less than 10 mL of T36-C7, a commercial product containing 100% melaleuca oil. The child was referred to a nearby hospital. His condition improved and he was asymptomatic within 5 hours of ingestion. He was discharged to home the following day. Melaleuca oil, extracted from the Melaleuca alternifolia, contains 50-60% terpenes and related alcohols. Clinical experience with products containing melaleuca oil is limited. This case report suggests that ingestion of a modest amount of a concentrated form of this oil may produce signs of toxicity.

  1. Pepper Oil Surprise

    NASA Video Gallery

    Astronauts Cady Coleman and Paolo Nespoli perform the Pepper Oil Surprise experiment from Potlatch Elementary School in Potlatch, Idaho. This research investigates the interaction of liquid pepper/...

  2. Treatment of vegetable oils

    SciTech Connect

    Bessler, T.R.

    1986-05-13

    A process is described for preparing an injectable vegetable oil selected from the group consisting of soybean oil and sunflower oil and mixtures thereof which comprise: (a) first treating the vegetable oil at a temperature of 80/sup 0/C to about 130/sup 0/C with an acid clay; (b) deodorizing the vegetable oil with steam at a temperature of 220/sup 0/C to about 280/sup 0/C and applying a vacuum to remove volatilized components; (c) treating the deodorized vegetable oil, at a temperature of from about 10/sup 0/C to about 60/sup 0/C, with an acid clay to reduce the content of a member selected from the group consisting of diglycerides, tocopherol components, and trilinolenin and mixtures thereof, wherein the acid clay is added in a weight ratio to the deoderized vegetable oil of from about 1:99 to about 1:1; and (d) thereafter conducting a particulate filtration to remove a substantial portion of the acid clay from the vegetable oil, wherein the filtration is accomplished with filters having a pore size of from about 0.1 to 0.45 microns, thereby obtaining the injectable oil.

  3. Oil in the Arctic

    DTIC Science & Technology

    1975-03-01

    density of North Slope crude oil Is 0.89. After aging two weeks In the Arctic suimer, this density rises to about 0.95 . Hence the oil can be...the Ice. In that case, puddles form at the high points of the ice- water Interface. A third feature is the fact that crude oils are sticky, and...this section Is to develop equations which describe the boiling point distribution of crude oil as it ages on ice or water. We assume, firstly, that

  4. Hot Oil Removes Wax

    NASA Technical Reports Server (NTRS)

    Herzstock, James J.

    1991-01-01

    Mineral oil heated to temperature of 250 degrees F (121 degrees C) found effective in removing wax from workpieces after fabrication. Depending upon size and shape of part to be cleaned of wax, part immersed in tank of hot oil, and/or interior of part flushed with hot oil. Pump, fittings, and ancillary tooling built easily for this purpose. After cleaning, innocuous oil residue washed off part by alkaline aqueous degreasing process. Serves as relatively safe alternative to carcinogenic and environmentally hazardous solvent perchloroethylene.

  5. Rheological and tribological behaviour of lubricating oils containing platelet MoS2 nanoparticles

    NASA Astrophysics Data System (ADS)

    Wan, Qingming; Jin, Yi; Sun, Pengcheng; Ding, Yulong

    2014-05-01

    This work concerns rheological and frictional behaviour of lubricating oils containing platelet molybdenum disulfide (MoS2) nanoparticles (average diameter 50 nm; single layer thickness 3 nm). Stable nano-MoS2 lubricants were formulated and measured for their rheological behaviour and tribological performance. Rheological experiments showed that the nano-MoS2 oils were non-Newtonian following the Bingham plastic fluid model. The viscosity data fitted the classic Hinch-Leal (H-L) model if an agglomeration factor of 1.72 was introduced. Tribological experiments indicated that the use of MoS2 nanoparticles could enhance significantly the tribological performance of the base lubricating oil (reduced frictional coefficient, reduced surface wear and increased stability). Scanning electron microscopy, laser confocal microscope and x-ray energy dispersive spectroscopy analyses suggested that the reduced frictional coefficient and surface wear be associated with surface patching effects. Such patching effects were shown to depend on the concentration of MoS2 nanoparticles, and an effective patching required a concentration over approximately 1 wt%. The increased stability could be attributed to the enhanced heat transfer and lubricating oil film strength due to the presence of nanoparticles.

  6. Mineral oil soluble borate compositions

    SciTech Connect

    Dulat, J.

