WorldWideScience

Sample records for suspended solid particles

  1. Ratios of total suspended solids to suspended sediment concentrations by particle size

    Science.gov (United States)

    Selbig, W.R.; Bannerman, R.T.

    2011-01-01

    Wet-sieving sand-sized particles from a whole storm-water sample before splitting the sample into laboratory-prepared containers can reduce bias and improve the precision of suspended-sediment concentrations (SSC). Wet-sieving, however, may alter concentrations of total suspended solids (TSS) because the analytical method used to determine TSS may not have included the sediment retained on the sieves. Measuring TSS is still commonly used by environmental managers as a regulatory metric for solids in storm water. For this reason, a new method of correlating concentrations of TSS and SSC by particle size was used to develop a series of correction factors for SSC as a means to estimate TSS. In general, differences between TSS and SSC increased with greater particle size and higher sand content. Median correction factors to SSC ranged from 0.29 for particles larger than 500m to 0.85 for particles measuring from 32 to 63m. Great variability was observed in each fraction-a result of varying amounts of organic matter in the samples. Wide variability in organic content could reduce the transferability of the correction factors. ?? 2011 American Society of Civil Engineers.

  2. Experimental study of the viscosity of suspensions: effect of solid fraction, particle size and suspending liquid

    NARCIS (Netherlands)

    Konijn, B.J.; Sanderink, O.B.J.; Kruyt, Nicolaas P.

    2014-01-01

    The behaviour of nearly neutrally-buoyant suspensions has been studied experimentally, using a concentric-cylinder rheometer. The effect on the suspension viscosity of: (i) solid fraction, (ii) diameter of the solid, spherical particles, (iii) viscosity of the suspending liquid, and (iv) shear rate

  3. Particle size distribution of suspended solids in the Chesapeake Bay entrance and adjacent shelf waters

    Science.gov (United States)

    Byrnes, M. R.; Oertel, G. F.

    1981-01-01

    Characteristics of suspended solids, including total suspended matter, total suspended inorganics, total suspended organics, particle size distribution, and the presence of the ten most prominent particle types were determined. Four research vessels simultaneously collected samples along four transects. Samples were collected within a 2-hour period that coincided with the maximum ebb penetration of Chesapeake Bay outwelling. The distribution of primary and secondary particle size modes indicate the presence of a surface or near-surface plume, possibly associated with three sources: (1) runoff, (2) resuspension of material within the Bay, and/or (3) resuspension of material in the area of shoals at the Bay mouth. Additional supportive evidence for this conclusion is illustrated with ocean color scanner data.

  4. The Influence of Suspended Inert Solid Particles on Zinc Corrosion

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1996-01-01

    The rate of corrosion of electroplated zinc in near-neutral chloride solutions can be lowered by as much as 75% by adding fine, inert particles of substances such as MnO2, Fe3O4, SiC and TiN to the well-stirred solution. Spreading of local areas of etching is also stopped. Copyright (C) 1996...

  5. Suspended-sediment concentrations, yields, total suspended solids, turbidity, and particle-size fractions for selected rivers in Minnesota, 2007 through 2011

    Science.gov (United States)

    Ellison, Christopher A.; Savage, Brett E.; Johnson, Gregory D.

    2015-01-01

    Excessive sediment transport in rivers causes problems for flood control, soil conservation, irrigation, aquatic health, and navigation, as well as transporting harmful contaminants like organic chemicals and eutrophication-causing nutrients. In Minnesota, more than 5,800 miles of streams are identified as impaired by the Minnesota Pollution Control Agency (MPCA) due to elevated levels of suspended sediment. The U.S. Geological Survey, in cooperation with the MPCA, established a sediment monitoring network in 2007 and began systematic sampling of suspended-sediment concentration (SSC), total suspended solids (TSS), and turbidity in rivers across Minnesota to improve the understanding of fluvial sediment transport relations. Suspended-sediment samples were collected from 14 sites from 2007 through 2011. Analyses of these data indicated that the Zumbro River at Kellogg in southeast Minnesota had the highest mean SSC of 226 milligrams per liter (mg/L) followed by the Minnesota River at Mankato with a mean SSC of 193 mg/L. The single highest SSC of 1,250 mg/L was measured at the Zumbro River during the 2011 spring runoff. The lowest mean SSC of 21 mg/L was measured at Rice Creek in the northern Minneapolis-St. Paul metropolitan area. Total suspended solids (TSS) have been used as a measure of fluvial sediment by the MPCA since the early 1970s; however, TSS concentrations have been known to underrepresent the amount of suspended sediment. For this study, comparisons between concurrently sampled SSC and TSS indicated significant differences at every site, with SSC on average two times larger than TSS concentrations. Regression analysis indicated that 7 out of 14 sites had poor or no relation between SSC and streamflow. Only two sites, the Knife River and the Wild Rice River at Twin Valley, had strong correlations between SSC and streamflow, with coefficient of determination (R2) values of 0.82 and 0.80, respectively. In contrast, turbidity had moderate to strong

  6. Suspended-sediment concentrations, loads, total suspended solids, turbidity, and particle-size fractions for selected rivers in Minnesota, 2007 through 2011

    Science.gov (United States)

    Ellison, Christopher A.; Savage, Brett E.; Johnson, Gregory D.

    2014-01-01

    Sediment-laden rivers and streams pose substantial environmental and economic challenges. Excessive sediment transport in rivers causes problems for flood control, soil conservation, irrigation, aquatic health, and navigation, and transports harmful contaminants like organic chemicals and eutrophication-causing nutrients. In Minnesota, more than 5,800 miles of streams are identified as impaired by the Minnesota Pollution Control Agency (MPCA) due to elevated levels of suspended sediment. The U.S. Geological Survey, in cooperation with the MPCA, established a sediment monitoring network in 2007 and began systematic sampling of suspended-sediment concentrations (SSC), total suspended solids (TSS), and turbidity in rivers across Minnesota to improve the understanding of fluvial sediment transport relations. Suspended-sediment samples collected from 14 sites from 2007 through 2011 indicated that the Zumbro River at Kellogg in the driftless region of southeast Minnesota had the highest mean SSC of 226 milligrams per liter (mg/L) followed by the Minnesota River at Mankato with a mean SSC of 193 mg/L. During the 2011 spring runoff, the single highest SSC of 1,250 mg/L was measured at the Zumbro River. The lowest mean SSC of 21 mg/L was measured at Rice Creek in the northern Minneapolis- St. Paul metropolitan area. Total suspended solids (TSS) have been used as a measure of fluvial sediment by the MPCA since the early 1970s; however, TSS concentrations have been determined to underrepresent the amount of suspended sediment. Because of this, the MPCA was interested in quantifying the differences between SSC and TSS in different parts of the State. Comparisons between concurrently sampled SSC and TSS indicated significant differences at every site, with SSC on average two times larger than TSS concentrations. The largest percent difference between SSC and TSS was measured at the South Branch Buffalo River at Sabin, and the smallest difference was observed at the Des Moines

  7. Sedimentation of suspended solids in ultrasound field

    Directory of Open Access Journals (Sweden)

    Vikulina Vera

    2018-01-01

    Full Text Available Physical and chemical effects of aquatic environment that occur in an ultrasonic field change the sedimentation rate of coagulated suspension. This might only happen in case of cavitation of ultrasonic filed that causes a change of potentials of the medium. Research of the influence of ultrasonic vibrations on coagulation of suspended solids within water purification allows expanding their scope of implementation. The objective of the research is to estimate the effect of ultrasound on the sedimentation of the suspended solids, to determine of the efficiency of the process in relation to the dose of the coagulant, and to calculate the numerical values of the constants in the theoretical equation. The experiment condition was held in the water with the clay substances before the introduction of the coagulant. The method of magnetostriction ultrasonic generator was applied to receive ultrasonic vibration. Estimate of concentration of clay particles in water was performed using photometry. As a result of the research, the obtained data allow determining the increase in efficiency of suspended particles sedimentation related to the dose of coagulant, depending on time of ultrasonic treatment. The experiments confirmed the connection between the effect of sedimentation in the coagulation process, the coagulant dose and the time of scoring. Studies have shown that the increase in the duration of ultrasonic treatment causes a decrease of administered doses of coagulant.

  8. Flow Laminarization and Acceleration by Suspended Particles

    NARCIS (Netherlands)

    Bertsch, M.; Hulshof, J.; Prostokishin, V.M.

    2015-01-01

    In [Comm. Appl. Math. Comput. Sci., 4(2009), pp. 153-175], Barenblatt presents a model for partial laminarization and acceleration of shear flows by the presence of suspended particles of different sizes, and provides a formal asymptotic analysis of the resulting velocity equation. In the present

  9. Particles matter: Transformation of suspended particles in constructed wetlands

    NARCIS (Netherlands)

    Mulling, B.T.M.

    2013-01-01

    This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator

  10. Geodetic monitoring of suspended particles in rivers

    Science.gov (United States)

    Kamnik, Rok; Maksimova, Daria; Kovačič, Boštjan

    2017-10-01

    There is a trend in modern approach to the management of space of collecting the spatial data, in order to obtain useful information. In this paper a research of suspended particles in the river Drava and Mura will be introduced. The goal is to connect different fields of water management in countries where the rivers Drava and Mura flows in purpose of water management sustainability. The methods such as GNSS for mapping cross sections of the river, the use of ADCP (Acoustic Doppler Current Profiler) measurement system and water sampling to monitor sediment in the water will be presented.

  11. Organics and Suspended Solids Removal from Hospital

    Directory of Open Access Journals (Sweden)

    Fakhri Y. Hmood

    2013-05-01

    Full Text Available The Sequencing Batch Reactor (SBR method is used for treating samples of waste water taken from hospitals in Mosul. Many run periods are used (6-24 hours for             6 months. It is found that the organics and suspended solids removal increase with increasing the period of run, it is in the range ( 96-82 % and ( 100-95 % respectively, while the pH values are nearly neutral (7.05 to 7.5.     BOD5 and SS concentrations of the effluent are within the limits of Iraqi standards,  40:30 mg/l respectively. Hence, SBR method could be used for treating hospitals, small factories and some  residential sectors waste waters.  

  12. A study of metal ion adsorption at low suspended-solid concentrations

    Science.gov (United States)

    Chang, Cecily C.Y.; Davis, J.A.; Kuwabara, J.S.

    1987-01-01

    A procedure for conducting adsorption studies at low suspended solid concentrations in natural waters (NaCl) concentration (0??1-0??002 m) and particle concentration (2-50 mg l-1). The lack of success of the Davis Leckie site bonding model in describing Zn(II) adsorption emphasizes the need for further studies of adsorption at low suspended-solid concentrations. ?? 1987.

  13. [Impacts of Sediment Disturbance on the Distribution of Suspended Particle Size and Phosphorus].

    Science.gov (United States)

    Guo, Jun-rui; Li, Da-peng; Liu, Yan-jian

    2016-04-15

    To clarify the influence of the sediments disturbance on the particle size distribution of suspended solids, and the influence of particle distribution on the forms of dissolved phosphorous in the overlaying water, the sediments and overlying water from Meiliang Bay, Taihu Lake, were used to conduct the indoor simulation experiments to investigate the particle size of suspended solids according to the Ubbelobde particle size criteria and the distribution of phosphorus compounds in the overlying water under the disturbance circumstances. The results indicated that the average proportions of small (0-10 microm), middle (10-20 microm) and large (> or = 20 microm) diameter particles presented different trends of increasing, decreasing and staying stable, respectively. It indicated the possible transformation of particle size of suspended solids from small-middle diameter to large diameter. In addition, the data of DTP/TP and DIP/TP showed a periodical variation with the corresponding periodical variety of particle diameter in suspended solids, while ns obvious variety of DTP and DIP was observed. It suggested that disturbance enhanced the ability of phosphorus immobilization by suspended solids. On the other band, the percentages of DTP in TP and DIP in TP were 19% and 13% under the disturbance, respectively, and they were obviously lower than those (DTP/TP, 80% and DIP/TP, 69% ) in the control. It indicated that tbs transformation of particle size of suspended solids from small-middle diameter to large diameter due to disturbance was in favor of tbe adsorption and sedimentation of dissolved phosphorus. Accordingly, the formation of particle phosphorus was enhanced. Therefore, it delayed the development of eutrophication in the water body.

  14. Characterization and morphology of solids suspended in rain water; Caracterizacion y morfologia de solidos suspendidos en agua de lluvia

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Mexico D.F. (Mexico)

    2000-07-01

    This work presents the results obtained from the analysis of rain water in Mexico. The study treats over the characterization and morphology of the solids suspended in form of particles in the atmosphere. The solids suspended were obtained of the pluvial precipitations after these have been centrifuged. Subsequently of the separation, the particulate matter was analysed by Sem and X-ray dispersive energy.

  15. Surface clogging process modeling of suspended solids during urban stormwater aquifer recharge.

    Science.gov (United States)

    Wang, Zijia; Du, Xinqiang; Yang, Yuesuo; Ye, Xueyan

    2012-01-01

    Aquifer recharge, which uses urban stormwater, is an effective technique to control the negative effects of groundwater over-exploitation, while clogging problems in infiltration systems remain the key restricting factor in broadening its practice. Quantitative understanding of the clogging process is still very poor. A laboratory study was conducted to understand surface physical clogging processes, with the primary aim of developing a model for predicting suspended solid clogging processes before aquifer recharge projects start. The experiments investigated the clogging characteristics of different suspended solid sizes in recharge water by using a series of one-dimensional fine quartz sand columns. The results showed that the smaller the suspended particles in recharge water, the farther the distance of movement and the larger the scope of clogging in porous media. Clogging extents in fine sand were 1 cm, for suspended particle size ranging from 0.075 to 0.0385 mm, and 2 cm, for particles less than 0.0385 mm. In addition, clogging development occurred more rapidly for smaller suspended solid particles. It took 48, 42, and 36 hr respectively, for large-, medium-, and small-sized particles to reach pre-determined clogging standards. An empirical formula and iteration model for the surface clogging evolution process were derived. The verification results obtained from stormwater recharge into fine sand demonstrated that the model could reflect the real laws of the surface clogging process.

  16. Development of a field test method for total suspended solids analysis.

    Science.gov (United States)

    2013-11-01

    Total suspended solids (TSS) are all particles in water that will not pass through a glass fiber filter with a pore size less : than 2 m, including sediments, algae, nutrients, and metals. TSS is an important water quality parameter because of its ...

  17. Suspended sediment concentration and particle size distribution ...

    Indian Academy of Sciences (India)

    face area, shape, minerals and source) and conse- quent interaction with heavy metal concentrations. (HMCs). Recent studies have shown a growing awareness of the wider environmental significance of the suspended sediment loads transported by rivers and streams. This includes the importance of fine grain sediment in ...

  18. Transport of suspended particles in turbulent open channel flows

    NARCIS (Netherlands)

    Breugem, W.A.

    2012-01-01

    Two experiments are performed in order to investigate suspended sediment transport in a turbulent open channel flow. The first experiment used particle image velocimetry (PIV) to measure the fluid velocity with a high spatial resolution, while particle tracking velocimetry (PTV) was used to measure

  19. Geochemistry of suspended and settling solids in two freshwater lakes.

    NARCIS (Netherlands)

    Koelmans, A.A.

    1998-01-01

    This study describes the 1987–1992 time variationof the bulk chemical composition, levels of heavymetals, arsenic, nitrogen and phosporous insuspended and settling solids in Lake Volkerak andLake Zoom (The Netherlands). Suspended and setlingsolids were collected with continuous flowcentrifuges and

  20. Comparison of Suspended Solid Separation in Advanced Storm Overflow Structures

    DEFF Research Database (Denmark)

    Larsen, Torben; Sørensen, Morten Steen

    1990-01-01

    This paper describes a laboratory investigation of the separation of suspended solids in a circular weir overflow and a vortex separator. The basic idea is to evaluate the efficiency of a vortical flow in the overflow chamber, and to compare these results with other overflow structures....

  1. Current-use insecticides, phosphates and suspended solids in the ...

    African Journals Online (AJOL)

    In Western Cape orchard areas, the last pesticide application of the growing season in summer takes place at the end of February. Pesticides, total phosphates and total suspended solids (TSS) were measured in the Lourens River at the beginning of April 1999 prior to the first rainfall of the rainy season and in the middle of ...

  2. IUTAM symposium on hydrodynamic diffusion of suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.H. [ed.

    1995-12-31

    Hydrodynamic diffusion refers to the fluctuating motion of nonBrownian particles (or droplets or bubbles) which occurs in a dispersion due to multiparticle interactions. For example, in a concentrated sheared suspension, particles do not move along streamlines but instead exhibit fluctuating motions as they tumble around each other. This leads to a net migration of particles down gradients in particle concentration and in shear rate, due to the higher frequency of encounters of a test particle with other particles on the side of the test particle which has higher concentration or shear rate. As another example, suspended particles subject to sedimentation, centrifugation, or fluidization, do not generally move relative to the fluid with a constant velocity, but instead experience diffusion-like fluctuations in velocity due to interactions with neighboring particles and the resulting variation in the microstructure or configuration of the suspended particles. In flowing granular materials, the particles interact through direct collisions or contacts (rather than through the surrounding fluid); these collisions also cause the particles to undergo fluctuating motions characteristic of diffusion processes. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  3. Suspended sediment concentration and particle size distribution ...

    Indian Academy of Sciences (India)

    ... particle size distribution (PSD) were correlated with HMC by using bivariate and multivariate regression models. Proposed models were then selected based on statistical criteria. The results showed high correlation between dissolved and particulate chromium content with efficiency coefficients beyond 77% ( > 0.001).

  4. Spatial and temporal dynamics of suspended particle characteristics and composition in Navigation Pool 19 of the Upper Mississippi River

    Science.gov (United States)

    Milde, Amanda S.

    2017-01-01

    Suspended particles are an essential component of large rivers influencing channel geomorphology, biogeochemical cycling of nutrients, and food web resources. The Upper Mississippi River (UMR) is a large floodplain river that exhibits pronounced spatiotemporal variation in environmental conditions and biota, providing an ideal environment for investigating dynamics of suspended particles in large river ecosystems. Here we investigated two questions: (1) How do suspended particle characteristics (e.g., size and morphology) vary temporally and spatially? and (2) What environmental variables have the strongest association with particle characteristics? Water sampling was conducted in June, August, and September of 2013 and 2014 in Navigation Pool 19 of the UMR. A FlowCAM particle imaging system was used to enumerate and measure particles 53–300 µm in diameter for size and shape characteristics (e.g., volume, elongation, and symmetry). Suspended particle characteristics varied considerably over space and time and were strongly associated with discharge and concentrations of nitrate + nitrite (NO3-) and soluble reactive phosphorous (SRP). Particle characteristics in backwaters were distinct from those in other habitats for most of the study period, likely due to reduced hydrologic connectivity and higher biotic production in backwaters. During low discharge, phytoplankton and zooplankton made up relatively greater proportions of the observed particles. Concurrently during low discharge, concentrations of chlorophyll, volatile suspended solids, and total phosphorous were higher. Our results suggest that there are complex interactions among space, time, discharge, and other environmental variables (e.g. water nutrients) which drive suspended particle dynamics in large rivers.

  5. Solid Particle Formation Mechanisms.

    Science.gov (United States)

    1986-04-01

    3421. Kuka , K., N. Wads, and A. Tasaki, "Magnetic Properties of Ferromagnetic Metal Alloy Flue Particles Prepared by Evaporation In Inert Gases," Japanese J. Applied Physics, Vol. 8, 1969, p. 603. [ II 7-- IATI.

  6. Study of Hydrophilic Electrospun Nanofiber Membranes for Filtration of Micro and Nanosize Suspended Particles

    Directory of Open Access Journals (Sweden)

    Nurxat Nuraje

    2013-11-01

    Full Text Available Polymeric nanofiber membranes of polyvinyl chloride (PVC blended with polyvinylpyrrolidone (PVP were fabricated using an electrospinning process at different conditions and used for the filtration of three different liquid suspensions to determine the efficiency of the filter membranes. The three liquid suspensions included lake water, abrasive particles from a water jet cutter, and suspended magnetite nanoparticles. The major goal of this research work was to create highly hydrophilic nanofiber membranes and utilize them to filter the suspended liquids at an optimal level of purification (i.e., drinkable level. In order to overcome the fouling/biofouling/blocking problems of the membrane, a coagulation process, which enhances the membrane’s efficiency for removing colloidal particles, was used as a pre-treatment process. Two chemical agents, Tanfloc (organic and Alum (inorganic, were chosen for the flocculation/coagulation process. The removal efficiency of the suspended particles in the liquids was measured in terms of turbidity, pH, and total dissolved solids (TDS. It was observed that the coagulation/filtration experiments were more efficient at removing turbidity, compared to the direct filtration process performed without any coagulation and filter media.

  7. Deterministic separation of suspended particles in a reconfigurable obstacle array

    CERN Document Server

    Du, Siqi

    2015-01-01

    We use a macromodel of a flow-driven deterministic lateral displacement (DLD) microfluidic system to investigate conditions leading to size-separation of suspended particles. This model system can be easily reconfigured to establish an arbitrary orientation between the average flow field and the array of obstacles comprising the stationary phase (forcing angle). We also investigate the effect of obstacle size using two arrays with different obstacles but same surface-to-surface distance between them. In all cases, we observe the presence of a locked mode at small forcing angles, in which particles move along a principal direction in the lattice until a locked-to-zigzag transition takes place when the driving force reaches a critical angle. We show that the transition occurs at increasing angles for larger particles, thus enabling particle separation at specific forcing angles. Moreover, we observe a linear correlation between the critical angle and the size of the particles that could be used in the design of...

  8. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Science.gov (United States)

    2010-07-01

    ... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Liquid, suspended particulate, and solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL PROTECTION...

  9. High suspended solids as a factor in reproductive failure of a freshwater mussel

    Science.gov (United States)

    Andrew M. Gascho-Landis; Wendell R. Haag; James A. Stoeckel

    2013-01-01

    Elevated suspended solids are a widespread stressor of aquatic ecosystems, but their effects on growth and reproduction in freshwater mussels are largely unknown. We fertilized experimental ponds to create a gradient in total suspended solids (TSS) and examined the effects of TSS on growth, nutritional status, reproduction, and clearance rate in Ligumia subrostrata....

  10. Physical and biological changes of suspended particles in a free surface flow constructed wetland

    NARCIS (Netherlands)

    Mulling, B.T.M.; van den Boomen, R.M.; Claassen, T.H.L.; van der Geest, H.G.; Kappelhof, J.W.N.M.; Admiraal, W.

    2013-01-01

    Suspended particles are considered as contaminants in treated wastewater and can have profound effects on the biological, physical and chemical properties of receiving aquatic ecosystems, depending on the concentration, type and nature of the suspended particles. Constructed wetlands are known to

  11. Effects of temperature, total dissolved solids, and total suspended solids on survival and development rate of larval Arkansas River Shiner

    Science.gov (United States)

    Mueller, Julia S.; Grabowski, Timothy B.; Brewer, Shannon K.; Worthington, Thomas A.

    2017-01-01

    Decreases in the abundance and diversity of stream fishes in the North American Great Plains have been attributed to habitat fragmentation, altered hydrological and temperature regimes, and elevated levels of total dissolved solids and total suspended solids. Pelagic-broadcast spawning cyprinids, such as the Arkansas River Shiner Notropis girardi, may be particularly vulnerable to these changing conditions because of their reproductive strategy. Our objectives were to assess the effects of temperature, total dissolved solids, and total suspended solids on the developmental and survival rates of Arkansas River Shiner larvae. Results suggest temperature had the greatest influence on the developmental rate of Arkansas River Shiner larvae. However, embryos exposed to the higher levels of total dissolved solids and total suspended solids reached developmental stages earlier than counterparts at equivalent temperatures. Although this rapid development may be beneficial in fragmented waters, our data suggest it may be associated with lower survival rates. Furthermore, those embryos incubating at high temperatures, or in high levels of total dissolved solids and total suspended solids resulted in less viable embryos and larvae than those incubating in all other temperature, total dissolved solid, and total suspended solid treatment groups. As the Great Plains ecoregion continues to change, these results may assist in understanding reasons for past extirpations and future extirpation threats as well as predict stream reaches capable of sustaining Arkansas River Shiners and other species with similar early life-history strategies.

  12. Event-based total suspended sediment particle size distribution model

    Science.gov (United States)

    Thompson, Jennifer; Sattar, Ahmed M. A.; Gharabaghi, Bahram; Warner, Richard C.

    2016-05-01

    One of the most challenging modelling tasks in hydrology is prediction of the total suspended sediment particle size distribution (TSS-PSD) in stormwater runoff generated from exposed soil surfaces at active construction sites and surface mining operations. The main objective of this study is to employ gene expression programming (GEP) and artificial neural networks (ANN) to develop a new model with the ability to more accurately predict the TSS-PSD by taking advantage of both event-specific and site-specific factors in the model. To compile the data for this study, laboratory scale experiments using rainfall simulators were conducted on fourteen different soils to obtain TSS-PSD. This data is supplemented with field data from three construction sites in Ontario over a period of two years to capture the effect of transport and deposition within the site. The combined data sets provide a wide range of key overlooked site-specific and storm event-specific factors. Both parent soil and TSS-PSD in runoff are quantified by fitting each to a lognormal distribution. Compared to existing regression models, the developed model more accurately predicted the TSS-PSD using a more comprehensive list of key model input parameters. Employment of the new model will increase the efficiency of deployment of required best management practices, designed based on TSS-PSD, to minimize potential adverse effects of construction site runoff on aquatic life in the receiving watercourses.

  13. Dynamics of Single Chains of Suspended Ferrofluid Particles

    Science.gov (United States)

    Cutillas, S.; Liu, J.

    1999-01-01

    We present an experimental study of the dynamics of isolated chains made of super-paramagnetic particles under the influence of a magnetic field. The motivation of this work is to understand if the chain fluctuations exist and, if it does, how does the fluctuation affect chain aggregation. We find that single chains strongly fluctuate and that the characteristic frequency of their fluctuations is inversely proportional to the magnetic field strength. The higher the field the lower the characteristic frequency of the chain fluctuations. In the high magnetic field limit, chains behave like rigid rods without any internal motions. In this work, we used ferrofluid particles suspended in water. These particles do not have any intrinsic magnetization. Once a magnetic field is applied, a dipole moment is induced in each particle, proportional to the magnetic field. A dipolar magnetic interaction then occurs between particles. If dipole-dipole magnetic energy is higher than the thermal energy, the result is a structure change inside the dipolar fluid. The ratio of these two energies is expressed by a coupling constant lambda as: lambda = (pi(a(exp 3))(chi(exp 2))(mu(sub 0))(H(sub 0))(exp 2))/18kT Where a is the particle radius, mu(sub 0) is the vacuum magnetic permeability, H(sub 0) the applied magnetic field, k the Boltzmann constant and T the absolute temperature. If lambda > 1, magnetic particles form chains along the field direction. The lateral coalescence of several chains may form bigger aggregates especially if the particle volume fraction is high. While many studies and applications deal with the rheological properties and the structural changes of these dipolar fluids, this work focuses on the understanding of the chain dynamics. In order to probe the chain dynamics, we used dynamic light scattering (DLS) in self-beating mode as our experimental technique. The experimental geometry is such that the scattering plane is perpendicular to the magnetic field

  14. The clam (Chamelea gallina: evaluation of the effects of solids suspended in seawater on bivalve molluscs

    Directory of Open Access Journals (Sweden)

    Salvatora Angela Angioni

    2010-03-01

    Full Text Available The study was designed to evaluate the effects of solids in suspension in seawater on clams (Chamelea gallina. The aim was to investigate the possible correlation between the widespread deaths of clams in the coastal waters of the central and northern Adriatic in the last five years and increased concentrations of solids in suspension. The research involved conducting 96-hour tests on clams farmed in aquariums containing filtered seawater. The tests were preceded by a 7-day adaptation stage to allow the molluscs to acclimatise. During this period, the clams were fed on unicellular seaweed (Dunaliella tertiolecta. The molluscs were exposed to particles of solids in suspension consisting of pools of silica gel (SiO2 granules of various sizes, similar to those constituting silt, whose presence and suspension in the sea considerably increase after heavy rain and heavy seas. The study established that the number of deaths caused by solids suspended in seawater at the concentrations used in the tests was not statistically significant.

  15. Biologically Induced Deposition of Fine Suspended Particles by Filter-Feeding Bivalves in Land-Based Industrial Marine Aquaculture Wastewater

    Science.gov (United States)

    Zhou, Yi; Zhang, Shaojun; Liu, Ying; Yang, Hongsheng

    2014-01-01

    Industrial aquaculture wastewater contains large quantities of suspended particles that can be easily broken down physically. Introduction of macro-bio-filters, such as bivalve filter feeders, may offer the potential for treatment of fine suspended matter in industrial aquaculture wastewater. In this study, we employed two kinds of bivalve filter feeders, the Pacific oyster Crassostrea gigas and the blue mussel Mytilus galloprovincialis, to deposit suspended solids from marine fish aquaculture wastewater in flow-through systems. Results showed that the biodeposition rate of suspended particles by C. gigas (shell height: 8.67±0.99 cm) and M. galloprovincialis (shell height: 4.43±0.98 cm) was 77.84±7.77 and 6.37±0.67 mg ind−1•d−1, respectively. The total solid suspension (TSS) deposition rates of oyster and mussel treatments were 3.73±0.27 and 2.76±0.20 times higher than that of the control treatment without bivalves, respectively. The TSS deposition rates of bivalve treatments were significantly higher than the natural sedimentation rate of the control treatment (Paquaculture wastewater, and simultaneously yield value-added biological products. PMID:25250730

  16. Biologically induced deposition of fine suspended particles by filter-feeding bivalves in land-based industrial marine aquaculture wastewater.

    Science.gov (United States)

    Zhou, Yi; Zhang, Shaojun; Liu, Ying; Yang, Hongsheng

    2014-01-01

    Industrial aquaculture wastewater contains large quantities of suspended particles that can be easily broken down physically. Introduction of macro-bio-filters, such as bivalve filter feeders, may offer the potential for treatment of fine suspended matter in industrial aquaculture wastewater. In this study, we employed two kinds of bivalve filter feeders, the Pacific oyster Crassostrea gigas and the blue mussel Mytilus galloprovincialis, to deposit suspended solids from marine fish aquaculture wastewater in flow-through systems. Results showed that the biodeposition rate of suspended particles by C. gigas (shell height: 8.67 ± 0.99 cm) and M. galloprovincialis (shell height: 4.43 ± 0.98 cm) was 77.84 ± 7.77 and 6.37 ± 0.67 mg ind(-1) • d(-1), respectively. The total solid suspension (TSS) deposition rates of oyster and mussel treatments were 3.73 ± 0.27 and 2.76 ± 0.20 times higher than that of the control treatment without bivalves, respectively. The TSS deposition rates of bivalve treatments were significantly higher than the natural sedimentation rate of the control treatment (P treatments were significantly lower than those in the sediments of the control (P aquaculture wastewater, and simultaneously yield value-added biological products.

  17. Monosaccharide composition of suspended particles from the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Sankaran, P.D.; Wagh, A.B.

    Neutral carbohydrates were determined as alditol acetates by capillary gas chromatography in the hydrolysates of suspended particulate samples (40) collected from 8 depths (approx 1 to 1,000 m) at 5 stations of the Bay of Bengal. Eight individual...

  18. Biologically induced deposition of fine suspended particles by filter-feeding bivalves in land-based industrial marine aquaculture wastewater.

    Directory of Open Access Journals (Sweden)

    Yi Zhou

    Full Text Available Industrial aquaculture wastewater contains large quantities of suspended particles that can be easily broken down physically. Introduction of macro-bio-filters, such as bivalve filter feeders, may offer the potential for treatment of fine suspended matter in industrial aquaculture wastewater. In this study, we employed two kinds of bivalve filter feeders, the Pacific oyster Crassostrea gigas and the blue mussel Mytilus galloprovincialis, to deposit suspended solids from marine fish aquaculture wastewater in flow-through systems. Results showed that the biodeposition rate of suspended particles by C. gigas (shell height: 8.67 ± 0.99 cm and M. galloprovincialis (shell height: 4.43 ± 0.98 cm was 77.84 ± 7.77 and 6.37 ± 0.67 mg ind(-1 • d(-1, respectively. The total solid suspension (TSS deposition rates of oyster and mussel treatments were 3.73 ± 0.27 and 2.76 ± 0.20 times higher than that of the control treatment without bivalves, respectively. The TSS deposition rates of bivalve treatments were significantly higher than the natural sedimentation rate of the control treatment (P < 0.001. Furthermore, organic matter and C, N in the sediments of bivalve treatments were significantly lower than those in the sediments of the control (P < 0.05. It was suggested that the filter feeders C. gigas and M. galloprovincialis had considerable potential to filter and accelerate the deposition of suspended particles from industrial aquaculture wastewater, and simultaneously yield value-added biological products.

  19. Experimental investigation of suspended particles transport through porous media: particle and grain size effect.

    Science.gov (United States)

    Liu, Quansheng; Cui, Xianze; Zhang, Chengyuan; Huang, Shibing

    2016-01-01

    Particle and grain size may influence the transportation and deposition characteristics of particles within pollutant transport and within granular filters that are typically used in wastewater treatment. We conducted two-dimensional sandbox experiments using quartz powder as the particles and quartz sand as the porous medium to study the response of transportation and deposition formation to changes in particle diameter (ds, with median diameter 18, 41, and 82 μm) and grain diameter (dp, with median diameter 0.36, 1.25, and 2.82 mm) considering a wide range of diameter ratios (ds/dp) from 0.0064 to 0.228. Particles were suspended in deionized water, and quartz sand was used as the porous medium, which was meticulously cleaned to minimize any physicochemical and impurities effects that could result in indeterminate results. After the experiments, the particle concentration of the effluent and particle mass per gram of dry sands were measured to explore changes in transportation and deposition characteristics under different conditions. In addition, a micro-analysis was conducted to better analyse the results on a mesoscopic scale. The experimental observation analyses indicate that different diameter ratios (ds/dp) may lead to different deposit formations. As ds/dp increased, the deposit formation changed from 'Random Deposition Type' to 'Gradient Deposition Type', and eventually became 'Inlet Deposition Type'.

  20. Thermal instability of Walters B' viscoelastic fluid permeated with suspended particles in hydromagnetics in porous medium

    Directory of Open Access Journals (Sweden)

    Kumar Pardeep

    2004-01-01

    Full Text Available The effect of suspended particles on the thermal instability of Walters B' viscoelastic fluid in hydromantic in porous medium is considered. For stationary convection, Walters B' viscoelastic fluid behaves like a Newtonian fluid. The medium permeability and suspended particles has ten the onset of convection whereas the magnetic field postpones the onset of convection, for the case of stationary convection. The magnetic field and viscoelasticity intro duce oscillatory modes in the system which was non-existent in their absence.

  1. Finite Element Modeling of Suspended Particle Migration in Non-Newtonian Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Altobelli, S.; Baer, T.; Mondy, L.; Rao, R.; Stephens, T.

    1999-03-04

    Shear-induced migration of particles is studied during the slow flow of suspensions of spheres (particle volume fraction {phi} = 0.50) in an inelastic but shear-thinning, suspending fluid in flow between counterrotating concentric cylinders, The conditions are such that nonhydrodynamic effects are negligible. The movement of particles away from the high shear rate region is more pronounced than in a Newtonian suspending liquid. We test a continuum constitutive model for the evolution of particle concentration in a flowing suspension proposed by Phillips et al. (1992) by using shear-thinning, suspending fluids. The fluid constitutive equation is Carreau-like in its shear-thinning behavior but also varies with the local particle concentration. The model is compared with the experimental data gathered with nuclear magnetic resonance (NMR) imaging.

  2. SEBARAN TOTAL SUSPENDED SOLID (TSS PADA PROFIL VERTIKAL DI PERAIRAN SELAT MADURA KABUPATEN BANGKALAN

    Directory of Open Access Journals (Sweden)

    Aries Dwi Siswanto

    2015-04-01

    Full Text Available Sebaran sedimen tersuspensi (Total Suspended Solid (TSS dapat dipelajari secara horizontal maupun vertikal. Akumulasi sedimen tersuspensi (TSS secara horizontal sangat dipengaruhi oleh arus permukaan maupun gelombang yang dibangkitkan oleh angin. Keterdapatan TSS ini diduga berpengaruh terhadap sebarannya pada profil vertical. Kedua kondisi sebaran sedimen tersuspensi (TSS berpengaruh terhadap optimalisasi penetrasi cahaya matahari di perairan. Sedimen tersuspensi (TSS menjadi salah satu factor fisika yang penting sebagai indicator kondisi perairan. Penelitian ini bertujuan untuk mengetahui sebaran Total Suspended Solid (TSS di perairan Kabupaten Bangkalan. Materi utama yang digunakan dalam penelitian ini adalah contoh air dan data parameter lingkungan (pasang surut dan kecerahan yang diambil pada 7 stasiun pada bulan Agustus-September 2013 di Perairan Selat Madura, Kabupaten Bangkalan. Metode gravimetric (SNI-06-6989.3-2004 digunakan untuk analisa Total Suspended Solid (TSS. Data parameter lingkungan dianalisa secara deskriptif. Analisa TSS menunjukkan nilai yang berbeda pada beberapa stasiun penelitian untuk setiap minggunya. Konsentrasi TSS terendah sebesar 35 mg/L (Stasiun 3, profil permukaan, minggu pertama dan tertinggi sebesar 620 mg/L (Stasiun 4, profil dasar, minggu pertama. Secara umum, konsentrasi TSS secara vertikal (dari permukaan-dasar cenderung semakin besar, diduga dipengaruhi oleh jenis substrat dan parameter arus yang berpeluang untuk menimbulkan pengadukan di profil dasar. Kondisi lingkungan (kecerahan dan arus menunjukkan bahwa daerah dengan konsentrasi TSS yang tinggi cenderung memilki nilai kecerahan yang rendah dengan kecepatan arus yang lebih besar.Kata Kunci: kecerahan, pola arus, Total Suspended Solid (TSS DISTRIBUTION OF TOTAL SUSPENDED SOLID (TSS IN THE VERTICAL PROFILE IN THE MADURA STRAIT WATERS BANGKALAN DISTRICTABSTRACTDistribution of suspended sediment (Total Suspended Solid (TSS can be studied through

  3. Delineating Effects of Ionic Strength and Suspended Solids on Ammonia Volatilization from Dairy Manure Slurry

    Science.gov (United States)

    Koirala, K.

    2014-12-01

    Ammonia emission is a major concern due to its adverse effects on animal and human health. Ionic strength and suspended solids play key roles in the ammonia volatilization process. These two parameters, however, are usually lumped together in form of total solids. The objective of this study was to separate the contribution of suspended solids (SS) from that of ionic strength (IS) on ammonia volatilization in liquid dairy manure. A two-way factorial experiment was conducted to simultaneously test the effects of IS and SS on ammonium dissociation: a key element of the ammonia volatilization process. The fraction of ammonia (β) in total ammoniacal nitrogen (TAN) was experimentally determined in a convective emission chamber, for each level of SS and IS, at a constant wind speed of 1.5 m s-1, and air and liquid temperature of 25°C. The two way analysis of variance showed a significant effect of SS concentration (p = 0.04) on fraction of ammonia in the liquid dairy manure, while the effect of ionic strength was marginal (p = 0.05). The highest dissociation of ammonium was observed in manure with the lowest SS concentration (0%) and the lowest ionic strength (0.10 mol L-1). Significant increases in suspended solids concentration and ionic strength were necessary to influence the ammonium dissociation in dairy manure. Results revealed that substantially high content of suspended solids (> 3.0%) or relatively high dilution of manure with water (30%) were necessary for these two parameters to play significant roles in the ammonia volatilization mechanism in liquid dairy manure. Results also showed that the β was more sensitive to the changes in suspended solids concentration than in the changes in ionic strength within the ranges of SS and IS examined in this study. Overall, the SS and IS effects on ammonium dissociation (and by extension on ammonia volatilization process) were thus found negligible within the normal ranges of liquid dairy manure characteristics.

  4. Solid and suspended/dissolved waste (N, P, O) from rainbow trout (Oncorynchus mykiss)

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Pedersen, Per Bovbjerg

    2011-01-01

    Quantifying aquaculture waste into different waste fractions will make it possible to design different treatment setups for obtaining specific cleaning objectives. The aim of this study was therefore to measure “all” solid and suspended/dissolved (i.e. unsedimented) waste from juvenile rainbow...... trout (Oncorynchus mykiss) fed three commonly applied commercial diets, “all” waste referring to: total nitrogen (N), total ammonia nitrogen (TAN=NH3-N+NH4-N), total phosphorus (P), and organicmatter characterized by the chemical oxygen demand (COD) and the biological oxygen demand after 5 days (BOD5...... (ADCs) were used to calculate the solid amounts of undigested nutrients. These were subsequently used for calculating the solid COD output, verified by direct COD measurements. The output of solid and suspended/dissolved BOD5 and COD was measured in the second experiment. There were just minor...

  5. Impact of suspended solids concentration on sludge filterability in Full-scale membrane bioreactors

    NARCIS (Netherlands)

    Lousada Ferreira, M.D.C.; Van Lier, J.B.; Van der Graaf, J.H.J.M.

    2015-01-01

    The relation between activated sludge filterability and mixed liquor suspended solids (MLSS) concentration in membrane bioreactors (MBRs) is framed in a single hypothesis, explaining results seemingly contradictory. A total of 44 activated sludge samples were collected and analyzed on a variety of

  6. Laser-induced incandescence of suspended particles as a source of excitation of dye luminescence

    CERN Document Server

    Zelensky, S

    2003-01-01

    The interaction of pulsed YAG-Nd sup 3 sup + laser radiation with submicron light-absorbing particles suspended in an aqueous solution of Rhodamine 6G is investigated experimentally. The experiments demonstrate that the laser-induced incandescence of suspended particles excites the luminescence of the dissolved dye molecules. The mechanism of the luminescence excitation consists in the reabsorption of the thermal radiation within the volume of the sample cell. On the ground of this mechanism of excitation, a method of measurement of the luminescence quantum yield is proposed and realized. The method requires the knowledge of the geometrical parameters of the cell and does not require the use of reference samples.

  7. Infrared Spectroscopy of Noh Suspended in Solid Parahydrogen: Part Two

    Science.gov (United States)

    Balabanoff, Morgan E.; Mutunga, Fredrick M.; Anderson, David T.

    2015-06-01

    The only report in the literature on the infrared spectroscopy of the parent oxynitrene NOH was performed using Ar matrix isolation spectroscopy at 10 K. In this previous study, they performed detailed isotopic studies to make definitive vibrational assignments. NOH is predicted by high-level calculations to be in a triplet ground electronic state, but the Ar matrix isolation spectra cannot be used to verify this triplet assignment. In our 2013 preliminary report, we showed that 193 nm in situ photolysis of NO trapped in solid parahydrogen can also be used to prepare the NOH molecule. Over the ensuing two years we have been studying the infrared spectroscopy of this species in more detail. The spectra reveal that NOH can undergo hindered rotation in solid parahydrogen such that we can observe both a-type and b-type rovibrational transitions for the O-H stretch vibrational mode, but only a-type for the mode assigned to the bend. In addition, both observed a-type infrared absorption features (bend and OH stretch) display fine structure; an intense central peak with weaker peaks spaced symmetrically to both lower and higher wavenumbers. The spacing between the peaks is nearly identical for both vibrational modes. We now believe this fine structure is due to spin-rotation interactions and we will present a detailed analysis of this fine structure. Currently, we are performing additional experiments aimed at making 15NOH to test these preliminary assignments. The most recent data and up-to-date analysis will be presented in this talk. G. Maier, H. P. Reisenauer, M. De Marco, Angew. Chem. Int. Ed. 38, 108-110 (1999). U. Bozkaya, J. M. Turney, Y. Yamaguchi, and H. F. Schaefer III, J. Chem. Phys. 136, 164303 (2012). David T. Anderson and Mahmut Ruzi, 68th Ohio State University International Symposium on Molecular Spectroscopy, talk TE01 (2013).

  8. Nutrient and suspended solids removal from petrochemical wastewater via microalgal biofilm cultivation.

    Science.gov (United States)

    Hodges, Alan; Fica, Zachary; Wanlass, Jordan; VanDarlin, Jessica; Sims, Ronald

    2017-05-01

    Wastewater derived from petroleum refining currently accounts for 33.6 million barrels per day globally. Few wastewater treatment strategies exist to produce value-added products from petroleum refining wastewater. In this study, mixed culture microalgal biofilm-based treatment of petroleum refining wastewater using rotating algae biofilm reactors (RABRs) was compared with suspended-growth open pond lagoon reactors for removal of nutrients and suspended solids. Triplicate reactors were operated for 12 weeks and were continuously fed with petroleum refining wastewater. Effluent wastewater was monitored for nitrogen, phosphorus, total suspended solids (TSS), and chemical oxygen demand (COD). RABR treatment demonstrated a statistically significant increase in removal of nutrients and suspended solids, and increase in biomass productivity, compared to the open pond lagoon treatment. These trends translate to a greater potential for the production of biomass-based fuels, feed, and fertilizer as value-added products. This study is the first demonstration of the cultivation of mixed culture biofilm microalgae on petroleum refining wastewater for the dual purposes of treatment and biomass production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Elemental Spatiotemporal Variations of Total Suspended Particles in Jeddah City

    Directory of Open Access Journals (Sweden)

    Mohammad W. Kadi

    2014-01-01

    Full Text Available Elements associated with total suspended particulate matter (TSP in Jeddah city were determined. Using high-volume samplers, TSP samples were simultaneously collected over a one-year period from seven sampling sites. Samples were analyzed for Al, Ba, Ca, Cu, Mg, Fe, Mn, Zn, Ti, V, Cr, Co, Ni, As, and Sr. Results revealed great dependence of element contents on spatial and temporal variations. Two sites characterized by busy roads, workshops, heavy population, and heavy trucking have high levels of all measured elements. Concentrations of most elements at the two sites exhibit strong spatial gradients and concentrations of elements at these sites are higher than other locations. The highest concentrations of elements were observed during June–August because of dust storms, significant increase in energy consumption, and active surface winds. Enrichment factors of elements at the high-level sites have values in the range >10~60 while for Cu and Zn the enrichment factors are much higher (~0–>700 indicating that greater percentage of TSP composition for these three elements in air comes from anthropogenic activities.

  10. In Situ Solid Particle Generator

    Science.gov (United States)

    Agui, Juan H.; Vijayakumar, R.

    2013-01-01

    Particle seeding is a key diagnostic component of filter testing and flow imaging techniques. Typical particle generators rely on pressurized air or gas sources to propel the particles into the flow field. Other techniques involve liquid droplet atomizers. These conventional techniques have drawbacks that include challenging access to the flow field, flow and pressure disturbances to the investigated flow, and they are prohibitive in high-temperature, non-standard, extreme, and closed-system flow conditions and environments. In this concept, the particles are supplied directly within a flow environment. A particle sample cartridge containing the particles is positioned somewhere inside the flow field. The particles are ejected into the flow by mechanical brush/wiper feeding and sieving that takes place within the cartridge chamber. Some aspects of this concept are based on established material handling techniques, but they have not been used previously in the current configuration, in combination with flow seeding concepts, and in the current operational mode. Unlike other particle generation methods, this concept has control over the particle size range ejected, breaks up agglomerates, and is gravity-independent. This makes this device useful for testing in microgravity environments.

  11. Movement of Solid Particles in Swirling Flow

    Directory of Open Access Journals (Sweden)

    A. M. Volk

    2009-01-01

    Full Text Available The mathematical model has been developed and calculation of solid particle movement due to the action of swirling gas flow in a cylindrical element has been made in the paper. The paper investigates hydrodynamics of gas flow and forces influencing on a solid particle, both in the basic flow and during a contact with cylindrical surface. He obtained data can be used for research of processes pertaining to division of two-phase flows in a vortical device.

  12. Solid Hydrogen Particles Analyzed for Atomic Fuels

    Science.gov (United States)

    Palaszewski, Bryan A.

    2001-01-01

    Solid hydrogen particles have been selected as a means of storing atomic propellants in future launch vehicles (refs. 1 to 2). In preparation for this, hydrogen particle formation in liquid helium was tested experimentally. These experiments were conducted to visually characterize the particles and to observe their formation and molecular transformations (aging) while in liquid helium. The particle sizes, molecular transformations, and agglomeration times were estimated from video image analyses. The experiments were conducted at the NASA Glenn Research Center in the Supplemental Multilayer Insulation Research Facility (SMIRF, ref. 3). The facility has a vacuum tank, into which the experimental setup was placed. The vacuum tank prevented heat leaks and subsequent boiloff of the liquid helium, and the supporting systems maintained the temperature and pressure of the liquid helium bath where the solid particles were created. As the operation of the apparatus was developed, the hydrogen particles were easily visualized. The figures (ref. 1) show images from the experimental runs. The first image shows the initial particle freezing, and the second image shows the particles after the small particles have agglomerated. The particles finally all clump, but stick together loosely. The solid particles tended to agglomerate within a maximum of 11 min, and the agglomerate was very weak. Because the hydrogen particles are buoyant in the helium, the agglomerate tends to compact itself into a flat pancake on the surface of the helium. This pancake agglomerate is easily broken apart by reducing the pressure above the liquid. The weak agglomerate implies that the particles can be used as a gelling agent for the liquid helium, as well as a storage medium for atomic boron, carbon, or hydrogen. The smallest particle sizes that resulted from the initial freezing experiments were about 1.8 mm. About 50 percent of the particles formed were between 1.8 to 4.6 mm in diameter. These very

  13. Porous media grain size distribution and hydrodynamic forces effects on transport and deposition of suspended particles.

    Science.gov (United States)

    Ahfir, Nasre-Dine; Hammadi, Ahmed; Alem, Abdellah; Wang, HuaQing; Le Bras, Gilbert; Ouahbi, Tariq

    2017-03-01

    The effects of porous media grain size distribution on the transport and deposition of polydisperse suspended particles under different flow velocities were investigated. Selected Kaolinite particles (2-30μm) and Fluorescein (dissolved tracer) were injected in the porous media by step input injection technique. Three sands filled columns were used: Fine sand, Coarse sand, and a third sand (Mixture) obtained by mixing the two last sands in equal weight proportion. The porous media performance on the particle removal was evaluated by analysing particles breakthrough curves, hydro-dispersive parameters determined using the analytical solution of convection-dispersion equation with a first order deposition kinetics, particles deposition profiles, and particle-size distribution of the recovered and the deposited particles. The deposition kinetics and the longitudinal hydrodynamic dispersion coefficients are controlled by the porous media grain size distribution. Mixture sand is more dispersive than Fine and Coarse sands. More the uniformity coefficient of the porous medium is large, higher is the filtration efficiency. At low velocities, porous media capture all sizes of suspended particles injected with larger ones mainly captured at the entrance. A high flow velocity carries the particles deeper into the porous media, producing more gradual changes in the deposition profile. The median diameter of the deposited particles at different depth increases with flow velocity. The large grain size distribution leads to build narrow pores enhancing the deposition of the particles by straining. Copyright © 2016. Published by Elsevier B.V.

  14. Suspended particle transport through constriction channel with Brownian motion

    Science.gov (United States)

    Hanasaki, Itsuo; Walther, Jens H.

    2017-08-01

    It is well known that translocation events of a polymer or rod through pores or narrower parts of micro- and nanochannels have a stochastic nature due to the Brownian motion. However, it is not clear whether the objects of interest need to have a larger size than the entrance to exhibit the deviation from the dynamics of the surrounding fluid. We show by numerical analysis that the particle injection into the narrower part of the channel is affected by thermal fluctuation, where the particles have spherical symmetry and are smaller than the height of the constriction. The Péclet number (Pe) is the order parameter that governs the phenomena, which clarifies the spatio-temporal significance of Brownian motion compared to hydrodynamics. Furthermore, we find that there exists an optimal condition of Pe to attain the highest flow rate of particles relative to the dispersant fluid flow. Our finding is important in science and technology from nanopore DNA sequencers and lab-on-a-chip devices to filtration by porous materials and chromatography.

  15. Study of agglomeration of ice particles and of trichlorofluoromethane hydrate particles suspended in a hydrocarbon phase

    Energy Technology Data Exchange (ETDEWEB)

    Colombel, E.; Palermo, T.; Barre, L.; Gateau, P. [Inst. Francais du Petrole, Rueil Malmaison (France). Dept. of Applied Chemistry and Physico-Chemistry; Gruy, F. [Ecole Nationale Superieure des Mines, Saint Etienne (France)

    2008-07-01

    Gas hydrates may lead to pipeline blockage during oil production in offshore conditions. A study was conducted to better understand the agglomeration mechanism of gas hydrate particles in water in oil emulsions. The model system chosen to study this mechanism was ice or trichlorofluoromethane (CCl{sub 3}F) hydrate particles dispersed in xylene with asphaltenes as surfactants. The system illustrated what occurs in pipelines as produced water with oil is dispersed by surfactants that are naturally present in the oil phase. Freon was selected because it models methane behaviour very well. Both methane and freon are soluble in oil and insoluble in water. CCl{sub 3}F hydrates are stable under atmospheric pressure. As such, different techniques can be applied without being limited by high pressure conditions. The agglomeration mechanism in these particles can be modelled and compared with ice crystals. This study focused on the kinetics of agglomeration formation and mechanisms of hydrate and ice particle agglomeration in a hydrocarbon phase. Two characterization techniques were implemented in this study, notably nuclear magnetic resonance (NMR) relaxometry and rheology. The different relaxation rate for solids or liquids was used to monitor in situ the ratio between the solid and total hydrogen or fluorine as a function of time with controlled shearing conditions. NMR provided information on the formation kinetics and the conversion rate of water in ice crystals. The rest of the study focused on the formation of Freon hydrate crystals. The study confirmed that the physico-chemistry of the water/oil interface has an important role in agglomeration. 9 refs., 5 tabs., 18 figs.

  16. Particle Size Characteristics of Fluvial Suspended Sediment in Proglacial Streams, King George Island, South Shetland Island

    Science.gov (United States)

    Szymczak, Ewa

    2017-12-01

    In this study, the characterization of particle size distribution of suspended sediment that is transported by streams (Ornithologist Creek, Ecology Glacier Creeks, Petrified Forest Creek, Czech Creek, Vanishing Creek, Italian Creek) in the area of the Arctowski Polish Antarctic Station is presented. During the first period of the summer season, the aforementioned streams are supplied by the melting snow fields, while later on, by thawing permafrost. The water samples were collected from the streams at monthly intervals during the Antarctic summer season (January - March) of 2016. The particle size distribution was measured in the laboratory with a LISST-25X laser diffraction particle size analyser. According to Sequoia Scientific Inc., LISST-25X can measure particle sizes (Sauter Mean Diameter) between 2.50 and 500 μm. The results of particle size measurements were analysed in relation to flow velocity (0.18–0.89 m/s), the cross-sectional parameters of the streams, suspended sediment concentration (0.06–167.22 mg/dm3) and the content of particulate organic matter (9.8–84.85%). Overall, the mean particle size ranged from 28.8 to 136 μm. The grain size of well-sorted sediments ranged from 0.076 to 0.57, with the skewness and kurtosis values varying from -0.1 to 0.4, and from 0.67 to 1.3, respectively. Based on the particle size characteristics of suspended sediment, the streams were divided into two groups. For most of the streams, the sediment was very well sorted, while fine sand and very fine sand were dominant fractions displaying symmetric and platykurtic distributions, respectively. Only in two streams, the suspended sediment consisted of silt-size grains, well or moderately well sorted, with coarse-skewness and mostly mesokurtic distribution. The C-M chart suggested that the transportation processes of suspended sediment included the suspended mode only. The grain-size distribution of suspended sediment was mainly influenced by the stream runoff

  17. Coagulation-Sedimentation-Extraction Pretreatment Methods for The Removal of Suspended Solids and Residual Oil From Palm Oil Mill Effluent (Pome

    Directory of Open Access Journals (Sweden)

    Abdul Latif Ahmad, Norliza Ibrahim , Suzylawati Ismail and Subhash Bhatia

    2012-08-01

    Full Text Available Suspended solids and residual oil removal in a liquid are relevant to numerous research areas and industry. The suspended solid cannot be removed completely by plain settling. Large and heavy particles can settle out readily, but smaller and lighter particles settle very slowly or in some cases do not settle at all. Because of this, it requires efficient physical-chemical pretreatment methods.   Our current research is to study the pretreatment methods in the removal of suspended solids and residual oil content in POME. Preliminary analysis shows that POME contains 40,000 mg/L suspended solid and 4,000 mg/L oil and grease content that relatively very high compared to the maximum allowable limit by the Malaysian Department of Environment which are only 400 mg/L and 50 mg/L respectively. The methods chosen were coagulation-sedimentation method for suspended solids removal and solvent extraction for residual oil removal.  Jar test apparatus was used as the standard procedure for bench-scale testing and alum was used as the coagulant. Parameters studied were alum dosage, mixing time, mixing speed, sedimentation time and pH. For removal of residual oil, six different organic solvents; n-hexane, n-heptane, benzene, petroleum ether, pentane and petroleum benzene were used. For every solvent the effect of solvent ratio, mixing time, mixing speed and pH were analyzed. The results show that the optimum conditions in removal of suspended solid from POME were at pH 4.11, sedimentation time of 100 minutes and 150 rpm mixing speed with 1.5 hr mixing time. N-hexane give the best performance in extracting residual oil from POME with solvent to POME ratio of 6:10. It was estimated about 0.54 grams of oil and grease can be extracted with optimum variables at pH 4, mixing speed of 200 rpm, and 20 minutes mixing time.  Key Words: palm oil mill effluent, coagulation, suspended solid, residual oil, solvent extraction.

  18. Separating Device for solid Particles

    NARCIS (Netherlands)

    De Jong, T.P.R.; Kattentidt, H.U.R.; Schokker, E.A.

    2001-01-01

    The invention relates to a separating device for solid fragments, comprising a conveyor belt for supplying the fragments, at least one sensor for detecting the fragments, and an ejector for dislodging the fragments from the belt. The ejector is embodied as mechanical impulse-transmitting organ

  19. Experimental Design of Electrocoagulation and Magnetic Technology for Enhancing Suspended Solids Removal from Synthetic Wastewater

    Directory of Open Access Journals (Sweden)

    Moh Faiqun Ni'am

    2014-10-01

    Full Text Available Design of experiments (DOE is one of the statistical method that is used as a tool to enhance and improve experimental quality. The changes to the variables of a process or system is supposed to give the optimal result (response and quite satisfactory. Experimental design can defined as a test or series of test series by varying the input variables (factors of a process that can known to cause changes in output (response. This paper presents the results of experimental design of wastewater treatment by electrocoagulation (EC technique. A combined magnet and electrocoagulation (EC technology were designed to increase settling velocity and to enhance suspended solid removal efficiencies from wastewater samples. In this experiment, a synthetic wastewater samples were prepared by mixing 700 mg of the milk powder in one litre of water and treated by using an acidic buffer solution. The monopolar iron (Fe plate anodes and cathodes were employed as electrodes. Direct current was varied in a range of between 0.5 and 1.1 A, and flowrate in a range of between 1.00 to 3.50 mL/s. One permanent magnets namely AlNiCo with a magnetic strength of 0.16T was used in this experiment. The results show that the magnetic field and the flowrate have major influences on suspended solids removal. The efficiency removals of suspended solids, turbidity and COD removal efficiencies at optimum conditions were found to be more than 85%, 95%, and 75%, respectively.

  20. Dynamic modeling of total suspended solids in the wetland Jaboque, Bogotá (Colombia

    Directory of Open Access Journals (Sweden)

    Julio Eduardo Beltrán-Vargas

    2012-12-01

    Full Text Available We propose a dynamic simulation model to provide a general explanation for the behavior of total suspended solids in the Jaboque wetland (Bogotá DC. The analyses were performed in three areas with distinct physical and chemical characteristics. The model predicted concentrations of total suspended solids in the months of April, May, June, October and November. Values ranged from 85 mg L-1 and 101 mg L-1 with an average of 65.12 mg L-1 with a hydraulic time retention between eight and nine days per year for the first area, the second area between 57 and 69 with an average of 50 mg L-1 with a hydraulic time between 20 and 23 days per year and in the third area between 56 mg L-1 and 67 mg L-1 with a mean of 48.8 mg L-1 and a hydraulic retention time between 24 and 26 days per year. The months of December, January, February, August and September showed a tendency to have lower values. The estimated values of total suspended solids based on our model had an acceptable correspondence, R2 = 0.95, 0.71, 0.67, with the actual values in all cases. The relative error for each area was 0.10, 0.20 and 0.26, demonstrating that the model does not overestimate the results.

  1. Parchar – Characterization of Suspended Particles Through Image Processing in Matlab

    Directory of Open Access Journals (Sweden)

    Thor Nygaard Markussen

    2016-07-01

    Full Text Available Studies of suspended particles and particle dynamics in aquatic environments increasingly rely on camera systems to characterize the particles. Numerous systems exist and all use different codes and practises to process the images from the systems. Here, a step-by-step guide to an image processing and particle characterization code for Matlab is presented with the aim of bringing the particle community towards standardized image processing techniques. The code uses morphological reconstruction and simple block processing to filter out noise, out-of-focus particles and light source inconsistencies. It has been implemented on a specific camera system but is applicable to numerous systems and on highly variable particle types due to the standardized setup.

  2. Scattering signatures of suspended particles: an integrated system for combining digital holography and laser diffraction.

    Science.gov (United States)

    Davies, Emlyn J; Nimmo-Smith, W Alex M; Agrawal, Yogesh C; Souza, Alejandro J

    2011-12-05

    The use of laser diffraction is now common practice for the determination of an in situ particle size distribution in the marine environment. However, various imaging techniques have shown that particles vary greatly in shape, leading to uncertainty in the response of laser diffraction instruments when subjected to this diverse range of complex particles. Here we present a novel integrated system which combines both digital in-line holography and a LISST-100 type C, to simultaneously record in-focus images of artificial and natural particles with their small-angle forward scattering signature. The system will allow for further development of a reliable alternative to Mie Theory when using laser diffraction for the in situ measurement of complex suspended particles. A more detailed knowledge of the performance of laser diffraction when subjected to the wide variety of complex particles found in the marine environment will then be possible.

  3. Photocurrent spectroscopy of exciton and free particle optical transitions in suspended carbon nanotube pn-junctions

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Shun-Wen [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089 (United States); Theiss, Jesse; Hazra, Jubin; Aykol, Mehmet; Kapadia, Rehan [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Cronin, Stephen B. [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089 (United States); Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Department of Chemistry, University of Southern California, Los Angeles, California 90089 (United States)

    2015-08-03

    We study photocurrent generation in individual, suspended carbon nanotube pn-junction diodes formed by electrostatic doping using two gate electrodes. Photocurrent spectra collected under various electrostatic doping concentrations reveal distinctive behaviors for free particle optical transitions and excitonic transitions. In particular, the photocurrent generated by excitonic transitions exhibits a strong gate doping dependence, while that of the free particle transitions is gate independent. Here, the built-in potential of the pn-junction is required to separate the strongly bound electron-hole pairs of the excitons, while free particle excitations do not require this field-assisted charge separation. We observe a sharp, well defined E{sub 11} free particle interband transition in contrast with previous photocurrent studies. Several steps are taken to ensure that the active charge separating region of these pn-junctions is suspended off the substrate in a suspended region that is substantially longer than the exciton diffusion length and, therefore, the photocurrent does not originate from a Schottky junction. We present a detailed model of the built-in fields in these pn-junctions, which, together with phonon-assistant exciton dissociation, predicts photocurrents on the same order of those observed experimentally.

  4. Pyrosequencing Reveals Bacterial Communities in Unchlorinated Drinking Water Distribution System: An Integral Study of Bulk Water, Suspended Solids, Loose Deposits, and Pipe Wall Biofilm

    KAUST Repository

    Liu, G.

    2014-05-20

    The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

  5. Pyrosequencing reveals bacterial communities in unchlorinated drinking water distribution system: an integral study of bulk water, suspended solids, loose deposits, and pipe wall biofilm.

    Science.gov (United States)

    Liu, G; Bakker, G L; Li, S; Vreeburg, J H G; Verberk, J Q J C; Medema, G J; Liu, W T; Van Dijk, J C

    2014-05-20

    The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

  6. Concentration Measurements of Suspended Load using ADV with Influence of the Particle Size

    Science.gov (United States)

    Schwarzwälder, Kordula

    2017-04-01

    ADV backscatter data can be used under certain conditions to gain information about the concentrations of suspended loads. This was shown in many studies before (Fugate and Friedrichs 2002; Chanson et al 2008; Ha et al. 2009). This paper reports on a pre-study to investigate the influence of particle size on concentration measurements for suspended sediment load with ADV. The study was conducted in a flume in the Oskar-von-Miller-Institute using fresh water from a river including the natural suspended load. The ADV used in the experiments was a Vectrino Profiler (Nortek). In addition water samples were taken for TSS and TOC. For the measurements a surge was generated in the flume to ensure that also particles of larger size will be present in the water phase. The measurements and samples were taken during the whole surge event. Therefore we were able to find a good correlation between the backscatter data of the ADV and the TSS as well as TOC results. For the decreasing part of the flow event the concentration of TOC in the suspended load of the water phase is decreasing much slower than the TSS and results in a damped decrease of the backscatter values. This means that the results for concentration measurements might be slightly influenced by the size of the particles. Further evaluations of measurements conducted with a LISST SL (Sequoia) will be investigated to show the trend of the particle sizes during this process and fortify this result. David C. Fugate, Carl T. Friedrichs, Determining concentration and fall velocity of estuarine particle populations using ADV, OBS and LISST, Continental Shelf Research, Volume 22, Issues 11-13, 2002 H.K. Ha, W.-Y. Hsu, J.P.-Y. Maa, Y.Y. Shao, C.W. Holland, Using ADV backscatter strength for measuring suspended cohesive sediment concentration, Continental Shelf Research, Volume 29, Issue 10, 2009 Hubert Chanson, Maiko Takeuchi, Mark Trevethan, Using turbidity and acoustic backscatter intensity as surrogate measures of

  7. Application of PAC and flocculants for improving settling of solid particles in oilfield wastewater with high salinity and Ca2.

    Science.gov (United States)

    Liu, Guoliang; Zhang, Fusheng; Qu, Yuanzhi; Liu, He; Zhao, Lun; Cui, Mingyue; Ou, Yangjian; Geng, Dongshi

    2017-09-01

    The suspended solids in wastewater from Rekabak oilfield, Kazakhstan, were characterized and treated with flocculants to enhance settling. The wastewater contained a high concentration of total dissolved solids and calcium ion. Scanning electron microscopy and energy dispersive X-ray analyses showed that suspended solids were mainly composed of corrosion products (iron oxides) and silicon dioxide particles. Also, much salt deposition from wastewater caused a large increase in the suspended solids value. The settling of solid particles in wastewater was investigated by turbidity decrease within 60 min. The particle settling was enhanced by adding polyaluminum chloride (PAC) as coagulant and hydrolyzed polyacryamide (HPAM) or cationic polyacrylamide (CPAM) as flocculant. At optimal dose, the particle settling ability with PAC and CPAM was better than that with PAC and HPAM. Particle size analysis showed that HPAM or CPAM with high molecular weight played an important role for enlarging the particle size. The experiments with simulated wastewater showed that particle settling by using HPAM deteriorated significantly compared to that by CPAM at high calcium ion. This study provides further understanding about the effect of high salinity and Ca2+ on solids formation, flocculant performance and particle settling. Meanwhile, the results are also helpful to develop novel flocculants used for high salinity wastewater.

  8. Viruses, bacteria and suspended particles in a backwater and main channel site of the Danube (Austria)

    OpenAIRE

    Peduzzi, Peter; Luef, Birgit

    2008-01-01

    A short overview of currently available studies on the ecology of viruses in running waters is provided. Additionally, a survey was conducted on the dynamics of both viruses and bacteria in an isolated floodplain segment of the Danube River and in the main channel near Vienna (Austria) during the hydrologically most dynamic phase (spring – summer). The study evaluates the differences between the main channel and the floodplain segment for suspended particle abundance and quality in relation t...

  9. Daylighting and Thermo-Electrical performance of an Autonomous Suspended Particle Device Evacuated Glazing

    OpenAIRE

    Ghosh, Aritra

    2016-01-01

    Suspended particle device (SPD) glazing is an AC powered switchable glazing. PV powered SPD evacuated (vacuum) glazing was proposed with the potential of reducing the heating demand, cooling demand and artificial lighting demand of a building. To achieve an autonomous SPD vacuum glazing, semi empirical simulation and outdoor characterisation was explored in this thesis. Transmission of SPD glazing (area 0.058 m2) varied from 5% when opaque to 55% when transparent in the presence of 110 V, 0.0...

  10. Vanadium Inhalation in a Mouse Model for the Understanding of Air-Suspended Particle Systemic Repercussion

    Directory of Open Access Journals (Sweden)

    T. I. Fortoul

    2011-01-01

    Full Text Available There is an increased concern about the health effects that air-suspended particles have on human health which have been dissected in animal models. Using CD-1 mouse, we explore the effects that vanadium inhalation produce in different tissues and organs. Our findings support the systemic effects of air pollution. In this paper, we describe our findings in different organs in our conditions and contrast our results with the literature.

  11. Instability of two rotating viscoelastic (Walters B' superposed fluids with suspended particles in porous medium

    Directory of Open Access Journals (Sweden)

    Kumar Pardeep

    2007-01-01

    Full Text Available The instability of the plane interface between two Walters B' viscoelastic superposed fluids permeated with suspended particles and uniform rotation in porous medium is considered following the linearized perturbation theory and normal mode analysis. For the stable configuration the system is found to be stable or unstable if ν' k1/Є, depending on kinematic viscoelasticity, permeability of the medium and porosity of the medium. However, the system is found to be unstable for the potentially unstable configuration. .

  12. Three dimensional open cavity flow for the continuous separation of suspended particles

    Science.gov (United States)

    Bernate, Jorge A.; Paul, Colin; Liu, Chengxun; Lagae, Liesbet; Konstantopoulos, Konstantinos; Gagnon, Zachary; Drazer, German

    2012-11-01

    We present a microfluidic platform for the continuous separation of suspended particles based on their size and settling velocity, which relies on the reorientation of the flow field created by applying a pressure gradient across and along a periodic array of open cavities. The flow along the open cavities deflects different particles to a different degree depending on the extent to which they penetrate into the open cavities. Two regimes can be distinguished depending on the ratio r between the settling velocity of the particles and their velocity across the cavities. When r ~ 1 , heavier particles settle deeper into the open cavities and deflect more than lighter ones. When r centrifuge depleting RBCs and enriching spiked MCF-7 cancer cells. This platform can be easily integrated with external fields resulting in a potentially versatile technique. In particular, we use dielectrophoretic forces for the high-throughput separation of particles of the same size.

  13. Tracking suspended particle transport via radium isotopes ((226)Ra and (228)Ra) through the Apalachicola-Chattahoochee-Flint River system.

    Science.gov (United States)

    Peterson, Richard N; Burnett, William C; Opsahl, Stephen P; Santos, Isaac R; Misra, Sambuddha; Froelich, Philip N

    2013-02-01

    Suspended particles in rivers can carry metals, nutrients, and pollutants downstream which can become bioactive in estuaries and coastal marine waters. In river systems with multiple sources of both suspended particles and contamination sources, it is important to assess the hydrologic conditions under which contaminated particles can be delivered to downstream ecosystems. The Apalachicola-Chattahoochee-Flint (ACF) River system in the southeastern United States represents an ideal system to study these hydrologic impacts on particle transport through a heavily-impacted river (the Chattahoochee River) and one much less impacted by anthropogenic activities (the Flint River). We demonstrate here the utility of natural radioisotopes as tracers of suspended particles through the ACF system, where particles contaminated with arsenic (As) and antimony (Sb) have been shown to be contributed from coal-fired power plants along the Chattahoochee River, and have elevated concentrations in the surficial sediments of the Apalachicola Bay Delta. Radium isotopes ((228)Ra and (226)Ra) on suspended particles should vary throughout the different geologic provinces of this river system, allowing differentiation of the relative contributions of the Chattahoochee and Flint Rivers to the suspended load delivered to Lake Seminole, the Apalachicola River, and ultimately to Apalachicola Bay. We also use various geochemical proxies ((40)K, organic carbon, and calcium) to assess the relative composition of suspended particles (lithogenic, organic, and carbonate fractions, respectively) under a range of hydrologic conditions. During low (base) flow conditions, the Flint River contributed 70% of the suspended particle load to both the Apalachicola River and the bay, whereas the Chattahoochee River became the dominant source during higher discharge, contributing 80% of the suspended load to the Apalachicola River and 62% of the particles entering the estuary. Neither of these hydrologic

  14. Stochastic Models of Solid Particles Grinding

    Directory of Open Access Journals (Sweden)

    G. A. Zueva

    2010-01-01

    Full Text Available Solid particle grinding is considered as a Markov process. Mathematical models of disintegration kinetics are classified on the basis of the class of Markov process that they belong to. A mathematical description of the disintegration kinetics of polydisperse particles by milling in a shock-loading grinder is proposed on the basis of the theory of Markov processes taking into account the operational conditions in the device. The proposed stochastic model calculates the particle size distribution of the material at any instant in any place in the grinder. The experimental data is in accordance with the predicted values according to the proposed model.

  15. A suspended-particle rosette multi-sampler for discrete biogeochemical sampling in low-particle-density waters

    Energy Technology Data Exchange (ETDEWEB)

    Breier, J. A.; Rauch, C. G.; McCartney, K.; Toner, B. M.; Fakra, S. C.; White, S. N.; German, C. R.

    2010-06-22

    To enable detailed investigations of early stage hydrothermal plume formation and abiotic and biotic plume processes we developed a new oceanographic tool. The Suspended Particulate Rosette sampling system has been designed to collect geochemical and microbial samples from the rising portion of deep-sea hydrothermal plumes. It can be deployed on a remotely operated vehicle for sampling rising plumes, on a wire-deployed water rosette for spatially discrete sampling of non-buoyant hydrothermal plumes, or on a fixed mooring in a hydrothermal vent field for time series sampling. It has performed successfully during both its first mooring deployment at the East Pacific Rise and its first remotely-operated vehicle deployments along the Mid-Atlantic Ridge. It is currently capable of rapidly filtering 24 discrete large-water-volume samples (30-100 L per sample) for suspended particles during a single deployment (e.g. >90 L per sample at 4-7 L per minute through 1 {mu}m pore diameter polycarbonate filters). The Suspended Particulate Rosette sampler has been designed with a long-term goal of seafloor observatory deployments, where it can be used to collect samples in response to tectonic or other events. It is compatible with in situ optical sensors, such as laser Raman or visible reflectance spectroscopy systems, enabling in situ particle analysis immediately after sample collection and before the particles alter or degrade.

  16. Calibration of a turbidity meter for making estimates of total suspended solids concentrations and beam attenuation coefficients in field experiments

    Science.gov (United States)

    Usry, J. W.; Whitlock, C. H.

    1981-01-01

    Management of water resources such as a reservoir requires using analytical models which describe such parameters as the suspended sediment field. To select or develop an appropriate model requires making many measurements to describe the distribution of this parameter in the water column. One potential method for making those measurements expeditiously is to measure light transmission or turbidity and relate that parameter to total suspended solids concentrations. An instrument which may be used for this purpose was calibrated by generating curves of transmission measurements plotted against measured values of total suspended solids concentrations and beam attenuation coefficients. Results of these experiments indicate that field measurements made with this instrument using curves generated in this study should correlate with total suspended solids concentrations and beam attenuation coefficients in the water column within 20 percent.

  17. Single particle Brownian motion with solid friction.

    Science.gov (United States)

    Das, Prasenjit; Puri, Sanjay; Schwartz, Moshe

    2017-06-01

    We study the Brownian dynamics of a solid particle on a vibrating solid surface. Phenomenologically, the interaction between the two solid surfaces is modeled by solid friction, and the Gaussian white noise models the vibration of the solid surface. The solid friction force is proportional to the sign of relative velocity. We derive the Fokker-Planck (FP) equation for the time-dependent probability distribution to find the particle at a given location. We calculate analytically the steady state velocity distribution function, mean-square velocity and diffusion coefficient in d-dimensions. We present a generic method of calculating the autocorrelations in d-dimensions. This results in one dimension in an exact evaluation of the steady state velocity autocorrelation. In higher dimensions our exact general expression enables the analytic evaluation of the autocorrelation to any required approximation. We present approximate analytic expressions in two and three dimensions. Next, we numerically calculate the mean-square velocity and steady state velocity autocorrelation function up to d = 3 . Our numerical results are in good agreement with the analytically obtained results.

  18. Gas suspension flows of a moderately dense binary mixture of solid particles in vertical tubes

    Energy Technology Data Exchange (ETDEWEB)

    Zamankhan, P.; Huotari, J. [VTT Energy, Jyvaeskylae (Finland). Combustion and Conversion Lab.

    1996-12-01

    The turbulent, steady, fully-developed flow of a moderately dense (solid volume faction >>0.001) binary mixture of spherical particles in a gaseous carrier is investigated for the case of flow in a vertical riser. The suspended particles are considered to be in turbulent motion, driven by random aerodynamic forces acting between the particle and the gaseous carrier as well as particle-particle interactive forces. A model is constructed based on the combination of the time-averaged after volume-averaged conservation equations of mass, momentum and mechanical energy of the gas phase in the continuum theory and the corresponding equations for the solid particles obtained using the recently developed Enskog theory for dense multi-component mixtures of slightly inelastic spherical particles. The model properly takes into account the contributions of particle-particle collisions, as well as the fluid-dynamic fluctuating forces on individual particles. To demonstrate the validity of this approach, the fully-developed steady-state mean velocity and concentration distributions of a moderately dense binary mixture of solid particles in a turbulent vertical flow calculated by the present model are compared with available experimental measurements. The results provide a qualitative description of the experimentally observed motion of coarse particles in a fast bed of fine solids. (author)

  19. A review of the effects of particle types on oil-suspended particulate matter aggregate formation

    Science.gov (United States)

    Loh, Andrew; Yim, Un Hyuk

    2016-12-01

    Oil-suspended particulate matter aggregate (OSA) can form naturally when oil and particles interact. The interaction between oil and suspended particulate matter makes oil less sticky, and facilitates its dispersion in the water column. The high oil-water surface contact enhances the biodegradation of oil and thus increases the efficiency of remediation processes. There are many factors that affect OSA formation, but, particle type is one of the most important. Because different particle types have different physical, chemical, and biological properties, their interactions with oil differ greatly. Particle properties such as interlayer spaces, hydrophobicity, surface charges, polarity, organic content, and size affect the interactions between materials and oil. These different interactions determine the type, buoyancy, size, and stability of OSA that forms, thus determining its fate in the environment. This review provides a current understanding of (1) OSA formation mechanisms, (2) sources and classes of marine materials, (3) oil-particle interactions, (4) material properties and their effects on oil interaction, and (5) future research needs.

  20. Ferroelectric hollow particles obtained by solid-state reaction

    Energy Technology Data Exchange (ETDEWEB)

    Buscaglia, Maria Teresa; Buscaglia, Vincenzo; Viviani, Massimo; Nanni, Paolo [Institute of Energetics and Interphases, National Research Council, Via De Marini 6, I-16149 Genoa (Italy); Dondero, Giovanni [Institute for Macromolecular Studies, National Research Council, Via De Marini 6, I-16149 Genoa (Italy); Roehrig, Serge; Ruediger, Andreas [Institute of Solid State Research, Centre of Nanoelectronic Systems for Information Technology, Research Centre Juelich, 52425 Juelich (Germany)], E-mail: v.buscaglia@ge.ieni.cnr.it

    2008-06-04

    Hollow particles of barium titanate were obtained by a two-step process combining colloidal chemistry and solid-state reaction. BaCO{sub 3} crystals (size {approx}1 {mu}m) suspended in a peroxy-Ti(IV) aqueous solution were coated with an amorphous TiO{sub 2} shell using a precipitation process. Calcination of the BaCO{sub 3}-TiO{sub 2} core-shell particles at 700 deg. C resulted in the formation of BaTiO{sub 3} hollow particles (shell thickness of {approx}70 nm) which retain the morphology of the BaCO{sub 3} crystals. Formation of the cavity occurs because out-diffusion of the core phase is much faster than in-diffusion of the shell material. X-ray diffraction (XRD) and Raman spectroscopy indicate that the hollow particles possess a tetragonal ferroelectric structure with axial ratio c/a = 1.005. Piezoresponse force microscopy has shown strong piezoactivity and 180 deg. ferroelectric domains. The process described provides a general route to fabricate hollow ferroelectric structures of several compounds.

  1. Ferroelectric hollow particles obtained by solid-state reaction.

    Science.gov (United States)

    Buscaglia, Maria Teresa; Buscaglia, Vincenzo; Viviani, Massimo; Dondero, Giovanni; Röhrig, Serge; Rüdiger, Andreas; Nanni, Paolo

    2008-06-04

    Hollow particles of barium titanate were obtained by a two-step process combining colloidal chemistry and solid-state reaction. BaCO(3) crystals (size ≈1 µm) suspended in a peroxy-Ti(IV) aqueous solution were coated with an amorphous TiO(2) shell using a precipitation process. Calcination of the BaCO(3)@TiO(2) core-shell particles at 700 °C resulted in the formation of BaTiO(3) hollow particles (shell thickness of ≈70 nm) which retain the morphology of the BaCO(3) crystals. Formation of the cavity occurs because out-diffusion of the core phase is much faster than in-diffusion of the shell material. X-ray diffraction (XRD) and Raman spectroscopy indicate that the hollow particles possess a tetragonal ferroelectric structure with axial ratio c/a = 1.005. Piezoresponse force microscopy has shown strong piezoactivity and 180° ferroelectric domains. The process described provides a general route to fabricate hollow ferroelectric structures of several compounds.

  2. Viruses, bacteria and suspended particles in a backwater and main channel site of the Danube (Austria)

    Science.gov (United States)

    Peduzzi, Peter; Luef, Birgit

    2010-01-01

    A short overview of currently available studies on the ecology of viruses in running waters is provided. Additionally, a survey was conducted on the dynamics of both viruses and bacteria in an isolated floodplain segment of the Danube River and in the main channel near Vienna (Austria) during the hydrologically most dynamic phase (spring – summer). The study evaluates the differences between the main channel and the floodplain segment for suspended particle abundance and quality in relation to bacterial and viral parameters; both free-living forms and those attached to particles are examined. The hydrological disconnection of these two contrasting sampling sites influenced particle abundance and quality as well as the distribution of free-living vs. attached bacteria and viruses. The per-cell activity of bacteria attached to particles was significantly higher than that of the free-living fraction, particularly in the isolated water body. The abundance of bacteria and viruses on particles depended on particle quality (size). In the main channel, bacteria were significantly more abundant on surfaces (per mm2) of suspended matter > 5 μm (aggregates with organic constituents) compared to particles 5μm and attached viruses; free-living viruses were less abundant at high > 5μm particle loads. Only in the isolated floodplain section was viral abundance positively influenced by elevated per-cell productivity of potential host bacteria. The results demonstrate that system variability on a relatively small topographical scale (within a river-floodplain system) has consequences for microbial life, including viruses. PMID:21151810

  3. EFFECT OF SUSPENDED PARTICLES ON THERMAL CONVECTION IN RIVLIN-ERICKSEN FLUID IN A DARCY-BRINKMAN POROUS MEDIUM

    Directory of Open Access Journals (Sweden)

    G.C. Rana

    2012-06-01

    Full Text Available In this paper, the effect of suspended particles on thermal convection in an incompressible Rivlin-Ericksen elastico-viscous fluid in a porous medium is considered. For the porous medium, the Brinkman model is employed. By applying a normal mode analysis method, the dispersion relation has been derived and solved analytically. It is observed that the medium permeability, suspended particles, gravity field and viscoelasticity introduce oscillatory modes. For stationary convection, it is observed that the Darcy number has a stabilising effect, whereas the suspended particles and medium permeability have destabilising effects on the system. The effects of suspended particles, the Darcy number and the medium permeability have been presented graphically to depict the stability characteristics, which are in good agreement with the results derived analytically.

  4. Thermosolutal Convection in Compressible Walters' (Model B′ Fluid Permeated with Suspended Particles in a Brinkman Porous Medium

    Directory of Open Access Journals (Sweden)

    G. C. Rana

    2012-06-01

    Full Text Available In this paper, the thermosolutal convection in compressible Walters' (model B′ elastico-viscous fluid permeated with suspended particles in a porous medium is considered. For the porous medium, the Brinkman model is employed. By applying normal mode analysis method, the dispersion relation has been derived and solved analytically. It is observed that the medium permeability, suspended particles, gravity field and viscoelasticity introduce oscillatory modes. For stationary convection, it is observed that the Darcy number and stable solute gradient have stabilizing effects whereas the suspended particles and medium permeability has destabilizing effects on the system. The effects of Darcy number, stable solute gradient, suspended particles and medium permeability has also been shown graphically.

  5. Coalescence of freely moving bubbles in water by the action of suspended hydrophobic particles

    NARCIS (Netherlands)

    van der Zon, M.; Hamersma, P.J.; Poels, E.K.; Bliek, A.

    2002-01-01

    The presence of (catalyst) particles in slurry columns may induce significant changes in the overall column hydrodynamics. This is commonly attributed to changes in the apparent viscosity and density of the slurry phase as a result of the presence of particles. However, in case of solids

  6. The acceleration of solid particles subjected to cavitation nucleation

    DEFF Research Database (Denmark)

    Borkent, B.M.; Arora, M.; Ohl, C.-D.

    2008-01-01

    The cavity -particle dynamics at cavitation inception on the surface of spherical particles suspended in water and exposed to a strong tensile stress wave is experimentally studied with high-speed photography. Particles, which serve as nucleation sites for cavitation bubbles, are set into a fast...

  7. Temporal and spatial variations in total suspended and dissolved solids in the upper part of Manoa stream, Hawaii

    NARCIS (Netherlands)

    Augustijn, Dionysius C.M.; Fares, Ali; Tran, Dai Ngia

    2011-01-01

    Hawaiian watersheds are small, steep, and receive high intensity rainfall events of non-uniform distribution. These geographic and weather patterns result in flashy streams of strongly variable water quality even within various stream segments. Total suspended solids (TSS) and total dissolved solids

  8. Inertial Effects on the Vertical Transport of Suspended Particles in a Turbulent Boundary Layer

    Science.gov (United States)

    Richter, David; Chamecki, Marcelo

    2017-11-01

    In many atmospheric flows, a dispersed phase is actively suspended by turbulence, whose competition with gravitational settling ultimately dictates its vertical distribution. Examples of dispersed phases include snow, sea-spray droplets, dust, or sand, where individual elements of much larger density than the surrounding air are carried by turbulent motions after emission from the surface. In cases where the particle is assumed to deviate from local fluid motions only by its gravitational settling (i.e., they are inertialess), traditional flux balances predict a power-law dependence of particle concentration with height. It is unclear, however, how particle inertia influences this relationship, and this question is the focus of this work. Direct numerical simulations are conducted of turbulent open-channel flow, laden with Lagrangian particles of specified inertia; in this way the study focuses on the turbulent transport which occurs in the lowest few meters of the planetary boundary layer, in regions critical for connecting emission fluxes to the fluxes felt by the full-scale boundary layer. Simulations over a wide range of particle Stokes number, while holding the dimensionless settling velocity constant, are performed to understand the role of particle inertia on vertical dispersion. It is found that particles deviate from their inertialess behaviour in ways that are not easily captured by traditional theory; concentrations are reduced with increasing Stokes number. Furthermore, a similarity-based eddy diffusivity for particle concentration fails as particles experience inertial acceleration, precluding a closed-form solution for particle concentration as in the case of inertialess particles. The primary consequence of this result is that typical flux parametrizations connecting surface emission models (e.g., saltation models or sea-spray generation functions) to elevated boundary conditions may overestimate particle concentrations due to the reduced vertical

  9. Influence of land use on total suspended solid and dissolved ion concentrations: Baton Rouge, Louisiana area

    Directory of Open Access Journals (Sweden)

    D. Carlson

    2015-03-01

    Full Text Available Past studies in the Baton Rouge, Louisiana area considered streamwater quality during storm events but ignored water quality during low flow periods. This study includes determination of streamwater quality during low flow time periods for none watersheds in East Baton Rouge Parish, Louisiana. These samples were collected during dry-low flow periods as indicated by water levels at USGS stream gauging sites for each stream. Chemical analysis for ions was completed using colorimeters and gravimetric analysis for total dissolved solids (TDS and total suspended solids (TSS. Land use appears to impact concentrations of ions, TDS and TSS in a variety of ways during periods of low flow. The two most rural watersheds, which are mainly underdeveloped, have higher concentrations of Fe and Mn. By contrast the three most urban watersheds, that are mainly commercial, industrial or residential, have higher concentrations of Si, SO4 and TDS.

  10. Spatial and Temporal Dynamics of Fecal Coliform and Associated with Suspended Solids and Water within Five Northern California Estuaries.

    Science.gov (United States)

    Lewis, David J; Atwill, Edward R; Pereira, Maria das Graças C; Bond, Ronald

    2013-01-01

    Fecal coliform and associated with suspended solids (SS) and water in five northern California estuaries were studied to document process influences and water quality monitoring biases affecting indicator bacteria concentrations. We collected and analyzed 2371 samples during 10 sampling events for the five studied estuaries. Concentrations during wet-season stormflow conditions were greater than during wet-season base flow and dry-season base flow conditions. Results also document concentration gradients across the length of the studied estuaries and with depth of sample collection. Highest concentrations were associated with shallow samples collected furthest inland. Corresponding decreases occurred the deeper and closer to the estuary mouth a sample was collected. Results also identify direct relationships of wind speed and discharge velocity and indirect relationship of tide stage to indicator bacteria concentrations. Bacteria associated with suspended solids (SS), after conversion to the same units of measurement (mass), were three orders of magnitude greater than in the water fraction. However, the mean proportion contributed by SS to composite water sample concentrations was 8% (SE 0.3) for fecal coliform and 7% (SE 0.3) for . Bacteria from the SS proportion is related to seasonality, tide stage, and discharge velocity that are consistent with mechanisms for entrainment, transport of SS, and reduced particle settling. These results are important for both managing and monitoring these systems by improving sample spatial and temporal context and corresponding bacteria concentration values across the freshwater-saltwater interface. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. Resuspension and transport of suspended solids in Eurajoensalmi Bay. Final report of monitoring activities in 2009-2011; Resuspensio ja kiintoaineen kulkeutuminen Eurajoensalmessa. Vesistoemittausten loppuraportti

    Energy Technology Data Exchange (ETDEWEB)

    Mykkanen, J.; Kiirikki, M.; Lindfors, A. [Luode Consulting Oy, Espoo (Finland)

    2012-11-15

    The goal of monitoring activities carried out in Eurajoensalmi Bay was to indentify factors affecting dispersal of river waters and suspended solid matter in the estuary area. In addition to suspended solids load and dispersal of river water, also release of sedimented particles from the sea bed in resuspension was studied. River water quality and discharge as well as resuspension in Eurajoensalmi estuary area were monitored with Luode automatic monitoring stations equipped with water quality, water level, wave height and weather sensors. Dynamics of Eurajoensalmi estuary area was studied by installing profiling current meters (ADCP) and water quality sensors to the sea floor at the mouth of Eurajoensalmi. Spatial variation of surface water quality was monitored with a flow-through method from a moving vessel and manual profiling several times during the monitoring period. Collected data was processed and used in determining suspended solids balance of Eurajoensalmi Bay. The balance was determined by creating a regression model for water exchange and sediment flux over the cross section at the mouth of Eurajoensalmi. Regression model was created also to determine resuspension in Eurajoensalmi area. Sediment flux and resuspension were modeled using long term wind data from Kylmaepihlaja meteorological station as a variable to determine overall sediment balance of Eurajoensalmi.

  12. Effects of transparent exopolymer particles and suspended particles on the survival of Salmonella enterica serovar Typhimurium in seawater.

    Science.gov (United States)

    Davidson, Marion C F; Berardi, Terra; Aguilar, Beatriz; Byrne, Barbara A; Shapiro, Karen

    2015-03-01

    The bacterium Salmonella enterica can infect marine mammals and has been increasingly implicated in seafood-borne disease outbreaks in humans. Despite the risk this zoonotic agent poses to animals and people, little is known regarding the environmental factors that affect its persistence in the sea. The goal of this study was to evaluate the impact of two constituents on the survival of Salmonella in the marine environment: transparent exopolymer particles (TEP) and suspended particles. A decay experiment was conducted by spiking Salmonella into bottles containing seawater, seawater with alginic acid as a source of TEP, filtered seawater or filtered seawater with alginic acid. Survival of Salmonella was monitored using culture followed by enrichment assays to evaluate if the bacteria entered a viable but non-cultivable (VBNC) state. Salmonella cell counts dropped significantly faster (P ≤ 0.05) in the unfiltered seawater samples with and without TEP. The slowest decay occurred in filtered seawater containing alginic acid, with VBNC Salmonella persisting for 17 months. These findings suggest that TEP may favor Salmonella survival while suspended particles facilitate its decay. Insight on the survival of allochthonous, zoonotic pathogens in seawater can guide monitoring, management and policy decisions relevant to wildlife and human public health. © FEMS 2015. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Solid particles in the tropical lowest stratosphere

    Directory of Open Access Journals (Sweden)

    J. K. Nielsen

    2007-01-01

    Full Text Available We report in situ and remote observations proving occasional occurrence of solid particles in the tropical lowest stratosphere, 200 km from deep convective events. The particles were found during field campaigns in Southeast Brazil (49.03 W 22.36 S. They occur in the altitude range from 17.5 to 20.8 km, at temperatures up to at least 10 K above the expected frost point temperature. While stability of ice particles at these altitudes is unexpected from a theoretical point of view, it is argued that these observations are indications of tropospheric air masses penetrating into the stratosphere during convective overshoots. It is argued that the intrusion of tropospheric air must have carried a large amount of water with it, which effectively hydrated the lowest stratosphere, and consequently suppressed sublimation. This conclusion is further supported by a separate water vapor mixing ratio profile obtained at the same observation site.

  14. Inertial migration regimes of spherical particles suspended in square tube flows

    Science.gov (United States)

    Shichi, Hiroyuki; Yamashita, Hiroshi; Seki, Junji; Itano, Tomoaki; Sugihara-Seki, Masako

    2017-04-01

    The inertial migration of neutrally buoyant spherical particles suspended in tube flows of square cross sections was investigated experimentally in the range of Reynolds numbers (Re) from 1 to 800 for particle-to-tube-size ratios from 0.075 to 0.175. Direct observations of the particle distribution in the cross section at various distances from the tube inlet revealed that at low Re, smaller than a certain critical value, particles were focused on four equilibrium positions, located at the center of channel faces, consistent with previous studies on microchannel flows, whereas at higher Re, larger than another critical value, four additional equilibrium positions were observed near the channel corners. At intermediate Re, between these two critical values, we observed new focusing positions of particles, located on a heteroclinic orbit joining the channel face and corner equilibrium positions. Comparing these results with corresponding numerical simulations, we examined the migration properties in detail and categorized their types. It was found that the critical Re values depended considerably on the particle-to-tube-size ratio.

  15. Dynamics of suspended sediment concentration, flow discharge and sediment particle size interdependency to identify sediment source

    Science.gov (United States)

    Sadeghi, Seyed Hamidreza; Singh, Vijay P.

    2017-11-01

    Spatiotemporal behavior of sediment yield is a key for proper watershed management. This study analyzed statistical characteristics and trends of suspended sediment concentration (SCS), flow discharge (FD) and sediment particle sizes using data from 24 gage stations scattered throughout the United States. Analysis showed significant time- and location-specific differences of these variables. The median values of SSC, FD and percentage of particle sizes smaller than 63 μm (P63) for all 24 gage stations were found to be 510.236 mg l-1 (right skewed), 45.406 m3 s-1 (left skewed) and 78.648% (right skewed), respectively. Most of the stations exhibited significant trends (P management practices which may call for local or regional planning based on natural (i.e., precipitation amount, type and erosivity, watershed area, and soil erodibility) and human-affected (i.e., land use and hydraulic structures and water resources management) factors governing the study variables.

  16. Pesticide survey in water and suspended solids from the Uruguay River Basin, Argentina.

    Science.gov (United States)

    Williman, Celia; Munitz, Martín S; Montti, María I T; Medina, María B; Navarro, Agustín F; Ronco, Alicia E

    2017-06-01

    The Uruguay River is receptor of pollutants, such as pesticides, from agriculture activities along its course. The present study reports concentration levels of organochlorinate, organophosphorus, and other pesticides in water and suspended solids in nine sampling sites of the Uruguay River. Data analyses included principal component analysis (PCA) to assess differences between sampling sites contamination. Most of the tested pesticides were ubiquitous due to the widely use in the chemical control of pests implemented in the region. Detected concentrations of aldrin, chlordane, dieldrin, endrin, heptachlor epoxide, lindane, 4,4'-DDT, endosulfan, chlorpyrifos, diazinon, methyl-parathion, and malathion were found to be over regional and international concentration level guidelines, according to the European Union, the US Environmental Protection Agency, or the Argentinean Secretariat of Environment and Sustainable Development. For this reason, future studies in Uruguay River Basin are needed.

  17. Chromium in water, suspended particles, sediments and biota in the Iraja River estuary

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiffer, W.C.; Fiszman, M.; de Lacerda, L.D.; van Weerfelt, M.; Carbonell, N.

    1982-11-01

    Analyses of chromium concentrations in waters, suspended particles, bottom sediments, fish (Poecilia reticulata), plants (Paspalum vaginatum, Sesuvium portulacastrum, Philoxeros vermicularis), soils and barnacles (Balanus sp.) were performed from August 1976 to September 1980 in samples collected from the Iraja River and inside its estuary in Guanabara Bay (Rio de Janeiro, Brazil). Sediments and water from the Iraja River showed chromium concentrations of 17536 and 23.39 ppm--a thousand times higher than the published data for freshwater systems. Chromium removed from solution by bottom sediments reaches Guanabara Bay linked to particulate matter. Fish and emergent grass inside the river concentrate chromium from water and/or sediment, returning the metal to the system as detritus. Soil and plants inside the estuary concentrate chromium thirty and ten times higher than in the control area. The vegetal community exhibits a concentration factor smaller than that related to soil and prevents the return of chromium to the estuarine waters. Inside the Guanabara Bay, Balanus sp. appears to be an effective biological monitor as it concentrates chromium in soft tissues 10/sup 3/ times higher than values found in suspended particles (0.012 ..mu..g ml/sup -1/).

  18. Suspended solids and nutrient retention in rural constructed wetlands in cold climate

    Science.gov (United States)

    Koskiaho, Jari; Siimekselä, Tiina; Puustinen, Markku

    2016-04-01

    Three constructed wetlands (CWs), two located in southern and one in central Finland, were monitored during 2013-2015. The southern CWs Hovi (0.6 ha wet area) and Rantamo-Seitteli (24 ha wet area) were monitored continuously by s::can nitro::lyser (www.s-can.at) sensors. On average 10 pairs (inflow and outflow) of water samples were annually taken in the two southern CWs and 20 pairs in the northernmost Tarvaala CW (wet area 1.4 ha). In Tarvaala, a portable, continuously measuring Micromac 1000 -phosphate analyzer (www.systea.it) was also tested at the CW outlet in 2015. The CWs differed in their size, dimensioning (CW-to-catchment area ratio) and in the characteristics of their upstream catchments. The Hovi CW has 5.0% CW-to-catchment area ratio and 100% agricultural land use in its clayey catchment. The corresponding percentages were for the Rantamo-Seitteli CW (clayey catchment) 1.3% and 42%, and for the Tarvaala CW (coarse soil type in the catchment) 1.0% and 16%. The average annual total suspended solids (TSS) retentions in Hovi, Rantamo-Seitteli and Tarvaala CWs were 79%, 6% and 50%, respectively. The average annual total phosphorus (TP) retentions were 61% at Hovi, 22% at Rantamo-Seitteli and 23% at Tarvaala. The unexpectedly high TSS and TP retentions at Tarvaala were probably due to the coarse soil type with more readily settling particles than in two other CWs. In Hovi and Rantamo-Seitteli CWs also dissolved reactive phosphorus (DRP) was measured. The DRP retentions (83% at Hovi and 27% at Rantamo-Seitteli) were higher than those of TP, which was probably due to the high contents of P-binding Al- and Fe-oxides in the soil of these two CWs. In the Hovi CW, vivid biological activity (abundant vegetation, algae and microbes) might also have played a role. The average annual total nitrogen (TN) retentions in Hovi and Rantamo-Seitteli CWs were 66% and 14%, respectively. At Tarvaala, TN retention varied annually so that no net retention over the whole period

  19. Hysteresis in suspended sediment to turbidity relations due to changing particle size distributions

    Science.gov (United States)

    Landers, Mark N.; Sturm, Terry W.

    2013-01-01

    Turbidity (T) is the most ubiquitous of surrogate technologies used to estimate suspended-sediment concentration (SSC). The effects of sediment size on turbidity are well documented; however, effects from changes in particle size distributions (PSD) are rarely evaluated. Hysteresis in relations of SSC-to-turbidity (SSC~T) for single stormflow events was observed and quantified for a data set of 195 concurrent measurements of SSC, turbidity, discharge, velocity, and volumetric PSD collected during five stormflows in 2009–2010 on Yellow River at Gees Mill Road in metropolitan Atlanta, Georgia. Regressions of SSC-normalized turbidity (T/SSC) on concurrently measured PSD percentiles show an inverse, exponential influence of particle size on turbidity that is not constant across the size range of the PSD. The majority of the influence of PSD on T/SSC is from particles of fine-silt and smaller sizes (finer than 16 microns). This study shows that small changes in the often assumed stability of the PSD are significant to SSC~T relations. Changes of only 5 microns in the fine silt and smaller size fractions of suspended sediment PSD can produce hysteresis in the SSC~T rating that can increase error and produce bias. Observed SSC~T hysteresis may be an indicator of changes in sediment properties during stormflows and of potential changes in sediment sources. Trends in the PSD time series indicate that sediment transport is capacity-limited for sand-sized sediment in the channel and supply-limited for fine silt and smaller sediment from the hillslope.

  20. Intergrating cavity absorption meter measurements of dissolved substances and suspended particles in ocean water

    Science.gov (United States)

    Pope, Robin M.; Weidemann, Alan D.; Fry, Edward S.

    2000-01-01

    We have developed a new device to measure the separate contributions to the spectral absorption coefficient due to a pure liquid, due to the particles suspended in it, and due to the substances dissolved in it. This device, the Integrating Cavity Absorption Meter (ICAM), is essentially independent of scattering effects in the sample. In April 1993, a prototype of the ICAM was field tested on board the research vessel USNS Bartlett. A major part of the cruise track included criss-crossing the area where the Mississippi flows into the Gulf of Mexico at various ranges from the mouth of the river; thus samples were collected from areas of blue, green, and brown/black water. We evaluated 35 seawater samples collected with 5-l Niskin bottles from 22 locations to determine absorption spectra (380-700 nm) of suspended particles and dissolved substances (gelbstoff). Results validate the ICAM as a viable tool for marine optical absorption research. Gelbstoff absorption at 432.5 nm ranged from 0.024 to 0.603 m -1. Over the spectral region 380→560 nm, gelbstoff absorption by each of the samples could be accurately fit to a decaying exponential. The particle absorption spectra are generally characteristic of those of phytoplankton and exhibit a local maximum at 430-440 nm. Absorption values at 432.5 nm ranged from ˜zero to ˜1.0 m -1. Some samples with moderate particulate absorption, however, did not show the characteristic local maximum of phytoplankton in the blue and instead resembled the characteristic decaying exponential of detritus with a shape similar to that observed in the gelbstoff. The ratio of gelbstoff to particulate absorption at 432.5 nm ranged from 0.46 to 152.

  1. Turbidimetric method for evaluation of photocatalytic activities of suspended fine particles

    Directory of Open Access Journals (Sweden)

    Hideki Aoyagi

    2010-10-01

    Full Text Available Hideki Aoyagi1, Katsumi Yabusaki21Life Science and Bioengineering, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan; 2Electronics and Optics Research Laboratory, Kowa Ltd, Chofugaoka, Chofu City, Tokyo, JapanAbstract: A spectrophotometer with special cuvette was developed for evaluating the photocatalytic activities of suspended fine particles. The spectrophotometer can continuously irradiate UV light using LED to the sample solution, and changes in the absorbance at 664 nm during photocatalytic degradation of methylene blue (MB were monitored continuously. From the onset of MB degradation, the absorbance decreased and reached a steady value at the end of the reaction. This process was expressed by first order kinetics and the photocatalytic activities of various fine particles could be evaluated quantitatively based on the reaction rate constant (k. The effect of photocatalysis using various TiO2 fine particles on the physiological activities of Euglena gracilis was related with k value.Keywords: photocatalyst, fine nano sized particles, specialized spectrophotometer, Euglena gracilis, rate constant

  2. Elementary Particle Spectroscopy in Regular Solid Rewrite

    Science.gov (United States)

    Trell, Erik

    2008-10-01

    The Nilpotent Universal Computer Rewrite System (NUCRS) has operationalized the radical ontological dilemma of Nothing at All versus Anything at All down to the ground recursive syntax and principal mathematical realisation of this categorical dichotomy as such and so governing all its sui generis modalities, leading to fulfilment of their individual terms and compass when the respective choice sequence operations are brought to closure. Focussing on the general grammar, NUCRS by pure logic and its algebraic notations hence bootstraps Quantum Mechanics, aware that it "is the likely keystone of a fundamental computational foundation" also for e.g. physics, molecular biology and neuroscience. The present work deals with classical geometry where morphology is the modality, and ventures that the ancient regular solids are its specific rewrite system, in effect extensively anticipating the detailed elementary particle spectroscopy, and further on to essential structures at large both over the inorganic and organic realms. The geodetic antipode to Nothing is extension, with natural eigenvector the endless straight line which when deployed according to the NUCRS as well as Plotelemeian topographic prescriptions forms a real three-dimensional eigenspace with cubical eigenelements where observed quark-skewed quantum-chromodynamical particle events self-generate as an Aristotelean phase transition between the straight and round extremes of absolute endlessness under the symmetry- and gauge-preserving, canonical coset decomposition SO(3)×O(5) of Lie algebra SU(3). The cubical eigen-space and eigen-elements are the parental state and frame, and the other solids are a range of transition matrix elements and portions adapting to the spherical root vector symmetries and so reproducibly reproducing the elementary particle spectroscopy, including a modular, truncated octahedron nano-composition of the Electron which piecemeal enter into molecular structures or compressed to each

  3. Hydromagnetic thermosolutal instability of compressible walters' (model B' rotating fluid permeated with suspended particles in porous medium

    Directory of Open Access Journals (Sweden)

    G Rana

    2016-09-01

    Full Text Available The thermosolutal instability of compressible Walters' (model B' elastico-viscous rotating fluid permeated with suspended particles (fine dust in the presence of vertical magnetic field in porous medium is considered. By applying normal mode analysis method, the dispersion relation has been derived and solved analytically. It is observed that the rotation, magnetic field, suspended particles and viscoelasticity introduce oscillatory modes. For stationary convection the Walters' (model B' fluid behaves like an ordinary Newtonian fluid and it is observed that the rotation and stable solute gradient has stabilizing effects and suspended particles are found to have destabilizing effect on the system, whereas the medium permeability has stabilizing or destabilizing effect on the system under certain conditions. The magnetic field has destabilizing effect in the absence of rotation, whereas in the presence of rotation, magnetic field has stabilizing or destabilizing effect under certain conditions.

  4. Study of Suspended Solid in Constructed Wetland Using Rare Earth Elements

    Science.gov (United States)

    Xiao, Z. X. Z.

    2015-12-01

    Constructed wetland (CW) is one of the commonly used technologies in wastewater treatment. By means of the biochemical interactions among water, microscopic organism, aquatic plant and sediments in natural environment CW can remove biochemical oxygen demand (BOD), ammoniacal nitrogen, suspended solid (SS) and heavy metals. In this study, rare earth elements (REEs) were used as a natural tracer for the study of SS in the CW. The studied CW, Hebao Island free water surface CW, is located in Chiayi County, south Taiwan. The CW is designed for removing SS and BOD due to the pollution from livestock farms in the upstream area. However, the removal of SS was not effective. In some cases, the SS concentration of inflow is even higher than that of outflow. That the sediments on the slope were flushed into the CW was considered as the main problem. After all the refinement, the issue has not improved yet. In the study, the water samples were filtered with 1.0μm filter paper. Then, part of water samples were digested by ultrapure nitric acid to obtain the water representing the total of dissolved and suspended matters. The others were filtered by 0.1μm filter, which represent the matters in dissolved form. REEs and most of metals were subsequently measured with ICP-MS. REEs generally have a unique source and would fractionate in certain regular patterns during biochemical reactions due to lanthanide contraction. They can be an excellent natural tracer in the environmental researches. After normalized by North American Shale Composite, the REEs pattern for the samples with the total of dissolved and suspended matters is characterized by a middle REE (MREE) enrichment and light REE (LREE) depletion. According to the previous theoretical studies, the MREE enrichment could be achieved by a selected adsorption of MREEs by organic matters, which is generally humic substance in natural surface water. It is suggested that the refinement of removal efficiency of SS should focus on

  5. Optimized goniometer for determination of the scattering phase function of suspended particles: simulations and measurements.

    Science.gov (United States)

    Foschum, Florian; Kienle, Alwin

    2013-08-01

    We present simulations and measurements with an optimized goniometer for determination of the scattering phase function of suspended particles. We applied the Monte Carlo method, using a radially layered cylindrical geometry and mismatched boundary conditions, in order to investigate the influence of reflections caused by the interfaces of the glass cuvette and the scatterer concentration on the accurate determination of the scattering phase function. Based on these simulations we built an apparatus which allows direct measurement of the phase function from ϑ=7  deg to ϑ=172  deg without any need for correction algorithms. Goniometric measurements on polystyrene and SiO2 spheres proved this concept. Using the validated goniometer, we measured the phase function of yeast cells, demonstrating the improvement of the new system compared to standard goniometers. Furthermore, the scattering phase function of different fat emulsions, like Intralipid, was determined precisely.

  6. Determination of suspended particulate matter concentration from turbidity measurements: particle size effects and calibration procedures

    Science.gov (United States)

    Pfannkuche, J.; Schmidt, A.

    2003-07-01

    Measurements of suspended particulate matter concentration and turbidity point towards the possibility of a site-specific algorithm (SPM), relating SPM to nephelometric turbidity units (NTU). In this paper regression models are presented that account for changes in the relationship of SPM and NTU as a result of changes in particle properties. The models have been developed by the use of daily measurements of SPM concentration and a continuous record of turbidity for the period from June 1996 to February 2001 in the River Elbe, a major river in the eastern part of Germany.The effect of changes in the particle properties with increasing water discharge was taken into account by varying the slope of a linear regression equation according to a logistic function. Water discharge, Q, was defined to be the only variable of this function - as an adequate substitute of the parameter bottom shear stress, which cannot be measured directly. Measurements of flow velocity in the River Elbe show that bottom shear stress is related almost linearly to water discharge up to bankful discharges.Regression models with slopes varying continuously with hydraulic parameters may account for the effects resulting from changes of particle characteristics and thus may have some advantages compared with models with a constant slope or models calibrated for different seasons.

  7. Study on submerged anaerobic membrane bioreactor (SAMBR) treating high suspended solids raw tannery wastewater for biogas production.