    1981-09-15

    Alkali metal borates are reacted with fatty acids or oils in the presence of a low hlb value surfactant to give a stable mineral oil-soluble product. Mineral oil containing the borate can be used as a cutting fluid.

  7. Thermal Stability of Oil Palm Empty Fruit Bunch (OPEFB) Nanocrystalline Cellulose: Effects of post-treatment of oven drying and solvent exchange techniques

    NASA Astrophysics Data System (ADS)

    Indarti, E.; Marwan; Wanrosli, W. D.

    2015-06-01

    Nanocrystallinecellulose (NCC) from biomass is a promising material with huge potentials in various applications. A big challenge in its utilization is the agglomeration of the NCC's during processing due to hydrogen bonding among the cellulose chains when in close proximity to each other. Obtaining NCC's in a non-agglomerated and non-aqueous condition is challenging. In the present work NCC's was isolated from oil palm empty fruit bunch (OPEFB) using TEMPO-oxidation reaction method. To obtain non-agglomerated and non-aqueous products, the NCC's underwent post-treatment using oven drying (OD) and solvent exchanged (SE) techniques. The thermal stability of all samples was determined from TGA and DTG profiles whilst FTIR was used to analyzethe chemical modifications that occurred under these conditions. NCC-SE has better thermal stability than the NCC-OD and its on-set degradation temperature and residue are also higher. FTIR analysis shows that NCC-SE has a slightly different chemical composition whereby the absorption band at 1300 cm-1 (due to C-O symmetric stretching) is absent as compared to NCC-OD indicating that in NCC-SE the carboxylate group is in acid form which contribute to its thermal stability

  8. Improving the heat transfer efficiency of synthetic oil with silica nanoparticles.

    PubMed

    Timofeeva, Elena V; Moravek, Michael R; Singh, Dileep

    2011-12-01

    The heat transfer properties of synthetic oil (Therminol 66) used for high temperature applications was improved by introducing 15 nm silicon dioxide nanoparticles. Stable suspensions of inorganic nanoparticles in the non-polar fluid were prepared using a cationic surfactant (benzalkonium chloride). The effects of nanoparticle and surfactant concentrations on thermo-physical properties (viscosity, thermal conductivity and total heat absorption) of these nanofluids were investigated in a wide temperature range. The surfactant-to-nanoparticle (SN) ratio was optimized for higher thermal conductivity and lower viscosity, which are both critical for the efficiency of heat transfer. The rheological behavior of SiO(2)/TH66 nanofluids was correlated to average agglomerate sizes, which were shown to vary with SN ratio and temperature. The conditions of ultrasonic treatment were studied and the temporary decrease of agglomerate size from an equilibrium size (characteristic to SN ratio) was demonstrated. The heat transfer efficiencies were estimated for the formulated nanofluids for both turbulent and laminar flow regimes and were compared to the performance of the base fluid.

  9. Exploring Oil Spills.

    ERIC Educational Resources Information Center

    Czerniak, Charlene M.; And Others

    1996-01-01

    Presents activities in which elementary and middle school students work together to gain environmental awareness about oil spills. Involves students experiencing a simulated oil spill and attempting to clean it up. Discusses the use of children's literature after the activity in evaluation of the activity. (JRH)

  10. Tree nut oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major tree nuts include almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachio nuts, and walnuts. Tree nut oils are appreciated in food applications because of their flavors and are generally more expensive than other gourmet oils. Research during the last de...

  11. Kapok oil methyl esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increased need for biodiesel feedstocks has caused various vegetable oils to be examined for this purpose. In the present work, the methyl esters of kapok (Ceiba pentandra) oil were prepared. The essential fuel properties were comprehensively determined and evaluated in comparison to specificati...

  12. Vegetable oil as fuel

    SciTech Connect

    Not Available

    1980-11-01

    A review is presented of various experiments undertaken over the past few years in the U.S. to test the performance of vegetable oils in diesel engines, mainly with a view to on-farm energy self-sufficiency. The USDA Northern Regional Research Center in Peoria, Illinois, is screening native U.S. plant species as potential fuel oil sources.