    Science.gov (United States)

    Umaiyakunjaram, R; Shanmugam, P

    2016-09-01

    This study deals with the treatment of high suspended solids raw tannery wastewater using flat sheet Submerged Anaerobic Membrane (0.4μm) Bioreactor (SAMBR) acclimatized with hypersaline anaerobic seed sludge for recovering biogas. The treatability of SAMBR achieved higher CODremoval efficiency (90%) and biogas yield (0.160L.g(-1) CODremoved) coincided with high r(2) values between permeate flux and TSS (0.95), biogas and COD removed (0.96). The acidification of hypersaline influent wastewater by biogas mixing with high CO2, achieved quadruplet benefit of gas liquid and solid separation, in-situ pH and NH3 control, in-situ CH4 enrichment, and prevention of membrane fouling. The initial high VFA became stable as time elapsed reveals the hydrolysing ability of particulate COD into soluble COD and into biogas, confirms the suitability of SAMBR for high suspended solids tannery wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Loads of nitrate, phosphorus, and total suspended solids from Indiana watersheds

    Science.gov (United States)

    Bunch, Aubrey R.

    2016-01-01

    Transport of excess nutrients and total suspended solids (TSS) such as sediment by freshwater systems has led to degradation of aquatic ecosystems around the world. Nutrient and TSS loads from Midwestern states to the Mississippi River are a major contributor to the Gulf of Mexico Hypoxic Zone, an area of very low dissolved oxygen concentration in the Gulf of Mexico. To better understand Indiana’s contribution of nutrients and TSS to the Mississippi River, annual loads of nitrate plus nitrite as nitrogen, total phosphorus, and TSS were calculated for nine selected watersheds in Indiana using the load estimation model, S-LOADEST. Discrete water-quality samples collected monthly by the Indiana Department of Environmental Management’s Fixed Stations Monitoring Program from 2000–2010 and concurrent discharge data from the U. S. Geological Survey streamflow gages were used to create load models. Annual nutrient and TSS loads varied across Indiana by watershed and hydrologic condition. Understanding the loads from large river sites in Indiana is important for assessing contributions of nutrients and TSS to the Mississippi River Basin and in determining the effectiveness of best management practices in the state. Additionally, evaluation of loads from smaller upstream watersheds is important to characterize improvements at the local level and to identify priorities for reduction.

  9. PENGGUNAAN MEMBRAN KERAMIK UNTUK MENURUNKAN BAKTERI E. COLI DAN TOTAL SUSPENDED SOLID (TSS PADA AIR PERMUKAAN

    Directory of Open Access Journals (Sweden)

    Ir kasam

    2015-10-01

    Full Text Available digunakan sebagai air minum. Adapun parameter yang cukup tinggi pada air permukaan adalah bakteri E. Coli dan Total Suspended Solid (TSS. Salah satu alternative pengolahan untuk parameter bakteri E. Coli dan TSS adalah dengan filtrasi dengan membran filter. Membran keramik adalah salah satu alat yang bisa digunakan sebagai filter pada air permukaan. Penelitian ini bertujuan untuk mengetahui kinerja membran keramik dalam menurunkan E.Coli dan TSS pada air permukan. Metode penelitian dilakukan dengan menggunakan membran keramik ukuran diameter 10 cm dan tinggi 20 cm yang terbuat dari tanah lempung, pasir kwarsa dan serbuk gergaji dengan komposisi 7,5% (membran 1 dan 10% (membran 2 bertujuan untuk membuat porositas dan pembakaran pada temperatur 900 – 1200 oC. Selanjutnya air permukaan dialirkan pada membran keramik secara kontinyu. Pengujian E.Coli dan TSS dilakukan pada menit ke 30, 60, 90, 120, 150, dan 180 dari waktu pengaliran. Dari hasil pengujian E. Coli dan TSS, diketahui bahwa membran keramik dapat menurunkan parameter E.Coli dan TSS pada air permukaan. E. Coli menurun hingga 98% untuk kedua membran 7,5% dan 10 % serbuk gergaji. Sedangkan TSS menurun hingga 72,55% pada membran keramik 7,5 % dan 65,22% pada membran 10%.

  10. Effect of particle size and composition of suspended sediment on denitrification in river water

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Zhimei; Liu, Ting; Xia, Xinghui, E-mail: xiaxh@bnu.edu.cn; Xia, Na

    2016-01-15

    Rivers with high suspended sediment (SPS) concentration are common worldwide, and previous studies reported the occurrence of denitrification on SPS. In this work, effect of particle size and composition of SPS on denitrification in river water was studied in laboratory. The {sup 15}N isotope tracer technique was used to investigate the denitrification in water containing 8 g L{sup −1} SPS with different particle sizes, including < 20 μm, 20–50 μm, 50–100 μm, and 100–200 μm. The results showed that the denitrification rate was negatively related to particle size, and the SPS with particle size below 20 μm had the highest {sup 15}N{sub 2} emission rate of 0.27 mg-N/m{sup 3}·d, which was twice that of 100–200 μm. The denitrifying bacteria population in the system decreased with the increase of particle size, which was positively correlated with denitrification rate (p < 0.05). There was a positive correlation between organic carbon content of SPS and denitrifying bacteria population (p < 0.01), indicating that organic carbon is a key factor influencing denitrifying bacteria. Different from the {sup 15}N{sub 2} production, {sup 15}N{sub 2}O emission rate reached the highest of 1.02 μg-N/m{sup 3}·d in the system containing SPS of 20–50 μm, which was 14.8 times that of 100–200 μm. This was due to the difference in denitrifying bacteria species in different systems due to different oxic/anoxic conditions around SPS. This study suggests that not only the SPS concentration but also the SPS size and composition should be considered in studying the nitrogen cycle in river systems, especially for the production of N{sub 2}O. - Highlights: • Denitrification rate was negatively related to particle size of SPS. • Denitrification in the < 20 μm SPS had the highest N{sub 2} emission rate of 0.27 mg-N/m{sup 3} d. • {sup 15}N{sub 2}O production in the system with SPS of 20–50 μm was 14.8 times that of 100–200 μm. • The denitrifying bacteria

  11. Gravity driven deterministic lateral displacement for suspended particles in a 3D obstacle array.

    Science.gov (United States)

    Du, Siqi; Drazer, German

    2016-08-16

    We present a simple modification to enhance the separation ability of deterministic lateral displacement (DLD) systems by expanding the two-dimensional nature of these devices and driving the particles into size-dependent, fully three-dimensional trajectories. Specifically, we drive the particles through an array of long cylindrical posts, such that they not only move parallel to the basal plane of the posts as in traditional two-dimensional DLD systems (in-plane motion), but also along the axial direction of the solid posts (out-of-plane motion). We show that the (projected) in-plane motion of the particles is completely analogous to that observed in 2D-DLD systems. In fact, a theoretical model originally developed for force-driven, two-dimensional DLD systems accurately describes the experimental results. More importantly, we analyze the particles out-of-plane motion and observe, for certain orientations of the driving force, significant differences in the out-of-plane displacement depending on particle size. Therefore, taking advantage of both the in-plane and out-of-plane motion of the particles, it is possible to achieve the simultaneous fractionation of a polydisperse suspension into multiple streams.

  12. Suspended particles only marginally reduce pyrethroid toxicity to the freshwater invertebrate Gammarus pulex (L.) during pulse exposure

    DEFF Research Database (Denmark)

    Rasmussen, Jes; Cedergreen, Nina; Kronvang, Brian

    2016-01-01

    Current ecotoxicological research on particle associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin on the epi......Current ecotoxicological research on particle associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin...... on the epibenthic freshwater amphipod Gammarus pulex (L.) using brief pulse exposures followed by a 144 h post exposure recovery phase. Humic acid (HA) and the clay mineral montmorillonite (MM) were used as model sorbents in environmentally realistic concentrations (5, 25 and 125 mg L-1). Mortality of G. pulex...

  13. THERMAL INSTABILITY OF COMPRESSIBLE WALTERS' (MODEL B' FLUID IN THE PRESENCE OF HALL CURRENTS AND SUSPENDED PARTICLES

    Directory of Open Access Journals (Sweden)

    Urvashi GUPTA

    2011-01-01

    Full Text Available Effect of Hall currents and suspended particles is considered on the hydromagnetic stability of a compressible, electrically conducting Walters' (Model B' elastico-viscous fluid. After linearizing the relevant hydromagnetic equations, the perturbation equations are analyzed in terms of normal modes. A dispersion relation governing the effects of visco-elasticity, magnetic field, Hall currents and suspended particles is derived. It has been found that for stationary convection, the Walters' (Model B' fluid behaves like an ordinary Newtonian fluid due to the vanishing of the visco-elastic parameter. The compressibility and magnetic field have a stabilizing effect on the system, as such their effect is to postpone the onset of thermal instability whereas Hall currents and suspended particles are found to hasten the onset of thermal instability for permissible range of values of various parameters. Also, the dispersion relation is analyzed numerically and the results shown graphically. The critical Rayleigh numbers and the wavenumbers of the associated disturbances for the onset of instability as stationary convection are obtained and the behavior of various parameters on critical thermal Rayleigh numbers has been depicted graphically. The visco-elasticity, suspended particles and Hall currents (hence magnetic field introduce oscillatory modes in the system which were non-existent in their absence.

  14. [Remote sensing inversion mode of suspended particles concentration in Hangzhou Bay based on in situ measurement spectrum].

    Science.gov (United States)

    Wang, Fan; Zhou, Bin; Xu, Jian-Ming; Ling, Zai-Ying

    2008-11-01

    Suspended particles are one of major parameters of coastal water color remote sensing in China. The reflectances spectral of water were measured using an ASD field spectroscope, synchronously the suspended particles concentrations of surface water were acquired in Hangzhou Bay. Two remote sensing inversion models for suspended particles concentrations (SPC) were developed based on t hesimulated reflectance of MODIS & MERIS channels using artificial neural network (ANN) algorithm. Measurement results show that the total SPC of Hangzhou bay is comparatively high where the suspended sediments concentrations (SSC) are far more than chlorophyll concentrations, averagely 705 mg/L and 1.164 mg/m3, reseparately. The SPC in two measurement stations appears spatio-temporal variation, especially the short period change due to tidal cycle. There are two reflectance peaks in the measured spectral curves, one is between 650 nm to 750 nm, and the other is near 800 nm. The first order derivative curves of reflectance spectral indicate that the first reflectance peaks shift to long wavelength according to the increased SSC. The ANN models make full use of the spectral information in different channels which can simulate the pigment and non-pigment particles concentrations at same time. The fitting effects are preferable with R2 more than 0.95 for each model. The ANN mode can be used for satellite remote sensing inversion, especially MERIS data, because of its comparatively high spatial resolution.

  15. Treatment of wastewater containing a large amount of suspended solids by a novel multi-staged UASB reactor.

    Science.gov (United States)

    Uemura, S; Harada, H; Ohashi, A; Torimura, S

    2005-12-01

    Treatment of artificial wastewater containing a large amount of suspended solids comprised of soybean processing waste and pig fodder was studied using a novel multi-staged upflow anaerobic sludge blanket reactor. The reactor consisted of three compartments, each containing a gas solid separator. The wastewater had chemical oxygen demand of approximately 21600 mg l(-1), suspended solids of 12800 mg l(-1), and an ammonia concentration of 945 mg l(-1). A continuous experiment without effluent circulation showed that the multi-staged reactor was not that effective for the treatment of wastewater containing a large amount of suspended solids. However, operation of the reactor with circulation of effluent enabled the reactor to achieve organic removal of 85% and approximately 70% methane conversion at loading rates of between 4.0 to 5.4 kg-chemical oxygen demand per cubic meter per day, meaning that the reactor was more effective when effluent was circulated. Morphological investigation revealed that the crude fiber in the sludge was partially degraded and that it had many small depressions on its surface. Evolved biogas may have become caught in these depressions of the fibers and caused washout of the sludge.

  16. Changes in particle size distribution of suspended sediment affected by gravity erosion on the Loess Plateau, China

    Science.gov (United States)

    Guo, Wen-Zhao; Xu, Xiang-Zhou; Liu, Ya-Kun; Zhang, Hong-Wu; Zhu, Ming-Dong

    2017-04-01

    Gravity erosion generates an enormous volume of sediment on the steep hillslopes throughout the world, yet the response from particle size distribution (PSD) of suspended sediment to mass failure remains poorly understood. Here rainfall simulation experiments were conducted on the natural loess slopes to induce a series of mass failures under rainfall intensity of 48 mm h-1, and then an index of enrichment/dilution ratio was used to quantitatively explore the change trend of suspended sediment PSD affected by gravity erosion. To determine suspended sediment, water samples were collected in a polyethylene bottle directly from the gully runoff and channel flow in the pre and during- slope failures events. Then, the particle fractions of samples were done by combining sieving method and photoelectric sedimentometer technique. The results are shown as follows: (1) Gravity erosion has a significant influence on the particle size distribution of suspended sediment. As the mass erosion occurred, the proportion of sand-sized particles was decreased from 71.2 to 50.8%, whereas the proportions of clay and silt were increased remarkably from 1.3 to 7.3% and 27.5 to 41.9%, respectively. Hence the sediment can be more easily transported into channel flow while the suspended sediment load becomes finer as gravitational erosion occurs. (2) The median particle size (d50), sediment heterogeneity (H) and fractal dimensions (D) were significantly correlated with gravity erosion. As a result, d50 was decreased from 0.084 to 0.051 mm, H was increase from 5.6 to 26.8, and D was magnified from 2.60 to 2.78. This implies that mass failure makes the particle size distribution of suspended sediment more nonuniform and irregular. (3) Suspended sediment tended to enrich in the silt and clay fractions, while it diluted in the sand fractions during landslide erosion. Meanwhile, the enrichment/dilution ratios were 13.9 for the clay fractions, 1.4 for clay, and 0.7 for sand. This reflects the

  17. Occurrence and persistence of fungicides in bed sediments and suspended solids from three targeted use areas in the United States

    Science.gov (United States)

    Smalling, Kelly L.; Reilly, Timothy J.; Sandstrom, Mark W.; Kuivila, Kathryn

    2013-01-01

    To document the environmental occurrence and persistence of fungicides, a robust and sensitive analytical method was used to measure 34 fungicides and an additional 57 current-use pesticides in bed sediments and suspended solids collected from areas of intense fungicide use within three geographic areas across the United States. Sampling sites were selected near or within agricultural research farms using prophylactic fungicides at rates and types typical of their geographic location. At least two fungicides were detected in 55% of the bed and 83% of the suspended solid samples and were detected in conjunction with herbicides and insecticides. Six fungicides were detected in all samples including pyraclostrobin (75%), boscalid (53%), chlorothalonil (41%) and zoxamide (22%). Pyraclostrobin, a strobilurin fungicide, used frequently in the United States on a variety of crops, was detected more frequently than p,p′-DDE, the primary degradate of p,p′-DDT, which is typically one of the most frequently occurring pesticides in sediments collected within highly agricultural areas. Maximum fungicide concentrations in bed sediments and suspended solids were 198 and 56.7 μg/kg dry weight, respectively. There is limited information on the occurrence, fate, and persistence of many fungicides in sediment and the environmental impacts are largely unknown. The results of this study indicate the importance of documenting the persistence of fungicides in the environment and the need for a better understanding of off-site transport mechanisms, particularly in areas where crops are grown that require frequent treatments to prevent fungal diseases.

  18. Effects of cold water injection on injectivity impairment due to suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Bedrikovetsky, Pavel; Fonseca, Diogo R. [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil); Paiva, Ronaldo O. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This paper presents an analytical model to interpret pressure injection data following cold-water injection into a hot-oil reservoir. The injected water contains solid and liquid particles causing permeability decline. The relative permeability characteristics of the porous medium are accounted for, as is the temperature dependence of the fluid mobilities. It is shown that the temperature difference between injected and formation waters and the water-oil mobility variation have significant effects on the pressure data during the impairment of rock by particles from the injected suspension. The matching of field data to type curves generated from analytical solutions provides estimates of the formation damage parameters - filtration and formation damage coefficients, critical porosity ratio and cake permeability. The effect of injected water temperature on well injectivity decline is particularly sounded for cold water injection into heavy oil reservoirs. (author)

  19. Improving suspended sediment measurements by automatic samplers.

    Science.gov (United States)

    Gettel, Melissa; Gulliver, John S; Kayhanian, Masoud; DeGroot, Gregory; Brand, Joshua; Mohseni, Omid; Erickson, Andrew J

    2011-10-01

    Suspended solids either as total suspended solids (TSS) or suspended sediment concentration (SSC) is an integral particulate water quality parameter that is important in assessing particle-bound contaminants. At present, nearly all stormwater runoff quality monitoring is performed with automatic samplers in which the sampling intake is typically installed at the bottom of a storm sewer or channel. This method of sampling often results in a less accurate measurement of suspended sediment and associated pollutants due to the vertical variation in particle concentration caused by particle settling. In this study, the inaccuracies associated with sampling by conventional intakes for automatic samplers have been verified by testing with known suspended sediment concentrations and known particle sizes ranging from approximately 20 μm to 355 μm under various flow rates. Experimental results show that, for samples collected at a typical automatic sampler intake position, the ratio of sampled to feed suspended sediment concentration is up to 6600% without an intake strainer and up to 300% with a strainer. When the sampling intake is modified with multiple sampling tubes and fitted with a wing to provide lift (winged arm sampler intake), the accuracy of sampling improves substantially. With this modification, the differences between sampled and feed suspended sediment concentration were more consistent and the sampled to feed concentration ratio was accurate to within 10% for particle sizes up to 250 μm.

  20. Assessment of conservation easements, total phosphorus, and total suspended solids in West Fork Beaver Creek, Minnesota, 1999-2012

    Science.gov (United States)

    Christensen, Victoria G.; Kieta, Kristen A.

    2014-01-01

    This study examined conservation easements and their effectiveness at reducing phosphorus and solids transport to streams. The U.S. Geological Survey cooperated with the Minnesota Board of Water and Soil Resources and worked collaboratively with the Hawk Creek Watershed Project to examine the West Fork Beaver Creek Basin in Renville County, which has the largest number of Reinvest In Minnesota land retirement contracts in the State (as of 2013). Among all conservation easement programs, a total of 24,218 acres of agricultural land were retired throughout Renville County, and 2,718 acres were retired in the West Fork Beaver Creek Basin from 1987 through 2012. Total land retirement increased steadily from 1987 until 2000. In 2000, land retirement increased sharply because of the Minnesota River Conservation Reserve Enhancement Program, then leveled off when the program ended in 2002. Streamflow data were collected during 1999 through 2011, and total phosphorus and total suspended solids data were collected during 1999 through 2012. During this period, the highest peak streamflow of 1,320 cubic feet per second was in March 2010. Total phosphorus and total suspended solids are constituents that tend to increase with increases in streamflow. Annual flow-weighted mean total-phosphorus concentrations ranged from 0.140 to 0.759 milligrams per liter, and annual flow-weighted mean total suspended solids concentrations ranged from 21.3 to 217 milligrams per liter. Annual flow-weighted mean total phosphorus and total suspended solids concentrations decreased steadily during the first 4 years of water-quality sample collection. A downward trend in flow-weighted mean total-phosphorus concentrations was significant from 1999 through 2008; however, flow-weighted total-phosphorus concentrations increased substantially in 2009, and the total phosphorus trend was no longer significant. The high annual flow-weighted mean concentrations for total phosphorus and total suspended solids

  1. Suspended particles only marginally reduce pyrethroid toxicity to the freshwater invertebrate Gammarus pulex (L.) during pulse exposure.

    Science.gov (United States)

    Rasmussen, Jes Jessen; Cedergreen, Nina; Kronvang, Brian; Andersen, Maj-Britt Bjergager; Nørum, Ulrik; Kretschmann, Andreas; Strobel, Bjarne Westergaard; Hansen, Hans Christian Bruun

    2016-04-01

    Current ecotoxicological research on particle-associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin on the epibenthic freshwater amphipod Gammarus pulex (L.) using brief pulse exposures followed by a 144 h post exposure recovery phase. Humic acid (HA) and the clay mineral montmorillonite (MM) were used as model sorbents in environmentally realistic concentrations (5, 25 and 125 mg L(-1)). Mortality of G. pulex was recorded during the post exposure recovery phase and locomotor behavior was measured during exposure to lambda-cyhalothrin. We found that HA in concentrations ≥25 mg L(-1) adsorbed the majority of pyrethroids but only reduced mortality of G. pulex up to a factor of four compared to pyrethroid-only treatments. MM suspensions adsorbed a variable fraction of pyrethroids (10% for bifenthrin and 70% for lambda-cyhalothrin) but did not significantly change the concentration-response relationship compared to pure pyrethroid treatments. Behavioral responses and immobilisation rate of G. pulex were reduced in the presence of HA, whereas behavioral responses and immobilisation rate were increased in the presence of MM. This indicates that G. pulex was capable of sensing the bioavailable fraction of lambda-cyhalothrin. Our results imply that suspended particles reduce to only a limited extent the toxicity of pyrethroids to G. pulex and that passive uptake of pyrethroids can be significant even when pyrethroids are adsorbed to suspended particles.

  2. Seasonal and spatial variability of light absorption by suspended particles in the southern Baltic: A mathematical description

    Science.gov (United States)

    Meler, Justyna; Ostrowska, Mirosława; Stoń-Egiert, Joanna; Zabłocka., Monika

    2017-06-01

    This paper analyses the relationships between the light absorption coefficients at 440 nm ap(440) for particles suspended in the surface waters of the southern Baltic Sea and the concentrations of some optically significant constituents in these waters. The analysis covers two main groups of particles: phytoplankton and non-algal. For this purpose we use the extensive database of optical measurements acquired from 2006 to 2013 during 40 cruises of r/v Oceania in various regions of the southern Baltic: open waters, coastal waters, the Gulf of Gdańsk, the Pomeranian Bay and river mouths. Expressions are derived for each of these regions to describe the seasonal variations of the dependence of the light absorption coefficients for phytoplankton aph(440) and non-algal particles aNAP(440) on concentrations of chlorophyll a (Tchla) and suspended particulate matter in sea water (SPM). With a knowledge of these dependences, one can determine the overall absorption coefficient for all suspended particles in any part of the Baltic Sea in particular seasons from known Tchla and SPM concentrations using the relationship ap(440) = aph(440) + aNAP(440) = f(Tchla, SPM). These dependences reflect the characteristics of a study area and season, and their application increases the accuracy of determination of the overall absorption properties of suspended particles and their main constituents as confirmed by statistical error reduction, e.g. standard error factor falls from 1.46 to 1.38. The relationships derived in this work can be applied in the local remote sensing algorithms used for monitoring the southern Baltic.

  3. Impact of surfactants on the crystallization of aqueous suspensions of celecoxib amorphous solid dispersion spray dried particles.

    Science.gov (United States)

    Chen, Jie; Ormes, James D; Higgins, John D; Taylor, Lynne S

    2015-02-02

    Amorphous solid dispersions are frequently prepared by spray drying. It is important that the resultant spray dried particles do not crystallize during formulation, storage, and upon administration. The goal of the current study was to evaluate the impact of surfactants on the crystallization of celecoxib amorphous solid dispersions (ASD), suspended in aqueous media. Solid dispersions of celecoxib with hydroxypropylmethylcellulose acetate succinate were manufactured by spray drying, and aqueous suspensions were prepared by adding the particles to acidified media containing various surfactants. Nucleation induction times were evaluated for celecoxib in the presence and absence of surfactants. The impact of the surfactants on drug and polymer leaching from the solid dispersion particles was also evaluated. Sodium dodecyl sulfate and Polysorbate 80 were found to promote crystallization from the ASD suspensions, while other surfactants including sodium taurocholate and Triton X100 were found to inhibit crystallization. The promotion or inhibition of crystallization was found to be related to the impact of the surfactant on the nucleation behavior of celecoxib, as well as the tendency to promote leaching of the drug from the ASD particle into the suspending medium. It was concluded that surfactant choice is critical to avoid failure of amorphous solid dispersions through crystallization of the drug.

  4. Stability Of Superposed Fluids Through Magnetic Field With Suspended Particles Of Different Permeability Saturated Through Porous Layer

    Science.gov (United States)

    Singh, M.

    2015-12-01

    The instability of plane interface between two superposed Rivlin-Ericksen elastico-viscous fluids saturated through a porous medium has been studied to include the suspended (dust) particles effect. Following the linearized stability theory and normal mode analysis the dispersion relation is obtained. For stationary convection, the Rivlin-Ericksen elastico-viscous fluid behaves like Newtonian fluids. It found that for a potentially stable arrangement the Rivlin-Ericksen elastico-viscous fluid of different permeabilities in the presence of suspended particles in a porous medium is stable, whereas in a potentially unstable case instability of the system occurs. In the presence of a magnetic field for a potentially stable arrangement the system is always stable and for the potentially unstable arrangement, the magnetic field succeeds in stabilizing certain wave-number band which was unstable in the absence of the magnetic field.

  5. Method of Comprehensive Assessment of Efficiency of Decrease of Fire and Explosion Risk of Coal Suspended Particles

    Directory of Open Access Journals (Sweden)

    Arkhipov Vladimir

    2016-01-01

    Full Text Available Methods and results of experimental study of explosive and wetting characteristics of coal dust are presented. Modified evaluation method of explosive characteristics of coal dust allows estimating critical concentrations of suspended dust at variation of temperature of ionizing ignition source corresponding to beginning of flame propagation by means of approximation method. Method of measuring the contact angle of particles of coal powder is based on visualization of the drop placed on the pressed coal.

  6. Probing of the Changing Shapes and Viscosity of Suspended Organic Particles as a Function of Relative Humidity

    Science.gov (United States)

    Zhang, Y.; Sanchez, M. S.; Douet, C.; Wang, Y.; Bateman, A. P.; Gong, Z.; Kuwata, M.; Wolff, L. R.; Liu, P.; Sato, B. B.; Bertram, A. K.; Geiger, F.; Martin, S. T.

    2014-12-01

    Aerosol particles of secondary organic material (SOM) were produced by α-pinene ozonolysis in a flow tube reactor. The aerosol flow was passed into a chamber with a long residence time where coagulation of primary particles occurred. An experimental apparatus, consisting of a differential mobility analyzer coupled to a particle mass analyzer (DMA-APM), was used to classify coagulated particles by particle electric mobility diameter (52.4 to 190.0 nm) and then to measure associated particle mass. From these data, the dynamic shape factor was determined for particles of known material density. Experiments were conducted for variable relativity humidity (RH). The results showed that the dynamic shape factor depended on post-coagulation particle number concentration, particle diameter, and relative humidity. For some particle number concentrations, coagulation occurred between particles of similar diameters under dry conditions (< 5% RH), thereby forming non-spherical particles. The dynamic shape factors were observed to change from 1.24 to 1.02 between 5 and 35% RH, and 1.27 to 1.03 between 20% to 60% RH, implying a transformation from non-spherical to round shapes. The shape change arose from decreased viscosity at elevated RH, allowing the material to flow and thereby form a spherical shape (i.e., as favored by minimization of surface area). Numerical modeling was used to estimate the particle viscosity associated with this flow. Based on the particle size and exposure time to elevated RH, the viscosity was determined from 109 Pa s down to 107 Pa s from 3% RH to 65% RH. The experiments establish a method for estimating the viscosity of suspended submicron aerosol particles based on changes in particle shape.

  7. Numerical study of solid particle erosion in butterfly valve

    Science.gov (United States)

    Liu, Bo; Zhao, Jiangang; Qian, Jianhua

    2017-07-01

    In the actual operation of butterfly valve, the butterfly valve is found severe erosion wear. A solid particle erosion analysis of butterfly valve based on the erosion theory is researched in this study. A CFD model has been built to simulate the flow erosion. Different parameters of butterfly valve including inlet velocity, particle mass fraction and solid particle diameter are separately analysed. The results show that erosion rate increase with the increase of inlet velocity, particle mass fraction and solid particle diameter. The peak erosion rate is up to 4.63E-5 (kg/m2/s) and erosion of valve disc mainly occurs around the upstream edge and the cylinder face.

  8. Solid Hydrogen Particles and Flow Rates Analyzed for Atomic Fuels

    Science.gov (United States)

    Palaszewski, Bryan A.

    2003-01-01

    The experiments were conducted at Glenn's Small Multipurpose Research Facility (SMIRF, ref. 5). The experimental setup was placed in the facility's vacuum tank to prevent heat leaks and subsequent boiloff of the liquid helium. Supporting systems maintained the temperature and pressure of the liquid helium bath where the solid particles were created. Solid hydrogen particle formation was tested from February 23 to April 2, 2001. Millimeter-sized solid-hydrogen particles were formed in a Dewar of liquid helium as a prelude to creating atomic fuels and propellants for aerospace vehicles. Atomic fuels or propellants are created when atomic boron, carbon, or hydrogen is stored in solid hydrogen particles. The current testing characterized the solid hydrogen particles without the atomic species, as a first step to creating a feed system for the atomic fuels and propellants. This testing did not create atomic species, but only sought to understand the solid hydrogen particle formation and behavior in the liquid helium. In these tests, video images of the solid particle formation were recorded, and the total mass flow rate of the hydrogen was measured. The mass of hydrogen that went into the gaseous phase was also recorded using a commercially available residual gas analyzer. The temperatures, pressures, and flow rates of the liquids and gases in the test apparatus were recorded as well. Testing conducted in 1999 recorded particles as small as 2 to 5 mm in diameter. The current testing extended the testing conditions to a very cold Dewar ullage gas of about 20 to 90 K above the 4 K liquid helium. With the very cold Dewar gas, the hydrogen freezing process took on new dimensions, in some cases creating particles so small that they seemed to be microscopic, appearing as infinitesimally small scintillations on the videotaped images.

  9. The active surface of suspended particles as a predictor of lung function and pulmonary symptoms in Austrian school children

    Science.gov (United States)

    Moshammer, Hanns; Neuberger, Manfred

    At a central elementary school in the capital of Upper Austria children aged 7-10 years underwent repeated respiratory health checkups (questionnaires, diaries, spirometry). Between March and May 2001 the daily means of the signals of a diffusion charging sensor, measuring the "active surface" of suspended particles, and a photoelectric aerosol sensor, measuring the particle-bound polycyclic aromatic hydrocarbons, were related to spirometric results of the total 164 children examined and to the daily symptom scores of a susceptible subgroup. Significant reductions of forced vital capacity ( p=0.006) and forced expiratory volume in the first second ( p=0.001) and significant increases of wheezing ( p=0.001), shortness of breath ( p=0.041), cough in the evening ( p=0.031) and at night ( p=0.018) were found with increase of "active surface" of suspended particles measured at the adjacent outdoor monitoring station, but not with the increase of particle-bound polycyclic aromatic hydrocarbons. Monitoring "active surface" of particles with diameters of about 10 nm-1 μm by means of a diffusion charging sensor might provide additional information in surveillance of particulate matter for prevention of acute effects on respiratory health.

  10. Occurrence and persistence of fungicides in bed sediments and suspended solids from three targeted use areas in the United States.

    Science.gov (United States)

    Smalling, Kelly L; Reilly, Timothy J; Sandstrom, Mark W; Kuivila, Kathryn M

    2013-03-01

    To document the environmental occurrence and persistence of fungicides, a robust and sensitive analytical method was used to measure 34 fungicides and an additional 57 current-use pesticides in bed sediments and suspended solids collected from areas of intense fungicide use within three geographic areas across the United States. Sampling sites were selected near or within agricultural research farms using prophylactic fungicides at rates and types typical of their geographic location. At least two fungicides were detected in 55% of the bed and 83% of the suspended solid samples and were detected in conjunction with herbicides and insecticides. Six fungicides were detected in all samples including pyraclostrobin (75%), boscalid (53%), chlorothalonil (41%) and zoxamide (22%). Pyraclostrobin, a strobilurin fungicide, used frequently in the United States on a variety of crops, was detected more frequently than p,p'-DDE, the primary degradate of p,p'-DDT, which is typically one of the most frequently occurring pesticides in sediments collected within highly agricultural areas. Maximum fungicide concentrations in bed sediments and suspended solids were 198 and 56.7 μg/kg dry weight, respectively. There is limited information on the occurrence, fate, and persistence of many fungicides in sediment and the environmental impacts are largely unknown. The results of this study indicate the importance of documenting the persistence of fungicides in the environment and the need for a better understanding of off-site transport mechanisms, particularly in areas where crops are grown that require frequent treatments to prevent fungal diseases. Published by Elsevier B.V.

  11. Report of meeting on measurement of suspended solids in the Meuse

    NARCIS (Netherlands)

    Joziasse, J.; Klaver, G.; Bakker, I.

    2004-01-01

    On June 19/20, 2007 a visit was paid to a suspended particulate matter (SPM) sampling and monitoring site in the Ourthe river (Liège region), between the confluence with the Vesdre river and the mouth of the Ourthe in the Meuse river. The next day, a workshop was organised in which backgrounds,

  12. Electrodialytic extraction of Cu, Pb and Cl from municipal solid waste incineration fly ash suspended in water

    DEFF Research Database (Denmark)

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

    2006-01-01

    The possibility of using fly ash from municipal solid waste incineration (MSWI) in, for example, concrete is considered. MSWI fly ash, however, has too high a concentration of heavy metals, which may cause leaching problems during use or problems with waste handling at the end of the lifetime...... of the concrete. The Cl content in MSWI fly ash is also too high and will cause corrosion problems in reinforced concrete. The possibility of removing some of the unwanted heavy metals (Cu and Pb) together with Cl from an MSWI fly ash suspended in water using an electrodialytic separation method was investigated...

  13. Comparison of Suspended Solids and Turbidity Estimates from MODIS and MERIS Images in the Three Gorges Dam Area

    Science.gov (United States)

    Di Trapani, Antonio; Corbari, Chiara; Mancini, Marco

    2016-08-01

    The aim of this work is to evaluate turbidity and total suspended matter (TSM) along the Yangtze river and the Three Gorges Reservoir, China, applying different retrieval algorithms to satellite imagery (MOD09GQ and MERIS FRS L2). Turbidity and TSM are then correlated to ground daily discharges, showing good correlations. Daily estimates of TSM are then obtained even for the days for which satellite scenes are not available, applying the obtained relations between ground discharge and satellite estimates of TSM. Daily satellite TSM are compared with literature values of solid discharge measurements.

  14. Comparison of solid particles, globular proteins and surfactants as emulsifiers.

    Science.gov (United States)

    Tcholakova, S; Denkov, N D; Lips, A

    2008-03-28

    The aim of this paper is to present a short overview of the main mechanisms operative in the formation and stabilization of emulsions by solid particles and, on this basis, to make comparisons between solid particles, surfactants and globular proteins as emulsifiers. When available, simple quantitative relations are presented, with the respective numerical estimates and discussion of the applicability of these relations to particle-stabilized systems. Non-obvious similarities between the different types of emulsifiers are outlined in several cases in which the description of the system can be performed at a phenomenological level. Examples are presented for the process of emulsification, where we show that several simple theoretical expressions, derived originally in the studies of surfactants and protein emulsifiers, can be successfully applied to particle-stabilized emulsions. In contrast, for the phenomena in which the detailed mechanisms of particle adsorption and film stabilization are important, the differences between the various emulsifiers prevail, thus making it impossible to use the same theoretical description. The most important specific characteristics of the solid particles which strongly affect their behavior are the high barrier to particle adsorption, high desorption energy and strong capillary forces between particles trapped in liquid films, which all originate in the relatively large particle size (as compared to the size of surfactant and protein molecules). The capillary mechanism of stabilization of liquid films by solid particles is reviewed in some detail, to emphasize its specific features and to demonstrate the applicability of several simple expressions for approximate estimates. Interestingly, we found that the hypothesis for some exceptionally high coalescence stability of the particle-stabilized emulsions is not supported by the experimental data available in literature. On the other hand, the particles are able to completely arrest

  15. Individual particle analysis of coarse air suspended particulate material by synchrotron radiation X-ray micro fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Silvana; Melo Junior, Ariston [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Dept. de Recursos Hidricos]. E-mail: silvana@fec.unicamp.br; Perez, Carlos Alberto [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)]. E-mail: perez@lnls.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br

    2005-07-01

    The purpose of this work is evaluate the size of individual particles present in the air suspended particulate material collected in Campinas, Sao Paulo State, and analyze quantitatively the particles using the synchrotron radiation X-ray micro fluorescence ({mu}-SRXRF) associated with the fundamental parameter method to correct attenuation/absorption effects by the matrix. The particles analyzed have size between 50-10 {mu}m and to perform the spatial distribution a white beam of synchrotron radiation condensed by a conical capillary (13 {mu}m diameter) was used. For the quantitative analysis punctual measures in thin films standards in Mylar subtract were performed. The elements detected were Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb. (author)

  16. Large-eddy simulation of a solid-particles suspension in a turbulent boundary layer

    Science.gov (United States)

    Rahman, Mustafa; Samtaney, Ravi

    2014-11-01

    We decribe a framework for the large-eddy simulation of solid particles suspended and transported within an incompressible turbulent boundary layer. The underlying approach to simulate the solid-particle laden flow is Eulerian-Eulerian in which the particles are characterized by statistical descriptors. For the fluid phase, the large-eddy simulation (LES) of incompressible turbulent boundary layer employs stretched spiral vortex subgrid-scale model and a virtual wall model similar to the work of Inoue & Pullin (J. Fluid Mech. 2011). Furthermore, a recycling method to generate turbulent inflow is implemented. For the particle phase, the direct quadrature method of moments (DQMOM) is chosen in which the weights and abscissas of the quadrature approximation are tracked directly rather than the moments themselves. The numerical method in this framework is based on a fractional-step method with an energy-conservative fourth-order finite difference scheme on a staggered mesh. It is proposed to utilize this framework to examine transport of sand in desert sandstorms. Supported by KAUST OCRF funded CRG project on simulation of sandstorms.

  17. Influences of suspended particles on the runoff of pesticides from an agricultural field at Askim, SE-Norway.

    Science.gov (United States)

    Wu, Q; Riise, G; Lundekvam, H; Mulder, J; Haugen, L E

    2004-01-01

    Field and laboratory experiments were conducted to study the loss of particles from agricultural fields, and the role of suspended particles in carrying pesticides in surface runoff and drainage water. Propiconazole, a widely used fungicide was applied to experimental fields located at Askim, SE-Norway. Samples from surface runoff and drainage water were collected and analyzed for sediment mass, pesticides, particulate and dissolved organic carbon through a whole year. The surface soil and the runoff material were characterized by its particle size distribution, organic carbon content in size fractions and its ability to bind propiconazole. The results show that (1) particle runoff mostly occurred during the rainfall event shortly after harrowing in autumn. The highest particle concentration observed in the surface runoff water was 4600 mg l(-1), and in the drainage water 1130 mg l(-1); (2) the erosion of surface soil is size selective. The runoff sediment contained finer particle/aggregates rich in organic matter compared to its original surface soil; (3) the distribution coefficient (Kd) of propiconazole was significantly higher in the runoff sediment than in the parent soil. According to our calculation, particle-bound propiconazole can represent up to 23% of the total amount of propiconazole in a water sample with a sediment concentration of 7600 mg l(-1), which will significantly influence the transport behavior of the pesticide.

  18. Cavitation inception by almost spherical solid particles in water

    DEFF Research Database (Denmark)

    Marschall, H.B.; Mørch, Knud Aage; Keller, A.P.

    2003-01-01

    The tensile strength of water increases when solid particles are filtered out, and it becomes greater the smaller the remaining particles are. Natural particles are of random shape, making parametric studies on the relationship between tensile strength and particle characteristics difficult. In t...... that cavitation nuclei are related to the fine scale surface structures observed on the balls, and in dependence of their global radii of curvature, critical cavities are developed. A model of this development is presented. ©2003 American Institute of Physics....

  19. Particle size distribution of river-suspended sediments determined by in situ measured remote-sensing reflectance.

    Science.gov (United States)

    Zhang, Yuanzhi; Huang, Zhaojun; Chen, Chuqun; He, Yijun; Jiang, Tingchen

    2015-07-10

    Suspended sediments in water bodies are classified into organic and inorganic matter and have been investigated by remote-sensing technology for years. Focusing on inorganic matter, however, detailed information such as the grain size of this matter has not been provided yet. In this study, we present a new solution for estimating inorganic suspended sediments' size distribution in highly complex Case 2 waters by using a simple spectrometer sensor rather than a backscattering sensor. An experiment was carried out in the Pearl River Estuary (PRE) in the dry season to collect the remote-sensing reflectance (Rrs) and particle size distribution (PSD) of inorganic suspended sediments. Based on Mie theory, PSDs in the PRE waters were retrieved by Rrs, colored dissolved organic matter, and phytoplankton. The retrieved median diameters in 12 stations show good agreement with those of laboratory analysis at root mean square error of 2.604 μm (27.63%), bias of 1.924 μm (20.42%), and mean absolute error of 2.298 μm (24.37%). The retrieved PSDs and previous PSDs were compared, and the features of PSDs in the PRE waters were concluded.

  20. A corrected solid boundary treatment method for Smoothed Particle Hydrodynamics

    Science.gov (United States)

    Chen, Yun-sai; Zheng, Xing; Jin, Shan-qin; Duan, Wen-yang

    2017-04-01

    Smoothed Particle Hydrodynamics method (SPH) has a good adaptability for simulating of free surface flow problems. However, there are some shortcomings of SPH which are still in open discussion. This paper presents a corrected solid boundary handling method for weakly compressible SPH. This improved method is very helpful for numerical stability and pressure distribution. Compared with other solid boundary handling methods, this corrected method is simpler for virtual ghost particle interpolation and the ghost particle evaluation relationship is clearer. Several numerical tests are given, like dam breaking, solitary wave impact and sloshing tank waves. The results show that the corrected solid boundary processing method can recover the spurious oscillations of pressure distribution when simulating the problems with complex geometry boundary.

  1. Smoothed particle hydrodynamics modelling of fluids and solids

    Directory of Open Access Journals (Sweden)

    Lobovský L.

    2007-11-01

    Full Text Available The study is concerned about the application of the smoothed particle hydrodynamics (SPH method within the computational fluid dynamics and elastodynamics. A brief description of the SPH model for an incompressible fluid and for an elastic solid is presented. The implemented model of incompressible fluid is tested for internal flows as well as for flows involving a free surface of the fluid. The implemented elastic solid model is examined during the simulation of the mechanical response of rubber rings.

  2. Study of Solid Particle Behavior in High Temperature Gas Flows

    Science.gov (United States)

    Majid, A.; Bauder, U.; Stindl, T.; Fertig, M.; Herdrich, G.; Röser, H.-P.

    2009-01-01

    The Euler-Lagrangian approach is used for the simulation of solid particles in hypersonic entry flows. For flow field simulation, the program SINA (Sequential Iterative Non-equilibrium Algorithm) developed at the Institut für Raumfahrtsysteme is used. The model for the effect of the carrier gas on a particle includes drag force and particle heating only. Other parameters like lift Magnus force or damping torque are not taken into account so far. The reverse effect of the particle phase on the gaseous phase is currently neglected. Parametric analysis is done regarding the impact of variation in the physical input conditions like position, velocity, size and material of the particle. Convective heat fluxes onto the surface of the particle and its radiative cooling are discussed. The variation of particle temperature under different conditions is presented. The influence of various input conditions on the trajectory is explained. A semi empirical model for the particle wall interaction is also discussed and the influence of the wall on the particle trajectory with different particle conditions is presented. The heat fluxes onto the wall due to impingement of particles are also computed and compared with the heat fluxes from the gas.

  3. Suspended organic particles drive the development of attached algal communities in degraded peatlands

    NARCIS (Netherlands)

    Goldenberg Vilar, A.; Vonk, J.A.; Bichebois, S.; van Dam, H.; Admiraal, W.; van der Geest, H.G.

    2015-01-01

    Mineral particles in rivers have been shown to cover adnate algal species, promoting motile and filamentous species. Such effects and the role of detrital particles have not been studied in stagnant waters. In degraded peat lands, detrital particles are very prominent and therefore we studied the

  4. Suspended organic particles drive the development of attached algal communities in degraded peatlands

    NARCIS (Netherlands)

    Goldenberg Vilar, Alejandra; Vonk, J. Arie; van der geest, Harm; van Dam, Herman; Bichebois, Simon; Admiraal, Wim

    2014-01-01

    Mineral particles in rivers have been shown to cover adnate algal species, promoting motile and filamentous species. Such effects and the role of detrital particles have not been studied in stagnant waters. In degraded peat lands, detrital particles are very prominent and therefore we studied the

  5. Appropriate maximum holding times for analysis of total suspended solids concentration in water samples taken from open-channel waterways.

    Science.gov (United States)

    Oudyn, Frederik W; Lyons, David J; Pringle, M J

    2012-01-01

    Many scientific laboratories follow, as standard practice, a relatively short maximum holding time (within 7 days) for the analysis of total suspended solids (TSS) in environmental water samples. In this study we have subsampled from bulk water samples stored at ∼4 °C in the dark, then analysed for TSS at time intervals up to 105 days after collection. The nonsignificant differences in TSS results observed over time demonstrates that storage at ∼4 °C in the dark is an effective method of preserving samples for TSS analysis, far past the 7-day standard practice. Extending the maximum holding time will ease the pressure on sample collectors and laboratory staff who until now have had to determine TSS within an impractically short period.

  6. A Comparison of Suspended Solids Sediment and Turbidity from MODIS and MERIS Imagery in the Three Gorges Dam Area, China

    Science.gov (United States)

    Di Trapani, Antonio; Corbari, Chiara; Mancini, Marco

    2016-08-01

    The aim of this work is to evaluate turbidity magnitude and total suspended matter (TSM) concentrations of the Three Gorges Reservoir, China, applying different retrieval algorithms to satellite imagery (MOD09GQ and MERIS FRS L2) 250 m: turbidity and TSM values retrieved from the satellite scenes were correlated to discharge values measured daily on the ground, leading to relations between TSM and discharge. Applying the obtained relations to the discharge dataset made possible to have daily estimations of TSM values even for the days for which satellite scenes were lacking. The estimations from the various retrieval algorithms and sediment discharge values were compared with literature values of solid discharge measured on the ground.

  7. Chemical composition shape form and size of suspended solids in the atmosphere carried by rain water; Composicion quimica, forma y tamano de solidos suspendidos en la atmosfera acarreados por el agua de lluvia

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    The interest of this work is to know about shape form, size and chemical composition of the suspended solids in the atmosphere of Toluca city and which are carried by the rains. The harvest of the samples was carried out during january to november 1999. The separation of the particulate matter from the rain water was realized through centrifugation. The solids were analysed by Scanning Electron Microscopy to know the shape form and size and the chemical composition was determined by X-ray dispersive energy in general form and of some particles individually analysed. The p H was measured to the solutions and the quantification of some dissolved ions by the Icp technique was realized. The results of the solids showed C, O, Na, Mg, Al, Si, S, P, K, Ca, Ti and Fe. Moreover they present sizes which varying from a ten of nanometers until some tens of microns. (Author)

  8. Evaluating unsupervised methods to size and classify suspended particles using digital in-line holography

    Science.gov (United States)

    Davies, Emlyn J.; Buscombe, Daniel D.; Graham, George W.; Nimmo-Smith, W. Alex M.

    2015-01-01

    Substantial information can be gained from digital in-line holography of marine particles, eliminating depth-of-field and focusing errors associated with standard lens-based imaging methods. However, for the technique to reach its full potential in oceanographic research, fully unsupervised (automated) methods are required for focusing, segmentation, sizing and classification of particles. These computational challenges are the subject of this paper, in which we draw upon data collected using a variety of holographic systems developed at Plymouth University, UK, from a significant range of particle types, sizes and shapes. A new method for noise reduction in reconstructed planes is found to be successful in aiding particle segmentation and sizing. The performance of an automated routine for deriving particle characteristics (and subsequent size distributions) is evaluated against equivalent size metrics obtained by a trained operative measuring grain axes on screen. The unsupervised method is found to be reliable, despite some errors resulting from over-segmentation of particles. A simple unsupervised particle classification system is developed, and is capable of successfully differentiating sand grains, bubbles and diatoms from within the surf-zone. Avoiding miscounting bubbles and biological particles as sand grains enables more accurate estimates of sand concentrations, and is especially important in deployments of particle monitoring instrumentation in aerated water. Perhaps the greatest potential for further development in the computational aspects of particle holography is in the area of unsupervised particle classification. The simple method proposed here provides a foundation upon which further development could lead to reliable identification of more complex particle populations, such as those containing phytoplankton, zooplankton, flocculated cohesive sediments and oil droplets.

  9. Particle resolved simulations of liquid/solid and gas/solid fluidized beds

    Science.gov (United States)

    Esteghamatian, Amir; Hammouti, Abdelkader; Lance, Michel; Wachs, Anthony

    2017-03-01

    The present work studies particle resolved simulations of liquid/solid and gas/solid fluidization in a cuboid domain with periodic lateral boundary conditions. The focus is on investigating particles' dynamics, while a particular care is devoted to the spatial grid resolution and statistical time convergence of the results. A statistical analysis of particles' motion and fluid fluctuations asserts the intrinsic differences in the flow characteristics and mixing properties of these two configurations. Results reveal anisotropic mechanisms driving particles' motion and highlight the dominance of diffusive and convective mechanisms in liquid/solid and gas/solid regimes, respectively. Following a framework similar to that of Nicolai et al. ["Particle velocity fluctuations and hydrodynamic self-diffusion of sedimenting non-Brownian spheres," Phys. Fluids 7(1), 12-23 (1995)], we estimate the correlation time and the fluctuation length of particles' motion. A force budget analysis is discussed to gain more insight into the role of collision in isotropization of the system. Owing to the wide range of employed grid resolutions and accurate error analysis, the present dataset is also deemed to be useful in calibrating the grid resolution for a desired accuracy of the solution in a fluidization configuration.

  10. Validating a universal model of particle transport lengths with laboratory measurements of suspended grain motions

    Science.gov (United States)

    Naqshband, Suleyman; McElroy, Brandon; Mahon, Robert C.

    2017-05-01

    The mechanics of sediment transport are of fundamental importance for fluvio-deltaic morphodynamics. The present study focuses on quantifying particle motions and trajectories across a wide range of flow conditions. In particular, a continuous model is presented that predicts particle travel distances for saltation and suspension based on Rouse number and relative grain roughness. By utilizing a series of eight video cameras in a plexiglass flume direct measurements of the distributions of particle travel distances (excursion lengths) were obtained. To this end, experiments were carried out in dark under black lights with fluorescent painted plastic and quartz sand particles. For relatively high Rouse numbers indicating bed load dominant transport regime (P≥2.5), particle motion is governed by the effect of gravitational forces (settling velocities) and measured excursion lengths closely follow a Gaussian distribution. For P=2.5, particle motion is equally subjected to both gravitational and turbulent forces. Consequently, measured excursion lengths exhibit a bimodal distribution with two distinct peaks. As turbulent fluctuations increase and dominate particle motion over gravity (P(P=1.8-8.9). Furthermore, measured excursion lengths are observed to fit within the predicted range of excursion lengths with no significant difference between measured excursion lengths of plastic and quartz sand particles.

  11. DNS with Discrete Element Modeling of Suspended Sediment Particles in an Open Channel Flow

    Science.gov (United States)

    Paksereht, Pedram; Apte, Sourabh; Finn, Justin

    2015-11-01

    Interactions of glass particles in water in a turbulent open channel flow over a smooth bed with gravity perpendicular to the mean flow is examined using direct numerical simulation (DNS) together with Lagrangian Discrete-Element-Model (DEM) for particles. The turbulent Reynolds number (Reτ) is 710 corresponding to the experimental observations of Righetti & Romano (JFM, 2004). Particles of size 200 microns with volume loading on the order of 10-3 are simulated using four-way coupling with standard models for drag, added mass, lift, pressure, and inter-particle collision forces. The presence of particles affect the outer as well as inner region of the wall layer where particle inertia and concentration are higher. The DNS-DEM is able to capture the fluid-particle interactions in the outer layer accurately. However, in the inner layer, an increase in mean as well as rms fluid velocity, as observed in the experiments, is not predicted by the DNS-DEM model. It is conjectured that particles slide and roll on the bottom wall, creating slip-like condition. Predictions using different models for drag and lift forces, as well as strong torque coupling are explored and compared with experimental data. Funding: NSF project #1133363, Sediment-Bed-Turbulence Coupling in Oscillatory Flows.

  12. Validating a universal model of particle transport lengths with laboratory measurements of suspended grain motions

    NARCIS (Netherlands)

    Naqshband, Suleyman; McElroy, Brandon; Mahon, Robert C.

    2017-01-01

    The mechanics of sediment transport are of fundamental importance for fluvio-deltaic morphodynamics. The present study focuses on quantifying particle motions and trajectories across a wide range of flow conditions. In particular, a continuous model is presented that predicts particle travel

  13. Combined technology for observing, understanding and predicting suspended particle transport and fate from anthropogenic discharges in coastal waters

    Science.gov (United States)

    Davies, E. J.

    2016-02-01

    The combined observation, understanding and prediction of suspended particle transport and fate in coastal waters is essential for assessing environmental stresses that originate from anthropogenic sources. We present a toolbox consisting of an optics-based instrument suite, post-processing and analysis tools, and numerical models for understanding particle transport and fate, and its effect on the marine environment. We show results from a combined measurement and modelling campaign, focussed on understanding the transport of flocculating particulate material discharged into a Norwegian fjord, and demonstrate the application of this approach to real-time monitoring of drilling discharges in the vicinity of coral reefs. Unique measurements and images of suspended particulates, obtained from multiple water column profiles within a fjord, are presented. Initial model predictions of particle transport were used to highlight target areas for the field campaign, where model uncertainty was highest. Regular discharges of flocculating material were released into the fjord, requiring particle observations to span several orders of magnitude in size and concentration. This was achieved by combining data from a LISST-100, LISST-HOLO, and a bespoke Silhouette particle imaging system. Together, these instruments produced size distributions ranging from 2.5-10000microns. In-situ imaging proved essential in providing a realistic picture of the nature of the flocculated material, with many long, string-like flocs of several cm in length being advected hundreds of metres from their discharge location. Observations surrounding the discharge within this fjord system are used to help validate an improved particle transport model aimed at accurately accounting for flocculation, subsequent sedimentation and modifications to seabed bathymetry. The numerical formulation enhanced by this combined measurement and modelling approach is applicable for a wide variety of scenarios where human

  14. Heavy metal content of total suspended air particles in the heavily industrialized town of Gebze, Turkey.

    Science.gov (United States)

    Ergenekon, Pinar; Ulutaş, Kadir

    2014-01-01

    Air pollution is a serious environmental problem in industrialized towns, where a significant portion of the residents live in close proximity to factories and major highways with high traffic load. In this study, the ambient air quality in Gebze, an industrial region with an area of 438 km(2) and a population of 300,000, was characterized in terms for total suspended particulate matter and its composition of trace elements, i.e. Cd, Cr, Cu, Fe, Mn, Ni and Pb. Samples were collected using high volume samplers from March to June 2009 at two sites during the day and the night. A significantly higher Cu concentrations during night suggested that Cu emissions were the result of a local source. The known air toxics, Cd and Ni, had average concentrations (34 and 43 ng/m(3), respectively) higher than proposed by the European Union's ambient air quality standards. These results highlight the potential health risks for the local population.

  15. An isolation-enhanced quad-element antenna using suspended solid wires for LTE small-cell base stations

    Science.gov (United States)

    Chen, Yen-Sheng; Zhou, Huang-Cheng

    2017-05-01

    This paper presents a multiple-input-multiple-output (MIMO) antenna that has four-unit elements enabled by an isolation technique for long-term evolution (LTE) small-cell base stations. While earlier studies on MIMO base-station antennas cope with either a lower LTE band (698-960 MHz) or an upper LTE band (1710-2690 MHz), the proposed antenna meets the full LTE specification, yet it uses the maximum number of unit elements to increase channel capacity. The antenna configuration is optimized for good impedance matching and high radiation efficiency. In particular, as the spacing between unit elements is so small that severe mutual coupling occurs, we propose a simple structure with extremely low costs to enhance the isolation. By using suspended solid wires interconnecting the position having strong coupled current of two adjacent elements, an isolation enhancement of 37 dB is achieved. Although solid wires inherently aim at direct-current applications, this work successfully employs such a low-cost technique to microwave antenna development. Experimental results have validated the design guidelines and the proposed configuration, showing that antenna performances including impedance matching, isolation, radiation features, signal correlation, and channel capacity gain are highly desired for LTE small-cell base stations.

  16. Particle size distributions and the vertical distribution of suspended matter in the upwelling region off Oregon

    Science.gov (United States)

    Kitchen, J. C.

    1977-01-01

    Various methods of presenting and mathematically describing particle size distribution are explained and evaluated. The hyperbolic distribution is found to be the most practical but the more complex characteristic vector analysis is the most sensitive to changes in the shape of the particle size distributions. A method for determining onshore-offshore flow patterns from the distribution of particulates was presented. A numerical model of the vertical structure of two size classes of particles was developed. The results show a close similarity to the observed distributions but overestimate the particle concentration by forty percent. This was attributed to ignoring grazing by zooplankton. Sensivity analyses showed the size preference was most responsive to the maximum specific growth rates and nutrient half saturation constants. The verical structure was highly dependent on the eddy diffusivity followed closely by the growth terms.

  17. Exactly solvable model for drift of suspended ferromagnetic particles induced by the Magnus force

    Science.gov (United States)

    Denisov, S. I.; Pedchenko, B. O.; Kvasnina, O. V.; Denisova, E. S.

    2017-12-01

    The phenomenon of drift motion of single-domain ferromagnetic particles induced by the Magnus force in a viscous fluid is studied analytically. We use a minimal set of equations to describe the translational and rotational motions of these particles subjected to a harmonic force and a non-uniformly rotating magnetic field. Assuming that the azimuthal angle of the magnetic field is a periodic triangular function, we analytically solve the rotational equation of motion in the steady state and calculate the drift velocity of particles. We study in detail the dependence of this velocity on the model parameters, discuss the applicability of the drift phenomenon for separation of particles in suspensions, and verify numerically the analytical predictions.

  18. Gravity driven deterministic lateral displacement for suspended particles in a 3D obstacle array

    OpenAIRE

    Du, Siqi; Drazer, German

    2016-01-01

    We present a simple modification to enhance the separation ability of deterministic lateral displacement (DLD) systems by expanding the two-dimensional nature of these devices and driving the particles into size-dependent, fully three-dimensional trajectories. Specifically, we drive the particles through an array of long cylindrical posts, such that they not only move parallel to the basal plane of the posts as in traditional two-dimensional DLD systems (in-plane motion), but also along the a...

  19. Measurements of Plutonium and Americium in Soil Samples from Project 57 using the Suspended Soil Particle Sizing System (SSPSS)

    Energy Technology Data Exchange (ETDEWEB)

    John L. Bowen; Rowena Gonzalez; David S. Shafer

    2001-05-01

    As part of the preliminary site characterization conducted for Project 57, soils samples were collected for separation into several size-fractions using the Suspended Soil Particle Sizing System (SSPSS). Soil samples were collected specifically for separation by the SSPSS at three general locations in the deposited Project 57 plume, the projected radioactivity of which ranged from 100 to 600 pCi/g. The primary purpose in focusing on samples with this level of activity is that it would represent anticipated residual soil contamination levels at the site after corrective actions are completed. Consequently, the results of the SSPSS analysis can contribute to dose calculation and corrective action-level determinations for future land-use scenarios at the site.

  20. A new approach in the prediction of the dissolution behavior of suspended particles by means of their particle size distribution.

    NARCIS (Netherlands)

    Tinke, A.P.; Houtte, K.J.A. van; Maesschalck, R. de; Verheyen, S.; Winter, H. de

    2005-01-01

    Though various attempts have been made in literature to model the particle size distribution of an active pharmaceutical ingredient (API) in function of the required release profile of the pharmaceutical product, so far one has not succeeded to develop a universal approach in the correlation of

  1. Analysing the correlations of long-term seasonal water quality parameters, suspended solids and total dissolved solids in a shallow reservoir with meteorological factors.

    Science.gov (United States)

    Zhang, Chen; Zhang, Wenna; Huang, Yixuan; Gao, Xueping

    2017-03-01

    To explore the correlations among water quality parameters, suspended solids (SS) and total dissolved solids (TDS) with meteorological factors in a shallow reservoir in China, the long-term variations of water quality were considered. A non-parametric regression method, generalized additive models (GAM), was used to analyse the correlations among eleven physicochemical and biological parameters as well as three meteorological factors (wind speed, rainfall and solar radiation) which we collected from 2000 to 2011. The results indicate that the three meteorological factors may have positive effects on SS. Moreover, statistically significant correlations between many water quality parameters and SS or TDS were exhibited seasonally. The correlations between electrical conductivity (EC) and SS were opposite to correlations between EC and TDS. This finding reveals that TDS have a positive impact on EC, while EC negatively affects SS. The results indicated that many parameters, such as total nitrogen, total phosphorus, biological oxygen demand (BOD) and chemical oxygen demand (COD), were related to SS due to the adsorption of SS. Moreover, both positive and negative correlations between COD and TDS were observed in this freshwater reservoir. The positive correlation between chlorophyll a and SS suggested that the change of SS concentration in autumn was caused by the growth of algae. Meanwhile, significant correlations between SS and meteorological factors were also observed, indicating that meteorological factors had effects on SS dynamics. This study provides useful information regarding the correlations among water quality parameters, SS and TDS with meteorological factors in a freshwater reservoir.

  2. Fine-Grid Eulerian Simulation of Sedimenting Particles: Liquid-Solid and Gas-Solid Systems

    Science.gov (United States)

    Zaheer, Muhammad; Hamid, Adnan; Ullah, Atta

    2017-06-01

    A computational study of mono-dispersed spherical sedimenting particles was performed with Eulerian two-fluid model (TFM). The aim was to investigate the applicability and accuracy of TFM with proper closure laws from kinetic theory of granular flow (KTGF) for sedimentation studies. A three-dimensional cubical box with full periodic boundaries was employed. The volume fraction of particles (ϕs) was varied from very low (ϕs = 0.01) to dense regimes (ϕs = 0.4), for two different types of fluids, i.e., gas and liquid. It is observed that the results for liquid-solid sedimentation are in good agreement with simulation studies and experimental correlation of Richardson and Zaki. However, for gas-solid system, results show different behavior at low volume fractions, which is more pronounced with increasing Stokes number. This can be attributed to inhomogeneous distribution of solid particles in gas phase at dilute concentrations, which causes meso-scale clusters and streamers formation. It is concluded that the ratio of density of particles to density of fluid which appears in Stokes number plays critical role in settling behavior of particles.

  3. Influence of Rainfall Characteristics on Total Suspended Solids in Urban Runoff: A Case Study in Beijing, China

    Directory of Open Access Journals (Sweden)

    Yongwei Gong

    2016-07-01

    Full Text Available An urban rainfall-runoff water quality model was developed to simulate total suspend solids (TSS using the stormwater management model (SWMM for a 3.8 ha university campus in Beijing (approximately 76.5% impervious, and calibrated and validated against data from two observed rainfall events (221.2 and 16.6 mm rainfall. Model performance is satisfactory (Nash–Sutcliffe model efficiency 0.8 and 0.72 for flow and 0.74 and 0.51 for TSS concentration, respectively. A series of sensitivity model runs were conducted using the calibrated SWMM to study the influences of rainfall characteristics (rainfall hyetographs, depths and durations and surface flooding on the TSS concentration in outlet runoff of the catchment. The Pilgrim and Cordery rainfall distribution defines a first-quartile storm (the most severe and results in the highest peak discharge and TSS concentration at the outlet but the lowest outlet TSS load because of the highest TSS flood loss (32.3%. The simulated TSS pollutograph resulting from the Keifer and Chu rainfall distribution (with r = 0.5 is almost identical to that resulting from the alternating block rainfall distribution. Under the same rainfall hyetograph, simulated peak discharge and outlet TSS load are positively correlated (R2 = 0.95 to the rainfall depth as a function of the return period.

  4. Influence of sampling intake position on suspended solid measurements in sewers: two probability/time-series-based approaches.

    Science.gov (United States)

    Sandoval, Santiago; Bertrand-Krajewski, Jean-Luc

    2016-06-01

    Total suspended solid (TSS) measurements in urban drainage systems are required for several reasons. Aiming to assess uncertainties in the mean TSS concentration due to the influence of sampling intake vertical position and vertical concentration gradients in a sewer pipe, two methods are proposed: a simplified method based on a theoretical vertical concentration profile (SM) and a time series grouping method (TSM). SM is based on flow rate and water depth time series. TSM requires additional TSS time series as input data. All time series are from the Chassieu urban catchment in Lyon, France (time series from 2007 with 2-min time step, 89 rainfall events). The probability of measuring a TSS value lower than the mean TSS along the vertical cross section (TSS underestimation) is about 0.88 with SM and about 0.64 with TSM. TSM shows more realistic TSS underestimation values (about 39 %) than SM (about 269 %). Interquartile ranges (IQR) over the probability values indicate that SM is more uncertain (IQR = 0.08) than TSM (IQR = 0.02). Differences between the two methods are mainly due to simplifications in SM (absence of TSS measurements). SM assumes a significant asymmetry of the TSS concentration profile along the vertical axis in the cross section. This is compatible with the distribution of TSS measurements found in the TSM approach. The methods provide insights towards an indicator of the measurement performance and representativeness for a TSS sampling protocol.

  5. An interlaboratory study as useful tool for proficiency testing of chemical oxygen demand measurements using solid substrates and liquid samples with high suspended solid content.

    Science.gov (United States)

    Raposo, F; de la Rubia, M A; Borja, R; Alaiz, M; Beltrán, J; Cavinato, C; Clinckspoor, M; Demirer, G; Diamadopoulos, E; Helmreich, B; Jenicek, P; Martí, N; Méndez, R; Noguerol, J; Pereira, F; Picard, S; Torrijos, M

    2009-11-15

    In 2008, the first Proficiency Testing Scheme of Chemical Oxygen Demand (1(st)COD-PT(ADG)) was conducted to assess the results obtained for different research groups whose field work is mainly anaerobic digestion. This study was performed using four samples, two solid samples as raw materials and two solid samples to prepare high concentration suspended solid solutions. Invitations were sent to a large number of laboratories, mainly to anaerobic digestion research groups. Finally, thirty labs from sixteen countries agreed to participate, but for different reasons four participants could not send any data. In total, twenty-six results were reported to the COD-PT coordinator. This study showed the importance of continuous participation in proficiency testing (PT) schemes in order to compare the results obtained. Taking into account the lack of a general standard method and high quality certified reference materials (CRMs), the traceability of COD determination is not currently easy to check. In addition, the spread of participants' results obtained was high and pointed to the advisability of using consensus values due to their unreliability. Therefore, the theoretical oxygen demand (ThOD) values were considered as assigned values for all the samples analysed. On the other hand, in this PT the established standard deviation (ESD) has been determined by the Horwitz modified function. Participants of this 1(st)COD-PT(ADG) were asked to give a short report on the analytical method used. Although all the participants used potassium dichromate as their oxidant reagent, their experimental procedures were very different. With the purpose of comparing the results obtained, the different experimental conditions used were classified into five methods, corresponding to two main categories, open and closed reflux. The performance of laboratories was expressed by the z-score, whose value is considered satisfactory when z-score

  6. Effect of particle clusters on turbulence modulations in liquid flow laden with fine solid particles

    Directory of Open Access Journals (Sweden)

    Mingjun Pang

    2011-09-01

    Full Text Available Studies on particle distributions and interactions between the particles and the liquid turbulence are extremely significant and can help to improve efficiency of industrial processes and final product quality. In this paper, the particle distribution and the particle - turbulence interaction in the solid - liquid flow were investigated in detail by a numerical method. The governing equations of the liquid were solved by direct numerical simulations and the particle was tracked by Newtonian motion equations considering the effects of drag force, lift force, pressure gradient force, and virtual mass force. Two - way coupling was used to explain the effect of the particles on the turbulence. The results showed that the vortex has a great influence on the particle distribution. Most of the particles aggregate at the centre of the channel. Particle clusters along the vortex circumference modulate the development of the vortex. The turbulence modulations showed anisotropy. The Reynolds stress is slightly reduced in a broad range; the energy balance is changed; and an extra term is introduced to maintain a new energy balance.

  7. Impact of suspended inorganic particles on phosphorus cycling in the Yellow River (China).

    Science.gov (United States)

    Pan, Gang; Krom, Michael D; Zhang, Meiyi; Zhang, Xianwei; Wang, Lijing; Dai, Lichun; Sheng, Yanqing; Mortimer, Robert J G

    2013-09-03

    Phosphorus (P) in water and sediment in the Yellow River was measured for 21 stations from the source to the Bohai Sea in 2006-2007. The average total particulate matter (TPM) increased from 40 mg/L (upper reaches) to 520 mg/L (middle reaches) and 950 mg/L in the lower reaches of the river. The average dissolved PO4 concentration (0.43 μmol/L) was significantly higher than that in 1980's but lower than the world average level despite high nutrient input to the system. Much of the P input was removed by adsorption, which was due to the high TPM rather than the surface activity of the particles since they had low labile Fe and low affinity for P. The sediment was a sink for P in the middle to lower reaches but not in the upper to middle reaches. TPM has been reduced by more than an order of magnitude due to artificial dams operating over recent decades. Modeling revealed that TPM of 0.2-1 g/L was a critical threshold for the Yellow River, below which most of the phosphate input cannot be removed by the particles and may cause eutrophication. These findings are important for river management and land-ocean modeling of global biogeochemical P cycling.

  8. Homogenous Surface Nucleation of Solid Polar Stratospheric Cloud Particles

    Science.gov (United States)

    Tabazadeh, A.; Hamill, P.; Salcedo, D.; Gore, Warren J. (Technical Monitor)

    2002-01-01

    A general surface nucleation rate theory is presented for the homogeneous freezing of crystalline germs on the surfaces of aqueous particles. While nucleation rates in a standard classical homogeneous freezing rate theory scale with volume, the rates in a surface-based theory scale with surface area. The theory is used to convert volume-based information on laboratory freezing rates (in units of cu cm, seconds) of nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD) aerosols into surface-based values (in units of sq cm, seconds). We show that a surface-based model is capable of reproducing measured nucleation rates of NAT and NAD aerosols from concentrated aqueous HNO3 solutions in the temperature range of 165 to 205 K. Laboratory measured nucleation rates are used to derive free energies for NAT and NAD germ formation in the stratosphere. NAD germ free energies range from about 23 to 26 kcal mole, allowing for fast and efficient homogeneous NAD particle production in the stratosphere. However, NAT germ formation energies are large (greater than 26 kcal mole) enough to prevent efficient NAT particle production in the stratosphere. We show that the atmospheric NAD particle production rates based on the surface rate theory are roughly 2 orders of magnitude larger than those obtained from a standard volume-based rate theory. Atmospheric volume and surface production of NAD particles will nearly cease in the stratosphere when denitrification in the air exceeds 40 and 78%, respectively. We show that a surface-based (volume-based) homogeneous freezing rate theory gives particle production rates, which are (not) consistent with both laboratory and atmospheric data on the nucleation of solid polar stratospheric cloud particles.

  9. The use of hand-held 35 mm color infrared imagery for estimates of suspended solids - A progress report. [in water pollution monitoring

    Science.gov (United States)

    Miller, W. F.; Whisler, F. D.; Robinette, H. R.; Finnie, D.; Cannon, T.

    1975-01-01

    A cost-effective aerial surveillance technique is proposed for detection and identification of suspended solids which would be operational for both governmental monitoring organizations and private individuals operating catfish farms. Sixteen catfish ponds were flown daily for seven days using two hand-held 35 mm cameras with both Kodachrome X and Ektachrome infrared film. Hue, value, and chroma designations were recorded for each pond on each date by three interpreters, and the accepted color was that recorded by at least two of the interpreters, or if there was a three hue range, the median was accepted. Relations between suspended solids and color designations were analyzed graphically, and chroma was discarded due to an apparent lack of correlation. The data obtained were then analyzed by multiple regression. Significant correlations were revealed between hue and value and total and inorganic suspended solids. If perfected, this technique could be developed to sufficent accuracy for large-scale reconnaissance surveys to monitor the quality of rivers and streams.

  10. [Distributions and pollution status of heavy metals in the suspended particles of the estuaries and coastal area of eastern Hainan].

    Science.gov (United States)

    Xin, Cheng-Lin; Ren, Jing-Ling; Zhang, Gui-Ling; Shao, Ya-Ping; Zhang, Guo-Ling; Liu, Su-Mei

    2013-04-01

    The distributions and pollution status of heavy metals in the suspended particles were investigated in the Wanquan and Wenchang/Wenjiao estuaries and the coastal area of eastern Hainan in July 2008. The concentrations of metal elements (Al, Fe, Mn, Cr, Cu, Ni, V, Zn) were determined by ICP-AES after microwave digestion. Multivariate statistical methods (e. g. correlation analysis and principal factor analysis) were used to discuss the major factors controlling the variability of heavy metal concentrations and the pollution status in those areas. There was an obvious variability in particulate metal concentrations from upstream to estuary of both rivers. The concentrations first increased with increasing salinity and then decreased with further increase of the salinity; the concentrations were slightly higher at the coastal area in the east. The variability of particulate metal concentrations reduced significantly after the normalization by Al, indicating the effects of grain size. Enrichment factor calculation results showed that there was heavy metal pollution (especially Cu, Ni) in the Wenchang/Wenjiao River and estuary, while the situation in Wanquan River remained at pristine level. Concentrations of particulate metals in the study area were mainly controlled by source geology and provenance, as well as contamination from the discharge of waste water and biological activity.

  11. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)]. E-mail: anderson@ucdavis.edu; Phillips, B.M. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Hunt, J.W. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Connor, V. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Richard, N. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Tjeerdema, R.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)

    2006-06-15

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River.

  12. The Role of Cohesive Particle Interactions on Solids Uniformity and Mobilization During Jet Mixing: Testing Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A.; Wells, Beric E.; Bamberger, Judith A.; Fort, James A.; Chun, Jaehun; Jenks, Jeromy WJ

    2010-04-01

    Radioactive waste that is currently stored in large underground tanks at the Hanford Site will be staged in selected double-shell tanks (DSTs) and then transferred to the Waste Treatment and Immobilization Plant (WTP). Before being transferred, the waste will be mixed, sampled, and characterized to determine if the waste composition and meets the waste feed specifications. Washington River Protection Solutions is conducting a Tank Mixing and Sampling Demonstration Program to determine the mixing effectiveness of the current baseline mixing system that uses two jet mixer pumps and the adequacy of the planned sampling method. The overall purpose of the demonstration program is to mitigate the technical risk associated with the mixing and sampling systems meeting the feed certification requirements for transferring waste to the WTP.The purpose of this report is to analyze existing data and evaluate whether scaled mixing tests with cohesive simulants are needed to meet the overall objectives of the small-scale mixing demonstration program. This evaluation will focus on estimating the role of cohesive particle interactions on various physical phenomena that occur in parts of the mixing process. A specific focus of the evaluation will be on the uniformity of suspended solids in the mixed region. Based on the evaluation presented in this report and the absence of definitive studies, the recommendation is to conduct scaled mixing tests with cohesive particles and augment the initial testing with non-cohesive particles. In addition, planning for the quantitative tests would benefit from having test results from some scoping experiments that would provide results on the general behavior when cohesive inter-particle forces are important.

  13. suspended solids and metals

    African Journals Online (AJOL)

    33.084722,. −117.300000). Lake Ellyn. Rectangle n/a. Striegl and Cowan. (1987) ..... V pp. /D pp. (12). T o tal. TS. S. No n e. +0.86. D p p. (12). T o tal. Pb Zn. B elow m ed ian. A b o ve m ed ian. −. 0.9. 6. −. 0.82. Pb. B elo w an d ab o ve m ed ian. −.

  14. Modular compact solid-state modulators for particle accelerators

    Science.gov (United States)

    Zavadtsev, A. A.; Zavadtsev, D. A.; Churanov, D. V.

    2017-12-01

    The building of the radio frequency (RF) particle accelerator needs high-voltage pulsed modulator as a power supply for klystron or magnetron to feed the RF accelerating system. The development of a number of solid-state modulators for use in linear accelerators has allowed to develop a series of modular IGBT based compact solid-state modulators with different parameters. This series covers a wide range of needs in accelerator technology to feed a wide range of loads from the low power magnetrons to powerful klystrons. Each modulator of the series is built on base of a number of unified solid-state modules connected to the pulse transformer, and covers a wide range of modulators: voltage up to 250 kV, a peak current up to 250 A, average power up to 100 kW and the pulse duration up to 20 μsec. The parameters of the block with an overall dimensions 880×540×250 mm are: voltage 12 kV, peak current 1600 A, pulse duration 20 μsec, average power 10 kW with air-cooling and 40 kW with liquidcooling. These parameters do not represent a physical limit, and modulators to parameters outside these ranges can be created on request.

  15. Longitudinal trends and discontinuities in nutrients, chlorophyll, and suspended solids in the Upper Mississippi River: Implications for transport, processing, and export by large rivers

    Science.gov (United States)

    Houser, J.N.; Bierman, D.W.; Burdis, R.M.; Soeken-Gittinger, L. A.

    2010-01-01

    Across the distances spanned by large rivers, there are important differences in catchment characteristics, tributary inputs, and river morphology that may cause longitudinal changes in nutrient, chlorophyll, and suspended solids concentrations. We investigated longitudinal and seasonal patterns in the Upper Mississippi River (UMR) using long-term data (1994-2005) from five study reaches that spanned 1300 km of the UMR. Lake Pepin, a natural lake in the most upstream study reach, had a clear effect on suspended material in the river. Suspended solids and total phosphorus (TP) concentrations were substantially lower downstream of the lake and percent organic material (OM%) in suspension was higher. Below L. Pepin, mean total and organic suspended solids (TSS, OSS) and TP increased downriver and exhibited approximately log-linear relationships with catchment area, whereas OM% declined substantially downriver. Despite the downriver increase in TSS and OSS, concentrations similar to those above L. Pepin do not occur until ~370 km downriver indicating the extent of the influence of L. Pepin on the UMR. Chlorophyll concentrations were lower in the most downstream study reach, likely reflecting the shorter residence time and poor light climate, but there was not a consistent longitudinal decline in chlorophyll across the study reaches. Dissolved silica (DSi), DSi:TN, and DSi:TP declined downriver suggesting that DSi uptake and sedimentation by river phytoplankton may be reducing DSi transport in the river, and indicating that the eutrophication of the river may contribute to a reduction of DSi export to the Gulf of Mexico. ?? 2010 US Government: USGS.

  16. Transformation and sorption of illicit drug biomarkers in sewer systems: understanding the role of suspended solids in raw wastewater

    DEFF Research Database (Denmark)

    Ramin, Pedram; Brock, Andreas Libonati; Polesel, Fabio

    2016-01-01

    substrates (primary metabolic processes) and transformation of illicit drug biomarkers (secondary metabolic processes) by suspended biomass. Sixteen drug biomarkers were targeted, including mephedrone, methadone, cocaine, heroin, codeine and tetrahydrocannabinol (THC) and their major human metabolites. Batch...

  17. Measurements of solids concentration and axial solids velocity in gas-solid two-phase flows.

    NARCIS (Netherlands)

    Nieuwland, J.J.; Nieuwland, J.J.; Meijer, R.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    1996-01-01

    Several techniques reported in the literature for measuring solids concentration and solids velocity in (dense) gas-solid two-phase flow have been briefly reviewed. An optical measuring system, based on detection of light reflected by the suspended particles, has been developed to measure local

  18. Nutrients and Suspended Solids in Surface Waters of the Upper Illinois River Basin in Illinois, Indiana, and Wisconsin, 1978-97

    Science.gov (United States)

    Sullivan, Daniel J.

    2000-01-01

    A retrospective analysis of selected data on nutrients and suspended solids in surface waters of the upper Illinois River Basin was done as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program. Approximately 91 percent of the upper Illinois River Basin is drained by three principal rivers: the Kankakee (and its major tributary, the Iroquois), the Des Plaines, and the Fox. The data analyzed were collected by the Illinois Environmental Protection Agency (IEPA), which operates 39 monitoring sites in the study area as part of its Ambient Water-Quality Monitoring Network, and included analyses for total ammonia nitrogen, total nitriteplus- nitrate nitrogen, total ammonia-plus-organic (total Kjeldahl) nitrogen, dissolved and total phosphorus, and total suspended solids and volatile solids. Nutrient and suspended-sediment data collected by the USGS as part of the upper Illinois River Basin NAWQA pilot study from 1987-90 were compared to IEPA data. For the 1978-97 period, in general, nutrient concentrations, with the exception of nitrate, were highest at streams in the urban areas of the Des Plaines River Basin. Streams in the Kankakee and Fox River Basins generally had lower concentrations, although the data indicate that concentrations increased in a downstream direction in these basins. These spatial patterns in nutrient concentrations correspond closely with land use in the respective basins. The elevated concentrations of ammonia and phosphorus in the urbanized Des Plaines River Basin, with respect to other sites in the study area, indicate that municipal- and industrial- waste discharges into streams of the basin increase concentrations of these nutrients in the receiving streams. In contrast, nitrate concentrations were highest in agricultural areas. Relatively large ratios of nitrogen to phosphorus and nitrate to ammonia are characteristic of agricultural drainage. On the other hand, urban tributaries were characterized by

  19. Removal of Cs{sup +}, Sr{sup 2+}, and Co{sup 2+} ions from the mixture of organics and suspended solids aqueous solutions by zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Xiang Hong; Fang, Fang; Lu, Chun Hai [College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu (China); Zheng, Lei [Southwest University of Science and Technology, Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Mianyang (China)

    2017-04-15

    Serving as an excellent adsorbent and inorganic ion exchanger in the water purification field, zeolite 4A has in this work presented a strong capability for purifying radioactive waste, such as Sr{sup 2+}, Cs{sup +}, and Co{sup 2+} in water. During the processes of decontamination and decommissioning of suspended solids and organics in low-level radioactive wastewater, the purification performance of zeolite 4A has been studied. Under ambient temperature and neutral condition, zeolite 4A absorbed simulated radionuclides such as Sr{sup 2+}, Cs{sup +}, and Co{sup 2+} with an absorption rate of almost 90%. Additionally, in alkaline condition, the adsorption percentage even approached 98.7%. After conducting research on suspended solids and organics of zeolite 4A for the treatment of radionuclides, it was found that the suspended clay was conducive to absorption, whereas the absorption of organics in solution was determined by the species of radionuclides and organics. Therefore, zeolite 4A has considerable potential in the treatment of radioactive wastewater.

  20. Removal of Cs+, Sr2+, and Co2+ Ions from the Mixture of Organics and Suspended Solids Aqueous Solutions by Zeolites

    Directory of Open Access Journals (Sweden)

    Xiang-Hong Fang

    2017-04-01

    Full Text Available Serving as an excellent adsorbent and inorganic ion exchanger in the water purification field, zeolite 4A has in this work presented a strong capability for purifying radioactive waste, such as Sr2+, Cs+, and Co2+ in water. During the processes of decontamination and decommissioning of suspended solids and organics in low-level radioactive wastewater, the purification performance of zeolite 4A has been studied. Under ambient temperature and neutral condition, zeolite 4A absorbed simulated radionuclides such as Sr2+, Cs+, and Co2+ with an absorption rate of almost 90%. Additionally, in alkaline condition, the adsorption percentage even approached 98.7%. After conducting research on suspended solids and organics of zeolite 4A for the treatment of radionuclides, it was found that the suspended clay was conducive to absorption, whereas the absorption of organics in solution was determined by the species of radionuclides and organics. Therefore, zeolite 4A has considerable potential in the treatment of radioactive wastewater.

  1. Automatic Extraction of Ferromagnetic Particle from Non-homogeneous Solid-Solid Mixture

    Directory of Open Access Journals (Sweden)

    Farhad Ismail

    2011-12-01

    Full Text Available Separation of magnetic particles in sand processing is very important for many industrial purposes. This paper presents an automation process to separate the magnetic particles from a non-homogeneous solid-solid mixture (sea sand. Here a magnetic force is created by changing the electric field and thus the particles are separated from the mixture of sand automatically. Here such a simple and cost effective design is prsented which can automatically take the the mixture as input and give the refined and separated product as output continuously. ABSTRAK : Pengasingan zarah-zarah bermagnet dalam pemprosesan pasir penting untuk pelbagai tujuan industri. Kertas ini membentangkan proses pengautomatikan untuk mengasingkan butir-butir bermagnet dari pepejal tak homogen - campuran pepejal (pasir pantai. Di sini, daya magnet dihasilkan dengan menukarkan medan elektrik dan seterusnya butir-butir ini terasing daripada campuran pasir dengan sendirinya. Kaedah yang mudah dan rekaan keberkesanan kos ini secara langsung mengambil campuran tersebut sebagai input dan memberikan hasil bertapis dan terpisah sebagai output dengan berterusan.

  2. Particle engineering in pharmaceutical solids processing: surface energy considerations.

    Science.gov (United States)

    Williams, Daryl R

    2015-01-01

    During the past 10 years particle engineering in the pharmaceutical industry has become a topic of increasing importance. Engineers and pharmacists need to understand and control a range of key unit manufacturing operations such as milling, granulation, crystallisation, powder mixing and dry powder inhaled drugs which can be very challenging. It has now become very clear that in many of these particle processing operations, the surface energy of the starting, intermediate or final products is a key factor in understanding the processing operation and or the final product performance. This review will consider the surface energy and surface energy heterogeneity of crystalline solids, methods for the measurement of surface energy, effects of milling on powder surface energy, adhesion and cohesion on powder mixtures, crystal habits and surface energy, surface energy and powder granulation processes, performance of DPI systems and finally crystallisation conditions and surface energy. This review will conclude that the importance of surface energy as a significant factor in understanding the performance of many particulate pharmaceutical products and processes has now been clearly established. It is still nevertheless, work in progress both in terms of development of methods and establishing the limits for when surface energy is the key variable of relevance.

  3. A new device to measure the settling properties of suspended particles : instrumental development and first applications during runoff events in small watersheds

    Science.gov (United States)

    Legoût, Cédric; Wendling, Valentin; Gratiot, Nicolas; Mercier, Bernard; Coulaud, Catherine; Nord, Guillaume; Droppo, Ian; Ribolzi, Olivier

    2016-04-01

    Most equations describing suspended particle transport balances the settling flux of particles against the turbulent flux of the flow. Although in-situ techniques have been developed to measure settling velocities of suspended particles in coastal areas, floodplain rivers and estuaries, they are not easily transferable to small and meso-scale watersheds. The main limitation lies in the range of concentrations frequently reaching several tens of grams per liter during runoff events. To overcome this instrumental limitation we developed an original System for the Characterization of Aggregates and Flocs (SCAF). An optical settling column, equipped with a vertical array of 16 optical sensors, was used to provide light transmission through a suspension during quiescent settling. It was specifically designed to be inserted in plastic bottles contained in classical sequential samplers, in order to obtain automatic measurements of the suspension immediately after its collection in the river. From the SCAF measurements, we calculate both the particle settling velocity distributions and the propensity of particles to flocculate. The prototypes were tested in laboratory conditions for a wide range of concentrations and material types, leading to consistent measurements with flocculation indices comprised between 0 and 80, respectively for non-cohesive and cohesive materials. First measurements in the field were achieved during runoff events at the outlet of small nested catchments in Lao PDR (MSEC network of environmental observatories) in order to explore the non-conservative behavior of the settling properties of eroded soil aggregates during their transfer.

  4. An investigation into the effectiveness of sand media amended with biochar to remove BOD5, suspended solids and coliforms using wetland mesocosms.

    Science.gov (United States)

    de Rozari, P; Greenway, M; El Hanandeh, A

    2015-01-01

    Constructed wetland ecotechnologies (CWEs) are a promising solution to effectively treat domestic wastewater in developing countries at low cost. This paper reports the findings of the effectiveness of sand media amended with woody biochar and two plants species (Melaleuca quinquenervia and Cymbopogon citratus) in removing biological oxygen demand (BOD5), suspended solids and coliforms. The experimental design consisted of 21 vertical flow (VF) mesocosms. There were seven media treatments using sand amended with varying proportions of biochar. During the first 8 months, the mesocosms were loaded with secondary clarified wastewater (SCW) then septage. The influent had a 4-day hydraulic retention time. Samples were monitored for BOD5, total suspended solids (TSS), total volatile solids (TVS), total coliforms and faecal coliforms. In the first 8 months, there were no significant performance differences between media treatments in the outflow concentrations of BOD5, TSS and TVS. The significant differences occurred during the last 3 months; using septage with biochar additions performed better than pure sand. For coliforms, the significant differences occurred after 6 months. In conclusion, the addition of biochar was not effective for SCW. The VF mesocosms system proved to be more effective in removing BOD5, TSS, TVS and coliforms when septage was loaded into the media.

  5. The Applicability of the Distribution Coefficient, KD, Based on Non-Aggregated Particulate Samples from Lakes with Low Suspended Solids Concentrations.

    Directory of Open Access Journals (Sweden)

    Aine Marie Gormley-Gallagher

    Full Text Available Separate phases of metal partitioning behaviour in freshwater lakes that receive varying degrees of atmospheric contamination and have low concentrations of suspended solids were investigated to determine the applicability of the distribution coefficient, KD. Concentrations of Pb, Ni, Co, Cu, Cd, Cr, Hg and Mn were determined using a combination of filtration methods, bulk sample collection and digestion and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS. Phytoplankton biomass, suspended solids concentrations and the organic content of the sediment were also analysed. By distinguishing between the phytoplankton and (inorganic lake sediment, transient variations in KD were observed. Suspended solids concentrations over the 6-month sampling campaign showed no correlation with the KD (n = 15 for each metal, p > 0.05 for Mn (r2 = 0.0063, Cu (r2 = 0.0002, Cr (r2 = 0.021, Ni (r2 = 0.0023, Cd (r2 = 0.00001, Co (r2 = 0.096, Hg (r2 = 0.116 or Pb (r2 = 0.164. The results implied that colloidal matter had less opportunity to increase the dissolved (filter passing fraction, which inhibited the spurious lowering of KD. The findings conform to the increasingly documented theory that the use of KD in modelling may mask true information on metal partitioning behaviour. The root mean square error of prediction between the directly measured total metal concentrations and those modelled based on the separate phase fractions were ± 3.40, 0.06, 0.02, 0.03, 0.44, 484.31, 80.97 and 0.1 μg/L for Pb, Cd, Mn, Cu, Hg, Ni, Cr and Co respectively. The magnitude of error suggests that the separate phase models for Mn and Cu can be used in distribution or partitioning models for these metals in lake water.

  6. The Applicability of the Distribution Coefficient, KD, Based on Non-Aggregated Particulate Samples from Lakes with Low Suspended Solids Concentrations.

    Science.gov (United States)

    Gormley-Gallagher, Aine Marie; Douglas, Richard William; Rippey, Brian

    2015-01-01

    Separate phases of metal partitioning behaviour in freshwater lakes that receive varying degrees of atmospheric contamination and have low concentrations of suspended solids were investigated to determine the applicability of the distribution coefficient, KD. Concentrations of Pb, Ni, Co, Cu, Cd, Cr, Hg and Mn were determined using a combination of filtration methods, bulk sample collection and digestion and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Phytoplankton biomass, suspended solids concentrations and the organic content of the sediment were also analysed. By distinguishing between the phytoplankton and (inorganic) lake sediment, transient variations in KD were observed. Suspended solids concentrations over the 6-month sampling campaign showed no correlation with the KD (n = 15 for each metal, p > 0.05) for Mn (r2 = 0.0063), Cu (r2 = 0.0002, Cr (r2 = 0.021), Ni (r2 = 0.0023), Cd (r2 = 0.00001), Co (r2 = 0.096), Hg (r2 = 0.116) or Pb (r2 = 0.164). The results implied that colloidal matter had less opportunity to increase the dissolved (filter passing) fraction, which inhibited the spurious lowering of KD. The findings conform to the increasingly documented theory that the use of KD in modelling may mask true information on metal partitioning behaviour. The root mean square error of prediction between the directly measured total metal concentrations and those modelled based on the separate phase fractions were ± 3.40, 0.06, 0.02, 0.03, 0.44, 484.31, 80.97 and 0.1 μg/L for Pb, Cd, Mn, Cu, Hg, Ni, Cr and Co respectively. The magnitude of error suggests that the separate phase models for Mn and Cu can be used in distribution or partitioning models for these metals in lake water.

  7. Nature of suspended particles in hydrothermal plume at 3°40'N Carlsberg ridge: A comparison with deep oceanic suspended matter

    Digital Repository Service at National Institute of Oceanography (India)

    Ray, D.; Babu, E.V.S.S.K.; SuryaPrakash, L.

    the plume. Concentration of particulate Mn is similar to that reported in Gorda Ridge plumes (0.76–1.66 nmol/l)3, but higher than Carlsberg event plume (0.46 nmol/l)9 or Rain- bow plume particulates (<0.5 nmol/l)4. Dissolved Mn in hydrothermal plume...-Sea Res. II, 1998, 45, 2637–2664. 4. Edmond, H. N. and German, C. R., Particle geochemistry of Rain- bow hydrothermal plume; Mid-Atlantic Ridge. Geochim. Cosmo- chim. Acta, 2004, 68, 759–772. 5. Lerche, D. and Nozaki, Y., Rare earth elements of sinking...

  8. A Landsat-based model for retrieving total suspended solids concentration of estuaries and coasts in China

    Science.gov (United States)

    Wang, Chongyang; Chen, Shuisen; Li, Dan; Wang, Danni; Liu, Wei; Yang, Ji

    2017-11-01

    Retrieving total suspended solids (TSS) concentration accurately is essential for sustainable management of estuaries and coasts, which plays a key role in the interaction between hydrosphere, pedosphere and atmosphere. Although many TSS retrieval models have been published, the general inversion method that is applicable to different field conditions is still under research. In order to obtain a TSS remote sensing model that is suitable for estimating TSS concentrations with wide range in estuaries and coasts by Landsat imagery, after reviewing a number of Landsat-based TSS retrieval models and improving a comparatively better one among them, this study developed a quadratic model using the ratio of logarithmic transformation of red band and near-infrared band and logarithmic transformation of TSS concentration (QRLTSS) based on 119 in situ samples collected in 2006-2013 from five regions of China. It was found that the QRLTSS model works well and shows a satisfactory performance. The QRLTSS model based on Landsat TM (Thematic Mapper), ETM+ (Enhanced Thematic Mapper Plus) and OLI (Operational Land Imager) sensors explained about 72 % of the TSS concentration variation (TSS: 4.3-577.2 mg L-1, N = 84, P value proposed to solve the two-valued issue of the QRLTSS model and to retrieve TSS concentration from Landsat imagery. After a 6S model-based atmospheric correction of Landsat OLI and ETM+ imagery, the TSS concentrations of three regions (Moyangjiang River estuary, Pearl River estuary and Hanjiang River estuary) in Guangdong Province in China were mapped by the QRLTSS model. The results indicated that TSS concentrations in the three estuaries showed large variation ranging from 0.295 to 370.4 mg L-1. Meanwhile we found that TSS concentrations retrieved from Landsat imagery showed good validation accuracies with the synchronous water samples (TSS: 7-160 mg L-1, RMSE: 11.06 mg L-1, N = 22). The further validation from EO-1 Hyperion imagery also showed good

  9. Effect of particle shape on the random packing density of amorphous solids

    NARCIS (Netherlands)

    Kyrylyuk, A.V.|info:eu-repo/dai/nl/269067590; Philipse, A.P.|info:eu-repo/dai/nl/073532894

    2011-01-01

    The packing density of a particulate solid strongly depends on the shape of the particles that are jammed at random close packing (RCP). To investigate the effect of particle shape on the RCP density of an amorphous solid, we studied jammed packings of binary mixtures of a-thermal or granular

  10. Modeling the optical properties of mineral particles suspended in seawater and their influence on ocean reflectance and chlorophyll estimation from remote sensing algorithms.

    Science.gov (United States)

    Woźniak, Sławomir B; Stramski, Dariusz

    2004-06-10

    The optical properties of mineral particles suspended in seawater were calculated from the Mie scattering theory for different size distributions and complex refractive indices of the particles. The ratio of the spectral backscattering coefficient to the sum of the spectral absorption and backscattering coefficients of seawater, b(b)(lambda)/[a(lambda) + b(b)(lambda)], was analyzed as a proxy for ocean reflectance for varying properties and concentrations of mineral particles. Given the plausible range of variability in the particle size distribution and the refractive index, the general parameterizations of the absorption and scattering properties of mineral particles and their effects on ocean reflectance in terms of particle mass concentration alone are inadequate. The variations in the particle size distribution and the refractive index must be taken into account. The errors in chlorophyll estimation obtained from the remote sensing algorithms that are due to the presence of mineral particles can be very large. For example, when the mineral concentration is 1 g m(-3) and the chlorophyll a concentration is low (0.05 mg m(-3)), current global algorithms based on a blue-to-green reflectance ratio can produce a chlorophyll overestimation ranging from approximately 50% to as much as 20-fold.

  11. Remote sensing and water quality indicators in the Korean West coast: Spatio-temporal structures of MODIS-derived chlorophyll-a and total suspended solids.

    Science.gov (United States)

    Kim, Hae-Cheol; Son, Seunghyun; Kim, Yong Hoon; Khim, Jong Seong; Nam, Jungho; Chang, Won Keun; Lee, Jung-Ho; Lee, Chang-Hee; Ryu, Jongseong

    2017-08-15

    The Yellow Sea is a shallow marginal sea with a large tidal range. In this study, ten areas located along the western coast of the Korean Peninsula are investigated with respect to remotely sensed water quality indicators derived from NASA MODIS aboard of the satellite Aqua. We found that there was a strong seasonal trend with spatial heterogeneity. In specific, a strong six-month phase-lag was found between chlorophyll-a and total suspended solid owing to their inversed seasonality, which could be explained by different dynamics and environmental settings. Chlorophyll-a concentration seemed to be dominantly influenced by temperature, while total suspended solid was largely governed by local tidal forcing and bottom topography. This study demonstrated the potential and applicability of satellite products in coastal management, and highlighted find that remote-sensing would be a promising tool in resolving orthogonality of large spatio-temporal scale variabilities when combining with proper time series analyses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Circular motion of particles suspended in a Gaussian beam with circular polarization validates the spin part of the internal energy flow.

    Science.gov (United States)

    Angelsky, O V; Bekshaev, A Ya; Maksimyak, P P; Maksimyak, A P; Mokhun, I I; Hanson, S G; Zenkova, C Yu; Tyurin, A V

    2012-05-07

    Non-spherical dielectric microparticles were suspended in a water-filled cell and exposed to a coherent Gaussian light beam with controlled state of polarization. When the beam polarization is linear, the particles were trapped at certain off-axial position within the beam cross section. After switching to the right (left) circular polarization, the particles performed spinning motion in agreement with the angular momentum imparted by the field, but they were involved in an orbital rotation around the beam axis as well, which in previous works [Y. Zhao et al, Phys. Rev. Lett. 99, 073901 (2007)] was treated as evidence for the spin-to orbital angular momentum conversion. Since in our realization the moderate focusing of the beam excluded the possibility for such a conversion, we consider the observed particle behavior as a demonstration of the macroscopic "spin energy flow" predicted by the theory of inhomogeneously polarized paraxial beams [A. Bekshaev et al, J. Opt. 13, 053001 (2011)].

  13. Concentration, flux, and trend estimates with uncertainty for nutrients, chloride, and total suspended solids in tributaries of Lake Champlain, 1990–2014

    Science.gov (United States)

    Medalie, Laura

    2016-12-20

    The U.S. Geological Survey, in cooperation with the New England Interstate Water Pollution Control Commission and the Vermont Department of Environmental Conservation, estimated daily and 9-month concentrations and fluxes of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids from 1990 (or first available date) through 2014 for 18 tributaries of Lake Champlain. Estimates of concentration and flux, provided separately in Medalie (2016), were made by using the Weighted Regressions on Time, Discharge, and Season (WRTDS) regression model and update previously published WRTDS model results with recent data. Assessment of progress towards meeting phosphorus-reduction goals outlined in the Lake Champlain management plan relies on annual estimates of phosphorus flux. The percent change in annual concentration and flux is provided for two time periods. The R package EGRETci was used to estimate the uncertainty of the trend estimate. Differences in model specification and function between this study and previous studies that used WRTDS to estimate concentration and flux using data from Lake Champlain tributaries are described. Winter data were too sparse and nonrepresentative to use for estimates of concentration and flux but were sufficient for estimating the percentage of total annual flux over the period of record. Median winter-to-annual fractions ranged between 21 percent for total suspended solids and 27 percent for dissolved phosphorus. The winter contribution was largest for all constituents from the Mettawee River and smallest from the Ausable River. For the full record (1991 through 2014 for total and dissolved phosphorus and chloride and 1993 through 2014 for nitrogen and total suspended solids), 6 tributaries had decreasing trends in concentrations of total phosphorus, and 12 had increasing trends; concentrations of dissolved phosphorus decreased in 6 and increased in 8 tributaries; fluxes of total phosphorus decreased in 5 and

  14. Gravitational sedimentation of cloud of solid spherical particles at small Reynolds numbers

    Directory of Open Access Journals (Sweden)

    Arkhipov Vladimir

    2015-01-01

    Full Text Available The experimental results of study of gravitational sedimentation of highly-concentrated systems of solid spherical particles at small Reynolds numbers Re<1 are presented. Empirical equation for drag coefficient of the particle assembly has been obtained. The influence of initial particle concentration in the cloud on its dynamics and velocity has been analysed.

  15. Predicting the Agglomeration of Cohesive Particles in a Gas-Solid Flow and its Effect on the Solids Flow

    Science.gov (United States)

    Kellogg, Kevin; Liu, Peiyuan; Lamarche, Casey; Hrenya, Christine

    2017-11-01

    In flows of cohesive particles, agglomerates will readily form and break. These agglomerates are expected to complicate how particles interact with the surrounding fluid in multiphase flows, and consequently how the solids flow. In this work, a dilute flow of particles driven by gas against gravity is studied. A continuum framework, composed of a population balance to predict the formation of agglomerates, and kinetic-theory-based balances, is used to predict the flow of particles. The closures utilized for the birth and death rates due to aggregation and breakage in the population balance take into account how the impact velocity (the granular temperature) affects the outcome of a collision as aggregation, rebound, or breakage. The agglomerate size distribution and solids velocity predicted by the continuum framework are compared to discrete element method (DEM) simulations, as well to experimental results of particles being entrained from the riser of a fluidized bed. Dow Corning Corporation.

  16. Suspended-sediment concentrations, bedload, particle sizes, surrogate measurements, and annual sediment loads for selected sites in the lower Minnesota River Basin, water years 2011 through 2016

    Science.gov (United States)

    Groten, Joel T.; Ellison, Christopher A.; Hendrickson, Jon S.

    2016-12-20

    Accurate measurements of fluvial sediment are important for assessing stream ecological health, calculating flood levels, computing sediment budgets, and managing and protecting water resources. Sediment-enriched rivers in Minnesota are a concern among Federal, State, and local governments because turbidity and sediment-laden waters are the leading impairments and affect more than 6,000 miles of rivers in Minnesota. The suspended sediment in the lower Minnesota River is deleterious, contributing about 75 to 90 percent of the suspended sediment being deposited into Lake Pepin. The Saint Paul District of the U.S. Army Corps of Engineers and the Lower Minnesota River Watershed District collaborate to maintain a navigation channel on the lower 14.7 miles of the Minnesota River through scheduled dredging operations. The Minnesota Pollution Control Agency has adopted a sediment-reduction strategy to reduce sediment in the Minnesota River by 90 percent by 2040.The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, the Minnesota Pollution Control Agency, and the Lower Minnesota River Watershed District, collected suspended-sediment, bedload, and particle-size samples at five sites in the lower Minnesota River Basin during water years 2011 through 2014 and surrogate measurements of acoustic backscatter at one of these sites on the lower Minnesota River during water years 2012 through 2016 to quantify sediment loads and improve understanding of sediment-transport relations. Annual sediment loads were computed for calendar years 2011 through 2014.Data collected from water years 2011 through 2014 indicated that two tributaries, Le Sueur River and High Island Creek, had the highest sediment yield and concentrations of suspended sediment. These tributaries also had greater stream gradients than the sites on the Minnesota River. Suspended fines were greater than suspended sand at all sites in the study area. The range of median particle sizes matched

  17. Activating Molecules, Ions, and Solid Particles with Acoustic Cavitation

    Science.gov (United States)

    Pflieger, Rachel; Chave, Tony; Virot, Matthieu; Nikitenko, Sergey I.

    2014-01-01

    The chemical and physical effects of ultrasound arise not from a direct interaction of molecules with sound waves, but rather from the acoustic cavitation: the nucleation, growth, and implosive collapse of microbubbles in liquids submitted to power ultrasound. The violent implosion of bubbles leads to the formation of chemically reactive species and to the emission of light, named sonoluminescence. In this manuscript, we describe the techniques allowing study of extreme intrabubble conditions and chemical reactivity of acoustic cavitation in solutions. The analysis of sonoluminescence spectra of water sparged with noble gases provides evidence for nonequilibrium plasma formation. The photons and the "hot" particles generated by cavitation bubbles enable to excite the non-volatile species in solutions increasing their chemical reactivity. For example the mechanism of ultrabright sonoluminescence of uranyl ions in acidic solutions varies with uranium concentration: sonophotoluminescence dominates in diluted solutions, and collisional excitation contributes at higher uranium concentration. Secondary sonochemical products may arise from chemically active species that are formed inside the bubble, but then diffuse into the liquid phase and react with solution precursors to form a variety of products. For instance, the sonochemical reduction of Pt(IV) in pure water provides an innovative synthetic route for monodispersed nanoparticles of metallic platinum without any templates or capping agents. Many studies reveal the advantages of ultrasound to activate the divided solids. In general, the mechanical effects of ultrasound strongly contribute in heterogeneous systems in addition to chemical effects. In particular, the sonolysis of PuO2 powder in pure water yields stable colloids of plutonium due to both effects. PMID:24747272

  18. Evaluating Suspended Particles Concentration of the Inside and Outside Air of the Classroom and Its Influencing Factors in Middle schools and High Schools of Yazd

    Directory of Open Access Journals (Sweden)

    MH Ehrampoosh

    2015-11-01

    Full Text Available Abstract Introduction: Airborne pollution in such public environments as schools has adverse health effects on pupils and teachers who spend a noticeable amount of time in the school. Therefore, this study aimed to measure the suspended particles concentration of indoor and outdoor air of Yazd schools as well as to determine the influencing parameters on the pollution intensity. Methods: This analytical cross-sectional study was conducted in 20 middle-schools and high schools of males and females in winter of 2013. The environmental aerosol monitoring device, (HAZ-DUST EPAM5000 model was used to measure the concentration of PM1, PM2.5 and PM10. The study data were analyzed via applying correlation, simple linear regression and means comparison tests. Moreover, the study results were compared with the standards of World health organization(WHO and Environmental Health Organization(EPA. Results: The mean concentration of PM10, PM2.5 and PM1 in indoor class air was reported higher compared to the outdoor air. The indoor and outdoor air quality of schools in terms of Air Quality Index9 (AQI Calculator indicated an average condition for PM10, and an unhealthy condition for PM2.5 in regard with the vulnerable groups. A significant relationship was detected between indoor and outdoor air concentration particles (P<0.05. The mean indoor per outdoor air particles ratio (I/O was 1.68, 1.31, 1.46 respectively for PM10, PM2.5, PM1. Conclusion: The study findings revealed a significant relationship between indoor and outdoor suspended particle concentration demonstrating the particles penetration into the classrooms. Therefore, utilizing appropriate air conditioner systems are regarded effective in order to mitigate indoor class pollution.  

  19. [Effect of stability and dissolution of realgar nano-particles using solid dispersion technology].

    Science.gov (United States)

    Guo, Teng; Shi, Feng; Yang, Gang; Feng, Nian-Ping

    2013-09-01

    To improve the stability and dissolution of realgar nano-particles by solid dispersion. Using polyethylene glycol 6000 and poloxamer-188 as carriers, the solid dispersions were prepare by melting method. XRD, microscopic inspection were used to determine the status of realgar nano-particles in solid dispersions. The content and stability test of As(2)0(3) were determined by DDC-Ag method. Hydride generation atomic absorption spectrometry was used to determine the content of Arsenic and investigated the in vitro dissolution behavior of solid dispersions. The results of XRD and microscopic inspection showed that realgar nano-particles in solid dispersions were amorphous. The dissolution amount and rate of Arsenic from realgar nano-particles of all solid dispersions were increased significantly, the reunion of realgar nano-particles and content of As(2)0(3) were reduced for the formation of solid dispersions. The solid dispersion of realgar nano-particles with poloxamer-188 as carriers could obviously improve stability, dissolution and solubility.

  20. Role of microbial Fe(III) reduction and solution chemistry in aggregation and settling of suspended particles in the Mississippi River Delta plain, Louisiana, USA

    Science.gov (United States)

    Jaisi, D.P.; Ji, S.; Dong, H.; Blake, R.E.; Eberl, D.D.; Kim, J.

    2008-01-01

    River-dominated delta areas are primary sites of active biogeochemical cycling, with productivity enhanced by terrestrial inputs of nutrients. Particle aggregation in these areas primarily controls the deposition of suspended particles, yet factors that control particle aggregation and resulting sedimentation in these environments are poorly understood. This study was designed to investigate the role of microbial Fe(III) reduction and solution chemistry in aggregation of suspended particles in the Mississippi Delta. Three representative sites along the salinity gradient were selected and sediments were collected from the sediment-water interface. Based on quantitative mineralogical analyses 88-89 wt.% of all minerals in the sediments are clays, mainly smectite and illite. Consumption of SO421 and the formation of H2S and pyrite during microbial Fe(III) reduction of the non-sterile sediments by Shewanella putrefaciens CN32 in artificial pore water (APW) media suggest simultaneous sulfate and Fe(III) reduction activity. The pHPZNPC of the sediments was ??? 3.5 and their zeta potentials at the sediment-water interface pH (6.9-7.3) varied from -35 to -45 mV, suggesting that both edges and faces of clay particles have negative surface charge. Therefore, high concentrations of cations in pore water are expected to be a predominant factor in particle aggregation consistent with the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Experiments on aggregation of different types of sediments in the same APW composition revealed that the sediment with low zeta potential had a high rate of aggregation. Similarly, addition of external Fe(II) (i.e. not derived from sediments) was normally found to enhance particle aggregation and deposition in all sediments, probably resulting from a decrease in surface potential of particles due to specific Fe(II) sorption. Scanning and transmission electron microscopy (SEM, TEM) images showed predominant face-to-face clay aggregation in native

  1. Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples

    Science.gov (United States)

    Czuba, Jonathan A.; Straub, Timothy D.; Curran, Christopher A.; Landers, Mark N.; Domanski, Marian M.

    2015-01-01

    Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In-Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8-415 µm in 32 log-spaced size classes. Measured SSCs and PSDs from the LISST-SL were compared to a suite of 22 datasets (262 samples in all) of concurrent suspended-sediment and streamflow measurements using a physical sampler and acoustic Doppler current profiler collected during 2010-12 at 16 U.S. Geological Survey streamflow-gaging stations in Illinois and Washington (basin areas: 38 – 69,264 km2). An unrealistically low computed effective density (mass SSC / volumetric SSC) of 1.24 g/ml (95% confidence interval: 1.05-1.45 g/ml) provided the best-fit value (R2 = 0.95; RMSE = 143 mg/L) for converting volumetric SSC to mass SSC for over 2 orders of magnitude of SSC (12-2,170 mg/L; covering a substantial range of SSC that can be measured by the LISST-SL) despite being substantially lower than the sediment particle density of 2.67 g/ml (range: 2.56-2.87 g/ml, 23 samples). The PSDs measured by the LISST-SL were in good agreement with those derived from physical samples over the LISST-SL's measureable size range. Technical and operational limitations of the LISST-SL are provided to facilitate the collection of more accurate data in the future. Additionally, the spatial and temporal variability of SSC and PSD measured by the LISST-SL is briefly described to motivate its potential for advancing our understanding of suspended-sediment transport by rivers.