  13. Multi Tasking Engine Oils

    DTIC Science & Technology

    2005-04-21

    Petroleum Institute has standards for engine and gear oils but none for multipurpose lubricants of the type described above. The concept of...Transmission Oils (UTTOs) to satisfy this consumer market. Unfortunately, there are no industry-wide standards for these UTTOs as the American

  14. Fossil Energy: Oil.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Detailed are the highlights of the history and technology of crude oil and its end products. Included also are some of the important programs that American industry and the Federal government are planning and undertaking in order to enhance the benefits of oil and make use of the limited available quantities as wisely as possible, both now and in…

  15. Cooking with Healthier Fats and Oils

    MedlinePlus

    ... use fats and oils, choose those with less saturated fat, trans fat, and cholesterol. Choose Less Often Choose More Often Percent of Saturated Fat Canola Oil Safflower Oil Sesame Oil Sunflower Oil ...

  16. Products from vegetable oils

    SciTech Connect

    Bagby, M.O.

    1995-12-01

    Vegetable oils serve various industrial applications such as plasticizers, emulsifiers, surfactants, plastics and resins. Research and development approaches may take advantage of natural properties of the oils. More often it is advantageous to modify those properties for specific applications. One example is the preparation of ink vehicles using vegetable oils in the absence of petroleum. They are cost competitive with petroleum-based inks with similar quality factors. Vegetable oils have potential as renewable sources of fuels for the diesel engine. However, several characteristics can restrict their use. These include poor cold-engine startup, misfire and for selected fuels, high pour point and cloud point temperatures. Other characteristics include incomplete combustion causing carbon buildup, lube oil dilution and degradation, and elevated NO{sub x} emissions. Precombustion and fuel quality data are presented as a tool for understanding and solving these operational and durability problems.

  17. Intraventricular Silicone Oil

    PubMed Central

    Mathis, Stéphane; Boissonnot, Michèle; Tasu, Jean-Pierre; Simonet, Charles; Ciron, Jonathan; Neau, Jean-Philippe

    2016-01-01

    Abstract Intracranial silicone oil is a rare complication of intraocular endotamponade with silicone oil. We describe a case of intraventricular silicone oil fortuitously observed 38 months after an intraocular tamponade for a complicated retinal detachment in an 82 year-old woman admitted in the Department of Neurology for a stroke. We confirm the migration of silicone oil along the optic nerve. We discuss this rare entity with a review of the few other cases reported in the medical literature. Intraventricular migration of silicone oil after intraocular endotamponade is usually asymptomatic but have to be known of the neurologists and the radiologists because of its differential diagnosis that are intraventricular hemorrhage and tumor. PMID:26735537

  18. Corrosivity Of Pyrolysis Oils

    SciTech Connect

    Keiser, James R; Bestor, Michael A; Lewis Sr, Samuel Arthur; Storey, John Morse

    2011-01-01

    Pyrolysis oils from several sources have been analyzed and used in corrosion studies which have consisted of exposing corrosion coupons and stress corrosion cracking U-bend samples. The chemical analyses have identified the carboxylic acid compounds as well as the other organic components which are primarily aromatic hydrocarbons. The corrosion studies have shown that raw pyrolysis oil is very corrosive to carbon steel and other alloys with relatively low chromium content. Stress corrosion cracking samples of carbon steel and several low alloy steels developed through-wall cracks after a few hundred hours of exposure at 50 C. Thermochemical processing of biomass can produce solid, liquid and/or gaseous products depending on the temperature and exposure time used for processing. The liquid product, known as pyrolysis oil or bio-oil, as produced contains a significant amount of oxygen, primarily as components of water, carboxylic acids, phenols, ketones and aldehydes. As a result of these constituents, these oils are generally quite acidic with a Total Acid Number (TAN) that can be around 100. Because of this acidity, bio-oil is reported to be corrosive to many common structural materials. Despite this corrosive nature, these oils have the potential to replace some imported petroleum. If the more acidic components can be removed from this bio-oil, it is expected that the oil could be blended with crude oil and then processed in existing petroleum refineries. The refinery products could be transported using customary routes - pipelines, barges, tanker trucks and rail cars - without a need for modification of existing hardware or construction of new infrastructure components - a feature not shared by ethanol.

  19. Impact of pyranose oxidase from Trametes multicolor, glucose oxidase from Aspergillus niger and hydrogen peroxide on protein agglomeration in wheat flour gluten-starch separation.