  2. Experimental investigation of evaporation enhancement for water droplet containing solid particles in flaming combustion area

    Directory of Open Access Journals (Sweden)

    Glushkov Dmitrii O.

    2016-01-01

    Full Text Available The experimental study of integral characteristics of extinguishing liquid (water droplet evaporation in flaming combustion area has been held. Optical methods of two-phase and heterogeneous mixtures diagnostics (“Particle Image Velocimetry” and “Interferometric Particle Imaging” have been used for heat and mass transfer process investigation. It was established that small-size solid particles (for example, carbon particles in droplet structure can enhance water evaporation in flame area. It was shown that the rate of evaporation process depends on concentration and sizes of solid particles in a water droplet. The correlations have been determined between the sizes of solid particles and water droplets for maximum efficiency of fire extinguishing. The physical aspects of the problem have been discussed.

  3. Concentration of lead, cadmium, and iron in sediment dust and total suspended particles before and after initialisation of integral production in iron and steel work plant Zenica.

    Science.gov (United States)

    Prcanović, Halim; Duraković, Mirnes; Beganović, Sanela

    2012-06-01

    Poor air quality is a common fact for all areas with base industry. The city of Zenica was once the metallurgical centre of Ex-Yugoslavia and is therefore highly polluted at present. Air pollution peaked in 1987 when average concentration of pollutants was extremely high (daily average concentration of SO(2) was 1800 μg m(-3)). With the beginning of the war in 1992, integral production in the steel work plant was shut down, to be re-launched in 2008. Limit values for iron do not exist, but iron has been monitored in Zenica for the past 28 years because of the presence of steel works. Concentrations of cadmium and lead have also been measured because they are very much present in polluted areas with steel works. The concentration of mentioned elements in air deposit and total suspended particles before and after integral production in the steel work plant was re-launched is the subject of this paper. Total suspended particles were measured in two locations using German standard VDI 2463 Blatt 4. Sediment dust was measured in nine locations using Bergerhoff method. The concentration of iron, lead, and cadmium was performed in the chemical laboratory of the Metallurgical Institute "Kemal Kapetanović" Zenica using standard methods. Higher concentrations of these parameters during the period of integral production clearly point to the impact of steel works on Zenica valley.

  4. The effect of compressibility, rotation and magnetic field on thermal instability of Walters’ fluid permeated with suspended particles in porous medium

    Directory of Open Access Journals (Sweden)

    Aggarwal Kumar Amrish

    2014-01-01

    Full Text Available The purpose of this paper is to study the effects of compressibility, rotation, magnetic field and suspended particles on thermal stability of a layer of visco-elastic Walters’ (model fluid in porous medium. Using linearized theory and normal mode analysis, dispersion relation has been obtained. In case of stationary convection, it is found that the rotation has stabilizing effect on the system. The magnetic field may have destabilizing effect on the system in the presence of rotation while in the absence of rotation it always has stabilizing effect. The medium permeability has destabilizing effect on the system in the absence of rotation while in the presence of rotation it may have stabilizing effect. The suspended particles and compressibility always have destabilizing effect. Due to vanishing of visco-elastic parameter, the compressible visco-elastic fluid behaves like Newtonian fluid. Graphs have also been plotted to depict the stability characteristics. The viscoelasticity, magnetic field and rotation are found to introduce oscillatory modes into the system which were non-existent in their absence.

  5. Remote Sensing and Water Quality Indicators in the West Flood Canal Semarang City: Spatio-temporal Structures of Lansat-8 Derived Chlorophyll-a and Total Suspended Solids

    Science.gov (United States)

    Subiyanto, Sawitri

    2017-12-01

    One of the waters that has been contaminated by industrial waste and domestic waste is the waters of West Flood Canal in Semarang City which is the estuary of the river system, which passes through the Western City of Semarang which is dense with residential and industrial. So, it is necessary to have information about the assessment of water quality in the estuary of the West Flood Canal. Remote sensing technology can analyze the results of recording the spectral characteristics of water with water quality parameters. One of the parameters for assessing water quality is Chlorophyll-a and Total Suspended Solid, can be estimated through remote sensing technology using multispectral Lansat-8 Satellite images data from April, June, and August, 2017 and there are three selected algorithms. Based on the results of TSS and Chlorophyll-A processing, the TSS shows values greater than or equal to 100 which can be said that West Flood Canal is damaged (hypertrophic). While the chlorophyll-a shows a value less than 100 indicating Eutrophic status (threatened). This is caused by the number of suspended materials in the water surface and also because of the disturbance of water vegetation in the form of weeds that destroy the function of the actual West Canal Flood.

  6. Flow cytometry is a promising and rapid method for differentiating between freely suspended Escherichia coli and E. coli attached to clay particles.

    Science.gov (United States)

    Liang, X; Soupir, M L; Rigby, S; Jarboe, L R; Zhang, W

    2014-12-01

    A standard procedure does not exist to distinguish between attached and unattached micro-organisms. In this study, we compared two methods to quantify between Escherichia coli attached to clay particles and E. coli freely suspended in solution: flow cytometry (attachment assay and viability assay) and settling (or centrifugation followed by settling). Methods were tested using three environmental strains collected from swine facilities (A, B and C) and one purchased modified pathogenic strain (ATCC 43888); four clay particles: Hectorite, Kaolinite, Ca-Montmorillonite, Montmorillonite K-10; and a range of surface area ratios (particle surface area to E. coli surface area). When comparing the two methods, the per cent attached obtained from the flow cytometry was lower, but not significantly different from the per cent attached obtained from the settling method for all conditions except when the particle was Hectorite or Montmorillonite K-10; when the strain was C; and when the surface area ratio was below 100. Differences between the methods are likely because traditional culture-based methods cannot detect the viable but nonculturable (VBNC) population, whereas flow cytometry can detect the fraction of VBNC with intact membranes. Our results indicate that flow cytometry is a rapid and culture-independent method for differentiating between attached and unattached micro-organisms. Flow cytometry is useful for laboratory-based studies of micro-organism-particle interactions. © 2014 The Society for Applied Microbiology.

  7. Particle dynamics during electronic sputtering of solid krypton

    DEFF Research Database (Denmark)

    Dutkiewicz, L.; Pedrys, R.; Schou, Jørgen

    1995-01-01

    We have modeled electronic sputtering of solid krypton by excimer production with molecular dynamics. Both excimer evolution in the solid and deexcitation processes have been incorporated in the simulation. The excimer dynamics in the lattice has been analyzed: the excimers formed near the surface...

  8. Influence of microorganism content in suspended particles on the particle–water partitioning of mercury in semi-enclosed coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jiyi [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Global Bioresources Research Center, Korea Institute of Ocean Science and Technology (KIOST), Ansan 426-744 (Korea, Republic of); Kim, Hyunji [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Han, Seunghee, E-mail: shan@gist.ac.kr [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of)

    2014-02-01

    It is known that particle scavenging of mercury (Hg) can be affected by the abundance of particulate organic matter in coastal waters. However, the role of living organic particles in Hg scavenging is not yet completely understood. In this study, we hypothesized that an abundance of living organic particles (i.e., phytoplankton and bacteria) would influence the particle–water partitioning of Hg in coastal waters. Surface seawater samples were collected from eight stations in Gwangyang Bay, Korea, in three seasons (November 2009, April 2010, and October 2010) for the determination of concentrations of suspended particulate matter (including chlorophyll-a and bacteria), and Hg in unfiltered and filtered waters. We found that more Hg partitioned toward particulate matter when phytoplankton biomass, indicated from the chlorophyll-a concentration in a particle, was higher. In the low algal season, when [chlorophyll-a] < 0.6 μg L{sup −1}, the bacterial number, instead of chlorophyll-a concentration in particle, showed a positive correlation with the particle–water partition coefficient of Hg. Overall, microbial abundance seems to play a critical role in particle scavenging of Hg in coastal water. Taking this result in light of Hg in pristine coastal zones, we predict that increases in algal biomass amplify the potential for algae to transfer Hg to marine food chains. - Highlights: • Abundance of phytoplankton and bacteria influenced particle–water partitioning of Hg. • More Hg partitioned toward particles when microorganism biomass in particle is large. • Increases of algal biomass may enhance Hg bioaccumulation in coastal ecosystem.

  9. Twelve Years of Monitoring Phosphorus and Suspended-Solids Concentrations and Yields in the North Fork Ninnescah River above Cheney Reservoir, South-Central Kansas 1997-2008

    Science.gov (United States)

    Stone, Mandy L.; Graham, Jennifer L.; Ziegler, Andrew C.

    2009-01-01

    Cheney Reservoir, located on the North Fork Ninnescah River in south-central Kansas, is the primary water supply for the city of Wichita and an important recreational resource. Concerns about taste-and-odor occurrences in Cheney Reservoir have drawn attention to potential pollutants, including total phosphorus (TP) and total suspended solids (TSS). July 2009 was the 15th anniversary of the establishment of the Cheney Reservoir Watershed pollution management plan. The U.S. Geological Survey (USGS), in cooperation with the city of Wichita, has collected water-quality data in the basin since 1996, and has monitored water quality continuously on the North Fork Ninnescah River since 1998. This fact sheet describes 12 years (1997-2008) of computed TP and TSS data and compares these data with water-quality goals for the North Fork Ninnescah River, the main tributary to Cheney Reservoir.

  10. Hydrology, phosphorus, and suspended solids in five agricultural streams in the Lower Fox River and Green Bay Watersheds, Wisconsin, Water Years 2004-06

    Science.gov (United States)

    Graczyk, David J.; Robertson, Dale M.; Baumgart, Paul D.; Fermanich, Kevin J.

    2011-01-01

    A 3-year study was conducted by the U.S. Geological Survey and the University of Wisconsin-Green Bay to characterize water quality in agricultural streams in the Fox/Wolf watershed in northeastern Wisconsin and provide information to assist in the calibration of a watershed model for the area. Streamflow, phosphorus, and suspended solids data were collected between October 1, 2003, and September 30, 2006, in five streams, including Apple Creek, Ashwaubenon Creek, Baird Creek, Duck Creek, and the East River. During this study, total annual precipitation was close to the 30-year normal of 29.12 inches. The 3-year mean streamflow was highest in the East River (113 ft3/s), followed by Duck Creek (58.2 ft3/s), Apple Creek (26.9 ft3/s), Baird Creek (12.8 ft3/s), and Ashwaubenon Creek (9.1 ft3/s). On a yield basis, during these three years, the East River had the highest flow (0.78 ft3/s/mi2), followed by Baird Creek (0.61 ft3/s/mi2), Apple Creek (0.59 ft3/s/mi2), Duck Creek (0.54 ft3/s/mi2), and Ashwaubenon Creek (0.46 ft3/s/mi2). The overall median total suspended solids (TSS) concentration was highest in Baird Creek (73.5 mg/L), followed by Apple and Ashwaubenon Creeks (65 mg/L), East River (40 mg/L), and Duck Creek (30 mg/L). The median total phosphorus (TP) concentration was highest in Ashwaubenon Creek (0.60 mg/L), followed by Baird Creek (0.47 mg/L), Apple Creek (0.37 mg/L), East River (0.26 mg/L), and Duck Creek (0.22 mg/L).

  11. Method for analysis of psychopharmaceuticals in real industrial wastewater and groundwater with suspended organic particulate matter using solid phase extraction disks extraction and ultra-high performance liquid chromatography/time-of-flight mass spectrometry.

    Science.gov (United States)

    Křesinová, Zdena; Linhartová, Lucie; Petrů, Klára; Krejčová, Lucie; Šrédlová, Kamila; Lhotský, Ondřej; Kameník, Zdeněk; Cajthaml, Tomáš

    2016-04-01

    A rapid and reliable analytical method was developed for the quantitative determination of psychopharmaceuticals, their precursors and by-products in real contaminated samples from a pharmaceutical company in Olomouc (Czech Republic), based on SPE disk extraction and detection by ultra performance liquid chromatography, combined with time-of-flight mass spectrometry. The target compounds were quantified in the real whole-water samples (water including suspended particles), both in the presence of suspended particulate matter (SPM) and high concentrations of other organic pollutants. A total of nine compounds were analyzed which consisted of three commonly used antidepressants (tricyclic antidepressants and antipsychotics), one antitussive agent and five by-products or precursors. At first, the SPE disk method was developed for the extraction of water samples (dissolved analytes, recovery 84-104%) and pressurised liquid extraction technique was verified for solid matrices (sludge samples, recovery 81-95%). In order to evaluate the SPE disk technique for whole water samples containing SPM, non contaminated groundwater samples were also loaded with different amounts (100 and 300mgL(-1)) of real contaminated sludge originating from the same locality. The recoveries from the whole-water samples obtained by SPE disk method ranged between 67 and 119% after the addition of the most contaminated sludge. The final method was applied to several real groundwater (whole-water) samples from the industrial area and high concentrations (up to 10(3)μgL(-1)) of the target compounds were detected. The results of this study document and indicate the feasibility of the SPE disk method for analysis of groundwater. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Behavior of ceramic particles at the solid-liquid metal interface in metal matrix composites

    Science.gov (United States)

    Stefanescu, D. M.; Dhindaw, B. K.; Kacar, S. A.; Moitra, A.

    1988-01-01

    Directional solidification results were obtained in order to investigate particle behavior at the solid-liquid interface in Al-2 pct Mg (cellular interface) and Al-6.1 pct Ni (eutectic interface) alloys. It is found that particles can be entrapped in the solid if adequate solidification rates and temperature gradients are used. Model results showed critical velocity values slightly higher than those obtained experimentally.

  13. Combined discrete particle and continuum model predicting solid-state fermentation in a drum fermentor

    NARCIS (Netherlands)

    Schutyser, M.A.I.; Schutyser, M.A.I.; Briels, Willem J.; Boom, R.M.; Boom, R.M.; Rinzema, A.

    2004-01-01

    The development of mathematical models facilitates industrial (large-scale) application of solid-state fermentation (SSF). In this study, a two-phase model of a drum fermentor is developed that consists of a discrete particle model (solid phase) and a continuum model (gas phase). The continuum model

  14. Effects of solid inertial particles on the velocity and temperature statistics of wall bounded turbulent flow

    DEFF Research Database (Denmark)

    Nakhaei, Mohammadhadi; Lessani, B.

    2016-01-01

    The effect of solid inertial particles on the velocity and temperature statistics of a non-isothermal turbulentchannel flow is studied using direct numerical simulation. The particles inertia is varied by changingthe particles diameter. The density of particles is kept constant. A two-way coupled...... Eulerian–Lagrangianapproach is adopted to solve the carrier flow field and the motion of dispersed particles. Three differentparticle Stokes numbers of St = 24, 60, 192, at a constant particle mass loading of φm = 0:54, are considered.The mean and rms profiles of velocity and temperature for fluid...... and particles, and the scatter plotsof fluid-particle temperature differences are presented. In addition, the variations of different budgetterms for the turbulent kinetic energy equation and fluctuating temperature variance equation in thepresence of particles are reported. The fluid turbulent heat flux...

  15. An apparatus for conducting physical, chemical, or biological interaction between gases and solid particles

    DEFF Research Database (Denmark)

    2013-01-01

    The invention provides an apparatus for conducting interaction between gases and solid particles. The apparatus has a vertical hollow shaft with a vertical row of constrictions formed internally and defining a series of intercommunicating chambers in the shaft for guiding the gas and particles e...... arranged vertically above each other or side-by-side whereby the apparatus becomes modular....

  16. Application of chitosan as flocculant for coprecipitation of Mn(II) and suspended solids from dual-alkali FGD regenerating process.

    Science.gov (United States)

    Wu, Zhong-Biao; Ni, Wei-Min; Guan, Bao-Hong

    2008-04-01

    Heavy metals and suspended solid (SS) needed to be removed from the recirculation of dual-alkali flue gas desulfurization (FGD) system. The feasibility of coprecipitation of heavy metal and SS by water-soluble chitosan was studied in a lab scale experiment. The association between chitosan and metal ions was verified through DSC and FT-IR. The pH investigation revealed that at the pH ranged from 5 to 9, there were three stages for different actions: adsorption of chitosan for Mn(II), precipitation of manganese hydroxide and coprecipitation of manganese hydroxide and chitosan-Mn(II) complex. The ion selectivity experiments showed that the occurrence of Ca(II) in the solution had little influence on the adsorption of chitosan for Mn(II). The decrease rate of adsorption capacity was about 0.0023 mmol g(-1) per 1 mg L(-1) Ca(II). When adsorption and flocculation of chitosan occurred at the same time and at the sufficient addition of chitosan, chitosan not only made solids flocculate but also enhanced sorption capacity of chitosan. Application of chitosan for coprecipitation of Mn(II) and SS could remove Mn(II) efficiently and improve the settling characteristics of SS from dual-alkali FGD regenerating process.

  17. Early-time particle dynamics and non-affine deformations during microstructure selection in solids

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Surajit [Centre for Advanced Materials, Indian Association for the Cultivation of Science, 2A and 2B, Raja S C Mullick Road, Jadavpur, Kolkata 700032 (India); Rao, Madan [Raman Research Institute, C V Raman Avenue, Bangalore 560 080 (India); Bhattacharya, Jayee [S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India)

    2011-07-27

    Solid-solid transitions are invariably associated with groups of particles whose deformations cannot be expressed as an affine strain about a reference configuration. The dynamics of these non-affine zones (NAZ) determine the subsequent microstructure, i.e. the mesoscale patterning resulting from the structural transition. Here, we focus on early-time dynamics of individual particles within an NAZ associated with a nucleation event. We show that the early-time behavior of these particles have distinctive characteristics depending on the transition temperature. The dynamics is heterogeneous, consisting of a few active particles exhibiting complex intermittent jamming and flow in response to internal stresses generated during the transformation. At low temperatures, the dynamics of these active particles is ballistic and the structural transformation proceeds via string-like correlated movement of active particles, along ridges in the potential energy topography set up by inactive particles. On increasing temperature, the dynamics of active particles show an abrupt transition from ballistic to diffusive behavior with a diffusion coefficient which appears to be independent of temperature. This dynamical transition in the nature of the trajectories of particles is coincident with a discontinuous transition in the microstructure of the solid. Finally, we characterize this transition in terms of a dynamical order parameter in the space of trajectories and discuss its connection with the glass transition and rheology of soft and granular matter.

  18. Nonisothermal particle modeling of municipal solid waste combustion with heavy metal vaporization

    Energy Technology Data Exchange (ETDEWEB)

    Mazza, G. [Facultad de Ingenieria, Departamento de Quimica, Universidad Nacional del Comahue, IDEPA (CONICET - UNCo), Buenos Aires 1400, 8300 Neuquen (Argentina); Falcoz, Q.; Gauthier, D.; Flamant, G. [Laboratoire Procedes et Materiaux et Energie Solaire (CNRS-PROMES), 7 Rue du Four Solaire, Odeillo, 66120 Font-Romeu Cedex (France); Soria, J. [Facultad de Ingenieria, Departamento de Quimica, Universidad Nacional del Comahue, IDEPA (CONICET - UNCo), Buenos Aires 1400, 8300 Neuquen (Argentina); Laboratoire Procedes et Materiaux et Energie Solaire (CNRS-PROMES), 7 Rue du Four Solaire, Odeillo, 66120 Font-Romeu Cedex (France)

    2010-12-15

    A particulate model was developed for municipal solid-waste incineration in a fluidized bed combining solid-waste-particle combustion and heavy metal vaporization from the burning particles. Based on a simpler, isothermal version presented previously, this model combines an asymptotic-combustion model for carbonaceous-solid combustion and a shrinking-core model to describe the heavy metal vaporization phenomenon, in which the particle is now considered nonisothermal. A parametric study is presented that shows the influence of temperature on the global metal-vaporization process. The simulation results are compared to experimental data obtained with a lab-scale fluid bed incinerator and to the results of the simpler isothermal model. It is shown that conduction in the particle strongly affects the variation of the vaporization rate with time and that the present version of the model well fits both the shape of the plots and the maximum heavy metal vaporization rates for all bed temperatures. (author)

  19. Numerical study of impact erosion of multiple solid particle

    Science.gov (United States)

    Zheng, Chao; Liu, Yonghong; Chen, Cheng; Qin, Jie; Ji, Renjie; Cai, Baoping

    2017-11-01

    Material erosion caused by continuous particle impingement during hydraulic fracturing results in significant economic loss and increased production risks. The erosion process is complex and has not been clearly explained through physical experiments. To address this problem, a multiple particle model in a 3D configuration was proposed to investigate the dynamic erosion process. This approach can significantly reduce experiment costs. The numerical model considered material damping and elastic-plastic material behavior of target material. The effects of impact parameters on erosion characteristics, such as plastic deformation, contact time, and energy loss rate, were investigated. Based on comprehensive studies, the dynamic erosion mechanism and geometry evolution of eroded crater was obtained. These findings can provide a detailed erosion process of target material and insights into the material erosion caused by multiple particle impingement.

  20. Single step bottom-up process to generate solid phospholipid nano-particles.

    Science.gov (United States)

    Brinkmann-Trettenes, Ulla; Barnert, Sabine; Bauer-Brandl, Annette

    2014-05-01

    The particularity of the Nano Spray Dryer B-90 is the nozzle containing a mesh vibrating at ultrasonic frequency. To study process parameters and processability of crude phospholipid dispersions, in particular the effect of concentration and mesh aperture on both particle size of the dry solid phospholipid nano-particles and on the re-dispersed powder. Phospholipid dispersions containing trehalose as a stabilizer were spray dried. Particle size distributions of dry powders were evaluated by SEM micrographs and by PCS and cryo-TEM for the re-dispersed particles. Spray drying of crude liposome dispersions revealed solid phospholipid nano-particles. Aperture of nozzle mesh and concentration of the dispersions, respectively, both increased the size of solid phospholipid nano-particles. For crude dispersions, an upper limit with respect to processability was found close to below 10% (m/m) even if the crude dispersion was passed along the mesh several times; however, more effective dispersing methods such as pre-sonication can push the limit of processability to higher values. The nano spray dryer is capable of spray drying crude dispersions of phospholipids in concentrations below 10% (m/m) generating solid phospholipid nano-particles relevant for pulmonary delivery. Re-dispersion of spray dried powder reveals liposomes.

  1. Two-structured solid particle model for predicting and analyzing supercritical extraction performance.

    Science.gov (United States)

    Samadi, Sara; Vaziri, Behrooz Mahmoodzadeh

    2017-07-14

    Solid extraction process, using the supercritical fluid, is a modern science and technology, which has come in vogue regarding its considerable advantages. In the present article, a new and comprehensive model is presented for predicting the performance and separation yield of the supercritical extraction process. The base of process modeling is partial differential mass balances. In the proposed model, the solid particles are considered twofold: (a) particles with intact structure, (b) particles with destructed structure. A distinct mass transfer coefficient has been used for extraction of each part of solid particles to express different extraction regimes and to evaluate the process accurately (internal mass transfer coefficient was used for the intact-structure particles and external mass transfer coefficient was employed for the destructed-structure particles). In order to evaluate and validate the proposed model, the obtained results from simulations were compared with two series of available experimental data for extraction of chamomile extract with supercritical carbon dioxide, which had an excellent agreement. This is indicative of high potentiality of the model in predicting the extraction process, precisely. In the following, the effect of major parameters on supercritical extraction process, like pressure, temperature, supercritical fluid flow rate, and the size of solid particles was evaluated. The model can be used as a superb starting point for scientific and experimental applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Encapsulation of solid dispersion in solid lipid particles for dissolution enhancement of poorly water-soluble drug.

    Science.gov (United States)

    Tran, Khanh Thi My; Vo, Toi Van; Tran, Phuong Ha-Lien; Lee, Beom-Jin; Duan, Wei; Tran, Thao Truong-Dinh

    2017-06-05

    The aim of this research was to engineer solid dispersion lipid particles (SD-SLs) in which a solid dispersion (SD) was encapsulated to form the core of solid lipid particles (SLs), thereby achieving an efficient enhancement in the dissolution of a poorly water-soluble drug. Ultrasonication was introduced into the process to obtain micro/nanoscale SLs. The mechanism of dissolution enhancement was investigated by analysing the crystalline structure, molecular interactions, and particle size of the formulations. The drug release from the SD-SLs was significantly greater than that from the SD or SLs alone. This enhancement in drug release was dependent on the preparation method and the drug-to-polymer ratio of the SD. With an appropriate amount of polymer in the SD, the solidification method had the potential to alter the drug crystallinity to an amorphous state, resulting in particle uniformity and molecular interactions in the SD-SLs. The proposed system provides a new strategy for enhancing the dissolution rate of poorly water-soluble drugs and further improving their bioavailability. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Confirmatory sediment analyses and solid and suspended particulate phase bioassays on sediment from Oakland Inner Harbor, San Francisco, California

    Energy Technology Data Exchange (ETDEWEB)

    Word, J.Q.; Ward, J.A.; Apts, C.W.; Woodruff, D.L.; Barrows, M.E.; Cullinan, V.I.; Hyland, J.L.; Campbell, J.F.

    1988-12-01

    The US Army Corps of Engineers (USACE), San Francisco District, was authorized by the US Congress to deepen the navigation channels of Inner and Outer Oakland Harbor, California. During review of the environmental impact statement required for this dredging and disposal project, a panel of national experts approved the open-water disposal of dredged sediment from selected areas within the Inner Harbor, subject to results of confirmatory solid phase bioassays. The San Francisco District of the Corps requested the Battle/Marine Sciences Laboratory (MSL) to conduct these confirmatory studies. The studies provided technical data for an evaluation of the potential environmental impact of this project. Within extremely narrow time constraints, these studies provided chemical and biological information required by ocean dumping regulations to determine suitability of the Oakland Inner Harbor and turning basin sediment for ocean disposal. 23 refs., 18 figs., 45 tabs.

  4. Complex plasmas and colloidal dispersions particle-resolved studies of classical liquids and solids

    CERN Document Server

    Ivlev, Alexei; Morfill, Gregor; Royall, C. Patrick

    2012-01-01

    Complex plasmas and colloidal dispersions represent different states of soft matter. They are complementary in many ways, with the most important being that complex plasmas are virtually undamped at the particle timescales, whereas colloidal dispersions are overdamped and therefore can be brought into equilibrium in a very controlled manner. Otherwise, both fields have similar advantages: fully resolved 3D particle trajectories can easily be visualized, the pair interactions are tunable, and particles can be manipulated individually or collectively. These unique properties allow us to investigate generic processes occurring in liquids or solids at the most fundamental individual particle level. The principal research topics to be addressed in the book include: particle dynamics in liquids, with the emphasis on mesoscopic processes in the supercooled (glassy) state, e.g. dynamical heterogeneity, phase transitions in solids, with particular attention to the evolutionary paths of crystal structure development an...

  5. Theoretical calculation of solid particles deposition from the air

    Directory of Open Access Journals (Sweden)

    Bobro Milan

    2002-03-01

    Full Text Available This paper presents the calculation of harmful substance deposition (air pollution from the point source (Slanèo, et al., 2001 using equation (1. The point source shall be understood as e.g. chimneys of factory, heat plant, incinerator, boiler plant, local heating plant, etc.The theoretical calculation of concentration (1, or deposition (8 is based on the study of transfer and dispersion of pollution in air (Slanèo, et al., 2000a. The movement of pollution in air consists of a movement of the air itself and a relative movement of pollution particles and air, while the movement of harmful substance in the smoke trail is under the influence of turbulent diffusion, convection and gravitation. Molecular diffusion is not important in this process. When calculating concentrations (1 and deposition (8 of air pollution on a particular place near the source, it is assumed that the air speed is constant, the direction of wind does not change with the height and the source of air pollution is time-constant. The change in the wind speed with the height depends on the stability class of atmosphere (temperature gradient (Slanèo, et al., 2000a and it is calculated using equation (10.The theoretical calculation of concentration and or deposition of harmful substance from the point source (1 and (8 shall be applied if the harmful substance particles, which leave the source, have the same density (composition, shape (spherical and size.The experimental observations of dust deposition showed the significance of 0.1-20 µm particles. The application of equation (1 to calculate the concentration is conditioned, in addition to the recognition of source parameters and meteorological conditions, by the recognition of the particle sedimentation speed, which changes with the size of particle radius (2.For a practical calculation of deposition it is therefore necessary to know the differential distribution function f(r of particle radii, which can be made on the basis

  6. Optimization of solid state fermentation of sugar cane by Aspergillus niger considering particles size effect

    Energy Technology Data Exchange (ETDEWEB)

    Echevarria, J.; Rodriguez, L.J.A.; Delgado, G. (Instituto Cubano de Investigaciones de los Derivados de la Cana de Azucar (ICIDCA), La Habana (Cuba)); Espinosa, M.E. (Centro Nacional de Investigaciones Cientificas, La Habana (Cuba))

    1991-01-01

    The protein enrichment of sugar cane by solid state fermentation employing Aspergillus niger was optimized in a packed bed column using a two Factor Central Composit Design {alpha} = 2, considering as independent factors the particle diameter corresponding to different times of grinding for a sample and the air flow rate. It was significative for the air flow rate (optimum 4.34 VKgM) and the particle diameter (optimum 0.136 cm). The average particle size distribution, shape factor, specific surface, volume-surface mean diameter, number of particles, real and apparent density and holloweness for the different times of grinding were determined, in order to characterize the samples. (orig.).

  7. Experimental research results of solid particle erosion resistance of blade steel with protective coating

    Science.gov (United States)

    Kachalin, G. V.; Mednikov, A. F.; Tkhabisimov, A. B.; Seleznev, L. I.

    2017-11-01

    The paper presents the results of metallographic studies and solid particle erosion tests of uncoated blade steel 20kH13 samples and samples with a protective coating based on chromium carbide (Cr-CrC) at a flow (air) velocity CA = 180 m/s, flow temperature tA = 25 °C, attack angle α = 30° and consumption of solid abrasive particles GP = 5·10-4 kg/s. It was found that the coating has a granular structure, a thickness is about 11 μm, the microhardness of the surface is 1520 ± 50 HV0.05. Processing of the obtained data by statistical analysis methods showed that the protective coating based on Cr-CrC increases the solid particle erosion resistance of the blade steel 20kH13 by the incubation-transitional period duration more than 2.5 times.

  8. Microspherical Particles of Solid Dispersion of Polyvinylpyrrolidone K29-32 for Inhalation Administration

    Directory of Open Access Journals (Sweden)

    L. S. Usmanova

    2018-01-01

    Full Text Available Inhalation administration is a promising alternative to the invasive drug delivery methods. The particle size required for ideal drug aerosol preparation is between 1 and 3 μm. The application of microspherical particles of solid dispersions enhances bioavailability of poorly soluble drugs due to the solubilization. In the present work, the spray drying process of the production of microspherical particles of solid dispersions of polyvinylpyrrolidone K29-32 with model hydrophobic drug, phenacetin, was optimized using the results of DSC, PXRD, and viscometry. The diameter of the obtained particles is within 1–3 μm range. The Gibbs energy of dissolution in water was shown to be negative for the mixture with polymer/phenacetin mass ratio 5 : 1. We have demonstrated that the optimal size distribution for the inhalation administration is obtained for microspherical particles produced using spray caps with 7.0 μm hole size. The dissolution rates of phenacetin from the produced microspherical particles were faster than that of drug powder. As evidenced by powder X-ray diffraction data, phenacetin stayed in amorphous state for 4 months in microspherical particles of solid dispersions. According to the obtained results, strategic application of the spray drying process could be beneficial for the improvement of the pharmaceutical properties of model drug, phenacetin.

  9. Application of nuclear techniques in two-phase liquid-solid particles hydrotransport investigations

    Directory of Open Access Journals (Sweden)

    Zych Marcin

    2016-01-01

    Full Text Available The paper presents gamma radiation application to two-phase flow investigation in a vertical pipeline, where the flow of solid particles transported by water was examined by use of both: radiotracers and gamma-absorption method. The simultaneous use of two methods allows analyzing of important parameters of solid particles hydrotransport. In the described experiments as solid phase the ceramic models representing natural polymetallic ocean nodules were used. Radiotracers allow to track the movements of selected models, representing specified grain size and the designation of its velocity. However gamma-absorption method enables measurement of average solid-phase velocity. For analysis of electrical signals obtained from scintillation detectors the cross-correlation method has been applied.

  10. Effects of Humic Acid and Suspended Solids on the Removal of Heavy Metals from Water by Adsorption onto Granular Activated Carbon

    Directory of Open Access Journals (Sweden)

    Danious P. Sounthararajah

    2015-08-01

    Full Text Available Heavy metals constitute some of the most dangerous pollutants of water, as they are toxic to humans, animals, and aquatic organisms. These metals are considered to be of major public health concern and, therefore, need to be removed. Adsorption is a common physico-chemical process used to remove heavy metals. Dissolved organic carbon (DOC and suspended solids (SS are associated pollutants in water systems that can interact with heavy metals during the treatment process. The interactions of DOC and SS during the removal of heavy metals by granular activated carbon were investigated in batch and fixed-bed column experiments. Batch adsorption studies indicated that Langmuir adsorption maxima for Pb, Cu, Zn, Cd, and Ni at pH 6.5 were 11.9, 11.8, 3.3, 2.0, and 1.8 mg/g, respectively. With the addition of humic acid (HA (DOC representative, they were 7.5, 3.7, 3.2, 1.6, and 2.5 mg/g, respectively. In the column experiment, no breakthrough (complete removal was obtained for Pb and Cu, but adding HA provided a breakthrough in removing these metals. For Zn, Cd and Ni, this breakthrough occurred even without HA being added. Adding kaolinite (representative of SS had no effect on Pb and Cu, but it did on the other metals.

  11. Accuracy of different sensors for the estimation of pollutant concentrations (total suspended solids, total and dissolved chemical oxygen demand) in wastewater and stormwater.

    Science.gov (United States)

    Lepot, Mathieu; Aubin, Jean-Baptiste; Bertrand-Krajewski, Jean-Luc

    2013-01-01

    Many field investigations have used continuous sensors (turbidimeters and/or ultraviolet (UV)-visible spectrophotometers) to estimate with a short time step pollutant concentrations in sewer systems. Few, if any, publications compare the performance of various sensors for the same set of samples. Different surrogate sensors (turbidity sensors, UV-visible spectrophotometer, pH meter, conductivity meter and microwave sensor) were tested to link concentrations of total suspended solids (TSS), total and dissolved chemical oxygen demand (COD), and sensors' outputs. In the combined sewer at the inlet of a wastewater treatment plant, 94 samples were collected during dry weather, 44 samples were collected during wet weather, and 165 samples were collected under both dry and wet weather conditions. From these samples, triplicate standard laboratory analyses were performed and corresponding sensors outputs were recorded. Two outlier detection methods were developed, based, respectively, on the Mahalanobis and Euclidean distances. Several hundred regression models were tested, and the best ones (according to the root mean square error criterion) are presented in order of decreasing performance. No sensor appears as the best one for all three investigated pollutants.

  12. Removal of Suspended Solids in Anaerobically Digested Slurries of Livestock and Poultry Manure by Coagulation Using Different Dosages of Polyaluminum Chloride

    Science.gov (United States)

    Li, P.; Zhang, C. J.; Zhao, T. K.; Zhong, H.

    2017-01-01

    In this study, anaerobically digested slurries of livestock and poultry manure were pretreated by coagulation-sedimentation using an inorganic polymer coagulant, polyaluminum chloride (PAC). The effect of different PAC dosages on suspended solids (SS) removal and pH in the biogas slurries was assessed to provide reference values for reducing the organic load of biogas slurry in the coagulation-sedimentation process and explore the feasibility of reducing the difficulty in subsequent utilization or processing of biogas slurry. The results showed that for the pig slurry containing approximately 5000 mg/L SS, the removal rate of SS reached up to 81.6% with the coagulant dosage of 0.28 g/L PAC. For the chicken slurry containing approximately 2600 mg/L SS, the removal rate of SS was 30.2% with the coagulant dosage of 0.33 g/L PAC. The removal rate of SS in both slurries of livestock and poultry manure exhibited a downward trend with high PAC dosage. Therefore, there is a need to control the PAC dosage in practical use. The pH changed little in the two types of biogas slurries after treatment with different PAC dosages and both were in line with the standard values specified in the “Standards for Irrigation Water Quality”.

  13. Efficient performance and the microbial community changes of submerged anaerobic membrane bioreactor in treatment of sewage containing cellulose suspended solid at 25°C.

    Science.gov (United States)

    Watanabe, Ryoya; Nie, Yulun; Takahashi, Shintaro; Wakahara, Shinichiro; Li, Yu-You

    2016-09-01

    Influence of cellulose as suspended solid (SS) on the performance of submerged anaerobic membrane bioreactor (SAnMBR) was evaluated at 25°C using two types of synthetic sewage (SS contained or not). During the 110days operation, COD and BOD removal, CH4 gas recovery and cellulose accumulation were investigated in detail. The influence of cellulose as SS in sewage on the SAnMBR performance was not significant at HRT longer than12h and 65-72% of the influent COD was recovered as methane gas at HRT of 12h. At HRT of 6h, the quality of effluent got worse and the accumulation of cellulose was found in reactor. 16S rRNA analysis revealed that the microbial diversity distribution including Archaea and Bacteria changed due to the addition of SS in sewage and specific microbe for cellulose degradation such as Proteobacteria was detected. Sludge in SAnMBR could acclimate to characteristics of sewage by self-adaptation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Effect of mixed liquor volatile suspended solids (MLVSS and hydraulic retention time (HRT on the performance of activated sludge process during the biotreatment of real textile wastewater

    Directory of Open Access Journals (Sweden)

    Kapil Kumar

    2014-03-01

    Full Text Available Adequate information is available on colour and organics removal in batch mode using pure microbial cultures from dye contaminated wastewater. There was a need to develop environment friendly and cost effective treatment technique for actual field conditions. Therefore, the present study was undertaken with an aim to evaluate the potential of acclimatized mixed microbial consortia for the removal of colour and organics from real textile wastewater. Experiments were performed in laboratory scale activated sludge process (ASP unit under steady state condition, varying mixed liquor volatile suspended solids (MLVSS (2500, 3500 and 5000 mg/l and hydraulic retention time (HRT (18, 24 and 36 h. The results showed that decolourization and chemical oxygen demand (COD removal increased with increase in MLVSS and HRT. At 18 h HRT, decolourization was found to be 46, 54 and 67%, which increased to 67, 75 and 90% (36 h HRT at 2500, 3500 and 5000 mg/l MLVSS, respectively. COD removal was found to be 62, 73 and 77% (at 18 h HRT which increased to 77, 85 and 91% (36 h HRT at 2000, 3500 and 5000 mg/l MLVSS, respectively. On the basis of the results obtained in this study suitable treatment techniques can be developed for the treatment of wastewater contaminated with variety of dyes in continuous mode of operation. This shall have the advantage of treatment of larger quantity of wastewater in shorter duration.

  15. Solid particle erosion and viscoelastic properties of thermoplastic polyurethanes

    Directory of Open Access Journals (Sweden)

    G. Arena

    2015-03-01

    Full Text Available The wear resistance of several thermoplastic polyurethanes (TPUs having different chemical nature and micronscale arrangement of the hard and soft segments has been investigated by means of erosion and abrasion tests. The goal was correlating the erosion performances of the materials to their macroscopic mechanical properties. Unlike conventional tests, such as hardness and tensile measurements, viscoelastic analysis proved to be a valuable tool to study the erosion resistance of TPUs. In particular, a strict correlation was found between the erosion rate and the high-frequency (~107 Hz loss modulus. The latter reflects the actual ability of TPU to dissipate the impact energy of the erodent particles.

  16. Optical characterisation of suspended particles in the Mackenzie River plume (Canadian Arctic Ocean and implications for ocean colour remote sensing

    Directory of Open Access Journals (Sweden)

    D. Doxaran

    2012-08-01

    Full Text Available Climate change significantly impacts Arctic shelf regions in terms of air temperature, ultraviolet radiation, melting of sea ice, precipitation, thawing of permafrost and coastal erosion. Direct consequences have been observed on the increasing Arctic river flow and a large amount of organic carbon sequestered in soils at high latitudes since the last glacial maximum can be expected to be delivered to the Arctic Ocean during the coming decade. Monitoring the fluxes and fate of this terrigenous organic carbon is problematic in such sparsely populated regions unless remote sensing techniques can be developed and proved to be operational.

    The main objective of this study is to develop an ocean colour algorithm to operationally monitor dynamics of suspended particulate matter (SPM on the Mackenzie River continental shelf (Canadian Arctic Ocean using satellite imagery. The water optical properties are documented across the study area and related to concentrations of SPM and particulate organic carbon (POC. Robust SPM and POC : SPM proxies are identified, such as the light backscattering and attenuation coefficients, and relationships are established between these optical and biogeochemical parameters. Following a semi-analytical approach, a regional SPM quantification relationship is obtained for the inversion of the water reflectance signal into SPM concentration. This relationship is reproduced based on independent field optical measurements. It is successfully applied to a selection of MODIS satellite data which allow estimating fluxes at the river mouth and monitoring the extension and dynamics of the Mackenzie River surface plume in 2009, 2010 and 2011. Good agreement is obtained with field observations representative of the whole water column in the river delta zone where terrigenous SPM is mainly constrained (out of short periods of maximum river outflow. Most of the seaward export of SPM is observed to occur within the west side of

  17. Optical Characterisation of Suspended Particles in the Mackenzie River Plume (Canadian Arctic Ocean) and Implications for Ocean Colour Remote Sensing

    Science.gov (United States)

    Doxaran, D.; Ehn, J.; Belanger, S.; Matsuoka, A.; Hooker, S.; Babin, M.

    2012-01-01

    Climate change significantly impacts Arctic shelf regions in terms of air temperature, ultraviolet radiation, melting of sea ice, precipitation, thawing of permafrost and coastal erosion. Direct consequences have been observed on the increasing Arctic river flow and a large amount of organic carbon sequestered in soils at high latitudes since the last glacial maximum can be expected to be delivered to the Arctic Ocean during the coming decade. Monitoring the fluxes and fate of this terrigenous organic carbon is problematic in such sparsely populated regions unless remote sensing techniques can be developed and proved to be operational. The main objective of this study is to develop an ocean colour algorithm to operationally monitor dynamics of suspended particulate matter (SPM) on the Mackenzie River continental shelf (Canadian Arctic Ocean) using satellite imagery. The water optical properties are documented across the study area and related to concentrations of SPM and particulate organic carbon (POC). Robust SPM and POC : SPM proxies are identified, such as the light backscattering and attenuation coefficients, and relationships are established between these optical and biogeochemical parameters. Following a semi-analytical approach, a regional SPM quantification relationship is obtained for the inversion of the water reflectance signal into SPM concentration. This relationship is reproduced based on independent field optical measurements. It is successfully applied to a selection of MODIS satellite data which allow estimating fluxes at the river mouth and monitoring the extension and dynamics of the Mackenzie River surface plume in 2009, 2010 and 2011. Good agreement is obtained with field observations representative of the whole water column in the river delta zone where terrigenous SPM is mainly constrained (out of short periods of maximum river outflow). Most of the seaward export of SPM is observed to occur within the west side of the river mouth. Future

  18. Hydrodynamic studies of the flow of fine particles through a fluidized dense bed of coarse solids

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, J.

    1993-12-31

    This study explains the hydrodynamics of a circulating fluidized bed (CFB) system, the Battelle Multi-Solids Fluidized Bed System (MSFB). It consists of a circulating fluidized bed of fine particles superimposed on a bubbling bed of coarse solids. One way to characterize such a system is to describe the mechanism of gas-solid flow through the bed. The gas flow in systems like these is through bubbles or slugs (regions of voids containing little or no solids). Bubbles are typically characterized by their size (length or diameter), their rise velocity, and their frequency. Another task of the initial phase of this study is to characterize an L-valve, a solids-recirculating device commonly used in an MSFB. Next, the mechanism of fine particle movement through a bubbling region of coarse fluidized solids is studied in considerable detail. Bubble characteristics are studied in a variety of systems of coarse particles with fines passing through at high velocity. Amongst numerous optical, electrical and other techniques available for the study of the passage of bubbles, the pressure fluctuation technique is the most robust. In this investigation, pressure probes are connected to pressure transducers which are in turn linked to an on-line data acquisition system supported on a microcomputer. A commercially available software package (Notebook) is used to sample pressure at specified points in the fluidized bed at extremely fast rates, of up to 200 Hz. This resulted in pressure-time traces which are analysed to give bubble length, bubble rise velocity, and bubble frequency. Another important objective of this study is to estimate the fine particle residence time in the dense bed section. A defluidization technique is utilized in experimentally measuring the solids holdup in the dense bed. A mathematical model is developed from first principles, based on a momentum balance on the fine particles.

  19. Solid lipid particles for oral delivery of peptide and protein drugs I - Elucidating the release mechanism of lysozyme during lipolysis

    DEFF Research Database (Denmark)

    Christophersen, Philip Carsten B; Zhang, L.; Yang, M

    2013-01-01

    The mechanism of protein release from solid lipid particles was investigated by a new lipolysis model in a biorelevant medium containing both bile salts and phospholipids. Lysozyme, a model protein, was formulated into solid lipid particles using four different types of lipids, two triglycerides ...... the drug release mechanism from solid lipid particles and can potentially be used in rational selection of lipid excipients for oral delivery of peptide/protein drugs....

  20. Majorana Fermions in Particle Physics, Solid State and Quantum Information

    Science.gov (United States)

    Borsten, L.; Duff, M. J.

    This review is based on lectures given by M. J. Duff summarising the far reaching contributions of Ettore Majorana to fundamental physics, with special focus on Majorana fermions in all their guises. The theoretical discovery of the eponymous fcrmion in 1937 has since had profound implications for particlc physics, solid state and quantum computation. The breadth of these disciplines is testimony to Majorana's genius, which continues to permeate physics today. These lectures offer a whistle-stop tour through some limited subset of the key ideas. In addition to touching on these various applications, we will draw out some fascinating relations connecting the normed division algebras R, ℂ, H, O to spinors, trialities. K-theory and the classification of stable topological states of symmetry-protected gapped free-fermion systems.

  1. Isostructural solid-solid phase transition in monolayers of soft core-shell particles at fluid interfaces: structure and mechanics.

    Science.gov (United States)

    Rey, Marcel; Fernández-Rodríguez, Miguel Ángel; Steinacher, Mathias; Scheidegger, Laura; Geisel, Karen; Richtering, Walter; Squires, Todd M; Isa, Lucio

    2016-04-21

    We have studied the complete two-dimensional phase diagram of a core-shell microgel-laden fluid interface by synchronizing its compression with the deposition of the interfacial monolayer. Applying a new protocol, different positions on the substrate correspond to different values of the monolayer surface pressure and specific area. Analyzing the microstructure of the deposited monolayers, we discovered an isostructural solid-solid phase transition between two crystalline phases with the same hexagonal symmetry, but with two different lattice constants. The two phases corresponded to shell-shell and core-core inter-particle contacts, respectively; with increasing surface pressure the former mechanically failed enabling the particle cores to come into contact. In the phase-transition region, clusters of particles in core-core contacts nucleate, melting the surrounding shell-shell crystal, until the whole monolayer moves into the second phase. We furthermore measured the interfacial rheology of the monolayers as a function of the surface pressure using an interfacial microdisk rheometer. The interfaces always showed a strong elastic response, with a dip in the shear elastic modulus in correspondence with the melting of the shell-shell phase, followed by a steep increase upon the formation of a percolating network of the core-core contacts. These results demonstrate that the core-shell nature of the particles leads to a rich mechanical and structural behavior that can be externally tuned by compressing the interface, indicating new routes for applications, e.g. in surface patterning or emulsion stabilization.

  2. Modelling the light absorption properties of particulate matter forming organic particles suspended in sea water. Part 3. Practical applications

    Directory of Open Access Journals (Sweden)

    Roman Majchrowski

    2006-12-01

    Full Text Available This paper brings to a close our cycle of articles on modelling the light absorption properties of particulate organic matter (POM in the sea. In the first two parts of this cycle (Woźniaket al. 2005a,b we discussed these properties with reference to various model chemical classes and physical types of POM. We have put these results into practice in the present third part. As a result of the appropriate theoretical speculations, logically underpinned by empirical knowledge, we selected 25 morphological variants of marine organic detritus, to which we ascribed definite chemical compositions and physical types. On this basis and using known spectra of the mass-specific coefficients of light absorption by various naturally occurring organic substances (systematised in Parts 1 and 2, we determined the absorption properties of these 25 morphological groups of particles, that is, the spectra of the imaginary part of the refractive index n'p(λ (in the 200-700 nm range of the particulate matter. They can be applied, with the aid of Mie's or some other similar theory, to calculate the bulk optical properties (absorbing and scattering of such sets of particles in the sea.

  3. Light Absorption by Suspended Particles in the Red Sea: Effect of Phytoplankton Community Size Structure and Pigment Composition

    KAUST Repository

    Kheireddine, Malika

    2018-01-10

    The light absorption properties of phytoplankton (aph(λ)) and non-algal particles (anap(λ)) associated with phytoplankton pigments were analyzed across the Red Sea, in the upper 200 m depth, between October 2014 and August 2016. The contribution by non-algal particles to the total particulate light absorption (aph(λ)+ anap(λ)) was highly variable (23 ± 17% at 440 nm) and no relationship between anap(440) and chlorophyll a concentration, [TChl a], was observed. Phytoplankton specific phytoplankton absorption coefficients at 440 and 676 nm for a given [TChl a], aph*(440) and aph*(676), were slightly higher than those derived from average relationships for open ocean waters within the surface layer as well as along the water column. Variations in the concentration of photosynthetic and photoprotective pigments were noticeable by changes in phytoplankton community size structure as well as in aph*(λ). This study revealed that a higher proportion of picophytoplankton and an increase in photoprotective pigments (mainly driven by zeaxanthin) tended to be responsible for the higher aph*(λ) values found in the Red Sea as compared to other oligotrophic regions with similar [TChl a]. Understanding this variability across the Red Sea may help improve the accuracy of biogeochemical parameters, such as [TChl a], derived from in situ measurements and ocean color remote sensing at a regional scale.

  4. Turbidity and suspended solids in the runoff susceptible of use for the artificial recharge of the deep granular aquifer subjacent to the town of San Luis de Potosi (Mexico); Turbidez y solidos en suspension de las aguas de escorrentia susceptibles de ser utilizadas en la recarga artificial del acuifero granular profundo subyacente a la ciudad de San Luis de Potosi (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, J. M.

    2009-07-01

    This article presents an analysis of the turbidity and solid contents in suspension of the runoff that might be used for artificially recharging a deep granular aquifer located by San Luis de Potosi. The programmed artificial recharge operation corresponds to a type known as Aquifer Storage and Recovery (ASR). A series of equations to correlate the solids in suspension with turbidity and its validity are put forth. Reference is also made to the maximum content in suspended solids that operations of USR-type recharge can assume. Through this analysis, we were able to corroborate that turbidity varies over time according to an exponential function of the decreasing type, which accounts both for the deposition of particles that sediment exclusively due to the effect of gravity, and the action of certain mechanisms that favour coagulation and the natural flocculation of colloidal particles. Given that the operations of artificial recharge by means of USR require very rigorous conditions, in terms of the maximum contents of solids in suspension, the analysis has also been carried out for surface installations such as infiltration ponds. (Author) 24 refs.

  5. Suspended microfluidics

    OpenAIRE

    Casavant, Benjamin P.; Berthier, Erwin; Theberge, Ashleigh B.; Jean BERTHIER; Montanez-Sauri, Sara I.; Bischel, Lauren L.; Brakke, Kenneth; Hedman, Curtis J.; Bushman, Wade; Keller, Nancy P.; Beebe, David J.

    2013-01-01

    Although the field of microfluidics has made significant progress in bringing new tools to address biological questions, the accessibility and adoption of microfluidics within the life sciences are still limited. Open microfluidic systems have the potential to lower the barriers to adoption, but the absence of robust design rules has hindered their use. Here, we present an open microfluidic platform, suspended microfluidics, that uses surface tension to fill and maintain a fluid in microscale...

  6. Differences in physical chemistry and dissolution rate of solid particle aerosols from solution pressurised inhalers.

    Science.gov (United States)

    Buttini, Francesca; Miozzi, Michele; Balducci, Anna Giulia; Royall, Paul G; Brambilla, Gaetano; Colombo, Paolo; Bettini, Ruggero; Forbes, Ben

    2014-04-25

    Solution composition alters the dynamics of beclomethasone diproprionate (BDP) particle formation from droplets emitted by pressurised metered dose inhalers (pMDIs). The hypothesis that differences in inhaler solutions result in different solid particle physical chemistry was tested using a suite of complementary calorimetric techniques. The atomisation of BDP-ethanol solutions from commercial HFA-pMDI produced aerodynamically-equivalent solid particle aerosols. However, differences in particle physico-chemistry (morphology and solvate/clathrate formation) were detected by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and supported by hot stage microscopy (HSM). Increasing the ethanol content of the formulation from 8 to 12% (w/w), which retards the evaporation of propellant and slows the increase in droplet surface viscosity, enhanced the likelihood of particles drying with a smooth surface. The dissolution rate of BDP from the 12% (w/w) ethanol formulation-derived particles (63% dissolved over 120 min) was reduced compared to the 8% (w/w) ethanol formulation-derived particles (86% dissolved over 120 min). The addition of 0.01% (w/w) formoterol fumarate or 1.3% (w/w) glycerol to the inhaler solution modified the particles and reduced the BDP dissolution rate further to 34% and 16% dissolved in 120 min, respectively. These data provide evidence that therapeutic aerosols from apparently similar inhaler products, including those with similar aerodynamic performance, may behave non-equivalently after deposition in the lungs. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Depositional ice nucleation on solid ammonium sulfate and glutaric acid particles

    Directory of Open Access Journals (Sweden)

    K. J. Baustian

    2010-03-01

    Full Text Available Heterogeneous ice nucleation on solid ammonium sulfate and glutaric acid particles was studied using optical microscopy and Raman spectroscopy. Optical microscopy was used to detect selective nucleation events as water vapor was slowly introduced into an environmental sample cell. Particles that nucleated ice were dried via sublimation and examined in detail using Raman spectroscopy. Depositional ice nucleation is highly selective and occurred preferentially on just a few ammonium sulfate and glutaric acid particles in each sample. For freezing temperatures between 214 K and 235 K an average ice saturation ratio of S = 1.10±0.07 for solid ammonium sulfate was observed. Over the same temperature range, S values observed for ice nucleation on glutaric acid particles increased from 1.2 at 235 K to 1.6 at 218 K. Experiments with externally mixed particles further show that ammonium sulfate is a more potent ice nucleus than glutaric acid. Our results suggest that heterogeneous nucleation on ammonium sulfate may be an important pathway for atmospheric ice nucleation and cirrus cloud formation when solid ammonium sulfate aerosol particles are available for ice formation. This pathway for ice formation may be particularly significant near the tropical tropopause region where sulfates are abundant and other species known to be good ice nuclei are depleted.

  8. Scalability, Scintillation Readout and Charge Drift in a Kilogram Scale Solid Xenon Particle Detector

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, J. [Fermilab; Cease, H. [Fermilab; Jaskierny, W. F. [Fermilab; Markley, D. [Fermilab; Pahlka, R. B. [Fermilab; Balakishiyeva, D. [Florida U.; Saab, T. [Florida U.; Filipenko, M. [Erlangen - Nuremberg U., ECAP

    2014-10-23

    We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employ a liquid nitrogen cooled cryostat combined with a xenon purification and chiller system to measure the scintillation light output and electron drift speed from both the solid and liquid phases of xenon. Scintillation light output from sealed radioactive sources is measured by a set of high quantum efficiency photomultiplier tubes suitable for cryogenic applications. We observed a reduced amount of photons in solid phase compared to that in liquid phase. We used a conventional time projection chamber system to measure the electron drift time in a kilogram of solid xenon and observed faster electron drift speed in the solid phase xenon compared to that in the liquid phase.

  9. Suction-recirculation device for stabilizing particle flows within a solar powered solid particle receiver

    Science.gov (United States)

    Kolb, Gregory J [Albuquerque, NM

    2012-02-07

    A suction-recirculation device for stabilizing the flow of a curtain of blackened heat absorption particles falling inside of a solar receiver with an open aperture. The curtain of particles absorbs the concentrated heat from a solar mirror array reflected up to the receiver on a solar power tower. External winds entering the receiver at an oblique angle can destabilize the particle curtain and eject particles. A fan and ductwork is located behind the back wall of the receiver and sucks air out through an array of small holes in the back wall. Any entrained particles are separated out by a conventional cyclone device. Then, the air is recirculated back to the top of the receiver by injecting the recycled air through an array of small holes in the receiver's ceiling and upper aperture front wall. Since internal air is recirculated, heat losses are minimized and high receiver efficiency is maintained. Suction-recirculation velocities in the range of 1-5 m/s are sufficient to stabilize the particle curtain against external wind speeds in excess of 10 m/s.

  10. Fabrication of solid alginate particles containing functionalized MWCNTs using a microfluidic technique

    Science.gov (United States)

    Yang, Rulu; Li, Yanan; Cai, Weiwei; Zhang, Hua; Li, Jiao

    2017-05-01

    A series of solid alginate particles containing different amounts of functionalized multi-walled carbon nanotubes (MWCNTs) have been successfully prepared by microfluidic technique. The influence of MWCNTs doping on the surface morphology, structure and properties of calcium alginate (CA) particles has been investigated using SEM, FTIR, XRD, TGA and UV-Vis spectra. SEM indicates that the obtained hybrid particles are of good morphological characteristics, and its color changes from yellow to black which proves MWCNTs is successfully dispersed in CA particles. Moreover, the particles surface changes rough from smooth after MWCNTs doping. FTIR results verify the interactions between functional groups of CA and MWCNTs. Besides, the incorporation of MWCNTs to CA particles can efficiently enhance the thermal stability of CA particles at high temperatures, which is ascribed to the better thermal stability of MWCNTs as well as the interactions between MWCNTs and CA particles. The removal efficiency of CA particles doped with a lower percentage of MWCNTs (0.06 wt. %) for methylene blue is 96.38%, which is much higher than that of pure CA particles (61.21 %).

  11. Large, solid particles in the clouds of Venus - Do they exist?

    Science.gov (United States)

    Toon, O. B.; Ragent, B.; Colburn, D.; Blamont, J.; Cot, C.

    1984-01-01

    The evidence for solid mode 3 particles in the clouds of Venus is reexamined. The sampling characteristics of the cloud particle size spectrometer (LCPS) are reviewed, and reasons are pointed out for believing that relatively small differences in interpreting the measurements of this instrument could produce systematic errors. It is shown that all of the Pioneer Venus and Venera measurements can be understood if it is assumed that the large particles observed by the LCPS form the tail of the mode 2, H2SO4 size distribution.

  12. Formulation of solid nano-sized particles in a gel-forming system

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to novel formulations comprising a plurality of nano-sized solid particles and a gel-forming system, useful e.g. for imaging of the body of a mammal. Also described are kits comprising such formulations and imaging methods utilizing such formulations or kits....

  13. Alpha and beta particle induced scintillations in liquid and solid neon

    CERN Document Server

    Michniak, R A; McKinsey, D N; Doyle, J M

    2002-01-01

    Scintillations induced by alpha and beta particles in liquid and solid neon are studied and their light yield measured. Charged particle scintillation in neon is primarily in the extreme ultraviolet (EUV). We detect this EUV light by converting it to blue using a wavelength shifting fluor and detecting the blue light with a photomultiplier tube. It is observed that liquid neon is a somewhat less-efficient scintillator than liquid helium for both alpha and beta radiation while the light yield in solid neon is greater than in liquid helium. Based on our measurements of the relative light yields of liquid and solid neon to liquid helium whose absolute light yield has previously been determined, we find that an alpha source in liquid neon produces up to 5900 photons per MeV while a beta source produces up to 7400 photons per MeV. In solid neon, we find that an alpha particle produces up to 9300 photons per MeV while a beta particle produces up to 17,000 photons per MeV. We observe a significant dependence of the ...

  14. The study of an interaction of solid particles with various surfaces using TSM sensors.

    Science.gov (United States)

    Zhang, Qiliang; Lec, Ryszard M; Pourrezaei, Kambiz

    2006-01-01

    The interaction of solid particles with various surfaces has been experiencing growing interest in many areas of nanotechnology, colloidal science, and biology. In this paper the interactions of solid particles with the surface of piezoelectric thickness shear mode (TSM) sensors have been studied. A mechanical model has been presented to evaluate the effect of particle loading on the behavior of a TSM sensor. The main sources contributing to the interaction, such as Van der Waals force, friction force, and electrostatic force, are discussed. Experiments have been designed for 10-100 microm particles on the 5-MHz and 10-MHz TSM sensors. It has been shown that the resonant frequencies of the TSM sensors might increase or decrease depending on the interaction conditions. The results have shown that the TSM sensor technique could provide the information on the mass/size of a particle and the binding energy between a particle and the sensor surface. This technique may find its applications in characterizing the properties of an interaction between particles and various surfaces.

  15. Ion-Induced Emission of Charged Particles from Solid Hydrogen and Deuterium

    DEFF Research Database (Denmark)

    Børgesen, P.; Schou, Jørgen; Sørensen, H.

    1980-01-01

    Measurements have been made of the emission of both positive and negative particles from solid hydrogen and deuterium for normal incidence of H+, H2+, H+3, D2H+, D3+ and He+ ions up to 10 keV. For positive particles the emission coefficient increased with increasing energy of incidence to reach...... a value of 0.08 per atom for 10 keV H+ onto hydrogen. Apparently the positive particles are sputtered ones. The negative particles emitted are predominantly electrons. The emission coefficient per incident atom as a function of the velocity of the incident particle agrees fairly well with results...... published earlier for incidence of hydrogen and deuterium ions. However, systematic differences of up to 10% are now observed between the coefficients for the different types of ions....

  16. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study.

    Science.gov (United States)

    Jia, Shuying; Yang, Zhen; Ren, Kexin; Tian, Ziqi; Dong, Chang; Ma, Ruixue; Yu, Ge; Yang, Weiben

    2016-11-05

    Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5mg/L), due to π-π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics' removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Suspended solids and total phosphorus loads and their spatial differences in a lake-rich river basin as determined by automatic monitoring network.

    Science.gov (United States)

    Koskiaho, Jari; Tattari, Sirkka; Röman, Elina

    2015-04-01

    Turbidity datasets recorded by sensors during 2009-2012 were collected in five observation sites in the 2046-km2 Karjaanjoki River Basin in southern Finland. From these and water sample-based data, total phosphorus (TP) and total suspended solids (TSS) fluxes were determined. Based on calculations made with combined sensor- and water sample-based dataset, the annual loading from the Karjaanjoki Basin in 2009-2012 varied between 11,300 and 23,900[corrected] kg of TP and 3300-8400 t of TSS. As compared with two other river basins discharging into the Baltic Sea in southern Finland, the TP loading from Karjaanjoki was low because the summed retention in the two major lakes Hiidenvesi and Lohjanjärvi was high: 48 and 49% of the TSS and TP loadings generated in their upstream catchments, respectively. Depending on how water sampling took place in relation to peak flow events, differences of annual fluxes as determined by "water samples only" vs. "sensors and water samples" data varied between -22 and 26 for TP and -31 and 39% for TSS. This study proved automatic monitoring being useful when spatial differences and lake retention of riverine fluxes are explored. Moreover, the loading estimates calculated on the base of well-functioning and well-maintained automatic monitoring system, supported with water sampling during periods when devices were off, are undoubtedly more accurate than those based on manual grab water sampling only. The findings of this study were in line with, and well contribute to, earlier Finnish and international research on automatic water quality monitoring.

  18. Three-dimensional solid particle positions in a flow via multiangle off-axis digital holography.

    Science.gov (United States)

    Boucherit, Sebti; Bouamama, Larbi; Benchickh, Halim; Lenoir, Jean-Michel; Simoëns, Serge

    2008-09-15

    We present a new development of digital off-axis (OA) holography for determining the instantaneous solid particle positions in a flow. This holographic imaging method uses a CCD camera for the simultaneous digital recording of two views of digital Fresnel OA holograms on the same support. The reconstruction is obtained numerically. The method provides two orthogonal views of the same flow area of interest at the same instant. It helps to overcome the depth of focus problem existing for the particle image reconstructions and that is inherent to the method. This method has the advantage of being simpler than the methods presently available, and it does not suffer from the flaws of in-line holographic configuration. Furthermore it is completely digital and thus avoids the cumbersome analysis following hologram recording. Digital holograms and digital reconstructions are obtained for solid particles of 200 mum moving into a stirred flow cell of 5 cm(3).

  19. Flow Mapping in a Gas-Solid Riser via Computer Automated Radioactive Particle Tracking (CARPT)

    Energy Technology Data Exchange (ETDEWEB)

    Muthanna Al-Dahhan; Milorad P. Dudukovic; Satish Bhusarapu; Timothy J. O' hern; Steven Trujillo; Michael R. Prairie

    2005-06-04

    Statement of the Problem: Developing and disseminating a general and experimentally validated model for turbulent multiphase fluid dynamics suitable for engineering design purposes in industrial scale applications of riser reactors and pneumatic conveying, require collecting reliable data on solids trajectories, velocities ? averaged and instantaneous, solids holdup distribution and solids fluxes in the riser as a function of operating conditions. Such data are currently not available on the same system. Multiphase Fluid Dynamics Research Consortium (MFDRC) was established to address these issues on a chosen example of circulating fluidized bed (CFB) reactor, which is widely used in petroleum and chemical industry including coal combustion. This project addresses the problem of lacking reliable data to advance CFB technology. Project Objectives: The objective of this project is to advance the understanding of the solids flow pattern and mixing in a well-developed flow region of a gas-solid riser, operated at different gas flow rates and solids loading using the state-of-the-art non-intrusive measurements. This work creates an insight and reliable database for local solids fluid-dynamic quantities in a pilot-plant scale CFB, which can then be used to validate/develop phenomenological models for the riser. This study also attempts to provide benchmark data for validation of Computational Fluid Dynamic (CFD) codes and their current closures. Technical Approach: Non-Invasive Computer Automated Radioactive Particle Tracking (CARPT) technique provides complete Eulerian solids flow field (time average velocity map and various turbulence parameters such as the Reynolds stresses, turbulent kinetic energy, and eddy diffusivities). It also gives directly the Lagrangian information of solids flow and yields the true solids residence time distribution (RTD). Another radiation based technique, Computed Tomography (CT) yields detailed time averaged local holdup profiles at

  20. Investigation of Gas Solid Fluidized Bed Dynamics with Non-Spherical Particles

    Energy Technology Data Exchange (ETDEWEB)

    Choudhuri, Ahsan [Univ. of Texas, El Paso, TX (United States). Dept. of Mechanical Engineering

    2013-06-30

    One of the largest challenges for 21st century is to fulfill global energy demand while also reducing detrimental impacts of energy generation and use on the environment. Gasification is a promising technology to meet the requirement of reduced emissions without compromising performance. Coal gasification is not an incinerating process; rather than burning coal completely a partial combustion takes place in the presence of steam and limited amounts of oxygen. In this controlled environment, a chemical reaction takes place to produce a mixture of clean synthetic gas. Gas-solid fluidized bed is one such type of gasification technology. During gasification, the mixing behavior of solid (coal) and gas and their flow patterns can be very complicated to understand. Many attempts have taken place in laboratory scale to understand bed hydrodynamics with spherical particles though in actual applications with coal, the particles are non-spherical. This issue drove the documented attempt presented here to investigate fluidized bed behavior using different ranges of non-spherical particles, as well as spherical. For this investigation, various parameters are controlled that included particle size, bed height, bed diameter and particle shape. Particles ranged from 355 µm to 1180 µm, bed diameter varied from 2 cm to 7 cm, two fluidized beds with diameters of 3.4 cm and 12.4 cm, for the spherical and non-spherical shaped particles that were taken into consideration. Pressure drop was measured with increasing superficial gas velocity. The velocity required in order to start to fluidize the particle is called the minimum fluidization velocity, which is one of the most important parameters to design and optimize within a gas-solid fluidized bed. This minimum fluidization velocity was monitored during investigation while observing variables factors and their effect on this velocity. From our investigation, it has been found that minimum fluidization velocity is independent of bed

  1. Impact of in situ polymer coating on particle dispersion into solid laser-generated nanocomposites.

    Science.gov (United States)

    Wagener, Philipp; Brandes, Gudrun; Schwenke, Andreas; Barcikowski, Stephan

    2011-03-21

    The crucial step in the production of solid nanocomposites is the uniform embedding of nanoparticles into the polymer matrix, since the colloidal properties or specific physical properties are very sensitive to particle dispersion within the nanocomposite. Therefore, we studied a laser-based generation method of a nanocomposite which enables us to control the agglomeration of nanoparticles and to increase the single particle dispersion within polyurethane. For this purpose, we ablated targets of silver and copper inside a polymer-doped solution of tetrahydrofuran by a picosecond laser (using a pulse energy of 125 μJ at 33.3 kHz repetition rate) and hardened the resulting colloids into solid polymers. Electron microscopy of these nanocomposites revealed that primary particle size, agglomerate size and particle dispersion strongly depend on concentration of the polyurethane added before laser ablation. 0.3 wt% polyurethane is the optimal polymer concentration to produce nanocomposites with improved particle dispersion and adequate productivity. Lower polyurethane concentration results in agglomeration whereas higher concentration reduces the production rate significantly. The following evaporation step did not change the distribution of the nanocomposite inside the polyurethane matrix. Hence, the in situ coating of nanoparticles with polyurethane during laser ablation enables simple integration into the structural analogue polymer matrix without additives. Furthermore, it was possible to injection mold these in situ-stabilized nanocomposites without affecting particle dispersion. This clarifies that sufficient in situ stabilization during laser ablation in polymer solution is able to prevent agglomeration even in a hot polymer melt.

  2. Inhibition effects of suspended and accumulated particles on adhesion and development of Undaria pinnatifida zoospores; Kaisuichu kendaku ryushi no chinko taiseki ga wakame yusoshi no chakusei to sono seicho ni oyobosu sogai sayo

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Y.; Maruyama, T.; Takami, T. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering; Miura, A. [Aomori University, Aomori (Japan). Faculty of Engineering

    1998-10-10

    In order to reveal effects of suspended and accumulated particles in sea water on the adhesion and development of Undaria pinnatifida zoospores on the substratum, adhesion Inhibition tests were conducted using kaolinite as model particles under the following three cases of natural conditions; Case 1: suspended particles together with zoospores, Case 2: zoospores released after accumulation of particles on the substratum, and Case 3: accumulated particles on zoospores adhered on the substratum. Case 2 provided the most effective inhibition for the adhesion of zoospores, and 50% of effective concentration of particles was 29{mu}g/cm{sup 2}. Zoospores adhered on the substratum were developed to gametophytes even when covered and deposited by kaolinite particles. It was difficult for these gametophytes to develop to sporophytes. Remarkable inhibition was observed in the development process via gametophytes and sporophytes to young sporophytes. The inhibition was observed for crust spores at lower concentration. Higher adhesion performance on the substratum was found for zoospores. 18 refs., 4 figs., 1 tab.

  3. The Effect of Solid Constituent Particle Size Distributions on TP-H1148 Propellant Slag

    Science.gov (United States)

    May, Douglas H.; Miles, William L.; Taylor, David S.; Rackham, Jon L.

    1997-01-01

    Special aluminum and ammonium perchlorate (AP) particle size distributions were prepared for a matrix of five-inch diameter, center-perforated (CP) motor tests to measure the aluminum oxide slag response in Space Shuttle Reusable Solid Rocket Motor (RSRM) propellant. Previous tests of TP-H1148 propellant in five-inch CP spin motors have shown a correlation between aluminum particle size and generated slag. The motors for this study were cast from thirteen five-gallon propellant mixes which used five particle size levels of aluminum powder, five of unground AP and three of ground AP. Aluminum had the greatest effect on slag formation, the more coarse fractions causing greater slag quantities and larger slag particles. Unground AP had about half the effect of aluminum with the coarser fractions again producing more and larger sized slag particles. The variation in ground AP did not have a significant effect on slag formation. Quench bomb tests showed the same trends as the spin motors, that is, larger aluminum and AP particle size distributions generated larger slag particles leaving the propellant surface. Cured propellant mechanical properties were also impacted by particle size variation.

  4. Integration of active pharmaceutical ingredient solid form selection and particle engineering into drug product design.

    Science.gov (United States)

    Ticehurst, Martyn David; Marziano, Ivan

    2015-06-01

    This review seeks to offer a broad perspective that encompasses an understanding of the drug product attributes affected by active pharmaceutical ingredient (API) physical properties, their link to solid form selection and the role of particle engineering. While the crucial role of active pharmaceutical ingredient (API) solid form selection is universally acknowledged in the pharmaceutical industry, the value of increasing effort to understanding the link between solid form, API physical properties and drug product formulation and manufacture is now also being recognised. A truly holistic strategy for drug product development should focus on connecting solid form selection, particle engineering and formulation design to both exploit opportunities to access simpler manufacturing operations and prevent failures. Modelling and predictive tools that assist in establishing these links early in product development are discussed. In addition, the potential for differences between the ingoing API physical properties and those in the final product caused by drug product processing is considered. The focus of this review is on oral solid dosage forms and dry powder inhaler products for lung delivery. © 2015 Royal Pharmaceutical Society.

  5. Multisized Inert Particle Loading for Solid Rocket Axial Combustion Instability Suppression

    Directory of Open Access Journals (Sweden)

    David R. Greatrix

    2012-01-01

    Full Text Available In the present investigation, various factors and trends, related to the usage of two or more sets of inert particles comprised of the same material (nominally aluminum but at different diameters for the suppression of axial shock wave development, are numerically predicted for a composite-propellant cylindrical-grain solid rocket motor. The limit pressure wave magnitudes at a later reference time in a given pulsed firing simulation run are collected for a series of runs at different particle sizes and loading distributions and mapped onto corresponding attenuation trend charts. The inert particles’ presence in the central core flow is demonstrated to be an effective means of instability symptom suppression, in correlating with past experimental successes in the usage of particles. However, the predicted results of this study suggest that one needs to be careful when selecting more than one size of particle for a given motor application.

  6. Thermally developed peristaltic propulsion of magnetic solid particles in biorheological fluids

    Science.gov (United States)

    Bhatti, M. M.; Zeeshan, A.; Tripathi, D.; Ellahi, R.

    2017-11-01

    In this article, effects of heat and mass transfer on MHD peristaltic motion of solid particles in a dusty fluid are investigated. The effects of nonlinear thermal radiation and Hall current are also taken into account. The relevant flow analysis is modelled for fluid phase and dust phase in wave frame by means of Casson fluid model. Computation of solutions is presented for velocity profile, temperature profile and concentration profile. The effects of all the physical parameters such as particle volume fraction, Hartmann number, Hall Effect, Prandtl number, Eckert number, Schmidt number and Soret number are discussed mathematically and graphically. It is noted that the influence of magnetic field and particle volume fraction opposes the flow. Also, the impact of particle volume fraction is quite opposite on temperature and concentration profile. This model is applicable in smart drug delivery systems and bacteria movement in urine flow through the ureter.

  7. Measurement and Image Processing Techniques for Particle Image Velocimetry Using Solid-Phase Carbon Dioxide

    Science.gov (United States)

    2014-03-27

    for particle image velocimetry (PIV) should not contaminate closed circuit wind tunnels and minimize residual deposits on walls. Solid carbon dioxide...All of these seeding requirements have led to the use of solid seed materials such as Titanium Dioxide (TiO2), Aluminum Oxide (Al2O3), Polystyrene and...from the inner log law and Pitot probe result near U/U0 = 0.9276 and then continues past the free stream velocity. This free stream “drift” is evident

  8. Numerical investigation of flow parameters for solid rigid spheroidal particle in a pulsatile pipe flow

    Science.gov (United States)

    Varghese, Joffin; Jayakumar, J. S.

    2017-09-01

    Quantifying, forecasting and analysing the displacement rates of suspended particles are essential while discussing about blood flow analysis. Because blood is one of the major organs in the body, which enables transport phenomena, comprising of numerous blood cells. In order to model the blood flow, a flow domain was created and numerically simulated. Flow field velocity in the stream is solved utilizing Finite Volume Method utilizing FVM unstructured solver. In pulsatile flow, the effect of parameters such as average Reynolds number, tube radius, particle size and Womersley number are taken into account. In this study spheroidal particle trajectory in axial direction is simulated at different values of pulsating frequency including 1.2 Hz, 3.33 Hz and 4.00 Hz and various densities including 1005 kg/m3 and 1025 kg/m3 for the flow domain. The analysis accomplishes the interaction study of blood constituents for different flow situations which have applications in diagnosis and treatment of cardio vascular related diseases.

  9. Self-Suspended Suspensions of Covalently Grafted Hairy Nanoparticles

    KAUST Repository

    Choudhury, Snehashis

    2015-03-17

    © 2015 American Chemical Society. Dispersions of small particles in liquids have been studied continuously for almost two centuries for their ability to simultaneously advance understanding of physical properties of fluids and their widespread use in applications. In both settings, the suspending (liquid) and suspended (solid) phases are normally distinct and uncoupled on long length and time scales. In this study, we report on the synthesis and physical properties of a novel family of covalently grafted nanoparticles that exist as self-suspended suspensions with high particle loadings. In such suspensions, we find that the grafted polymer chains exhibit unusual multiscale structural transitions and enhanced conformational stability on subnanometer and nanometer length scales. On mesoscopic length scales, the suspensions display exceptional homogeneity and colloidal stability. We attribute this feature to steric repulsions between grafted chains and the space-filling constraint on the tethered chains in the single-component self-suspended materials, which inhibits phase segregation. On macroscopic length scales, the suspensions exist as neat fluids that exhibit soft glassy rheology and, counterintuitively, enhanced elasticity with increasing temperature. This feature is discussed in terms of increased interpenetration of the grafted chains and jamming of the nanoparticles. (Chemical Presented).

  10. Gas−Solid Turbulent Flow in a Circulating Fluidized Bed Riser: Experimental and Numerical Study of Monodisperse Particle Systems

    NARCIS (Netherlands)

    He, Y.; Deen, N.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2009-01-01

    Hydrodynamics of gas-particle two-phase turbulent flow in a circulating fluidized bed riser is studied experimentally by particle image velocimetry (PIV) and numerically with the use of a 3D discrete hard sphere particle model (DPM). The influence of the superficial gas velocity and the solids flux

  11. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Shuying [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Zhen, E-mail: yangzhen@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Ren, Kexin [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Tian, Ziqi [Department of Chemistry, University of California, Riverside, CA 92521 (United States); Dong, Chang; Ma, Ruixue; Yu, Ge [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Weiben, E-mail: yangwb007@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China)

    2016-11-05

    Highlights: • Novel amino-acid-modified-chitosan flocculants are employed to remove antibiotics. • Effects of different structures of amino acids and antibiotics are investigated. • Correlation analysis shows coexisted kaolin and HA have synergistic removal effect. • Theoretical DFT calculation clarifies the interactions in molecular level. - Abstract: Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4 mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5 mg/L), due to π–π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics’ removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.

  12. From porous gold nanocups to porous nanospheres and solid particles - A new synthetic approach

    KAUST Repository

    Ihsan, Ayesha

    2015-05-01

    We report a versatile approach for the synthesis of porous gold nanocups, porous gold nanospheres and solid gold nanoparticles. Gold nanocups are formed by the slow reduction of gold salt (HAuCl4{dot operator}3H2O) using aminoantipyrene (AAP) as a reducing agent. Adding polyvinylpyrrolidone (PVP) to the gold salt followed by reduction with AAP resulted in the formation of porous gold nanospheres. Microwave irradiation of both of these porous gold particles resulted in the formation of slightly smaller but solid gold particles. All these nanoparticles are thoroughly characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and bright-field tomography. Due to the larger size, porous nature, low density and higher surface area, these nanomaterials may have interesting applications in catalysis, drug delivery, phototherapy and sensing.

  13. NATO Advanced Research Workshop on Ionization of Solids by Heavy Particles

    CERN Document Server

    1993-01-01

    This book collects the papers presented at the NATO Advanced Research Workshop on "Ionization of Solids by Heavy Particles", held in Giardini-Naxos (Taormina), Italy, on June 1 -5, 1992. The meeting was the first to gather scientists to discuss the physics of electron emission and other ionization effects occurring during the interaction of heavy particles with condensed matter. The central problem in the field is how to use observations of electron emission and final radiation damage to understand what happens inside the solid, like excitation mechanisms, the propagation of the electronic excitation along different pathways, and surface effects. The ARW began with a brief survey of the field, stressing the unknowns. It was pointed out that ionization theories can only address the very particular case of weak perturbations. For this problem, this meant high speed, low-charged projectiles (a perturbation treatment of interactions with slow, highly charged ions was later presented). Only semi-empirical ...

  14. Numerical Evaluation of the Use of Aluminum Particles for Enhancing Solid Rocket Motor Combustion Stability

    OpenAIRE

    David Greatrix

    2015-01-01

    The ability to predict the expected internal behaviour of a given solid-propellant rocket motor under transient conditions is important. Research towards predicting and quantifying undesirable transient axial combustion instability symptoms typically necessitates a comprehensive numerical model for internal ballistic simulation under dynamic flow and combustion conditions. On the mitigation side, one in practice sees the use of inert or reactive particles for the suppression of pressure wave ...

  15. Optical propagation in linear media atmospheric gases and particles, solid-state components, and water

    CERN Document Server

    Thomas, Michael E

    2006-01-01

    PART I: Background Theory and Measurement. 1. Optical Electromagnetics I. 2. Optical Electromagnetics II. 3. Spectroscopy of Matter. 4. Electrodynamics I: Macroscopic Interaction of Light and Matter. 5. Electrodynamics II: Microscopic Interaction of Light and Matter. 6. Experimental Techniques. PART II: Practical Models for Various Media. 7. Optical Propagation in Gases and the Atmosphere of the Earth. 8. Optical Propagation in Solids. 9. Optical Propagation in Liquids. 10. Particle Absorption and Scatter. 11. Propagation Background and Noise

  16. Assessment of the Stability of Condensed Solid Substance Ignition by a Hot Particle

    Directory of Open Access Journals (Sweden)

    Glushkov Dmitrii O.

    2015-01-01

    Full Text Available The paper presents a numerical simulation of composite fuel ignition by a disc-shaped hot metal particle. The study establishes the temperature and the source size limits, which are necessary and sufficient for condensed substance ignition. A diagram with coordinates “a heat flow the amplitude – ignition delay time” has been presented. The diagram shows the area of the sustainable initiate combustion of composite solid fuel at local heating by the source with limited energy capacity.

  17. Assessment of the Stability of Condensed Solid Substance Ignition by a Hot Particle

    OpenAIRE

    Glushkov Dmitrii O.; Nyashina Galina S.; Vershinina Ksenia Yu.

    2015-01-01

    The paper presents a numerical simulation of composite fuel ignition by a disc-shaped hot metal particle. The study establishes the temperature and the source size limits, which are necessary and sufficient for condensed substance ignition. A diagram with coordinates “a heat flow the amplitude – ignition delay time” has been presented. The diagram shows the area of the sustainable initiate combustion of composite solid fuel at local heating by the source with limited energy capacity.

  18. Development of stress boundary conditions in smoothed particle hydrodynamics (SPH) for the modeling of solids deformation

    Science.gov (United States)

    Douillet-Grellier, Thomas; Pramanik, Ranjan; Pan, Kai; Albaiz, Abdulaziz; Jones, Bruce D.; Williams, John R.

    2017-10-01

    This paper develops a method for imposing stress boundary conditions in smoothed particle hydrodynamics (SPH) with and without the need for dummy particles. SPH has been used for simulating phenomena in a number of fields, such as astrophysics and fluid mechanics. More recently, the method has gained traction as a technique for simulation of deformation and fracture in solids, where the meshless property of SPH can be leveraged to represent arbitrary crack paths. Despite this interest, application of boundary conditions within the SPH framework is typically limited to imposed velocity or displacement using fictitious dummy particles to compensate for the lack of particles beyond the boundary interface. While this is enough for a large variety of problems, especially in the case of fluid flow, for problems in solid mechanics there is a clear need to impose stresses upon boundaries. In addition to this, the use of dummy particles to impose a boundary condition is not always suitable or even feasibly, especially for those problems which include internal boundaries. In order to overcome these difficulties, this paper first presents an improved method for applying stress boundary conditions in SPH with dummy particles. This is then followed by a proposal of a formulation which does not require dummy particles. These techniques are then validated against analytical solutions to two common problems in rock mechanics, the Brazilian test and the penny-shaped crack problem both in 2D and 3D. This study highlights the fact that SPH offers a good level of accuracy to solve these problems and that results are reliable. This validation work serves as a foundation for addressing more complex problems involving plasticity and fracture propagation.

  19. Hypercrosslinked particles for the extraction of sweeteners using dispersive solid-phase extrction from environmental samples.

    Science.gov (United States)

    Lakade, Sameer S; Zhou, Qing; Li, Aimin; Borrull, Francesc; Fontanals, Núria; Marcé, Rosa M

    2017-12-26

    This work presents a new extraction material, namely, Q-100, based on hypercrosslinked magnetic particles, which was tested in dispersive solid-phase extraction for a group of sweeteners from environmental samples. The hypercrosslinked Q-100 magnetic particles had the advantage of suitable pore size distribution and high surface area, and showed good retention behavior towards sweeteners. Different dispersive solid-phase extraction parameters such as amount of magnetic particles or extraction time were optimized. Under optimum conditions, Q-100 showed suitable apparent recovery, ranging in the case of river water sample from 21 to 88% for all the sweeteners, except for alitame (12%). The validated method based on dispersive solid-phase extraction using Q-100 followed by liquid chromatography with tandem mass spectrometry provided good linearity and limits of quantification between 0.01 and 0.1 μg L -1 . The method was applied to analyze samples from river water and effluent wastewater, and four sweeteners (acesulfame, saccharin, cyclamate and sucralose) were found in both types of sample. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. 3D Simulation of Dam-break effect on a Solid Wall using Smoothed Particle Hydrodynamics

    CERN Document Server

    Suprijadi,; Naa, Christian; Putra, Anggy Trisnawan

    2013-01-01

    Dam is built for water supply, water flow or flooding control and electricity energy storage, but in other hand, dam is one of the most dangerous natural disaster in many countries including in Indonesia. The impact of dam break in neighbour area and is huge and many flooding in remote area, as happen in Dam Situ Gintung in Tangerang (close to Jakarta) in 2009. Smoothed Particle Hydrodynamics (SPH), is one of numerical method based on Lagrangian grid which is ap- plied in astrophysical simulation may be used to solve the simulation on dam break effect. The development of SPH methods become alternative methods to solving Navier Stokes equation, which is main key in fluid dynamic simulation. In this paper, SPH is developed for supporting solid par- ticles in use for 3D dam break effect (3D-DBE) simulation. Solid particle have been treated same as fluid particles with additional calculation for converting gained position became translation and rotation of solid object in a whole body. With this capability, the r...

  1. Combined discrete particle and continuum model predicting solid-state fermentation in a drum fermentor.

    Science.gov (United States)

    Schutyser, M A I; Briels, W J; Boom, R M; Rinzema, A

    2004-05-20

    The development of mathematical models facilitates industrial (large-scale) application of solid-state fermentation (SSF). In this study, a two-phase model of a drum fermentor is developed that consists of a discrete particle model (solid phase) and a continuum model (gas phase). The continuum model describes the distribution of air in the bed injected via an aeration pipe. The discrete particle model describes the solid phase. In previous work, mixing during SSF was predicted with the discrete particle model, although mixing simulations were not carried out in the current work. Heat and mass transfer between the two phases and biomass growth were implemented in the two-phase model. Validation experiments were conducted in a 28-dm3 drum fermentor. In this fermentor, sufficient aeration was provided to control the temperatures near the optimum value for growth during the first 45-50 hours. Several simulations were also conducted for different fermentor scales. Forced aeration via a single pipe in the drum fermentors did not provide homogeneous cooling in the substrate bed. Due to large temperature gradients, biomass yield decreased severely with increasing size of the fermentor. Improvement of air distribution would be required to avoid the need for frequent mixing events, during which growth is hampered. From these results, it was concluded that the two-phase model developed is a powerful tool to investigate design and scale-up of aerated (mixed) SSF fermentors. Copyright 2004 Wiley Periodicals, Inc.

  2. The Way that PEGyl-DSPC Liposomal Doxorubicin Particles Penetrate into Solid Tumor Tissue

    Directory of Open Access Journals (Sweden)

    Xing Qing Pan

    2006-01-01

    Full Text Available Background: For enhancement of drug effectiveness and reduction of drug toxicity, liposomal drugs have been studied in laboratories and clinics for decades. Although the results obtained from in vitro are encouraging, but the results from in vivo tests were not satisfactory. The main reasons for this situation were that we do not have enough information about the way how liposomal particles penetrating into solid tumor tissue, and what happening to the liposome particles after they got into the tumor tissue. In this paper, we are going to report the results from our observations on the way folic acid targeted and non-targeted PEGyl-DSPC liposomal doxorubicin particles penetrate into solid tumor tissue.Methods: Subcutaneous transplanted murine L1210JF solid tumors in mice were used as a model. PEGyl liposomal doxorubicins were injected through tail venue, and tumor tissue samples were collected at special time points. Cryosections were cut and dried by a fl owing of air after mounted on the slides right away. Then the dried cryosections were stained in water systems; the blood vessel cells were stained with green fluorescent FITC labeled antibody against CD31 antigen; the nuclei of the living cells were stained with a blue fluorescent dye DAPI. Since the whole procedure was carried out in aquatic system, the red color fluorescent liposomal doxorubicin particles remain visible under fl uorescence microscope.Results: Both folate conjugated and non-conjugated PEGyl-DSPC liposomal doxorubicin particles were only leaking out from the broken holes of blood vessels with a special direction and spread out for a limited distance, which was similar to the results showed before, in that observation a latex microsphere sample was used as a model.

  3. The Way that PEGyl-DSPC Liposomal Doxorubicin Particles Penetrate into Solid Tumor Tissue

    Directory of Open Access Journals (Sweden)

    Xing Qing Pan

    2006-01-01

    Full Text Available Background For enhancement of drug effectiveness and reduction of drug toxicity, liposomal drugs have been studied in laboratories and clinics for decades. Although the results obtained from in vitro are encouraging, but the results from in vivo tests were not satisfactory. The main reasons for this situation were that we do not have enough information about the way how liposomal particles penetrating into solid tumor tissue, and what happening to the liposome particles after they got into the tumor tissue. In this paper, we are going to report the results from our observations on the way folic acid targeted and non-targeted PEGyl-DSPC liposomal doxorubicin particles penetrate into solid tumor tissue. Methods Subcutaneous transplanted murine L1210JF solid tumors in mice were used as a model. PEGyl liposomal doxorubicins were injected through tail venue, and tumor tissue samples were collected at special time points. Cryosections were cut and dried by a flowing of air after mounted on the slides right away. Then the dried cryosections were stained in water systems; the blood vessel cells were stained with green fluorescent FITC labeled antibody against CD31 antigen; the nuclei of the living cells were stained with a blue fluorescent dye DAPI. Since the whole procedure was carried out in aquatic system, the red color fluorescent liposomal doxorubicin particles remain visible under fluorescence microscope. Results Both folate conjugated and non-conjugated PEGyl-DSPC liposomal doxorubicin particles were only leaking out from the broken holes of blood vessels with a special direction and spread out for a limited distance, which was similar to the results showed before, in that observation a latex microsphere sample was used as a model. Abbreviations DSPC:1, 2-Distearoyl-sn-Glycero-3-phosphatylcholine; PEG2000-DSPC:1, 2-Distearoyl-sn-Glycero 3-phosphatidylethanolamine-N-[methoxy(polyethylene glycol-2000]; Folate-PEG3400-DSPE:1, 2-Distearoyl

  4. Infrared spectroscopy of solid mixed ammonia-water and acetylene-water aerosol particles

    Science.gov (United States)

    Isenor, Merrill; Signorell, Ruth

    2015-04-01

    Mixed water aerosols are important components of planetary and lunar atmospheres. In this work, we use rapid-scan Fourier transform infrared (IR) spectroscopy to study solid ammonia-water and acetylene-water aerosol particles formed in a bath gas cooling cell at 78 K. With this set-up, we record time-dependent extinction spectra of particle ensembles in the mid-IR to monitor changes to the internal structure of the aerosol particles. Both ammonia-water and acetylene-water were found to form molecularly mixed structures. The mixing is observed by monitoring the profile for the ammonia ν2 band and the acetylene ν5 band, both of which are sensitive to particle properties. Depending on the injection conditions, the mixed particles form either immediately after sample injection or after a short mixing period of several tens of minutes. We confirm the formation of mixed particles by comparing the experimental spectra with spectra calculated with the vibrational exciton model.

  5. Numerical Evaluation of the Use of Aluminum Particles for Enhancing Solid Rocket Motor Combustion Stability

    Directory of Open Access Journals (Sweden)

    David Greatrix

    2015-02-01

    Full Text Available The ability to predict the expected internal behaviour of a given solid-propellant rocket motor under transient conditions is important. Research towards predicting and quantifying undesirable transient axial combustion instability symptoms typically necessitates a comprehensive numerical model for internal ballistic simulation under dynamic flow and combustion conditions. On the mitigation side, one in practice sees the use of inert or reactive particles for the suppression of pressure wave development in the motor chamber flow. With the focus of the present study placed on reactive particles, a numerical internal ballistic model incorporating relevant elements, such as a transient, frequency-dependent combustion response to axial pressure wave activity above the burning propellant surface, is applied to the investigation of using aluminum particles within the central internal flow (particles whose surfaces nominally regress with time, as a function of current particle size, as they move downstream as a means of suppressing instability-related symptoms in a cylindrical-grain motor. The results of this investigation reveal that the loading percentage and starting size of the aluminum particles have a significant influence on reducing the resulting transient pressure wave magnitude.

  6. Potential of High Spatial and Temporal Ocean Color Satellite Data to Study the Dynamics of Suspended Particles in a Micro-Tidal River Plume

    Directory of Open Access Journals (Sweden)

    Anouck Ody

    2016-03-01

    Full Text Available Ocean color satellite sensors are powerful tools to study and monitor the dynamics of suspended particulate matter (SPM discharged by rivers in coastal waters. In this study, we test the capabilities of Landsat-8/Operational Land Imager (OLI, AQUA&TERRA/Moderate Resolution Imaging Spectroradiometer (MODIS and MSG-3/Spinning Enhanced Visible and Infrared Imager (SEVIRI sensors in terms of spectral, spatial and temporal resolutions to (i estimate the seawater reflectance signal and then SPM concentrations and (ii monitor the dynamics of SPM in the Rhône River plume characterized by moderately turbid surface waters in a micro-tidal sea. Consistent remote-sensing reflectance (Rrs values are retrieved in the red spectral bands of these four satellite sensors (median relative difference less than ~16% in turbid waters. By applying a regional algorithm developed from in situ data, these Rrs are used to estimate SPM concentrations in the Rhône river plume. The spatial resolution of OLI provides a detailed mapping of the SPM concentration from the downstream part of the river itself to the plume offshore limits with well defined small-scale turbidity features. Despite the low temporal resolution of OLI, this should allow to better understand the transport of terrestrial particles from rivers to the coastal ocean. These details are partly lost using MODIS coarser resolutions data but SPM concentration estimations are consistent, with an accuracy of about 1 to 3 g·m−3 in the river mouth and plume for spatial resolutions from 250 m to 1 km. The MODIS temporal resolution (2 images per day allows to capture the daily to monthly dynamics of the river plume. However, despite its micro-tidal environment, the Rhône River plume shows significant short-term (hourly variations, mainly controlled by wind and regional circulation, that MODIS temporal resolution failed to capture. On the contrary, the high temporal resolution of SEVIRI makes it a powerful tool to

  7. Characterization of the constitutive behavior of municipal solid waste considering particle compressibility.

    Science.gov (United States)

    Lü, Xilin; Zhai, Xinle; Huang, Maosong

    2017-11-01

    This paper presents a characterization of the mechanical behavior of municipal solid waste (MSW) under consolidated drained and undrained triaxial conditions. The constitutive model was established based on a deviatoric hardening plasticity model. A power form function and incremental hyperbolic form function were proposed to describe the shear strength and the hardening role of MSW. The stress ratio that corresponds to the zero dilatancy was not fixed but depended on mean stress, making the Rowe's rule be able to describe the stress-dilatancy of MSW. A pore water pressure reduction coefficient, which attributed to the compressibility of a particle and the solid matrix, was introduced to the effective stress formulation to modify the Terzaghi's principle. The effects of particle compressibility and solid matrix compressibility on the undrained behavior of MSW were analyzed by parametric analysis, and the changing characteristic of stress-path, stress-strain, and pore-water pressure were obtained. The applicability of the proposed model on MSW under drained and undrained conditions was verified by model predictions of three triaxial tests. The comparison between model simulations and experiments indicated that the proposed model can capture the observed different characteristics of MSW response from normal soil, such as nonlinear shear strength, pressure dependent stress dilatancy, and the reduced value of pore water pressure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Long-term effects of clear-cutting and site preparation on carbon, nitrogen, phosphorus and suspended solids export to boreal first order streams

    Science.gov (United States)

    Palviainen, Marjo; Finér, Leena; Laurén, Ari; Launiainen, Samuli; Piirainen, Sirpa; Mattsson, Tuija; Starr, Mike

    2013-04-01

    Clear-cutting has been observed to generally increase leaching and element exports to adjacent watercourses. Most studies on the effects of clear-cutting on nutrient export in north European boreal forests have been short-term and were carried out in the 1970s and 1980s when forestry practices were different from those of today. Nowadays clear-cut areas are smaller, soil preparation methods are lighter (less soil disturbance), and buffer zones are left along watercourses. Several hundred thousand hectares of forests are clear-cut and soils are scarified before regeneration operations in Fennoscandia, but little is known of the long-term impacts of the current methods on the surface water quality. We studied the long-term (14 years) effects of clear-cutting and site preparation on runoff (mm) and the export of total nitrogen (total N), total organic nitrogen (TON), ammonium (NH4-N), nitrate (NO3-N), total phosphorus (total P), phosphate (PO4-P), total organic carbon (TOC) and suspended solids (SS) in two paired-catchments in Eastern Finland. In accordance with current forest management guidelines, clear cutting (stem-only removal) were carried out on 34% (C34) and 12% (C12) of the area of the treated catchments, scarification carried out after 2 years and planting with Scots pine seedlings after 3 years. Buffer zones were left between the clear-cut areas and the catchment outlet stream. In the case of the C34 catchment, clear-cutting increased annual runoff and exports of total N, TON, NO3-N, PO4-P and SS. Annual runoff increased by 4 - 102 mm (1-30%). The annual exports of total N, TON, NO3-N, PO4-P and SS increased by at most 0.36 (72%), 0.35 (76%), 0.15 (1056%), 0.002 (35%) and 2.0 (715%) kg/ha, respectively. For the C12 catchment, annual runoff did not change and only exports of PO4-P and SS increased. Annual export of PO4-P increased by at maximum 0.007 kg/ha (69%) and that of SS by at maximum 0.55 kg/ha (271%). Clear-cutting induced increases in runoff and

  9. The spatial and temporal variation of total suspended solid concentration in Pearl River Estuary during 1987-2015 based on remote sensing.

    Science.gov (United States)

    Wang, Chongyang; Li, Weijiao; Chen, Shuisen; Li, Dan; Wang, Danni; Liu, Jia

    2018-03-15

    The movement and migration of total suspended solid (TSS) are the essential component of global material cycling and change. Based on the TSS concentrations retrieved from 112 scenes of Landsat remote sensing imageries during 1987-2015, the spatial and temporal variations of TSS concentration in high flow season and low flow seasons of six sub-regions (west shoal, west channel, middle shoal, east channel, east shoal and Pearl River Estuary Chinese White Dolphin National Nature Reserve and its adjacent waters (NNR)) of Pearl River Estuary (PRE) were analyzed and compared by statistical simulation. It was found that TSS concentrations in east and west shoals were about 23mg/L and 64mg/L higher than that of the middle shoal, respectively. There was a significant decreasing trend of TSS concentration from the northwest (223.7mg/L) to southeast (51.4mg/L) of study area, with an average reduction of 5.86mg/Lperkm, which mainly attributes to unique interaction of runoff and tide in PRE. In high flow season, there existed a significant and definite annual cycle period (5-8years) of TSS concentration change primarily responding to the periodic variation of precipitation. There were five full-fledged period changes of TSS detected in west shoal and west channel (the years of changes in 1988, 1994, 1998, 2003, 2010, 2015), while there were the last four cycle periods found in middle shoal, east channel, east shoal and NNR only. TSS concentrations in shoals and channels of PRE showed a significant decreased trend mainly due to the dam construction at the same time, with an average annual TSS concentration decrease of 5.7-10.1mg/L in high flow season from 1988 to 2015. There was no significant change trend of TSS concentration in NNR before 2003, but the TSS concentration decreased significantly after the establishment of the NNR since June 2003, with an average annual decrease of 9.7mg/L from 2004 to 2015. It was deduced that man-made protection measures had a great influence

  10. Experimental study on solids circulation patterns and bubble behavior using particle imagevelocimetry combined with digital image analysis

    NARCIS (Netherlands)

    Laverman, J.A.; Roghair, Ivo; van Sint Annaland, M.; Kuipers, J.A.M.

    2008-01-01

    The hydrodynamics, viz. the solids circulation patterns and bubble behavior, of a freely bubbling gas-solid fluidized bed has been investigated experimentally using Particle Image Velocimetry (PIV) combined with Digital Image Analysis (DIA). Coupling of these non-invasive measuring techniques allows

  11. Direct measurement of particle size and 3D velocity of a gas-solid pipe flow with digital holographic particle tracking velocimetry.

    Science.gov (United States)

    Wu, Yingchun; Wu, Xuecheng; Yao, Longchao; Gréhan, Gérard; Cen, Kefa

    2015-03-20

    The 3D measurement of the particles in a gas-solid pipe flow is of great interest, but remains challenging due to curved pipe walls in various engineering applications. Because of the astigmatism induced by the pipe, concentric ellipse fringes in the hologram of spherical particles are observed in the experiments. With a theoretical analysis of the particle holography by an ABCD matrix, the in-focus particle image can be reconstructed by the modified convolution method and fractional Fourier transform. Thereafter, the particle size, 3D position, and velocity are simultaneously measured by digital holographic particle tracking velocimetry (DHPTV). The successful application of DHPTV to the particle size and 3D velocity measurement in a glass pipe's flow can facilitate its 3D diagnostics.

  12. Flame propagation in two-dimensional solids: Particle-resolved studies with complex plasmas

    Science.gov (United States)

    Yurchenko, S. O.; Yakovlev, E. V.; Couëdel, L.; Kryuchkov, N. P.; Lipaev, A. M.; Naumkin, V. N.; Kislov, A. Yu.; Ovcharov, P. V.; Zaytsev, K. I.; Vorob'ev, E. V.; Morfill, G. E.; Ivlev, A. V.

    2017-10-01

    Using two-dimensional (2D) complex plasmas as an experimental model system, particle-resolved studies of flame propagation in classical 2D solids are carried out. Combining experiments, theory, and molecular dynamics simulations, we demonstrate that the mode-coupling instability operating in 2D complex plasmas reveals all essential features of combustion, such as an activated heat release, two-zone structure of the self-similar temperature profile ("flame front"), as well as thermal expansion of the medium and temperature saturation behind the front. The presented results are of relevance for various fields ranging from combustion and thermochemistry, to chemical physics and synthesis of materials.

  13. Solid Particle Erosion of Date Palm Leaf Fiber Reinforced Polyvinyl Alcohol Composites

    Directory of Open Access Journals (Sweden)

    Jyoti R. Mohanty

    2014-01-01

    Full Text Available Solid particle erosion behavior of short date palm leaf (DPL fiber reinforced polyvinyl alcohol (PVA composite has been studied using silica sand particles (200 ± 50 μm as an erodent at different impingement angles (15–90° and impact velocities (48–109 m/s. The influence of fiber content (wt% of DPL fiber on erosion rate of PVA/DPL composite has also been investigated. The neat PVA shows maximum erosion rate at 30° impingement angle whereas PVA/DPL composites exhibit maximum erosion rate at 45° impingement angle irrespective of fiber loading showing semiductile behavior. The erosion efficiency of PVA and its composites varies from 0.735 to 16.289% for different impact velocities studied. The eroded surfaces were observed under scanning electron microscope (SEM to understand the erosion mechanism.

  14. First results from solid state neutral particle analyzer on experimental advanced superconducting tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. Z.; Zhao, J. L.; Wan, B. N.; Li, J. G. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhu, Y. B., E-mail: y.zhu@uci.edu; Heidbrink, W. W. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States)

    2016-11-15

    Full function integrated, compact solid state neutral particle analyzers (ssNPA) based on absolute extreme ultraviolet silicon photodiode have been successfully implemented on the experimental advanced superconducting tokamak to measure energetic particle. The ssNPA system has been operated in advanced current mode with fast temporal and spatial resolution capabilities, with both active and passive charge exchange measurements. It is found that the ssNPA flux signals are increased substantially with neutral beam injection (NBI). The horizontal active array responds to modulated NBI beam promptly, while weaker change is presented on passive array. Compared to near-perpendicular beam, near-tangential beam brings more passive ssNPA flux and a broader profile, while no clear difference is observed on active ssNPA flux and its profile. Significantly enhanced intensities on some ssNPA channels have been observed during ion cyclotron resonant heating.

  15. Toluene vapor capture by activated carbon particles in a dual gas-solid cyclone system.

    Science.gov (United States)

    Lim, Yun Hui; Ngo, Khanh Quoc; Park, Young Koo; Jo, Young Min

    2012-08-01

    Capturing of odorous compounds such as toluene vapor by a particulate-activated carbon adsorbent was investigated in a gas-solid cyclone, which is one type of mobile beds. The test cyclone was early modified with the post cyclone (PoC) and a spiral flow guide to the vortex finder. The proposed process may contribute to the reduction of gases and dust from industrial exhausts, especially when dealing with a low concentration of odorous elements and a large volume ofdust flow. In this device, the toluene capturing efficiency at a 400 ppm concentration rose up to 77.4% when using activated carbon (AC) particles with a median size of 27.03 microm. A maximum 96% of AC particles could be collected for reuse depending on the size and flow rate. The AC regenerated via thermal treatment showed an adsorption potential up to 66.7% throughout repeated tests.

  16. Assessment of the Atmospheric Suspended Particles Pollution in the Madrid Air Quality Networks; Evaluacion de la Contaminacion Atmosferica producida por Particulas en Suspension en las Redes de Calidad del Aire de la Comunidad de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, P.; Artinano, B.

    2000-07-01

    Suspended particles are a very complex type of atmospheric pollution because of their chemical composition and size. In fact, there are a quite high number of particles sources which are linked to different physico-chemical processes that determine their size. At present particles smaller than 10 {mu}m are considered the most dangerous, as has been recently pointed out by numerous epidemiologic studies. In this way, more restrictive concentration limit values have been approved in the EU countries, so an assessment of present airborne concentration values and the sources apportionment in their most representative areas is needed. In the Madrid Community a first approaching of these and other aims, has been carried out from an analysis of the Madrid Air Quality networks data. This will contribute to the stablishment of concentration levels abatement strategies. (Author) 111 refs.

  17. Next-generation solid-state detectors for charged particle spectroscopy

    Science.gov (United States)

    Ogasawara, K.; Livi, S. A.; Allegrini, F.; Broiles, T. W.; Dayeh, M. A.; Desai, M. I.; Ebert, R. W.; Llera, K.; Vines, S. K.; McComas, D. J.

    2016-07-01

    The performance of silicon avalanche photodiodes (APDs) and single crystal chemical vapor deposit diamond detectors (DDs) is reviewed in comparison with conventional silicon-based solid-state detectors (SSDs) from the perspective of space plasma applications. Although the low-energy threshold and the energy resolution are equivalent to SSDs, DDs offer a high radiation tolerance and very low leakage currents due to a wider band gap than silicon. In addition, DDs can operate at higher temperatures, are insensitive to light (>226 nm), and are capable of timing analysis due to the higher intrinsic carrier mobility. APDs also offer several advantageous features. Specifically, APDs have a lower energy threshold (linear response due to a strong electric field causing signal amplifications within the detector. Therefore, APDs can be used to detect lower energy particles, covering a larger portion of the energy spectrum than conventional SSDs. Further, the strong internal electric field gives them a subnanosecond response time by the charge mobility saturation, allowing them to make precise timing measurements of ions. These novel detector techniques can be potentially applied to improve the measurements of suprathermal particles, whose energies lie between typical ranges of conventional sensors for low-energy plasmas and energetic particles. Although the origin and evolution of the suprathermal particles are the key to understanding the acceleration and heating processes in space plasma, they are not well understood due to the technical difficulties of making the measurement.

  18. Large-eddy simulation of zero-pressure-gradient turbulent boundary layer with solid particle suspension

    Science.gov (United States)

    Rahman, Mustafa; Samtaney, Ravi

    2015-11-01

    We present results of solid particles suspension and transport in a fully-developed turbulent boundary layer flow using large-eddy simulation of the incompressible Navier-Stokes equations. We adopt the Eulerian-Eulerian approach to simulating particle laden flow with a large number of particles, in which the particles are characterized by statistical descriptors. For the particulate phase, the direct quadrature method of moments (DQMOM) is chosen in which the weights and abscissas of the quadrature approximation are tracked directly rather than the moments themselves. The underlying approach in modeling the turbulence of fluid phase utilizes the stretched spiral vortex subgrid-scale model and a virtual wall model similar to the work proposed by Inoue & Pullin (J. Fluid Mech. 2011). The solver is verified against simple analytical solutions and the computational results are found to be in a good agreement with these. The capability of the new numerical solver will be exercised to investigate turbulent transport of sand in sandstorms. Finally, the adequacy and limitations of the solver will be discussed. Supported by the KAUST Office of Competitive Research Funds under Award No. URF/1/1704-01.

  19. Dynamics of Elastic Bodies, Solid Particles, and Fluid Parcels in a Compressible Viscous Fluid (Review)

    Science.gov (United States)

    Guz, A. N.; Zhuk, A. P.; Bagno, A. M.

    2016-09-01

    The results of linearization of the basic equations describing a compressible viscous fluid in which low-amplitude oscillations occur or solids move or that interacts with elastic bodies in which small perturbations propagate are discussed. The general solutions of the linearized equations are presented. The results of studying wave processes in hydroelastic systems using the three-dimensional linearized theory of finite deformations and theory of compressible viscous fluid are discussed. The results of studying the propagation of acoustic waves of various types in waveguides with plane and circular cylindrical interfaces between elastic and liquid media and the influence of large (finite) initial deformations, viscosity and compressibility of the fluid on acoustic waves are presented. Studies of the motion of objects in compressible ideal and viscous fluids under the action of radiation forces due to the acoustic field are reviewed. The emphasis is placed on the studies that use a method involving the solution of hydrodynamic problems for a compressible fluid with solid particles and the evaluation of the forces acting on these particles. The radiation force is determined as the constant component of the hydrodynamic force. The numerical results are presented in the form of plots, which are then analyzed

  20. Absorption Study of Genistein Using Solid Lipid Microparticles and Nanoparticles: Control of Oral Bioavailability by Particle Sizes.