    PubMed

    Decamps, Karolien; Gryp, Glenn; Joye, Iris J; Courtin, Christophe M; Delcour, Jan A

    2014-04-01

    The impact of pyranose oxidase (P₂O), glucose oxidase (GO) and H₂O₂ on gluten agglomeration during wheat flour gluten-starch separation was studied. Analysis of gluten aggregate sizes in batter formed from wheat flour dough revealed that increasing levels of oxidising agents gradually decreased the tendency of gluten proteins to form large gluten aggregates. Low enzyme levels increased arabinoxylan (AX) and starch retention on the sieves, due to physical incorporation of AX and starch in the gluten aggregates. Higher enzyme levels increased retention of starch and AX on the smaller and larger sieves, respectively. Extensive oxidation leads to physical incorporation of AX and starch granules in the small gluten aggregates. AX is also crosslinked and hence more easily retained on the top sieves. Our results confirm that the size of gluten aggregates and the level of AX crosslinking and AX and starch incorporation in gluten proteins depend on the concentration of H₂O₂.

  20. Investigation of the agglomeration and amorphous transformation effects of neutron irradiation on the nanocrystalline silicon carbide (3C-SiC) using TEM and SEM methods

    NASA Astrophysics Data System (ADS)

    Huseynov, Elchin M.

    2017-04-01

    Nanocrystalline 3C-SiC particles irradiated by neutron flux during 20 h in TRIGA Mark II light water pool type research reactor. Silicon carbide nanoparticles were analyzed by Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM) devices before and after neutron irradiation. The agglomeration of nanoparticles was studied comparatively before and after neutron irradiation. After neutron irradiation the amorphous layer surrounding the nanoparticles was analyzed in TEM device. Neutron irradiation defects in the 3C-SiC nanoparticles and other effects investigated by TEM device. The effect of irradiation on the crystal structure of the nanomaterial was studied by selected area electron diffraction (SAED) and electron diffraction patterns (EDP) analysis.

  1. High efficiency shale oil recovery. Fourth quarterly report, October 1, 1992--December 31, 1992

    SciTech Connect

    Adams, D.C.

    1992-12-31

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical (heating, mixing) conditions exist in both systems. The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed and is reported on this quarter: (1) A software routine was written to eliminate intermittently inaccurate temperature readings. (2) We completed the quartz sand calibration runs, resolving calibration questions from the 3rd quarter. (3) We also made low temperature retorting runs to identify the need for certain kiln modifications and kiln modifications were completed. (4) Heat Conductance data on two Pyrolysis runs were completed on two samples of Occidental oil shale.

  2. How the guest molecules in nanoporous Zn(II) metal-organic framework can prevent agglomeration of ZnO nanoparticles

    SciTech Connect

    Moeinian, Maryam; Akhbari, Kamran

    2015-05-15

    The host and the apohost framework of [Zn{sub 2}(BDC){sub 2}(H{sub 2}O){sub 2}·(DMF){sub 2}]{sub n} (1·2H{sub 2}O·2DMF), (BDC{sup 2−}=benzene-1,4-dicarboxylate and DMF=N,N-Dimethylformamide), were synthesized and subsequently used for preparation of ZnO nanomaterials. With calcination of the host framework of 1·2H{sub 2}O·2DMF, ZnO nanoparticles were obtained. By the same process on the apohost framework of 1, agglomerated nanoparticles of ZnO were formed. These nano-structures were characterized by X-ray powder diffraction (XRD) and Scanning electron microscopy (SEM). These results indicate that with removal of the guest DMF and coordinated H{sub 2}O molecules from the one-dimensional channels of 1·2H{sub 2}O·2DMF, the tendency of nanoparticles to agglomerate increases and the role of this MOF in preparation of ZnO nanoparticles from this precursor was reduced. - Graphical abstract: Nano-porous zinc(II) MOF with guest DMF and coordinated H{sub 2}O molecules has been synthesized and characterized. The host and the apohost framework of it were used for preparation of ZnO nanomaterials. The role of these species in preparation of ZnO nanoparticles from the host framework is probably similar to the role of polymeric stabilizers in formation of nanoparticles. - Highlights: • Nanoparticles of ZnO were fabricated from nanoporous metal-organic framework. • The effect of guest DMF and coordinated H{sub 2}O molecules on this process was studied. • The effect of them in formation nanoparticle is similar to polymeric stabilizers.

  3. LEVEL OF SOMATIC DEVELOPMENT OF CHILDREN AGED SIX YEARS FROM AN URBAN AGGLOMERATION IN POLAND WITH RESPECT TO SELECTED ENVIRONMENTAL CONDITIONS.

    PubMed

    Trzcińska, Dorota; Tabor, Piotr; Olszewska, Elżbieta

    2015-11-01

    The aim of this study was to assess the somatic development of children from an urban agglomeration in Poland at the end of preschool education and the beginning of primary education with respect to selected socioeconomic and educational conditions. Data were collected for 742 children from selected Warsaw kindergartens in spring 2011 and 2012. Their mean age was 5.84±0.31 years. The sex categories were equal: 371 boys and 371 girls. Kindergartens chosen for the study constituted a representative sample. The diagnostic survey method (questionnaire technique) was used to assess the selected environmental conditions of development in the participating children. Body height and the sum of six skin folds (over the biceps, over the triceps, under the scapula, on the abdomen, over the wing of ilium and on the calf) were chosen from the assessed anthropometric parameters for the purpose of determining somatic development of study participants. The obtained data were analysed using selected descriptive statistics methods (including cluster analysis), data standardization (normalization by mean values and SD) and the chi-squared test. The results showed certain relationships between the selected parameters of somatic development and family living conditions. These relationships involved differences between individual clusters depending on given living conditions and were most prominent for mother's education, for which variable differences between clusters were found for both sexes. The somatic build of boys (including body height and body adiposity) also differed depending on the number of offspring in the family, while the somatic build of girls differed depending on father's employment and father's education. Furthermore, the obtained results lead to the conclusion that the total number of differences between the analysed clusters was relatively low. This indicates that the biological effects of social stratification tend to diminish in the environment of an urban

  4. Weathering patterns of polycyclic aromatic hydrocarbons contained in submerged Deepwater Horizon oil spill residues when re-exposed to sunlight.

    PubMed

    John, Gerald F; Han, Yuling; Clement, T Prabhakar

    2016-12-15

    The Deepwater Horizon (DWH) oil spill event released a large amount of sweet crude oil into the Gulf of Mexico (GOM). An unknown portion of this oil that arrived along the Alabama shoreline interacted with nearshore sediments and sank forming submerged oil mats (SOMs). A considerable amount of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs), were trapped within these buried SOMs. Recent studies completed using the oil spill residues collected along the Alabama shoreline have shown that several PAHs, especially higher molecular weight PAHs (four or more aromatic rings), are slowly weathering compared to the weathering levels experienced by the oil when it was floating over the GOM. In this study we have hypothesized that the weathering rates of PAHs in SOMs have slowed down because the buried oil was isolated from direct exposure to sunlight, thus hindering the photodegradation pathway. We further hypothesized that re-exposing SOMs to sunlight can reactivate various weathering reactions. Also, SOMs contain 75-95% sand (by weight) and the entrapped sand could either block direct sunlight or form large oil agglomerates with very little exposed surface area; these processes could possibly interfere with weathering reactions. To test these hypotheses, we completed controlled experiments to study the weathering patterns of PAHs in a field recovered SOM sample after re-exposing it to sunlight. Our experimental results show that the weathering levels of several higher molecular weight PAHs have slowed down primarily due to the absence of sunlight-induced photodegradation reactions. The data also show that sand particles in SOM material could potentially interfere with photodegradation reactions.

  5. Marine Oil Biodegradation

    SciTech Connect

    Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

    2015-12-23

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.

  6. Marine Oil Biodegradation

    DOE PAGES

    Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

    2015-12-23

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine watersmore » with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.« less

  7. Marine Oil Biodegradation.

    PubMed

    Hazen, Terry C; Prince, Roger C; Mahmoudi, Nagissa

    2016-03-01

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments, and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to "bloom" in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.

  8. 21 CFR 172.861 - Cocoa butter substitute from coconut oil, palm kernel oil, or both oils.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Cocoa butter substitute from coconut oil, palm... substitute from coconut oil, palm kernel oil, or both oils. The food additive, cocoa butter substitute from coconut oil, palm kernel oil, or both oils, may be safely used in food in accordance with the...

  9. 21 CFR 172.861 - Cocoa butter substitute from coconut oil, palm kernel oil, or both oils.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Cocoa butter substitute from coconut oil, palm... substitute from coconut oil, palm kernel oil, or both oils. The food additive, cocoa butter substitute from coconut oil, palm kernel oil, or both oils, may be safely used in food in accordance with the...