    Science.gov (United States)

    Kim, Jeong Tae; Barua, Sonia; Kim, Hyeongmin; Hong, Seong-Chul; Yoo, Seung-Yup; Jeon, Hyojin; Cho, Yeongjin; Gil, Sangwon; Oh, Kyungsoo; Lee, Jaehwi

    2017-07-01

    In this study, the effect of particle size of genistein-loaded solid lipid particulate systems on drug dissolution behavior and oral bioavailability was investigated. Genistein-loaded solid lipid microparticles and nanoparticles were prepared with glyceryl palmitostearate. Except for the particle size, other properties of genistein-loaded solid lipid microparticles and nanoparticles such as particle composition and drug loading efficiency and amount were similarly controlled to mainly evaluate the effect of different particle sizes of the solid lipid particulate systems on drug dissolution behavior and oral bioavailability. The results showed that genistein-loaded solid lipid microparticles and nanoparticles exhibited a considerably increased drug dissolution rate compared to that of genistein bulk powder and suspension. The microparticles gradually released genistein as a function of time while the nanoparticles exhibited a biphasic drug release pattern, showing an initial burst drug release, followed by a sustained release. The oral bioavailability of genistein loaded in solid lipid microparticles and nanoparticles in rats was also significantly enhanced compared to that in bulk powders and the suspension. However, the bioavailability from the microparticles increased more than that from the nanoparticles mainly because the rapid drug dissolution rate and rapid absorption of genistein because of the large surface area of the genistein-solid lipid nanoparticles cleared the drug to a greater extent than the genistein-solid lipid microparticles did. Therefore, the findings of this study suggest that controlling the particle size of solid-lipid particulate systems at a micro-scale would be a promising strategy to increase the oral bioavailability of genistein.

  1. Barrier coated drug layered particles for enhanced performance of amorphous solid dispersion dosage form.

    Science.gov (United States)

    Puri, Vibha; Dantuluri, Ajay K; Bansal, Arvind K

    2012-01-01

    Amorphous solid dispersions (ASDs) may entail tailor-made dosage form design to exploit their solubility advantage. Surface phenomena dominated the performance of amorphous celecoxib solid dispersion (ACSD) comprising of amorphous celecoxib (A-CLB), polyvinylpyrrolidone, and meglumine (7:2:1, w/w). ACSD cohesive interfacial interactions hindered its capsule dosage form dissolution (Puri V, Dhantuluri AK, Bansal AK 2011. J Pharm Sci 100:2460-2468). Furthermore, ACSD underwent significant devitrification under environmental stress. In the present study, enthalpy relaxation studies revealed its free surface to contribute to molecular mobility. Based on all these observations, barrier coated amorphous CLB solid dispersion layered particles (ADLP) were developed by Wurster process, using microcrystalline cellulose as substrate and polyvinyl alcohol (PVA), inulin, and polyvinyl acetate phthalate (PVAP) as coating excipients. Capsule formulations of barrier coated-ADLP could achieve rapid dispersibility and high drug release. Evaluation under varying temperature and RH conditions suggested the crystallization inhibitory efficiency in order of inulin coating material. Simulated studies using DSC evidenced drug-polymer mixing at the interface as a potential mechanism for surface stabilization. In conclusion, surface modification yielded a fast dispersing robust high drug load ASD based dosage form. Copyright © 2011 Wiley-Liss, Inc.

  2. Study of the Parametric Performance of Solid Particle Erosion Wear under the Slurry Pot Test Rig

    Directory of Open Access Journals (Sweden)

    S.R. More

    2017-12-01

    Full Text Available Stainless Steel (SS 304 is commonly used material for slurry handling applications like pipelines, valves, pumps and other equipment's. Slurry erosion wear is a common problem in many engineering applications like process industry, thermal and hydraulic power plants and slurry handling equipments. In this paper, experimental investigation of the influence of solid particle size, impact velocity, impact angle and solid concentration parameters in slurry erosion wear behavior of SS 304 using slurry pot test rig. In this study the design of experiments was considered using Taguchi technique. A comparison has been made for the experimental and Taguchi technique results. The erosion wear morphology was studied using micro-graph obtained by scanning electron microscope (SEM analysis. At shallow impact angle 30°, the material removal pattern was observed in the form of micro displacing, scratching and ploughing with plastic deformation of the material. At 60° impact angle, mixed type of micro indentations and pitting action is observed. At normal impact angle 90°, the material removal pattern was observed in form of indentation and rounded lips. It is found that particle velocity was the most influence factor than impact angle, size and solid concentration. From this investigation, it can be concluded that the slurry erosion wear is minimized by controlling the slurry flow velocity which improves the service life of the slurry handling equipments. From the comparison of experimental and Taguchi experimental design results it is found that the percentage deviation was very small with a higher correlation coefficient (r2 0.987 which is agreeable.

  3. Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis

    OpenAIRE

    I. Tolosa; S. Fiorini; B. Gasser; J. Martín; J. C. Miquel

    2013-01-01

    Molecular lipid biomarkers (hydrocarbons, alcohols, sterols and fatty acids) and compound-specific isotope analysis of suspended particulate organic matter (SPM) and surface sediments of the Mackenzie Shelf and slope (southeast Beaufort Sea, Arctic Ocean) were studied in summer 2009. The concentrations of the molecular lipid markers, characteristic of known organic matter sources, were grouped and used as proxies to evaluate the relative importance of fresh algal, detrital a...

  4. A Summary of Corrosion Properties of Al-Rich Solid Solution and Secondary Phase Particles in Al Alloys

    Directory of Open Access Journals (Sweden)

    Jichao Li

    2017-03-01

    Full Text Available The heterogeneous structure of Al alloys renders them susceptible to localized corrosion due to the different electrochemical properties existing in the Al-rich solid solution matrix and secondary phase particles. The galvanic interactions between these two phases can result in pit formation either through dissolution of the particles or corrosion of the matrix adjacent to the particles. This detrimentally localized corrosion behavior is closely related to the corrosion properties of the particles and the Al-rich matrix. The comprehensive characterization of this behavior under various and varying conditions is critical to understanding the mechanism of pit formation, selecting appropriate inhibitors, and developing protection strategies. The corrosion properties (corrosion potential, pitting potential and corrosion rate of both secondary phase particles and Al-solid solutions in Al alloys are summarized in this review, aiming to provide a database for corrosion research applicable to the localized corrosion of Al alloys.

  5. Improvement in retention of solid fission products in HTGR fuel particles by ceramic kernel additives

    Energy Technology Data Exchange (ETDEWEB)

    Foerthmann, R.; Groos, E.; Gruebmeier, H.

    1975-08-15

    Increased requirements concerning the retention of long-lived solid fission products in fuel elements for use in advanced High Temperature Gas-cooled Reactors led to the development of coated particles with improved fission product retention which represent an alternative to silicon carbide-coated fuel particles. Two irradiation experiments have shown that the release of strontium, barium, and caesium from pyrocarbon-coated particles can be reduced by orders of magnitude if the oxide kernel contains alumina-silica additives. It was detected by electron microprobe analysis that the improved retention of the mentioned fission products in the fuel kernel is caused by formation of the stable aluminosilicates SrAl2Si2O8, BaAl2Si2O8and CsAlSi2O6 in the additional alumina-silica phase of the kernel.

  6. Solid-state nuclear magnetic resonance studies of vinyl polymer/silica colloidal nanocomposite particles.

    Science.gov (United States)

    Lee, Daniel; Balmer, Jennifer A; Schmid, Andreas; Tonnar, Jeff; Armes, Steven P; Titman, Jeremy J

    2010-10-05

    Solid-state nuclear magnetic resonance (NMR) has been used to characterize the interface between the organic and inorganic components of "core-shell" colloidal nanocomposite particles synthesized by in situ aqueous (co)polymerization of styrene and/or n-butyl acrylate in the presence of a glycerol-functionalized silica sol. Polymer protons are in close proximity (nanocomposites studied, indicating that either styrene or n-butyl side groups extend between the glycerol-functional silane molecules toward the surface of the silica particles. For the poly(styrene-co-n-butyl acrylate)/silica nanocomposite n-butyl acrylate residues are located closer to the surface of the silica particle than styrene residues, suggesting a specific interaction between the former and the glycerol-functionalized silica surface. The most likely explanation is a hydrogen bond between the ester carbonyl and the glycerol groups, although this cannot be observed directly. For the Bindzil CC40 glycerol-functionalized silica sol the relative intensities of (29)Si NMR lines corresponding to T and Q(3) environments imply that there are approximately twice as many unreacted silanol groups on the silica surface as attached silane molecules.

  7. Estudo das partículas totais em suspensão e metais associados em áreas urbanas Study of total suspended particles and the associated metals in urban areas

    Directory of Open Access Journals (Sweden)

    Fabiana Goulart de Carvalho

    2000-10-01

    Full Text Available This work aims at the study of the air quality determination regarding the total suspended particles (TSP and the associated metals in the counties of Charqueadas and Sapucaia do Sul at the state of Rio Grande do Sul. The TSP samples were collected using high volume samplers and the analysis of the metallic elements was accomplished through ICP-AES. The results revealed that the TSP concentrations, found in the two studied regions, have exceded the current air quality patterns established by the Brazilian Legislation. They also revealed high levels of several of the elements being attributed to the presence of anthropogenic sources. The correlation between meteorological data (speed and wind direction and TSP concentrations were significant and revealed strong influence in particle dispersion.

  8. Preparation of calcium chloride-loaded solid lipid particles and heat-triggered calcium ion release

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Huangying; Kim, Jin-Chul [Kangwon National University, Chunchon (Korea, Republic of)

    2015-08-15

    CaCl{sub 2}-loaded solid lipid particles (SLPs) were prepared by a melt/emulsification/solidification method. CaCl{sub 2} microparticles (1-5 μm) could be obtained in a mortar with aid of the dispersant (Tween 80/Span80 (35/65, w/w)) when the ratio of CaCl{sub 2} to dispersant was 2 : 0.1 (w/w). SLP was prepared by dispersing 0.42 g of micronized CaCl{sub 2} particles in 2 g of molten PBSA, emulsifying the mixture at 85 .deg. C in 40 ml of Tween 20 solution (0.5% w/v), and quenching the emulsion in an ice bath. The diameter of CaCl{sub 2}-loaded SLP was 10-150 μm. The unenveloped CaCl{sub 2} could be removed by dialysis and the specific loading of CaCl{sub 2} in SLP was 0.036mg/mg. An EDS spectrum of CaCl{sub 2}-loaded SLP, which was dialyzed, showed that the unenveloped CaCl{sub 2} was completely removed. Any excipients (dispersant, Tween 20, CaCl{sub 2}) had little effect on the melting point of SLPs. No appreciable amount of Ca2+ was released in 20-50 .deg. C for 22 h. But the release degree at 60 .deg. C was significant (about 2.3%) during the same period. The matrix of the lipid particle was in a liquid state at 60 .deg. C, so CaCl{sub 2} particles could move freely and contact the surrounding water, leading to the release. At 70 .deg. C, the release degree at a given time was a few times higher than that obtained at 60 .deg. C.

  9. Application of the phase method in radioisotope measurements of the liquid - solid particles flow in the vertical pipeline

    Directory of Open Access Journals (Sweden)

    Hanus Robert

    2015-01-01

    Full Text Available The paper presents idea and an application of the gamma-absorption method to a two-phase flow investigation in a vertical pipeline, where the flow of solid particles transported by water was examined by a set of two 241Am radioactive sources and probes with NaI(Tl scintillation crystals. In the described experiments as solid phase the ceramic models representing natural polymetallic ocean nodules were used. For advanced analysis of electrical signals obtained from detectors the phase of cross-spectral density function has been applied. Results of the average solid-phase velocity measurements were compared with one obtained by application of the classical cross-correlation. It was found that the combined uncertainties of the velocity of solid particles evaluation in the presented experiment did not exceed 0.6% in phase method and 3.2% in cross-correlation method.

  10. Quantification of dermal exposure to nanoparticles from solid nanocomposites by using single particle ICP-MS

    DEFF Research Database (Denmark)

    Mackevica, Aiga; Olsson, Mikael Emil; Hansen, Steffen Foss

    2016-01-01

    Engineered nanoparticles are used in various applications due to their unique properties, which has led to their widespread use in consumer products. Silver, titanium and copper-based nanoparticles are few of the most commonly used nanomaterials in consumer products, mainly due to their biocidal......, optical or photocatalytical properties. There is a lot of research focusing on effects exerted by nanoparticles, but the knowledge concerning release and subsequential exposure to nanoparticles is very limited, and information regarding potential dermal exposure from nanomaterial containing solid articles...... in particular is currently lacking. Challenges with regard to qualitative and quantitative characterization of nanoparticle exposure have been increasingly addressed in the literature in the last decade, and single particle ICP-MS has shown to be one of the most promising techniques for nanoparticle detection...

  11. Experimental setup for the growth of solid crystals of inert gases for particle detection

    Science.gov (United States)

    Guarise, M.; Braggio, C.; Calabrese, R.; Carugno, G.; Dainelli, A.; Khanbekyan, A.; Luppi, E.; Mariotti, E.; Poggi, M.; Tomassetti, L.

    2017-11-01

    Low energy threshold detectors are necessary in many frontier fields of the experimental physics. In this work, we present a novel detection approach based on pure or doped matrices of inert gases solidified at cryogenic temperatures. The small energy release of the incident particle can be transferred directly (in pure crystals) or through a laser-driven ionization (in doped materials) to the electrons of the medium that are then converted into free electrons. The charge collection process of the electrons that consists in their drift within the crystal and their extraction through the solid-vacuum interface gives rise to an electric signal that we exploit for preliminary tests of charge collection and crystal quality. Such tests are carried out in different matrices of neon and methane using an UV-assisted apparatus for electron injection in crystals.

  12. Laboratory report on iodine (129I and 127I) speciation, transformation and mobility in Handford groundwater, suspended particles and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Santschi, P. H. [Texas A & M Univ., College Station, TX (United States); Xu, C. [Texas A & M Univ., College Station, TX (United States); Zhang, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ho, Y. [Texas A & M Univ., College Station, TX (United States); Li, H. [Texas A & M Univ., College Station, TX (United States); Schwehr, K. [Texas A & M Univ., College Station, TX (United States); Kaplan, D. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2012-09-01

    were on average 89% greater than iodide Kd values, and the Kd values for both species tended to increase with the amount of organic carbon (OC) present in the sediment. It is especially noteworthy that this trend existed at the very low OC concentrations that naturally exist in the Hanford sediments. Iodine and OC can form essentially irreversible covalent bonds, thereby providing a yet unstudied 129I retardation reaction at the Hanford Site. In addition to the transformation of iodine species, the sediment collected from the vadose zone also released stable iodide into the aqueous phase. It was found that the three sediments all took up the ambient iodate from the groundwater and slowly transformed it into iodide under the laboratory conditions, likely dependent on the abundance of reducing agents such as organic matter and Fe2+. Therefore two competitive iodine processes were identified, the tendency for the sediment to reduce iodate to iodide, and the groundwater chemistry to maintain the iodine as iodate, presumably it is largely the result of natural pH and dissolved O2/Eh levels. Suspended carbonate (and silica) particles collected from Hanford groundwater contained elevated amounts of iodine (142 ± 8 μg/g iodine), consisting mainly of iodate (>99%). Iodate was likely incorporated into the carbonate structure during calcite precipitation upon degasing of CO2 as the groundwater samples were removed from the subsurface. This concentration of groundwater iodate in precipitated carbonate has implication to long-term fate and transport of 129I and on active in-situ 129I groundwater remediation. This study provides some of the first groundwater radioiodine speciation studies conducted in arid environments and provides much needed mechanistic descriptions to permit making informed decisions about low-cost/high intellectual input remediation options, such as monitored natural

  13. High resolution spectroscopy of a small number of particles in a solid

    CERN Document Server

    Murray, T A

    2000-01-01

    The technique of single molecule spectroscopy in solids is investigated, with the view to extending this technique to the detection of single ions of titanium in sapphire. High-resolution experimental apparatus was set-up to study single particles in solids and to allow hole-burning experiments to be carried out. Hole-burning processes were investigated in samples of uranium doped strontium tungstate with concentrations of 500 ppm and 200 ppm. Hole-burning at different laser intensities revealed a homogeneous linewidth of (6.3 +- 0.1) MHz for the stronger doped sample. The weaker doped sample was determined to have a homogeneous linewidth less than the laser linewidth. The relaxation behaviour of holes, monitored between 10-20 K, was also examined. The relaxation process was found to be similar to an activated process with an attempt frequency of 309 s sup - sup 1 and it was concluded that the process was some form of tunnelling with strong phonon coupling. Repeatable, stable single molecules of terrylene in ...

  14. How long can culturable bacteria and total DNA persist in environmental waters? The role of sunlight and solid particles.

    Science.gov (United States)

    Gutiérrez-Cacciabue, Dolores; Cid, Alicia G; Rajal, Verónica B

    2016-01-01

    In this work, sunlight inactivation of two indicator bacteria in freshwater, with and without solid particles, was studied and the persistence of culturable cells and total DNA was compared. Environmental water was used to prepare two matrices, with and without solid particles, which were spiked with Escherichia coli and Enterococcus faecalis. These matrices were used to prepare microcosm bags that were placed in two containers: one exposed to sunlight and the other in the dark. During one month, samples were removed from each container and detection was done by membrane filter technique and real-time PCR. Kinetic parameters were calculated to assess sunlight effect. Indicator bacteria without solid particles exposed to sunlight suffered an immediate decay (DNA persisted much longer than culturable cells (T99>40h in the dark with particles). In this case active cells were more prone to sunlight than total DNA and the protective effect of solid particles was also observed. Results highlight that the effects caused by the parameters which describe the behavior of culturable microorganisms and total DNA in water are different and must be included in simulation models but without forgetting that these parameters will also depend on bacterial properties, sensitizers, composition, type, and uses of the aquatic environment under assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Colloidal interactions between Langmuir-Blodgett bitumen films and fine solid particles.

    Science.gov (United States)

    Long, Jun; Zhang, Liyan; Xu, Zhenghe; Masliyah, Jacob H

    2006-10-10

    In oil sand processing, accumulation of surface-active compounds at various interfaces imposes a significant impact on bitumen recovery and bitumen froth cleaning (i.e., froth treatment) by altering the interfacial properties and colloidal interactions among various oil sand components. In the present study, bitumen films were prepared at toluene/water interfaces using a Langmuir-Blodgett (LB) upstroke deposition technique. The surface of the prepared LB bitumen films was found to be hydrophobic, comprised of wormlike aggregates containing a relatively high content of oxygen, sulfur, and nitrogen, indicating an accumulation of surface-active compounds in the films. Using an atomic force microscope, colloidal interactions between the LB bitumen films and fine solids (model silica particles and clay particles chosen directly from an oil sand tailing stream) were measured in industrial plant process water and compared with those measured in simple electrolyte solutions of controlled pH and divalent cation concentrations. The results show a stronger long-range repulsive force and weaker adhesion force in solutions of higher pH and lower divalent cation concentration. In plant process water, a moderate long-range repulsive force and weak adhesion were measured despite its high electrolyte content. These findings provide more insight into the mechanisms of bitumen extraction and froth treatment.

  16. Particle Engineering in Pharmaceutical Solids Processing: Surface Energy 
Considerations

    Science.gov (United States)

    Williams, Daryl R.

    2015-01-01

    During the past 10 years particle engineering in the pharmaceutical industry has become a topic of increasing importance. Engineers and pharmacists need to understand and control a range of key unit manufacturing operations such as milling, granulation, crystallisation, powder mixing and dry powder inhaled drugs which can be very challenging. It has now become very clear that in many of these particle processing operations, the surface energy of the starting, intermediate or final products is a key factor in understanding the processing operation and or the final product performance. This review will consider the surface energy and surface energy heterogeneity of crystalline solids, methods for the measurement of surface energy, effects of milling on powder surface energy, adhesion and cohesion on powder mixtures, crystal habits and surface energy, surface energy and powder granulation processes, performance of DPI systems and finally crystallisation conditions and surface energy. This review will conclude that the importance of surface energy as a significant factor in understanding the performance of many particulate pharmaceutical products and processes has now been clearly established. It is still nevertheless, work in progress both in terms of development of methods and establishing the limits for when surface energy is the key variable of relevance. PMID:25876912

  17. Influência de diferentes teores de sólidos insolúveis suspensos nas características reológicas de sucos de abacaxi naturais e despectinizados Influence of different contents of insoluble suspended solidS on rheological characteristics of natural and despectinized pineapple juice

    Directory of Open Access Journals (Sweden)

    Alexandre José de Melo Queiroz

    2000-04-01

    Full Text Available Estudou-se, neste trabalho, a influência dos sólidos insolúveis suspensos nas características reológicas de sucos de abacaxi in natura e sucos tratados com enzima pectinolítica. Cada um dos dois tipos de suco foi estudado através de seis frações, divididas em quatro peneiradas, uma centrifugada e uma integral, representando seis teores de sólidos insolúveis suspensos. Os dados reométricos foram coletados através de um reômetro Haake rotovisco e os dados experimentais ajustados pelo modelo de Mizrahi-Berk. Das seis frações in natura, quatro apresentaram comportamento pseudoplástico, uma caracterizou-se como newtoniana e outra como dilatante enquanto das seis frações tratadas enzimaticamente cinco apresentaram comportamento pseudoplástico e uma caracterizou-se como newtoniana. O teor de sólidos insolúveis suspensos mostrou-se o principal fator responsável pelo comportamento reológico dos sucos de abacaxi naturais e despectinizados.The influence of insoluble suspended solid contents in rheological characteristics of pineapple juice, both natural and treated with pectinolytic enzymes, was studied. Each type of juice was examined by six fractions, divided into four sievings, one centrifuged and the others whole, representing six contents of insoluble suspended solids. The rheometric data were collected by means of Haake rotovisco rheometer and the experimental data were adjusted by the Mizrahi-Berk model. In the natural material four fractions showed pseudoplastic behaviour, one characterized as newtonian and the others as dilatant, whereas in the enzyme treated material, five fractions presented pseudoplastic behaviour and one was characterized as newtonian. The insoluble suspended solid content was found to be the principal factor responsible for this rheological behaviour of natural and despectinized pineapple juices.

  18. Circular motion of particles suspended in a Gaussian beam with circular polarization validates the spin part of the internal energy flow

    National Research Council Canada - National Science Library

    Angelsky, O V; Bekshaev, A Ya; Maksimyak, P P; Maksimyak, A P; Mokhun, I I; Hanson, S G; Zenkova, C Yu; Tyurin, A V

    2012-01-01

    .... After switching to the right (left) circular polarization, the particles performed spinning motion in agreement with the angular momentum imparted by the field, but they were involved in an orbital rotation around the beam axis as well...

  19. Fabrication, characterisation and stability of oil-in-water emulsions stabilised by solid lipid particles: the role of particle characteristics and emulsion microstructure upon Pickering functionality.

    Science.gov (United States)

    Zafeiri, I; Smith, P; Norton, I T; Spyropoulos, F

    2017-07-19

    The quest to identify and use bio-based particles with a Pickering stabilisation potential for food applications has lately been particularly substantial and includes, among other candidates, lipid-based particles. The present study investigates the ability of solid lipid particles to stabilise oil-in-water (o/w) emulsions against coalescence. Results obtained showed that emulsion stability could be achieved when low amounts (0.8 wt/wt%) of a surface active species (e.g. Tween 80 or NaCas) were used in particles' fabrication. Triple staining of the o/w emulsions enabled the visualisation of emulsion droplets' surface via confocal microscopy. This revealed an interfacial location of the lipid particles, hence confirming stabilisation via a Pickering mechanism. Emulsion droplet size was controlled by varying several formulation parameters, such as the type of the lipid and surface active component, the processing route and the polarity of the dispersed phase. Differential scanning calorimetry (DSC) was employed as the analytical tool to quantify the amount of crystalline material available to stabilise the emulsion droplets at different intervals during the experimental timeframe. Dissolution of lipid particles in the oil phase was observed and evolved distinctly between a wax and a triglyceride, and in the presence of a non-ionic surfactant and a protein. Yet, this behaviour did not result in emulsion destabilisation. Moreover, emulsion's thermal stability was found to be determined by the behaviour of lipid particles under temperature effects.

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

    Science.gov (United States)

    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.

  1. Review of total suspended particles (TSP) and PM2.5 concentration variations in Asia during the years of 1998-2015.

    Science.gov (United States)

    Fang, Guor-Cheng; Zhuang, Yuan-Jie; Cho, Meng-Hsien; Huang, Chao-Yang; Xiao, You-Fu; Tsai, Kai-Hsiang

    2017-06-05

    In Asian countries such as China, Malaysia, Pakistan, India, Taiwan, Korea, Japan and Hong Kong, ambient air total suspended particulates and PM2.5 concentration data were collected and discussed during the years of 1998-2015 in this study. The aim of the present study was to (1) investigate and collect ambient air total suspended particulates (TSP) and PM2.5 concentrations for Asian countries during the past two decades. (2) Discuss, analyze and compare those particulates (TSP and PM2.5) annual concentration distribution trends among those Asian countries during the past two decades. (3) Test the mean concentration differences in TSP and PM2.5 among the Asian countries during the past decades. The results indicated that the mean TSP concentration order was shown as China > Malaysia > Pakistan > India > Taiwan > Korea > Japan. In addition, the mean PM2.5 concentration order was shown as Vietnam > India > China > Hong Kong > Mongolia > Korea > Taiwan > Japan and the average percentages of PM2.5 concentrations for Taiwan, China, Japan, Korea, Hong Kong, Mongolia and Other (India and Vietnam) were 8, 21, 6, 8, 14, 13 and 30%, respectively, during the past two decades. Moreover, t test results revealed that there were significant mean TSP and PM2.5 concentration differences for either China or India to any of the countries such as Taiwan, Korea and Japan in Asia during the past two decades for this study. Noteworthy, China and India are both occupied more than 60% of the TSP and PM2.5 particulates concentrations out of all the Asia countries. As for Taiwan, the average PM2.5 concentration displayed increasing trend in the years of 1998-1999. However, it showed decreasing trend in the years of 2000-2010. As for Korea, the average PM2.5 concentrations showed decreasing trend during the years of 2001-2013. Finally, the average PM2.5 concentrations for Mongolia displayed increasing trend in the years of 2004-2013.

  2. Impact of different particle size distributions on anaerobic digestion of the organic fraction of municipal solid waste.

    Science.gov (United States)

    Zhang, Y; Banks, C J

    2013-02-01

    Particle size may significantly affect the speed and stability of anaerobic digestion, and matching the choice of particle size reduction equipment to digester type can thus determine the success or failure of the process. In the current research the organic fraction of municipal solid waste was processed using a combination of a shear shredder, rotary cutter and wet macerator to produce streams with different particle size distributions. The pre-processed waste was used in trials in semi-continuous 'wet' and 'dry' digesters at organic loading rate (OLR) up to 6kg volatile solids (VS) m(-3)day(-1). The results indicated that while difference in the particle size distribution did not change the specific biogas yield, the digester performance was affected. In the 'dry' digesters the finer particle size led to acidification and ultimately to process failure at the highest OLR. In 'wet' digestion a fine particle size led to severe foaming and the process could not be operated above 5kgVSm(-3)day(-1). Although the trial was not designed as a direct comparison between 'wet' and 'dry' digestion, the specific biogas yield of the 'dry' digesters was 90% of that produced by 'wet' digesters fed on the same waste at the same OLR. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Jamming/flowing transition of non-Brownian particles suspended in a iso-density fluid flowing in a 2D rectangular duct

    Directory of Open Access Journals (Sweden)

    Burel Maxym

    2017-01-01

    Full Text Available We present the results of an experimental study on the jamming/flowing transition. A suspension of neutrally buoyant large particles flows in an horizontal rectangular duct, where an artificial restriction triggers jamming. We show that the avalanche distribution size is exponential, that is memoryless. We further demonstrate that the avalanche size diverges when the restriction size approaches a critical value and that this divergence is well described by a power law. The parameters (critical opening size and divergence velocity are compared to literature values and show a strong similarity with others systems. Another result of this paper is the study of the influence of the particle morphology. We show that, for a moderate restriction size, the dead-zone formed right upstream of the restriction is larger for angular particles but, paradoxically, that the avalanche size is larger for polyhedra compared to spheres by at least one order of magnitude.

  4. Solid particle erosion of steels and nickel based alloys candidates for USC steam turbine blading

    Energy Technology Data Exchange (ETDEWEB)

    Cernuschi, Federico; Guardamagna, Cristina; Lorenzoni, Lorenzo [ERSE SpA, Milan (Italy); Robba, Davide [CESI, Milan (Italy)

    2010-07-01

    The main objective of COST536 Action is to develop highly efficient steam power plant with low emissions, from innovative alloy development to validation of component integrity. In this perspective, to improve the operating efficiency, materials capable of withstanding higher operating temperatures are required. For the manufacturing of components for steam power plants with higher efficiency steels and nickel-based alloys with improved oxidation resistance and creep strength at temperature as high as 650 C - 700 C have to be developed. Candidate alloys for manufacturing high pressure steam turbine diaphragms, buckets, radial seals and control valves should exhibit, among other properties, a good resistance at the erosion phenomena induced by hard solid particles. Ferric oxide (magnetite) scales cause SPE by exfoliating from boiler tubes and steam pipes (mainly super-heaters and re-heaters) and being transported within the steam flow to the turbine. In order to comparatively study the erosion behaviour of different materials in relatively short times, an accelerated experimental simulation of the erosion phenomena must be carried out. Among different techniques to induce erosion on material targets, the use of an air jet tester is well recognised to be one of the most valid and reliable. In this work the results of SPE comparative tests performed at high temperatures (550 C, 600 C and 650 C) at different impaction angles on some steels and nickel based alloys samples are reported. (orig.)

  5. Safety and pharmacokinetics of a solid lipid curcumin particle formulation in osteosarcoma patients and healthy volunteers.

    Science.gov (United States)

    Gota, Vikram S; Maru, Girish B; Soni, Tejal G; Gandhi, Tejal R; Kochar, Nitin; Agarwal, Manish G

    2010-02-24

    Curcumin is the lipid-soluble antioxidant compound obtained from the rhizome of Curcuma longa Linn, also known as turmeric. Curcumin targets multiple chemotherapeutic and inflammatory pathways and has demonstrated safety and tolerability in humans, supporting its potential as a therapeutic agent; however, the clinical literature lacks conclusive evidence supporting its use as a therapeutic agent due to its low bioavailability in humans. The purpose of this study was to quantify plasma levels of free curcumin after dosing of a solid lipid curcumin particle (SLCP) formulation versus unformulated curcumin in healthy volunteers and to determine its tolerability and dose-plasma concentration relationship in late-stage osteosarcoma patients. Doses of 2, 3, and 4 g of SLCP were evaluated in 11 patients with osteosarcoma. Plasma curcumin levels were measured using a validated high-performance liquid chromatography method. The limit of detection of the assay was 1 ng/mL of curcumin. In healthy subjects, the mean peak concentration of curcumin achieved from dosing 650 mg of SLCP was 22.43 ng/mL, whereas plasma curcumin from dosing an equal quantity of unformulated 95% curcuminoids extract was not detected. In both healthy individuals and osteosarcoma patients, high interindividual variability in pharmacokinetics and nonlinear dose dependency was observed, suggesting potentially complex absorption kinetics. Overall, good tolerability was noted in both healthy and osteosarcoma groups.

  6. Macromodel for assessing residential concentrations of combustion-generated pollutants: Model development and preliminary predictions for CO, NO/sub 2/, and respirable suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Traynor, G.W.; Aceti, J.C.; Apte, M.G.; Smith, B.V.; Green, L.L.; Smith-Reiser, A.; Novak, K.M.; Moses, D.O.

    1989-01-01

    A simulation model (also called a ''macromodel'') has been developed to predict residential air pollutant concentration distributions for specified populations. The model inputs include the market penetration of pollution sources, pollution source characteristics (e.g., emission rates, source usage rates), building characteristics (e.g., house volume, air exchange rates), and meteorological parameters (e.g., outside temperature). Four geographically distinct regions of the US have been modeled using Monte Carlo and deterministic simulation techniques. Single-source simulations were also conducted. The highest predicted CO and NO/sub 2/ residential concentrations were associated with the winter-time use of unvented gas and kerosene space heaters. The highest predicted respirable suspended particulate concentrations were associated with indoor cigarette smoking and the winter-time use of non-airtight wood stoves, radiant kerosene heaters, convective unvented gas space heaters, and oil forced-air furnaces. Future field studies in this area should (1) fill information gaps identified in this report, and (2) collect information on the macromodel input parameters to properly interpret the results. It is almost more important to measure the parameters that affect indoor concentration than it is to measure the concentrations themselves.

  7. Acoustic backscatter by suspended cohesive sediments: Field observations, Seine Estuary, France

    Science.gov (United States)

    Sahin, Cihan; Verney, Romaric; Sheremet, Alexandru; Voulgaris, George

    2017-02-01

    Observations of suspended sediment size and concentration, flow and acoustic backscatter intensity collected on the Seine Estuary (France) are used to study the acoustic response in cohesive-sediment dominated environments. Estimates of suspended sediment concentration based on optical backscatter sensors and water samples are used to calibrate the acoustic backscatter intensity. The vertical structure of suspended sediment concentration is then estimated from acoustic backscatter information. To our knowledge, this is the first field application of the recently proposed model of acoustic scattering by flocculating suspensions based on the variation of particle density (floc-scattering model). The estimates of sediment concentration reproduce well the observations under different tidal (neap/spring) conditions, confirming the applicability of the new model in the field when detailed particle size measurements are available. When particle size measurements are not available, using estimated floc sizes based on the turbulence intensities may provide reasonable SSC profiles. During spring tide events (associated with strong currents, small flocs and large concentrations), the performances of the new floc-scattering model and the previous models given for solid particle-scattering are comparable. The floc-scattering model increases the quality of the SSC estimates especially during low-energy conditions characterized with larger flocs.

  8. Circular motion of particles suspended in a Gaussian beam with circular polarization validates the spin part of the internal energy flow

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Bekshaev, A. Ya.; Maksimyak, P. P.

    2012-01-01

    )] was treated as evidence for the spin-to orbital angular momentum conversion. Since in our realization the moderate focusing of the beam excluded the possibility for such a conversion, we consider the observed particle behavior as a demonstration of the macroscopic “spin energy flow” predicted by the theory...

  9. Simulation of deterministic energy-balance particle agglomeration in turbulent liquid-solid flows

    Science.gov (United States)

    Njobuenwu, Derrick O.; Fairweather, Michael

    2017-08-01

    An efficient technique to simulate turbulent particle-laden flow at high mass loadings within the four-way coupled simulation regime is presented. The technique implements large-eddy simulation, discrete particle simulation, a deterministic treatment of inter-particle collisions, and an energy-balanced particle agglomeration model. The algorithm to detect inter-particle collisions is such that the computational costs scale linearly with the number of particles present in the computational domain. On detection of a collision, particle agglomeration is tested based on the pre-collision kinetic energy, restitution coefficient, and van der Waals' interactions. The performance of the technique developed is tested by performing parametric studies on the influence of the restitution coefficient (en = 0.2, 0.4, 0.6, and 0.8), particle size (dp = 60, 120, 200, and 316 μm), Reynolds number (Reτ = 150, 300, and 590), and particle concentration (αp = 5.0 × 10-4, 1.0 × 10-3, and 5.0 × 10-3) on particle-particle interaction events (collision and agglomeration). The results demonstrate that the collision frequency shows a linear dependency on the restitution coefficient, while the agglomeration rate shows an inverse dependence. Collisions among smaller particles are more frequent and efficient in forming agglomerates than those of coarser particles. The particle-particle interaction events show a strong dependency on the shear Reynolds number Reτ, while increasing the particle concentration effectively enhances particle collision and agglomeration whilst having only a minor influence on the agglomeration rate. Overall, the sensitivity of the particle-particle interaction events to the selected simulation parameters is found to influence the population and distribution of the primary particles and agglomerates formed.

  10. TOPICAL REVIEW Warm spraying—a novel coating process based on high-velocity impact of solid particles

    Directory of Open Access Journals (Sweden)

    Seiji Kuroda et al

    2008-01-01

    Full Text Available In recent years, coating processes based on the impact of high-velocity solid particles such as cold spraying and aerosol deposition have been developed and attracting much industrial attention. A novel coating process called 'warm spraying' has been developed, in which coatings are formed by the high-velocity impact of solid powder particles heated to appropriate temperatures below the melting point of the powder material. The advantages of such process are as follows: (1 the critical velocity needed to form a coating can be significantly lowered by heating, (2 the degradation of feedstock powder such as oxidation can be significantly controlled compared with conventional thermal spraying where powder is molten, and (3 various coating structures can be realized from porous to dense ones by controlling the temperature and velocity of the particles. The principles and characteristics of this new process are discussed in light of other existing spray processes such as high-velocity oxy-fuel spraying and cold spraying. The gas dynamics of particle heating and acceleration by the spraying apparatus as well as the high-velocity impact phenomena of powder particles are discussed in detail. Several examples of depositing heat sensitive materials such as titanium, metallic glass, WC–Co cermet and polymers are described with potential industrial applications.

  11. Controlled Dissolution of Griseofulvin Solid Dispersions from Electrosprayed Enteric Polymer Micromatrix Particles: Physicochemical Characterization and in Vitro Evaluation.

    Science.gov (United States)

    Roine, Jorma; Kaasalainen, Martti; Peurla, Markus; Correia, Alexandra; Araújo, Francisca; Santos, Hélder A; Murtomaa, Matti; Salonen, Jarno

    2015-07-06

    The oral bioavailability of a poorly water-soluble drug is often inadequate for the desired therapeutic effect. The bioavailability can be improved by enhancing the physicochemical properties of the drug (e.g., dissolution rate, permeation across the gastrointestinal tract). Other approach include shielding the drug from the gastric metabolism and targeted drug release to obtain optimal drug absorption. In this study, a poorly water-soluble model drug, griseofulvin, was encapsulated as disordered solid dispersions into Eudragit L 100-55 enteric polymer micromatrix particles, which were produced by electrospraying. Similar micromatrix particles were also produced with griseofulvin-loaded thermally oxidized mesoporous silicon (TOPSi) nanoparticles dispersed to the polymer micromatrices. The in vitro drug dissolution at pH 1.2 and 6.8, and permeation at pH 7.4 across Caco-2/HT29 cell monolayers from the micromatrix particles, were investigated. The micromatrix particles were found to be gastro-resistant, while at pH 6.8 the griseofulvin was released very rapidly in a fast-dissolving form. Compared to free griseofulvin, the permeability of encapsulated griseofulvin across the intestinal cell monolayers was greatly improved, particularly for the TOPSi-doped micromatrix particles. The griseofulvin solid dispersions were stable during storage for 6 months at accelerated conditions. Overall, the method developed here could prove to be a useful oral drug delivery solution for improving the bioavailability of poorly water-soluble or otherwise problematic drugs.

  12. Modelling the light absorption properties of particulate matter forming organic particles suspended in seawater.Part 1. Model description, classification of organic particles, and example spectra of the light absorption coefficient and the imaginary part of the refractive index of particulate matter for phytoplankton cells and phytoplankton-like particles

    Directory of Open Access Journals (Sweden)

    Bogdan Woźniak

    2005-06-01

    Full Text Available Data on organic substances in the sea are applied to distinguish hypothetical chemical classes and physical types of suspended particulate organic matter (POM in seawater. Spectra of the light absorption coefficients of particulate matter apm(λ and the imaginary refractive index n'p(λ, are assessed for some of these classes and types of POM in seawater, that is, for live phytoplankton cells and phytoplankton-like particles. The spectral characteristics of these coefficients are established and the probable ranges of variability of their absolute magnitudes defined on the basis of the mass-specific coefficients of light absorption by the various organic substances forming the particles. Also presented are mathematical relationships linking the coefficients apm(λ and n'p(λ for the various chemical classes of POM with their physical parameters, such as the relative contents of organic matter, water, air or some other gas. This article is part of a bio-optical study undertaken by the authors, the objective of which is to implement remote sensing techniques in the investigation of Baltic ecosystems (Woźniak et al. 2004.

  13. Study of the heavy metals speciation in the atmospheric suspended particles in Sevilla (Spain); Estudio de la especiacion de metales pesados en la materia particulada atmosferica de la ciudad de Sevilla

    Energy Technology Data Exchange (ETDEWEB)

    Ternero Rodriguez, M.; Sequeiros Madueno, L.; Jimenez Sanchez, C.; Barragan de la Rosa, J.; Bello Lopez, M.; Fernandez Espinosa, A.J.; Perez Bernal, J.L. [Facultad de Quimica, Universidad de Sevilla (Spain)

    1997-06-01

    This work develops analytical methods for the heavy metals speciation in the atmospheric suspended particles. In base to these methods, we study the atmospheric contamination of the city of Seville, determining the metals Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb. We also study the effects of metallic species in the alteration processes on rocks material, in base to the SO{sub 2}/SO{sub 4}{sup {minus}{minus}}. The project develops in two years: in the first, we develop the methods of chemistry speciation based on the extraction with different reagents and the methods of physical speciation based on the particle size distribution with cascade impactors. Also, we develop the methodology for the environmental simulation of alteration processes, in base to the heterogeneous catalysis, by metallic ions, of the SO{sub 2} on the surface of the stone. In the second year we apply the methods of speciation to the study of the contamination by heavy metals in the city of Seville. This part divides in two phases: a first of the preliminary study in the city in order to identify the different polluting focuses, and a secondary of study of the contamination produced by punctual sources, in the more polluted points of the city. On the other hand, the study of the alteration processes of rock materials has centred on materials employees in monuments of the city and on application of the catalyzers found in the particulate matter of the true environment of the materials. (Author)

  14. A study of the effect of solid particle impact and particle shape on the erosion morphology of ductile metals

    Science.gov (United States)

    Rao, P. V.; Young, S. G.; Buckley, D. H.

    1984-01-01

    Impulsive versus steady jet impingement of spherical glass bead particles on metal surfaces was studied using a gas gun facility and a commercial sand blasting apparatus. Crushed glass particles were also used in the sand blasting apparatus as well as glass beads. Comparisons of the different types of erosion patterns were made. Scanning electron microscopy, surface profilometry and energy dispersive X-ray spectroscopy analysis were used to characterize erosion patterns. The nature of the wear can be divided into cutting and deformation, each with its own characteristic features. Surface chemistry analysis indicates the possiblity of complex chemical and/or mechanical interactions between erodants and target materials.

  15. Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis

    Directory of Open Access Journals (Sweden)

    I. Tolosa

    2013-03-01

    Full Text Available Molecular lipid biomarkers (hydrocarbons, alcohols, sterols and fatty acids and compound-specific isotope analysis of suspended particulate organic matter (SPM and surface sediments of the Mackenzie Shelf and slope (southeast Beaufort Sea, Arctic Ocean were studied in summer 2009. The concentrations of the molecular lipid markers, characteristic of known organic matter sources, were grouped and used as proxies to evaluate the relative importance of fresh algal, detrital algal, fossil, C3 terrestrial plants, bacterial and zooplankton material in the organic matter (OM of this area. Fossil and detrital algal contributions were the major fractions of the freshwater SPM from the Mackenzie River with ~34% each of the total molecular biomarkers. Fresh algal, C3 terrestrial, bacterial and zooplanktonic components represented much lower percentages, 17, 10, 4 and 80%, with a minor contribution of fossil and C3 terrestrial biomarkers. Characterization of the sediments revealed a major sink of refractory algal material mixed with some fresh algal material, fossil hydrocarbons and a small input of C3 terrestrial sources. In particular, the sediments from the shelf and at the mouth of the Amundsen Gulf presented the highest contribution of detrital algal material (60–75%, whereas those from the slope contained the highest proportion of fossil (40% and C3 terrestrial plant material (10%. Overall, considering that the detrital algal material is marine derived, autochthonous sources contributed more than allochthonous sources to the OM lipid pool. Using the ratio of an allochthonous biomarker (normalized to total organic carbon, TOC found in the sediments to those measured at the river mouth water, we estimated that the fraction of terrestrial material preserved in the sediments accounted for 30–40% of the total carbon in the inner shelf sediments, 17% in the outer shelf and Amundsen Gulf and up to 25% in the slope sediments. These estimates are low

  16. Retrieval of Chlorophyll-a and Total Suspended Solids Using Iterative Stepwise Elimination Partial Least Squares (ISE-PLS Regression Based on Field Hyperspectral Measurements in Irrigation Ponds in Higashihiroshima, Japan

    Directory of Open Access Journals (Sweden)

    Zuomin Wang

    2017-03-01

    Full Text Available Concentrations of chlorophyll-a (Chl-a and total suspended solids (TSS are significant parameters used to assess water quality. The objective of this study is to establish a quantitative model for estimating the Chl-a and the TSS concentrations in irrigation ponds in Higashihiroshima, Japan, using field hyperspectral measurements and statistical analysis. Field experiments were conducted in six ponds and spectral readings for Chl-a and TSS were obtained from six field observations in 2014. For statistical approaches, we used two spectral indices, the ratio spectral index (RSI and the normalized difference spectral index (NDSI, and a partial least squares (PLS regression. The predictive abilities were compared using the coefficient of determination (R2, the root mean squared error of cross validation (RMSECV and the residual predictive deviation (RPD. Overall, iterative stepwise elimination based on PLS (ISE–PLS, using the first derivative reflectance (FDR, showed the best predictive accuracy, for both Chl-a (R2 = 0.98, RMSECV = 6.15, RPD = 7.44 and TSS (R2 = 0.97, RMSECV = 1.91, RPD = 6.64. The important wavebands for estimating Chl-a (16.97% of all wavebands and TSS (8.38% of all wavebands were selected by ISE–PLS from all 501 wavebands over the 400–900 nm range. These findings suggest that ISE–PLS based on field hyperspectral measurements can be used to estimate water Chl-a and TSS concentrations in irrigation ponds.

  17. Environmental toxicology: Acute effects of suspended particulate ...

    African Journals Online (AJOL)

    The elemental contents of suspended particulate matter (dust) samples from Maiduguri, Nigeria, were determined which showed appreciably high levels for especially Pb, Fe, Cu, Zn, K, Ca, and. Na. Wister albino rats were exposed to graded doses of phosphate buffered saline carried dust particles. The hematological ...

  18. Characterization of solid airborne particles deposited in snow in the vicinity of urban fossil fuel thermal power plant (Western Siberia).

    Science.gov (United States)

    Talovskaya, A V; Yazikov, E G; Filimonenko, E A; Lata, J-C; Kim, J; Shakhova, T S

    2017-07-20

    Recognition and detailed characterization of solid particles emitted from thermal power plants into the environment is highly important due to their potential detrimental effects on human health. Snow cover is used for the identification of anthropogenic emissions in the environment. However, little is known about types, physical and chemical properties of solid airborne particles (SAP) deposited in snow around thermal power plants. The purpose of this study is to quantify and characterize in detail the traceable SAP deposited in snow near fossil fuel thermal power plant in order to identify its emissions into the environment. Applying the scanning electron microscopy-energy dispersive spectroscopy, and X-ray diffraction, mineral and anthropogenic phase groups in SAP deposited in snow near the plant and in fly ash were observed. We identified quartz, albite and mullite as most abundant mineral phases and carbonaceous matter, slag and spherical particles as dominate anthropogenic phases. This is the first study reporting that zircon and anthropogenic sulphide-bearing, metal oxide-bearing, intermetallic compound-bearing and rare-earth element-bearing particles were detected in snow deposits near thermal power plant. The identified mineral and anthropogenic phases can be used as tracers for fossil fuel combustion emissions, especially with regard to their possible effect on human health.

  19. Study of Particle Rotation Effect in Gas-Solid Flows using Direct Numerical Simulation with a Lattice Boltzmann Method

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Kyung [Tuskegee Univ., Tuskegee, AL (United States); Fan, Liang-Shih [The Ohio State Univ., Columbus, OH (United States); Zhou, Qiang [The Ohio State Univ., Columbus, OH (United States); Yang, Hui [The Ohio State Univ., Columbus, OH (United States)

    2014-09-30

    fluid is accelerated from rest by a constant average pressure gradient toward a steady Stokes flow. The simulation results agree well with the theories for the short- and long-time behavior of the drag force. Flows through non-rotational and rotational spheres in simple cubic arrays and random arrays are simulated over the entire range of packing fractions, and both low and moderate particle Reynolds numbers to compare the simulated results with the literature results and develop a new drag force formula, a new lift force formula, and a new torque formula. Random arrays of solid particles in fluids are generated with Monte Carlo procedure and Zinchenko's method to avoid crystallization of solid particles over high solid volume fractions. A new drag force formula was developed with extensive simulated results to be closely applicable to real processes over the entire range of packing fractions and both low and moderate particle Reynolds numbers. The simulation results indicate that the drag force is barely affected by rotational Reynolds numbers. Drag force is basically unchanged as the angle of the rotating axis varies.

  20. Solid-phase extraction of organic compounds in atmospheric aerosol particles collected with the particle-into-liquid sampler and analysis by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Parshintsev, Jevgeni; Hyötyläinen, Tuulia; Hartonen, Kari; Kulmala, Markku; Riekkola, Marja-Liisa

    2010-01-15

    Atmospheric aerosol particles, collected with the particle-into-liquid sampler at SMEARII station in Finland in mid-August 2007, were analysed for biogenic acids. The sample pretreatment method, comprising solid-phase extraction with anion exchange and hydrophilic-lipophilic balance materials, was optimized. Extraction efficiencies of solid-phase extraction from 10 and 20ml samples were about 100%, with average relative standard deviation of 8.9%, in concentration range from 12.5 to 50ng/ml of the acid. Extraction of aldehydes was less successful, with efficiencies from 69 to 163% and average 10% deviation. Pretreated samples were analysed by reversed phase high performance liquid chromatography with ion trap mass spectrometric detection. Limits of detection achieved for organic acids with the analytical procedure developed ranged from 9 to 27microg/l of extracted sample, while limits of quantitation were from 31 to 90microg/l. Oxidation with ozone was used for the preparation of the acid of beta-caryophyllene (beta-caryophyllinic acid), which was also studied in aerosol samples. MS(2) experiments were used to confirm the identification of trans-pinic, trans-pinonic and beta-caryophyllinic acids. Azelaic, hexadecanoic, cis-pinonic, and cis- and trans-pinic acids were quantitated in the samples with use of authentic standards, while the concentrations of trans-pinonic and beta-caryophyllinic acids were determined with cis-pinonic acid as surrogate. Also, the contribution of beta-caryophyllene oxidation products to aerosol organic carbon was evaluated. Aldehydes could not be analysed in real samples due to the insufficient extraction. The particle-into-liquid sampler proved to be suitable for the collection of aerosol particles for the elucidation of daily and diurnal variation of selected species. The optimized sample pretreatment, together with the analysis method, offer a promising approach for the study of aerosol chemical composition, where artifact formation is

  1. Solid state speciation and potential bioavailability of depleted uranium particles from Kosovo and Kuwait

    Energy Technology Data Exchange (ETDEWEB)

    Lind, O.C. [Isotope Laboratory, Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 As (Norway)], E-mail: ole-christian.lind@umb.no; Salbu, B.; Skipperud, L. [Isotope Laboratory, Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 As (Norway); Janssens, K.; Jaroszewicz, J.; De Nolf, W. [Department of Chemistry, University of Antwerp, Universiteitsplein 1, Antwerp (Belgium)

    2009-04-15

    A combination of synchrotron radiation based X-ray microscopic techniques ({mu}-XRF, {mu}-XANES, {mu}-XRD) applied on single depleted uranium (DU) particles and semi-bulk leaching experiments has been employed to link the potential bioavailability of DU particles to site-specific particle characteristics. The oxidation states and crystallographic forms of U in DU particles have been determined for individual particles isolated from selected samples collected at different sites in Kosovo and Kuwait that were contaminated by DU ammunition during the 1999 Balkan conflict and the 1991 Gulf war. Furthermore, small soil or sand samples heavily contaminated with DU particles were subjected to simulated gastrointestinal fluid (0.16 M HCl) extractions. Characteristics of DU particles in Kosovo soils collected in 2000 and in Kuwait soils collected in 2002 varied significantly depending on the release scenario and to some extent on weathering conditions. Oxidized U (+6) was determined in large, fragile and bright yellow DU particles released during fire at a DU ammunition storage facility and crystalline phases such as schoepite (UO{sub 3}.2.25H{sub 2}O), dehydrated schoepite (UO{sub 3}.0.75H{sub 2}O) and metaschoepite (UO{sub 3}.2.0H{sub 2}O) were identified. As expected, these DU particles were rapidly dissolved in 0.16 M HCl (84 {+-} 3% extracted after 2 h) indicating a high degree of potential mobility and bioavailability. In contrast, the 2 h extraction of samples contaminated with DU particles originating either from corrosion of unspent DU penetrators or from impacted DU ammunition appeared to be much slower (20-30%) as uranium was less oxidized (+4 to +6). Crystalline phases such as UO{sub 2}, UC and metallic U or U-Ti alloy were determined in impacted DU particles from Kosovo and Kuwait, while the UO{sub 2,34} phase, only determined in particles from Kosovo, could reflect a more corrosive environment. Although the results are based on a limited number of DU particles

  2. Classification and Processing Optimization of Barley Milk Production Using NIR Spectroscopy, Particle Size, and Total Dissolved Solids Analysis

    Directory of Open Access Journals (Sweden)

    Jasenka Gajdoš Kljusurić

    2015-01-01

    Full Text Available Barley is a grain whose consumption has a significant nutritional benefit for human health as a very good source of dietary fibre, minerals, vitamins, and phenolic and phytic acids. Nowadays, it is more and more often used in the production of plant milk, which is used to replace cow milk in the diet by an increasing number of consumers. The aim of the study was to classify barley milk and determine the optimal processing conditions in barley milk production based on NIR spectra, particle size, and total dissolved solids analysis. Standard recipe for barley milk was used without added additives. Barley grain was ground and mixed in a blender for 15, 30, 45, and 60 seconds. The samples were filtered and particle size of the grains was determined by laser diffraction particle sizing. The plant milk was also analysed using near infrared spectroscopy (NIRS, in the range from 904 to 1699 nm. Furthermore, conductivity of each sample was determined and microphotographs were taken in order to identify the structure of fat globules and particles in the barley milk. NIR spectra, particle size distribution, and conductivity results all point to 45 seconds as the optimal blending time, since further blending results in the saturation of the samples.

  3. Simultaneous measurement of local particle movement, solids concentrations and bubble properties in fluidized bed reactors using a novel fiber optical technique

    Energy Technology Data Exchange (ETDEWEB)

    Tayebi, Davoud

    1998-12-31

    This thesis develops a new method for simultaneous measurements of local flow properties in highly concentrated multiphase flow systems such as gas-solid fluidized bed reactors. The method is based on fiber optical technique and tracer particles. A particle present in the measuring volume in front of the probe is marked with a fluorescent dye. A light source illuminates the particles and the detecting fibres receive reflected light from uncoated particles and fluorescent light from the tracer particle. Using optical filters, the fluorescent light can be distinguished and together with a small fraction of background light from uncoated particles can be used for determination of local flow properties. Using this method, one can simultaneously measure the local movement of a single tracer particle, local bubble properties and the local solids volume fractions in different positions in the bed. The method is independent of the physical properties of the tracer particles. It is also independent of the local solids concentrations in the range of 0 to 60 vol.-%, but is mainly designed for highly concentrated flow systems. A computer programme that uses good signals from at least three sensors simultaneously to calculate the tracer particle velocity in two dimensions have been developed. It also calculates the bubble properties and local solids volume fractions from the same time series. 251 refs., 150 figs., 5 tabs.

  4. From discrete particles to solids - about sintering and self-healing (Review)

    NARCIS (Netherlands)

    Luding, Stefan

    2011-01-01

    In this review, particulate materials are studied using the Discrete Element Method (DEM), where the particles keep their identity throughout. Loose particles can sinter due to time-, stress- or temperature-dependent forces. Large deformations of sintered samples will then lead to damage.