  10. 21 CFR 172.861 - Cocoa butter substitute from coconut oil, palm kernel oil, or both oils.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cocoa butter substitute from coconut oil, palm... substitute from coconut oil, palm kernel oil, or both oils. The food additive, cocoa butter substitute from coconut oil, palm kernel oil, or both oils, may be safely used in food in accordance with the...

  11. 21 CFR 172.861 - Cocoa butter substitute from coconut oil, palm kernel oil, or both oils.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Cocoa butter substitute from coconut oil, palm... substitute from coconut oil, palm kernel oil, or both oils. The food additive, cocoa butter substitute from coconut oil, palm kernel oil, or both oils, may be safely used in food in accordance with the...

  12. Kuwait Oil Fires, Kuwait

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Smoke from the burning oil fields to the north and south of Kuwait City, seen on the south shore of Kuwayt Bay almost totally obscures the view of the tiny, but oil rich, nation of Kuwait (29.0N, 48.0E). During the brief war between Iraq and the Allied forces, many of the oil wells in Kuwait were destroyed and set afire. For several months, those fires burned out of control, spewing wind borne smoke and ash for hundreds of miles.

  13. Kuwait Oil Fires, Kuwait

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The number of oil well fires from the Kuwait Oil Fields (29.5N, 48.0E) set afire by the retreating Iraqi Army during the 1991 Persian Gulf War, has been measurably diminished since the last observation although the smoke plumes were still intact as far south as Qatar. Most of the remaining approximately 300 oil fires are in the two largest fields: Sibirayah, north of Kuwait Bay and the larger Magwas-Burgan-Al Ahmadi field south of Kuwait City.

  14. Processing sunflower oil for fuel

    SciTech Connect

    Backer, L.F.; Jacobsen, L.; Olson, C.

    1982-05-01

    Research on processing of sunflower seed for oil was initiated to evaluate the equipment that might adapt best to on-farm or small factory production facilities. The first devices identified for evaluation were auger press expeller units, primary oil cleaning equipment, and final filters. A series of standard finishing filtration tests were carried out on sunflower oil and sunflower oil - diesel fuel blends using sunflower oil from four different sources.

  15. Fuel properties of cottonseed oil

    SciTech Connect

    Karaosmanoglu, F.; Tueter, M.; Goellue, E.; Yanmaz, S.; Altintig, E.

    1999-11-01

    The use of vegetable oils as fuel alternatives has an exceptional importance in the field of research. In this study, evaluation possibilities of cottonseed oil have been investigated as an alternative candidate for diesel fuel and fuel oil. The fuel property tests were performed according to standard analysis methods for oil and fuel. An overall evaluation of the results indicates that cottonseed oil can be proposed as a possible green substitute for fuel.

  16. Elastohydrodynamic properties of heat-bodied oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat-bodied oils are biobased oils obtained via thermal treatment of vegetable oils under inert (N2) atmospheric conditions. Most heat-bodied oils are based on soybean oil, but other vegetable oils and blends of vegetable oils can also be utilized to obtain specific properties. Depending on the temp...

  17. Essential Oils, Part VI: Sandalwood Oil, Ylang-Ylang Oil, and Jasmine Absolute.

    PubMed

    de Groot, Anton C; Schmidt, Erich

    In this article, some aspects of sandalwood oil, ylang-ylang oil, and jasmine absolute are discussed including their botanical origin, uses of the plants and the oils and absolute, chemical composition, contact allergy to and allergic contact dermatitis from these essential oils and absolute, and their causative allergenic ingredients.

  18. Eugenol oil overdose

    MedlinePlus

    Below are symptoms of a eugenol oil overdose in different parts of the body. AIRWAYS AND LUNGS Shallow breathing Rapid breathing Coughing up blood BLADDER AND KIDNEYS Blood in the urine No urine output Pain when you urinate EYES, EARS, ...

  19. Peppermint oil overdose

    MedlinePlus

    ... PA: Elsevier Saunders; 2007:chap 101. Murray MT. Mentha piperita (peppermint). In: Pizzorno JE, Murray MT, eds. ... B. Final report on the safety assessment of mentha piperita (peppermint) oil, mentha piperita (peppermint) leaf extract, ...

  20. UAVSAR_Gulf_Oil

    NASA Video Gallery

    NASA's Gulfstream III research aircraft carrying the Jet Propulsion Laboratory’s sophisticated UAVSAR synthetic aperture radar under its belly surveyed the spread of the Gulf of Mexico oil spill du...