  5. Particle size distribution of fly ash from co-incineration of bituminous coal with municipal solid waste

    Directory of Open Access Journals (Sweden)

    Cieślik Ewelina

    2018-01-01

    Full Text Available One of the source of air pollutants is emission from local coal-fired boiler-houses and domestic heating boilers. The consequence of incineration of municipal waste is the introduction of additional pollutants into the atmosphere, including fly ash. The aim of this work was to evaluate the particle size distribution of fly ash emitted by coal combustion and co-incineration of coal with municipal waste in a domestic 18 kW central heating boiler equipped with an automatic fuel feeder. Mixtures of bituminous coal with different types of solid waste (5, 10 and 15% of mass fraction were used. Solid waste types consisted of: printed, colored PE caps, fragmented cable trunking, fragmented car gaskets and shredded tires from trucks. During the incineration of a given mixture of municipal waste with bituminous coal, the velocity of exhaust gas was specified, the concentration and mass flow of fly ash were determined together with the physico-chemical parameters of the exhaust gas, the samples of emitted fly ash were taken as the test material. Particle size analysis of fly ash was performed using laser particle sizer Fritch Analysette 22. The PM10 share from all fly ashes from incineration of mixtures was about 100%. Differences were noted between PM2.5 and PM1.

  6. Analytical solutions for non-linear conversion of a porous solid particle in a gas–II. Non-isothermal conversion and numerical verification

    NARCIS (Netherlands)

    Brem, Gerrit; Brouwers, J.J.H.

    1990-01-01

    In Part I, analytical solutions were given for the non-linear isothermal heterogeneous conversion of a porous solid particle. Account was taken of a reaction rate of general order with respect to the gas reactant, intrinsic reaction surface area and effective pore diffusion, which change with solid

  7. Development of a depth-integrated sample arm (DISA) to reduce solids stratification bias in stormwater sampling

    Science.gov (United States)

    Selbig, William R.; ,; Roger T. Bannerman,

    2011-01-01

    A new depth-integrated sample arm (DISA) was developed to improve the representation of solids in stormwater, both organic and inorganic, by collecting a water quality sample from multiple points in the water column. Data from this study demonstrate the idea of vertical stratification of solids in storm sewer runoff. Concentrations of suspended sediment in runoff were statistically greater using a fixed rather than multipoint collection system. Median suspended sediment concentrations measured at the fixed location (near the pipe invert) were approximately double those collected using the DISA. In general, concentrations and size distributions of suspended sediment decreased with increasing vertical distance from the storm sewer invert. Coarser particles tended to dominate the distribution of solids near the storm sewer invert as discharge increased. In contrast to concentration and particle size, organic material, to some extent, was distributed homogenously throughout the water column, likely the result of its low specific density, which allows for thorough mixing in less turbulent water.

  8. Eulerian numerical simulation of gas-solid flows with several particles species; Modelisation numerique eulerienne des ecoulements gaz-solide avec plusieurs especes de particules

    Energy Technology Data Exchange (ETDEWEB)

    Patino-Palacios, G

    2007-11-15

    The simulation of the multiphase flows is currently an important scientific, industrial and economic challenge. The objective of this work is to improve comprehension via simulations of poly-dispersed flows and contribute the modeling and characterizing of its hydrodynamics. The study of gas-solid systems involves the models that takes account the influence of the particles and the effects of the collisions in the context of the momentum transfer. This kind of study is covered on the framework of this thesis. Simulations achieved with the Saturne-polyphasique-Tlse code, developed by Electricite de France and co-worked with the Institut de Mecanique des Fluides de Toulouse, allowed to confirm the feasibility of approach CFD for the hydrodynamic study of the injectors and dense fluidized beds. The stages of validation concern, on the one hand, the placement of the tool for simulation in its current state to make studies of validation and sensitivity of the models and to compare the numerical results with the experimental data. In addition, the development of new physical models and their establishments in the code Saturne will allow the optimization of the industrial process. To carry out this validation in a satisfactory way, a key simulation is made, in particular a monodisperse injection and the radial force of injection in the case of a poly-disperse flow, as well as the fluidization of a column made up of solid particles. In this last case, one approached three configurations of dense fluidized beds, in order to study the influence of the grid on simulations; then, one simulates the operation of a dense fluidized bed with which one characterizes the segregation between two various species of particles. The study of the injection of the poly-disperse flows presents two configurations; a flow Co-current gas-particle in gas (Case Hishida), and in addition, a poly-phase flow in a configuration of the jet type confined with zones of recirculation and stagnation (case

  9. Improvement of the Turbine Main Stop Valves with Flow Simulation in Erosion by Solid Particle Impact CFD

    Directory of Open Access Journals (Sweden)

    Z. Mazur

    2004-01-01

    Full Text Available The flow field in a steam turbine main stop valve bypass valve (MSVBV has been investigated by means of CFD simulations. Because the entire flow to the turbine during start ups is carried by the MSVBV it is subject to serious solid particle erosion problems and requires frequent replacement to avoid the catastrophic damage which can occurred when the MSVBV skirt eroded through causing large pieces of metal to be carried directly into the turbine. For some of the most important geometric parameters of the MSVBV, design recommendation have been made.

  10. Solid-particle erosion of an Al{sub 2}O{sub 3}-SiC-TiC composite

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, M.; Goretta, K.C.; Singh, D.; Routbort, J.L. [Argonne National Lab., IL (United States); Schuldies, J.J. [Industrial Ceramic Technology, Inc., Ann Arbor, MI (United States)

    1996-11-01

    An electrodischarge-machinable Al{sub 2}O{sub 3}-SiC-TiC composite developed by Industrial Ceramic Technology, Inc., has a high fracture toughness, 9.6{+-}0.6 MPm{sup 1/2}, as measured by indentation, and a Vickers hardness of 20.3{+-}0.6 GPa. The composite`s resistance to solid-particle erosion was measured for 143-{mu}m dia SiC particles impacting at 20-90{degree} angles and 50-100 m/s velocities. Erosion rate exhibited a maximum for normal incidence, and the erosion resistance was better than that of commercial Al{sub 2}O{sub 3}. SEM indicated that material wastage was by a combination of brittle fracture and microplasticity.

  11. Numerical investigation of the influence of crystallization of ultrafine particles of aluminum oxide on energy characteristics of solid-propellant rocket engine

    Science.gov (United States)

    Dyachenko, N. N.; Dyachenko, L. I.

    2014-08-01

    The results of numerical investigation of a multiphase flow considering coagulation, crushing and crystallization of the particles of polydispersed condensate in the nozzles of solid-propellant rocket engine are presented. The influence of particles crystallization on the energy characteristics of the engine is shown.

  12. Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D., E-mail: deyongl@uci.edu; Heidbrink, W. W.; Hao, G. Z.; Zhu, Y. B. [Departments of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Tritz, K. [Departments of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Fredrickson, E. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2016-11-15

    A compact and multi-view solid state neutral particle analyzer (SSNPA) diagnostic based on silicon photodiode arrays has been successfully tested on the National Spherical Torus Experiment-Upgrade. The SSNPA diagnostic provides spatially, temporally, and pitch-angle resolved measurements of fast-ion distribution by detecting fast neutral flux resulting from the charge exchange (CX) reactions. The system consists of three 16-channel subsystems: t-SSNPA viewing the plasma mid-radius and neutral beam (NB) line #2 tangentially, r-SSNPA viewing the plasma core and NB line #1 radially, and p-SSNPA with no intersection with any NB lines. Due to the setup geometry, the active CX signals of t-SSNPA and r-SSNPA are mainly sensitive to passing and trapped particles, respectively. In addition, both t-SSNPA and r-SSNPA utilize three vertically stacked arrays with different filter thicknesses to obtain coarse energy information. The experimental data show that all channels are operational. The signal to noise ratio is typically larger than 10, and the main noise is x-ray induced signal. The active and passive CX signals are clearly observed on t-SSNPA and r-SSNPA during NB modulation. The SSNPA data also indicate significant losses of passing particles during sawteeth, while trapped particles are weakly affected. Fluctuations up to 120 kHz have been observed on SSNPA, and they are strongly correlated with magnetohydrodynamics instabilities.

  13. Seasonal trends of benzo(apyrene in suspended particulate matter in urban areas of Belgrade, Serbia

    Directory of Open Access Journals (Sweden)

    Snežana Matić-Besarabić

    2010-09-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs were identified to be one of the major toxic air pollutants in urban environment. PAHs are mostly formed during incomplete combustion or pyrolysis of organic material. According to Serbian National Legislation, benzo(apyrene (BaP concentration in total suspended particles (TSP in ambient air in the Belgrade metropolitan area has been determined in the last ten years, as a part of a local air pollution monitoring program performed by the Public Health Institute of Belgrade and funded by Belgrade’s Municipality. Air samples for analysis of BaP in suspended particleshave been collected (as 24 h sample once per month at selected onitoring sites within the municipal air quality monitoring network. At the beginning, according to National Regulation, all samples were taken as total suspended particles (TSP. Since mid-2008, the procedure of sampling methodology was harmonized with EU requirements and solid fraction PM10 has been collected and analyzed using GC/MS. In this study, we have analyzed results of TSP collected between 2005 and 2008. Looking through the results obtained during the period of a whole year, it can be noticed that concentrations of BaP were much higher during winter season at almost all measuring sites.

  14. How fast are the ultra-fast nano-scale solid-liquid phase transitions induced by energetic particles in solids?

    Science.gov (United States)

    Lopasso, E. M.; Caro, A.; Caro, M.

    2003-12-01

    We study the thermodynamic forces acting on the evolution of the nanoscale regions excited by collisions of energetic particles into solid targets. We analyze the role of diffusion, thermo-migration, and the liquidus-solidus two-phase field crossing, as the system cools down from the collision-induced melt under different conditions of energy deposition. To determine the relevance of these thermodynamic forces, solute redistribution is evaluated using molecular dynamics simulations of equilibrium Au-Ni solid solutions. At low collision energies, our results show that the quenching of spherical cascades is too fast to allow for solute redistribution according to equilibrium solidification as determined from the equilibrium phase diagram (zone refining effect), and only thermo-migration is observed. At higher energies instead, in the cylindrical symmetry of ion tracks, quenching rate is in a range that shows the combined effects of thermo-migration and solute redistribution that, depending on the material, can reinforce or cancel each other. These results are relevant for the interpretation of the early stage of radiation damage in alloys, and show that the combination of ultra-fast but nano-scale characteristics of these processes can still be described in terms of linear response of the perturbed system.

  15. EXPERIMENTAL STUDIES AND SIMULATIONS ON GRAVITATIONAL SEDIMENTATION OF THE SOLID POLUTANTS IN SUSPENSION

    Directory of Open Access Journals (Sweden)

    Sorin Anghel

    2010-01-01

    Full Text Available Sedimentation of suspensions process is important, especially in pollution and biologic studies. Unlike usual methods,as those using pipettes, aerometer or balances, the optical ones are nondestructive and more accurate. During thesedimentation produced by the braked fall off the solid particles in suspension, fluctuations induced by an oppositevertical diffusion occur. We used a scattering method, based on the attenuation of a laser beam, which allows plottingsedimentation curves (the dependence on time of the suspended solid particles concentration of the process. Weobtained an empirical relation describing sedimentation curves as a function of some main parameters (related toinitial concentration, height in suspension, dimensions of suspended solid particles and we performed a simulation ofthe experimental sedimentation curves using the obtained relation and Mathcad software facilities. We notice that theresults of these studies allow using a fast method in order to determine the sedimentation time, which often can be verylong.

  16. Influence of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in cyclone heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Mothilal, T. [T. J. S. Engineering College, Gummidipoond (India); Pitchandi, K. [Sri Venkateswara College of Engineering, Sriperumbudur (India)

    2015-10-15

    Present work elaborates the effect of inlet velocity of air and solid particle feed rate on holdup mass and heat transfer characteristics in a cyclone heat exchanger. The RNG k-ε turbulence model was adopted for modeling high turbulence flow and Discrete phase model (DPM) to track solid particles in a cyclone heat exchanger by ANSYS FLUENT software. The effect of inlet air velocity (5 to 25 m/s) and inlet solid particle feed rate of (0.2 to 2.5 g/s) at different particle diameter (300 to 500 μm) on holdup mass and heat transfer rate in cyclone heat exchanger was studied at air inlet temperature of 473 K. Results show that holdup mass and heat transfer rate increase with increase in inlet air velocity and inlet solid particle feed rate. Influence of solid particle feed rate on holdup mass has more significance. Experimental setup was built for high efficiency cyclone. Good agreement was found between experimental and simulation pressure drop. Empirical correlation was derived for dimensionless holdup mass and Nusselt number based on CFD data by regression technique. Correlation predicts dimensional holdup mass with +5% to -8% errors of experimental data and Nusselt number with +9% to -3%.

  17. Inverse gas chromatography a tool to follow physicochemical modifications of pharmaceutical solids: Crystal habit and particles size surface effects.

    Science.gov (United States)

    Cares-Pacheco, M G; Calvet, R; Vaca-Medina, G; Rouilly, A; Espitalier, F

    2015-10-15

    Powders are complex systems and so pharmaceutical solids are not the exception. Nowadays, pharmaceutical ingredients must comply with well-defined draconian specifications imposing narrow particle size range, control on the mean particle size, crystalline structure, crystal habits aspect and surface properties of powders, among others. The different facets, physical forms, defects and/or impurities of the solid will alter its interaction properties. A powerful way of studying surface properties is based on the adsorption of an organic or water vapor on a powder. Inverse gas chromatography (IGC) appears as a useful method to characterize the surface properties of divided solids. The aim of this work is to study the sensitivity of IGC, in Henry's domain, in order to detect the impact of size and morphology in surface energy of two crystalline forms of an excipient, d-mannitol. Surface energy analyses using IGC have shown that the α form is the most energetically active form. To study size and shape influence on polymorphism, pure α and β mannitol samples were cryomilled (CM) and/or spray dried (SD). All forms showed an increase of the surface energy after treatment, with a higher influence for β samples (γs(d) of 40-62 mJ m(-2)) than for α mannitol samples (γs(d) of 75-86 mJ m(-2)). Surface heterogeneity analysis in Henry's domain showed a more heterogeneous β-CM sample (62-52 mJ m(-2)). Moreover, despite its spherical shape and quite homogeneous size distribution, β-SD mannitol samples showed a slightly heterogeneous surface (57-52 mJ m(-2)) also higher than the recrystallized β pure sample (∼40 mJ m(-2)). Copyright © 2015 Elsevier B.V. All rights reserved.

  18. The magnetochemistry of supramolecular particles: The transition from the molecular to the solid-state

    Science.gov (United States)

    Papaefthymiou, Georgia C.

    1992-05-01

    The magnetic properties of nanometer-sized molecular complexes or clusters that contain an increasing number n of superexchange-coupled iron ions participating in 3-D or lower-dimensional magnetic interactions were examined. The experimental criteria that establish the onset of incipient solid-state magnetic correlation effects in these molecules were emphasized. These chemical structures are beyond the molecular realm but convergence to the bulk has not yet been attained. Thus, they afforded appropriate experimental systems to test theoretical predictions that the onset of incipient solid-state phenomena - such as the emergence of a conduction band in metallic clusters and collective magnetic interactions responsible for magnetic ordering in solids - occurs at the vicinity of n greater than 10, where n is the number of atoms or interacting spins in the cluster. The study provided, by means of Mossbauer spectroscopy with a characteristic measuring time tau(sub m) approx. 10(exp -8) sec the first experimental observation of the onset of intramolecular magnetic ordering in 10 A diameter clusters whose magnetic exchange interaction network among iron ions was three-dimensional. Owing to the extremely small size of the magnetic domain transitional magnetic behavior and superparamagnetic relaxation phenomena dominated the Mossbauer spectra.

  19. Solid lipid particles for oral delivery of peptide and protein drugs III - the effect of fed state conditions on the in vitro release and degradation of desmopressin

    DEFF Research Database (Denmark)

    Christophersen, Philip C; Vaghela, Dimple; Müllertz, Anette

    2014-01-01

    The effect of food intake on the release and degradation of peptide drugs from solid lipid particles is unknown and was therefore investigated in vitro using different fed state media in a lipolysis model. Desmopressin was used as a model peptide and incorporated into solid lipid particles...... and the protease or desmopressin. Addition of a medium chain triglyceride, trilaurin, in combination with drug-loaded lipid particles diminished the food effect on the TG18 particles, and trilaurin is therefore proposed to be a suitable excipient for reduction of the food effect. Overall, the present study shows...... that strategies to reduce food effect, such as adding trilaurin, for lipid particle formulations should be considered as drug release from such formulations might be influenced by the presence of food in the gastrointestinal tract....

  20. Revisiting ignited–quenched transition and the non-Newtonian rheology of a sheared dilute gas–solid suspension

    Science.gov (United States)

    Saha, Saikat; Alam, Meheboob

    2017-12-01

    The hydrodynamics and rheology of a sheared dilute gas-solid suspension, consisting of inelastic hard-spheres suspended in a gas, are analysed using anisotropic Maxwellian as the single particle distribution function. The closed-form solutions for granular temperature and three invariants of the second-moment tensor are obtained as functions of the Stokes number ($St$), the mean density ($\

  1. Final Technical Report: Using Solid Particles as Heat Transfer Fluid for use in Concentrating Solar Power (CSP) Plants

    Energy Technology Data Exchange (ETDEWEB)

    Lattanzi, Aaron [Univ. of Colorado, Boulder, CO (United States); Hrenya, Christine [Univ. of Colorado, Boulder, CO (United States)

    2016-03-31

    In today’s industrial economy, energy consumption has never been higher. Over the last 15 years the US alone has consumed an average of nearly 100 quadrillion BTUs per year [21]. A need for clean and renewable energy sources has become quite apparent. The SunShot Initiative is an ambitious effort taken on by the United States Department of Energy that targets the development of solar energy that is cost-competitive with other methods for generating electricity. Specifically, this work is concerned with the development of concentrating solar power plants (CSPs) with granular media as the heat transfer fluid (HTF) from the solar receiver. Unfortunately, the prediction of heat transfer in multiphase flows is not well understood. For this reason, our aim is to fundamentally advance the understanding of multiphase heat transfer, particularly in gas-solid flows, while providing quantitative input for the design of a near black body receiver (NBB) that uses solid grains (like sand) as the HTF. Over the course of this three-year project, a wide variety of contributions have been made to advance the state-of-the art description for non-radiative heat transfer in dense, gas-solid systems. Comparisons between a state-of-the-art continuum heat transfer model and discrete element method (DEM) simulations have been drawn. The results of these comparisons brought to light the limitations of the continuum model due to inherent assumptions in its derivation. A new continuum model was then developed for heat transfer at a solid boundary by rigorously accounting for the most dominant non-radiative heat transfer mechanism (particle-fluid-wall conduction). The new model is shown to be in excellent agreement with DEM data and captures the dependence of heat transfer on particle size, a dependency that previous continuum models were not capable of. DEM and the new continuum model were then employed to model heat transfer in a variety of receiver geometries. The results provided crucial

  2. Cable suspended windmill

    Science.gov (United States)

    Farmer, Moses G. (Inventor)

    1990-01-01

    A windmill is disclosed which includes an airframe having an upwind end and a downwind end. The first rotor is rotatably connected to the airframe, and a generator is supported by the airframe and driven by the rotor. The airframe is supported vertically in an elevated disposition by poles which extend vertically upwardly from the ground and support cables which extend between the vertical poles. Suspension cables suspend the airframe from the support cable.

  3. Solid particle spreading in gas-dispersed confined swirling flow. Eulerian and Lagrangian approaches

    Science.gov (United States)

    Pakhomov, M. A.; Terekhov, V. I.

    2017-05-01

    Dynamics of a disperse phase in a swirling two-phase flow behind a sudden tube expansion is simulated with the aid of Eulerian and full Lagrangian descriptions. The carrier phase is described by three-dimensional Reynolds averaged Navier-Stokes equations with consideration of inverse influence of particles on the transport processes in gas. The velocity profiles calculated using these two approaches are practically the same. It is shown that the main difference between the Eulerian and Lagrangian approaches is presented by the concentration profile of the dispersed phase. The Eulerian approach underpredicts the value of particle concentration as compared with the Lagrangian approach (the difference reaches 15-20 %). The dispersed phase concentration predicted by the Lagrangian approach agrees with the measurement data somewhat better than the data obtained through the Eulerian approach.

  4. SIZE ANALYSIS OF SOLID PARTICLES AT THE EXPERIMENTAL DEVICE FOR MULTI-STAGE BIOMASS COMBUSTION

    Directory of Open Access Journals (Sweden)

    Michaela Hrnčířová

    2014-02-01

    Full Text Available This paper presents the results of an analysis of ash content particles produced in biomass combustion at an experimental device. The main parts of the device are: the water heater, the gasifying chamber, the air preheater, and the fuel feeder. This device can be modified for combustion in an oxygen-enriched atmosphere. Sawdust and wood chips were used as fuel, and were laid loosely into the device. Ash specimens were extracted from various parts of the device. For the measurements themselves, we used the Analysette 22 MicroTec Plus universal laser diffraction device manufactured by the Fritch Company, in the size range from 0.08 μm to 2000 μm. The device utilizes laser diffraction for particle size analysis.

  5. Solid-particle erosion behavior of cast alloys used in the mining industry

    Science.gov (United States)

    Atapek, Ş. Hakan; Fidan, Sinan

    2015-12-01

    The erosive-wear response of five commercial ferrous-based cast alloys used for crushing was examined in this study. The microstructures of the alloys were modified to elucidate the effect of microstructural features on wear. Erosion tests were conducted using aluminum oxide particles (90-125 μm) at 70 m/s and a normal impact angle (90°). The worn surfaces were characterized by scanning electron microscopy and 3D non-contact laser profilometry. It is found that (i) a pearlitic structure exhibiting a greater plastic deformation than both bainitic and martensitic structures shows the greatest resistance to erosive wear at normal impact and (ii) the fracture characteristics of carbide and graphite particles plays an important role in determining the erosion wear behavior of the cast alloy matrices.

  6. Modeling fragmentation of plasma-sprayed particles impacting on a solid surface at room temperature

    Science.gov (United States)

    McDonald, André; Xue, Michelle; Chandra, Sanjeev; Mostaghimi, Javad; Moreau, Christian

    2007-05-01

    Molybdenum particles were melted and accelerated by a plasma jet to impact on glass surfaces held at room temperature. A fast charge-coupled device (CCD) camera was triggered to capture images of the particles during spreading. Splats on the glass held at ambient temperature fragmented, leaving only a solidified central core. A 3D model of droplet impact and solidification was used to simulate the impact and spreading of these plasma-sprayed particles. The thermal contact resistance, which was estimated from an existing heat conduction model, was used as an input parameter in the 3D model. It was found that the thermal contact resistance between the splat central core and the glass was two orders of magnitude lower than that between the rest of the splat fluid and the surface. This suggests that the physical contact between the fluid in the splat central core and the glass surface can be improved by the large pressure generated during impact. To cite this article: A. McDonald et al., C. R. Mecanique 335 (2007).

  7. Mutagenicity of particle emissions from solid fuel cookstoves: A literature review and research perspective.

    Science.gov (United States)

    Shen, Guofeng

    2017-07-01

    Household solid fuel use is a major source of many air pollutants causing severe air pollution and adverse health outcomes. In evaluation of health impacts of household air pollution, it is essential to characterize toxic properties like mutagenicity of residential fuel combustion emissions and exposure assessments. Mutagenicity of emissions from solid fuel cookstoves were analyzed through a literature review. T98 and TA100 strains are two most widely used strains in mutagenic Ames test, and results for these two strains are generally positively correlated though they have different endpoints. Direct and indirect mutagenic activities are positively correlated, and statistically insignificantly different though indirect mutagenic emissions are apparently higher. Mutagenicity emission factors on the basis of fuel energy (MJ) or useful energy delivered (MJd) for solid fuel cookstoves vary in nearly 3 orders of magnitude, ranging from 3.0×10 4 rev./MJd to 1.8×10 7 rev./MJd (or 1.1×10 4 rev./MJ to 4.2×10 6 rev./MJ). Low mutagenic emissions are reported for high efficiency stoves such as a forced-draft one. Mutagenicity emission factors are positively correlated with emissions of PM 2.5 . Relationship between mutagenicity and polycyclic aromatic hydrocarbons (PAHs) emissions is inconsistent among studies as PAHs are minor fractions of toxic organics contributing to the total mutagenicity. Generally, studies on mutagenicity of emissions from household cookstoves are very limited, and future studies are encouraged on mutagenic emissions from different fuel types and household stoves, evaluation of mutagenic activities of both gaseous and particulate emissions, and toxicology and exposure assessments of household air pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Collisions of energetic particles with atoms, molecules & solids: A theoretical study

    Science.gov (United States)

    Quashie, Edwin Exam

    The detailed knowledge of the accurate ion-solid interaction is at the heart of many technological applications such as nuclear safety, applied material science, medical physics and fusion and fission applications. Its accurate evaluation poses an enormous challenge due to the need of incorporating electronic structure, bound states, size effects, basis sets, and the quantum classical aspects of the problem. Most recent approaches relying on the fitting to experimental data or phenomenological model, fail to describe the ion-solid interaction properly (see [S. N. Markin, D. Primetzhofer, M. Spitz, and P. Bauer, Phys. Rev. B 80 (2009)]) for slow ions. A general Time-Dependent Density Functional Theory (TDDFT) is used in this thesis to evaluate electron-dynamics easily. For the first time a unified theory is proposed to describe the ion-solid interaction accurately over several orders of magnitude in the ion velocities, unveiling different regimes that before were only partially seen by separate experiments and rarely by any level of existing theory. We identified an electronic stopping which in the band-regime produces a quantum friction that is nonlinear with a power-law with an exponent ˜1.5. At low velocity this nonlinear effect will provide a new impetus for experimental investigations and an improve microscopic models of electron-ion dissipative dynamics. Our study will potentially impact both the experimental and theoretical research in condensed matter. We have applied our developed theory to study stopping of H+ in Cu. The target Cu comprises complicated band structure and this system will help to understand radiation of matter, both in its experimental understanding and also in the modeling of the process, for example in the context of damped molecular dynamics for the simulation of radiation cascades. At this present stage in the field of ion-solid interactions and quantum dissipative dynamics, our findings remain very significant. The same techniques are

  9. Possibilities of radioisotope measuring in control of an unstable solid particles hydrotransport

    Directory of Open Access Journals (Sweden)

    Petryka Leszek

    2016-01-01

    Full Text Available The paper presents γ-radiation proposal to control a multiphase flow, independently from circumstances. So this method may be applied even in compound industrial or environmental processes. Moreover in many cases, it is the only method for applications for dense mixture containing coarse angular grains. The constructed equipment allows continuous measurement of density as well as solid phase for both concentration and average velocity. Due to pressure loss, it gives the output digital signal convenient for cybernation of the control process. The proposed procedures were tested at a laboratory installation modeling conditions expected during planned excavation of nodules from Pacific bottom.

  10. Performance Characterization of Gas-Solid Cyclone for Separation of Particle from Syngas Produced from Food Waste Gasifier Plant

    Directory of Open Access Journals (Sweden)

    Osezua O. Ibhadode

    2017-06-01

    Full Text Available A biofuel from any biodegradable formation process such as a food waste bio-digester plant is a mixture of several gases such as methane (CH4, carbon dioxide (CO2, hydrogen sulfide (H2S, ammonia (NH3 and impurities like water and dust particles. The results are reported of a parametric study of the process of separation of methane, which is the most important gas in the mixture and usable as a biofuel, from particles and H2S. A cyclone, which is a conventional, economic and simple device for gas-solid separation, is considered based on the modification of three Texas A&M cyclone designs (1D2D, 2D2D and 1D3D by the inclusion of an air inlet tube. A parametric sizing is performed of the cyclone for biogas purification, accounting for the separation of hydrogen sulfide (H2S and dust particles from the biofuel. The stochiometric oxidation of H2S to form elemental sulphur is considered a useful cyclone design criterion. The proposed design includes geometric parameters and several criteria for quantifying the performance of cyclone separators such as the Lapple Model for minimum particle diameter collected, collection efficiency and pressure drop. For biogas volumetric flow rates between 0 and 1 m/s and inlet flow velocities of 12 m/s, 15 m/s and 18 m/s for the 1D2D, 2D2D and 1D3D cyclones, respectively, it is observed that the 2D2D configuration is most economic in terms of sizing (total height and diameter of cyclone. The 1D2D configuration experiences the lowest pressure drop. A design algorithm coupled with a user-friendly graphics interface is developed on the MATLAB platform, providing a tool for sizing and designing suitable cyclones.

  11. Solid phospholipid nano-particles: investigations into formulation and dissolution properties of griseofulvin.

    Science.gov (United States)

    Brinkmann-Trettenes, Ulla; Bauer-Brandl, Annette

    2014-06-05

    Solid phospholipid (PL) nanoparticles with griseofulvin (GRIS) as a model drug were prepared by co-spray drying. Their dissolution properties were compared with formulations containing the physical blends of the native crystalline drug and excipient materials, and physical blends of the spray dried materials. Co-spray drying was performed from ethanol+water solutions (80+20) using Büchi Nano Spray Dryer B-90. Dissolution profiles in phosphate buffer (PBS), simulated intestinal fluids (fasted state simulated intestinal fluid (FaSSIF)) and pancreatin containing media (PAN) were studied. It was found that the influence of PL on the dissolution profile was affected by both the solid state of the drug formulation and the dissolution medium: the co-SD formulations showed the fastest release in all media. The amount of GRIS dissolved after 5h increases by a factor of 7 for the co SD as compared to physical blend of native materials in PBS, and a factor of 4 in FaSSIF respectively. Surprisingly, in contrast to PBS, dissolution rate in FaSSIF decreased with increasing the PL content. All the pancreatin containing media showed a decrease in dissolution rate and extent independently of the processing methods due to an incompatibility between GRIS and PAN. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Formation of a disordered solid via a shock-induced transition in a dense particle suspension.

    Science.gov (United States)

    Petel, Oren E; Frost, David L; Higgins, Andrew J; Ouellet, Simon

    2012-02-01

    Shock wave propagation in multiphase media is typically dominated by the relative compressibility of the two components of the mixture. The difference in the compressibility of the components results in a shock-induced variation in the effective volume fraction of the suspension tending toward the random-close-packing limit for the system, and a disordered solid can take form within the suspension. The present study uses a Hugoniot-based model to demonstrate this variation in the volume fraction of the solid phase as well as a simple hard-sphere model to investigate the formation of disordered structures within uniaxially compressed model suspensions. Both models are discussed in terms of available experimental plate impact data in dense suspensions. Through coordination number statistics of the mesoscopic hard-sphere model, comparisons are made with the trends of the experimental pressure-volume fraction relationship to illustrate the role of these disordered structures in the bulk properties of the suspensions. A criterion for the dynamic stiffening of suspensions under high-rate dynamic loading is suggested as an analog to quasi-static jamming based on the results of the simulations. © 2012 American Physical Society

  13. Method and Device for Extraction of Liquids from a Solid Particle Material

    Science.gov (United States)

    deMayo, Benjamin (Inventor)

    2017-01-01

    A method, system, and device for separating oil from oil sands or oil shale is disclosed. The method includes heating the oil sands, spinning the heated oil sands, confining the sand particles mechanically, and recovering the oil substantially free of the sand. The method can be used without the addition of chemical extraction agents. The system includes a source of centrifugal force, a heat source, a separation device, and a recovery device. The separation device includes a method of confining the sands while allowing the oil to escape, such as through an aperture.

  14. Solid colloidal particles inducing coalescence in bitumen-in-water emulsions.

    Science.gov (United States)

    Legrand, J; Chamerois, M; Placin, F; Poirier, J E; Bibette, J; Leal-Calderon, F

    2005-01-04

    Silica particles are dispersed in the continuous phase of bitumen-in-water emulsions. The mixture remains dispersed in quiescent storage conditions. However, rapid destabilization occurs once a shear is applied. Observations under the microscope reveal that the bitumen droplets form a colloidal gel and coalesce upon application of a shear. We follow the kinetic evolution of the emulsions viscosity, eta, at constant shear rate: eta remains initially constant and exhibits a dramatic increase after a finite time, tau. We study the influence of various parameters on the evolution of tau: bitumen droplet size and volume fraction, silica diameter and concentration, shear rate, etc.

  15. Investigation of Solid Particles Under the Action of an Acoustic Field

    Directory of Open Access Journals (Sweden)

    Egidijus Mykolaitis

    2014-02-01

    Full Text Available Iron is one of the most common elements in ground water. Bythe HN 24:2003 iron concentration in water can‘t be higher than200 μg/l. Water treatment with an acoustic field is a very relevanttopic. Acoustic field is widely used in industrion, medicine,chemical industry and manufacturing. When water is affectedby ultrasound, physical-chemical processes begin. Ultrasoundvibrations lead to dispersion, degasation and coagulation. Ironparticles connect to each other when distance between them istwo times bigger then their own radius. R = 2R. And if thisprocess continues particles connect one by one. In this article teststand and methodics using ultrasonic piezoceramic are shown.

  16. Lidar observations of Arctic polar stratospheric clouds, 1988 - Signature of small, solid particles above the frost point

    Science.gov (United States)

    Poole, L. R.; Osborn, M. T.; Hunt, W. H.

    1988-01-01

    The paper presents recent (January 1988) Arctic airborne lidar data which suggest that Type I polar stratospheric clouds (PSCs) are composed of small solid particles with radii on the order of 0.5 micron. PSCs were observed remotely in the 21-24 km altitude range north of Greenland during a round-trip flight from Andenes, Norway on January 29, 1988, aboard the NASA Wallops Flight Facility P-3 Orion aircraft. Synoptic analyses at the 30-mb level show local temperatures of 191-193 K, which are well above the estimated frost point temperature of 185 K; this suggests that the PSCs were probably of the binary HNO3-H2O (Type I) class.

  17. The SPRITE and POS-SPRITE user report: An extensible calculation of particle, positron and electron implantation in solids

    Energy Technology Data Exchange (ETDEWEB)

    Ritley, K.A. [Univ. of Illinois, Urbana, IL (United States); Ghosh, V.J.; Lynn, K.G.; McKewown, M.; Welch, D.O. [Brookhaven National Lab., Upton, NY (United States)

    1997-10-20

    SPRITE (Simulation of Particle Reemission, Implantation and Transmission--Extensible) is a Fortran computer program designed to model the transport of a stream of energetic particles as they scatter through a solid or multilayer. SPRITE is intended to be a user-friendly and easily-extensible engine for performing basic transport calculations, and SPRITE incorporates such physics as is required to simulate the transport process, but specifically omits the details of the scattering mechanisms. PSPRITE is a Fortran computer program, built around the SPRITE transport engine and incorporating physical information necessary for modeling the implantation and thermalization of a stream of positrons or electrons with a solid. This document is intended to be the primary source of information and the only operations manual for SPRITE and the POS-SPRITE family of programs. This information includes the mode of operation of SPRITE, the format of the required and optional file types, as well as information about the output and results of the calculation. Information about installing and running these programs on a variety of computer systems will not be addressed in this report. Such information is rapidly expanding as these programs are adapted to run on different platforms, and thus the user can expect such information to be contained with the source code distribution set. Detailed information about the calculations of the structure of the POS-SPRITE programs are provided in this report, but detailed benchmark comparisons between the output of these calculations and experimental data are an active topic of research, and they refer the reader to the published literature for this information.

  18. Transitional phase inversion of crude oil emulsions by solid particles; Inversao transicional de emulsoes de petroleo com particulas solidas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Troner A. de; Scheer, Agnes P.; Soares, Cristyan R.; Luz Junior, Luiz Fernando de Lima [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Oliveira, Marcia Cristina K. de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    In petroleum production water-in-oil emulsions (W/O) can be found, due to simultaneous flowing of the oil and formation water. This emulsions provide an increase in the viscosity; that can be reduced for the phase inversion in oil-in-water emulsions (O/W), resulting in pressure drop and consequently cost production reduction. The petroleum emulsions W/O were prepared at 60 deg C, with 50% v/v of saline water containing 50 g.L{sup -1} of NaCl. The hydrophilic solids content was varied between 0,5% and 8%, mass fraction, related to the water. The quantity of solids needed to phase inversion of the emulsion was measured by conductivimetry. The stability of the emulsions was verified, at 60 deg C, for the time determination in order to have two phases in four hours, checking the viability for production; and during 24 hours, checking the viability for transportation. Under dynamics conditions, was also noted the stability at 20 deg C, for reproduce the flowing condition. Two of the hydrophilic particles tested in the transitional phase inversion of petroleum emulsions presented better results in quantity and stability. Preliminaries rheological properties measurements were carried out adjusting the temperature of the sample in the range of 30 deg C to 12 deg C a shear rate from 20s{sup -1} to 250s {sup -1}, viscosity decrease was observed until two orders of magnitude. (author)

  19. Correlating gastric emptying of amphotericin B and paracetamol solid lipid nanoparticles with changes in particle surface chemistry.

    Science.gov (United States)

    Amekyeh, Hilda; Billa, Nashiru; Roberts, Clive

    2017-01-30

    Oral delivery of pharmaceuticals requires that they retain their physical and chemical attributes during transit within the gastrointestinal (GI) tract, for the manifestation of desired therapeutic profiles. Solid lipid nanoparticles (SLNs) are used as carriers to improve the absorption of hydrophobic drugs. In this study, we examine the stability of amphotericin B (AmB) and paracetamol (PAR) SLNs in simulated GI fluids during gastric emptying. On contact with the simulated fluids, the particles increased in size due to ingress of the dissolution media into the particles. Simulated gastric emptying revealed that the formulations had mean sizes <350nm and neutral surface charges, both of which are optimal for intestinal absorption of SLNs. There was ingress of the fluids into the SLNs, followed by diffusion of the dissolved drug, whose rate depended on the solubility of the loaded-drug in the particular medium. Time-of-flight secondary ion mass spectrometry analyses indicated that drug loading followed the core-shell model and that the AmB SLNs have a more drug-enriched core than the PAR SLNs do. The AmB SLNs are therefore a very suitable carrier of AmB for oral delivery. The stability of the SLNs in the simulated GI media indicates their suitability for oral delivery. Copyright © 2016. Published by Elsevier B.V.

  20. Suspended Sediment and Phosphorus Removal in a Woodchip Filter System Treating Agricultural Wash Water.

    Science.gov (United States)

    Choudhury, Tahina; Robertson, Will Dean; Finnigan, Darryl S

    2016-05-01

    Woodchip filters have received attention in recent years for their ability to sustain denitrification activity across multiyear time frames. However, in some freshwater aquatic ecosystems, P rather than N is the nutrient considered most responsible for eutrophication. Previous studies have indicated that woodchip filters have limited ability to remove dissolved P, but in agricultural terrain, P export in watercourses is often dominated by particulate P (PP). Woodchip media, because of their high porosity and permeability and the surface roughness of the particles, could be effective for PP removal. In this study, we tested a woodchip filter for its ability to remove suspended sediment and associated PP at a farm in southern Ontario, Canada, where vegetable wash water with extremely high total suspended solids (TSS) was generated. The treatment system consisted of a 12.3-m concrete sedimentation tank and a slightly larger woodchip filter (16.1 m) installed in a subsurface trench. During 7 mo of full-scale operation, treating 10.8 m d, the filter system removed 71% of influent total P (TP) averaging 8.8 mg L and 99% of TSS averaging 5800 mg L, with most of the removal occurring in the tank and a lesser amount (6-16%) occurring in the woodchip filter. Almost all of the TP removal was associated with PP (91% removal) because dissolved P, averaging 1.5 mg L in the wash water, was little changed. Woodchip filters, when coupled with a solids settling tank, have the potential to provide high-capacity, low-maintenance treatment of suspended solids and associated particulate P in turbid waters. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  1. Microstructure and mechanical properties of micro-SiCp particles reinforced magnesium matrix composites with semi-solid stir casting method

    Science.gov (United States)

    Bhiftime, E. I.; Belo, J. B.

    2017-01-01

    Metal matrix composites (MMCs) reinforced with ceramics offer high mechanical and good physical properties as compared with corresponding monolithic alloy. MMCs reinforced with SiCp particles in the semi-solid stir casting method was the most simple way. The purpose of the study was to investigate the difference of the microstructure and mechanical properties of SiCp particles reinforced magnesium matrix composites, as well as the changing effects on the extra level of SiCp and TiB, as well as the changing effects on the extra level of SiCp and TiB. The composites used were AZ81A Mg alloy as the matrix and SiCp as the reinforcement (3, 6, 9 wt%). The casting method used in the study was the semi-solid stir casting. The mechanical properties of the composites fabricated by different parameters indicated that semi-solid method resulted improved in nonhomogeneous particle distribution 3-9 wt.% SiCp/AZ81A composites were fabricated by the novel processing. The particle distribution was uniform in these composites. Grain sizes of composites will be much smoother by giving TiB. The ultimate tensile strength, yield strength, and elastic modulus were enhanced as the particle contents increased. The morphology of the composite between the reinforcing SiCp particle and the AZ81A matrix was to be able to unite and to be dispersed evenly. Specimens were tested focusing on the tensile strength, yield strength microstructure and SEM.

  2. A new compact solid-state neutral particle analyser at ASDEX Upgrade: Setup and physics modeling.

    Science.gov (United States)

    Schneider, P A; Blank, H; Geiger, B; Mank, K; Martinov, S; Ryter, F; Weiland, M; Weller, A

    2015-07-01

    At ASDEX Upgrade (AUG), a new compact solid-state detector has been installed to measure the energy spectrum of fast neutrals based on the principle described by Shinohara et al. [Rev. Sci. Instrum. 75, 3640 (2004)]. The diagnostic relies on the usual charge exchange of supra-thermal fast-ions with neutrals in the plasma. Therefore, the measured energy spectra directly correspond to those of confined fast-ions with a pitch angle defined by the line of sight of the detector. Experiments in AUG showed the good signal to noise characteristics of the detector. It is energy calibrated and can measure energies of 40-200 keV with count rates of up to 140 kcps. The detector has an active view on one of the heating beams. The heating beam increases the neutral density locally; thereby, information about the central fast-ion velocity distribution is obtained. The measured fluxes are modeled with a newly developed module for the 3D Monte Carlo code F90FIDASIM [Geiger et al., Plasma Phys. Controlled Fusion 53, 65010 (2011)]. The modeling allows to distinguish between the active (beam) and passive contributions to the signal. Thereby, the birth profile of the measured fast neutrals can be reconstructed. This model reproduces the measured energy spectra with good accuracy when the passive contribution is taken into account.

  3. Nanoscale science and engineering forum (706c) design of solid lipid particles with iron oxide quantum dots for the delivery of therapeutic agents

    Science.gov (United States)

    Solid lipid particles provide a method to encapsulate and control the release of drugs in vivo but lack the imaging capability provided by CdS quantum dots. This shortcoming was addressed by combining these two technologies into a model system that uses iron oxide as a non-toxic imaging component in...

  4. An Integrated Instrumentation System for Velocity, Concentration and Mass Flow Rate Measurement of Solid Particles Based on Electrostatic and Capacitance Sensors

    Directory of Open Access Journals (Sweden)

    Jian Li

    2015-12-01

    Full Text Available The online and continuous measurement of velocity, concentration and mass flow rate of pneumatically conveyed solid particles for the high-efficiency utilization of energy and raw materials has become increasingly significant. In this paper, an integrated instrumentation system for the velocity, concentration and mass flow rate measurement of dense phase pneumatically conveyed solid particles based on electrostatic and capacitance sensorsis developed. The electrostatic sensors are used for particle mean velocity measurement in combination with the cross-correlation technique, while the capacitance sensor with helical surface-plate electrodes, which has relatively homogeneous sensitivity distribution, is employed for the measurement of particle concentration and its capacitance is measured by an electrostatic-immune AC-based circuit. The solid mass flow rate can be further calculated from the measured velocity and concentration. The developed instrumentation system for velocity and concentration measurement is verified and calibrated on a pulley rig and through static experiments, respectively. Finally the system is evaluated with glass beads on a gravity-fed rig. The experimental results demonstrate that the system is capable of the accurate solid mass flow rate measurement, and the relative error is within −3%–8% for glass bead mass flow rates ranging from 0.13 kg/s to 0.9 kg/s.

  5. Numerical 3D simulation of the erosion due to solid particle impact in the main stop valve of a steam turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, Z.; Campos-Amezcua, R.; Urquiza-Beltran, G.; Garcia-Gutierrez, A. [Instituto de Investigaciones Electricas, Morelos (Mexico)

    2004-09-01

    Solid particle erosion in a steam turbine main stop valve bypass valve has been investigated by means of computational fluid dynamics. Previews attempt to couple fluid mechanics and erosion modeling and improvements in the hydrodynamics models together with improvements in the erosion models are reviewed. The solid particle bearing steam flow through the valve was investigated using a 3D numerical model and the finite volume code Fluent V6.0.12, looking for a reduction of the erosion process. The flow simulation was carried out for the valve original and modified designs with changes of the angle of particle impact on the valve surface. Numerical predictions have been carried out using the Renormalization Group (RNG) {kappa}-{epsilon} turbulence model. To account for the influence of turbulent fluid fluctuations on particle motion, the stochastic tracking Discrete Random Walk model is used, which includes the effect of instantaneous turbulent velocity fluctuations on the particle trajectories. The removal of wall material due to erosion is calculated using the Finnie model developed for ductile materials. The numerical predictions showed a 51% reduction of the erosion rate for the valve-modified design due to changes of the particles trajectories and impingement angle (angle of particle impact). The results obtained show that numerical simulation can be used in a predictive manner to solve a real practical design problem. (author)

  6. Modeling the Interaction of a Molten Seal and Solid Particles Using DEM and SPH Simulations: Application for a Passive New Scram System for LMR

    Directory of Open Access Journals (Sweden)

    S. Vanmaercke

    2012-09-01

    Full Text Available A new shutdown system that does not rely on absorber rods, is being developed at SCK.CEN and UCL for application in Liquid Metal Reactors (LMR. The system consists of tubes filled with absorber particles. During normal operation, these particles are kept above the active core by means of a metallic melt seal. In case of an accident, the system is activated by the temperature increase in the coolant. This leads to melting of the metal seal, releasing the absorber particles into the core. The resulting flow of the particles has been studied both experimentally, and with Discrete Element Method (DEM simulations. This paper focuses on the second important aspect of the safety system, being the melting and flowing of the metallic seal in interaction with the solid absorber particles moving through the molten seal.

  7. Remoção de sólidos suspensos na água de irrigação utilizando mantas sintéticas não tecidas Removal of suspended solids in irrigation water utilizing non-woven synthetic fabrics

    Directory of Open Access Journals (Sweden)

    Marcos E. Scatolini

    2001-12-01

    Full Text Available Com vistas à eficiência de remoção de sólidos em suspensão, quando utilizados em filtros para irrigação localizada, empregaram-se três tipos diferentes de manta sintética não tecida, além de elemento de tela e de disco. Como resultado, as mantas tiveram desempenho superior, ou seja, 27 a 29% de remoção de sólidos em suspensão, enquanto os elementos de tela e disco apresentaram apenas 19 a 20%; contudo, dentre as três mantas avaliadas não foram observadas diferenças significativas, o mesmo ocorrendo entre os elementos de tela e disco.The objective of this work was to verify the efficiency of trickle irrigation filters on the removal of suspended solids using as filter elements three different types of non-woven synthetic fabrics. Also, was conducted an experiment with disk and screen elements in order to compare with the non woven synthetic fabric element. The results have demonstrated that non-woven synthetic fabrics presented better performance, removing 27 to 29% of suspended solids, while screen and disk elements presented 19 to 20% removal. No significant differences were observed among the three fabrics evaluated as well as between the screen and disk elements

  8. Solid lipid particles for oral delivery of peptide and protein drugs II--the digestion of trilaurin protects desmopressin from proteolytic degradation.

    Science.gov (United States)

    Christophersen, Philip Carsten; Zhang, Long; Müllertz, Anette; Nielsen, Hanne Mørck; Yang, Mingshi; Mu, Huiling

    2014-09-01

    To investigate the in vitro release and degradation of desmopressin from saturated triglyceride microparticles under both lipolytic and proteolytic conditions. The release of desmopressin from different solid lipid microparticles in the absence and presence of a microbial lipase and protease was determined. Trilaurin (TG12), trimyristin (TG14), tripalmitin (TG16), and tristearin (TG18) were used as lipid excipients to produce solid lipid microparticles. In the presence of lipase, the rate of drug release from different lipid particles was in the order of TG14 > TG16 > TG18, which is the same rank order as the lipid degradation rate. A reverse rank order was found for the protection of desmopressin from enzymatic degradation due to spatial separation of desmopressin from the protease. TG12 accelerated the release of desmopressin from all lipid particles when added as either drug-free microparticles to the lipolysis medium or incorporated in TG16 particles. Additionally, TG12 particles protected desmopressin from degradation when present in the lipolysis medium with the other lipid microparticles. TG12 is a very interesting lipid for oral lipid formulations containing peptides and proteins as it alters release and degradation of the incorporated desmopressin. The present study demonstrates the possibility of bio-relevant in vitro evaluation of lipid-based solid particles.

  9. Dispersive suspended microextraction.

    Science.gov (United States)

    Yang, Zhong-Hua; Liu, Yu; Lu, Yue-Le; Wu, Tong; Zhou, Zhi-Qiang; Liu, Dong-Hui

    2011-11-14

    A novel sample pre-treatment technique termed dispersive suspended microextraction (DSME) coupled with gas chromatography-flame photometric detection (GC-FPD) has been developed for the determination of eight organophosphorus pesticides (ethoprophos, malathion, chlorpyrifos, isocarbophos, methidathion, fenamiphos, profenofos, triazophos) in aqueous samples. In this method, both extraction and two phases' separation process were performed by the assistance of magnetic stirring. After separating the two phases, 1 μL of the suspended phase was injected into GC for further instrument analysis. Varieties of experiment factors which could affect the experiment results were optimized and the following were selected: 12.0 μL p-xylene was selected as extraction solvent, extraction speed was 1200 rpm, extraction time was 30 s, the restoration speed was 800 rpm, the restoration time was 8 min, and no salt was added. Under the optimum conditions, limits of detections (LODs) varied between 0.01 and 0.05 μg L(-1). The relative standard deviation (RSDs, n=6) ranged from 4.6% to 12.1%. The linearity was obtained by five points in the concentration range of 0.1-100.0 μg L(-1). Correlation coefficients (r) varied from 0.9964 to 0.9995. The enrichment factors (EFs) were between 206 and 243. In the final experiment, the developed method has been successfully applied to the determination of organophosphorus pesticides in wine and tap water samples and the obtained recoveries were between 83.8% and 101.3%. Compared with other pre-treatment methods, DSME has its own features and could achieve satisfied results for the analysis of trace components in complicated matrices. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Evaluating the Performance of the Mixture Model Coupled with High and Low Reynolds Turbulence Closures in the Numerical Description of Concentrated Solid-Liquid Flows of Settling Particles

    Directory of Open Access Journals (Sweden)

    R. Silva

    2015-12-01

    Full Text Available In this manuscript, Computational Fluid Dynamics (CFD studies applying the Mixture Model coupled with both a High Reynolds and a Low Reynolds k-ε turbulence closures, were used to describe experimental pressure gradients and particle concentration profiles from the literature, for concentrated solid-liquid flows of settling particles in a horizontal pipe above the critical deposition velocity. With this work a new Mixture Model formulation is presented, incorporating the Jones-Launder Low Reynolds k-ε turbulence closure, to overcome the excessive turbulence production observed in the numerical studies using the High Reynolds k-ε turbulence model. Additionally, this formulation provides a more accurate representation of the wall turbulence damping phenomena, observed in the experimental testing for the flow of higher particle concentrations suspensions and higher flow velocities. Knowledge on the conditions that cause turbulence attenuation on solid-liquid flows is still scarce in the literature and of considerable value for industrial applications.

  11. Remoção de sólidos suspensos e totais em biofiltros operando com esgoto doméstico primário para reuso na agricultura Removal of suspended and total solids in biofilters operating with primary domestic sewage for reuse in agriculture

    Directory of Open Access Journals (Sweden)

    Rafael Oliveira Batista

    2013-02-01

    Full Text Available Este trabalho objetivou analisar a remoção de sólidos suspensos e totais em biofiltros, preenchidos com lixo compostado, bagaço de cana-de-açúcar e serragem de madeira, submetidos às taxas de aplicação do esgoto doméstico de 0,5, 1,0 e 1,5 m³ m-2 d-1, em Viçosa-MG. Para isso, foi montada uma bancada experimental, constituída de 27 biofiltros, em área experimental da Universidade Federal de Viçosa. As concentrações de sólidos suspensos e totais foram determinadas, mensalmente, durante período de 153 dias. O experimento foi montado no esquema de parcelas subsubdivididas, tendo, nas parcelas, as taxas de aplicação do esgoto doméstico; nas subparcelas, os tipos de material orgânico e, nas subsubparcelas, os períodos de avaliação, no delineamento em blocos casualizados, com três repetições. Os resultados indicaram que os biofiltros proporcionaram remoções de sólidos suspensos e totais de até 82 e 46%, no esgoto doméstico, após 153 dias de operação; a serragem de madeira foi o tipo de material orgânico filtrante com melhor desempenho no tratamento de esgoto doméstico; as aplicações de taxas de 0,5, 1,0 e 1,5 m³ m-2 d-1 de esgoto não apresentaram diferenças quanto à remoção de sólidos suspensos e totais; e a utilização de biofiltros minimiza a obstrução de emissores causada por sólidos suspensos, quando do aproveitamento agrícola de esgoto doméstico, por via do sistema de irrigação por gotejamento.This study aimed to evaluate the removal of suspended and total solids in biofilters filled with composted waste, sugar cane bagasse and sawdust submitted to the application rates of domestic sewage of 0.5, 1.0 and 1.5 m³ m-2 d-1 in Viçosa-MG. An experimental test unit was set up in experimental area of the Federal University of Viçosa. The concentrations of suspended and total solids were determined monthly during a period of 153 days. The experiment was arranged in a split split plot design, with

  12. Avaliação da concentração de mercúrio em sedimentos e material particulado no rio Acre, estado do Acre, Brasil Mercury concentration assessment in botton sediments and suspended solids from Acre river, in the State of Acre, Brazil

    Directory of Open Access Journals (Sweden)

    Artur Fernando Silva Mascarenhas

    2004-01-01

    Full Text Available A avaliação dos teores de mercúrio em sistemas aquáticos sem influência direta de fontes antropogênicas conhecidas não tem sido conduzida com freqüência na região Amazônica. Visando contribuir para esclarecer a ocorrência de valores elevados de Hg em peixes consumidos pela população de Rio Branco - AC, o Instituto Evandro Chagas - IEC, realizou um estudo para quantificar os teores de Hg em sedimentos de fundo e material particulado no rio Acre e alguns afluentes, além da caracterização físico-química das águas entre as cidades de Brasiléia e Assis Brasil. As amostras de sedimentos foram peneiradas na fração Mercury levels assessment in aquatic systems areas without influences of antropogenic sources have not been well studied in the Amazon region. For the identification of the origin of high values of Hg in fish consumed by population of Rio Branco City - AC, the Evandro Chagas Institute - IEC, studied the mercury levels in sediments, suspended solids and studied also the physical-chemical characterization of waters, in the Acre river and also some in afluents, between Brasiléia and Assis Brasil cities. Bottom sediments samples were sieved to <250 mesh fraction after drying. The suspended solid was obtained by precipitation with Al2SO4. About 250 mg of the material was submitted the acid digestion and the determinations of Hg were made by Could Vapor Atomic Absorption Spectrometry. The physical-chemical parameters pH, electric conductivity, temperature and dissolved total solids, were studied in the field, by potenciometric methods. The Hg levels in bottom sediments range 0,018 and 0,184 mug g-1, mean of 0,054 ± 0,034 mug g-1, while the suspended solids varied between 0,067 and 0,220 mug g-1, average of 0,098 ± 0,037 mug g-1. The waters were slightly acid with pH varying among 5,80 - 6,95 and conductivity electric 151,60 - 1.151,00 muS cm-1. The mercury levels in the analyzed materials was below of standard levels for

  13. Influence of changing particle structure on the rate of gas-solid gasification reactions. Final report, July 1981-March 1984

    Energy Technology Data Exchange (ETDEWEB)

    1984-04-04

    The objetive of this work is to determine the changes in the particle structure of coal as it undergoes the carbon/carbon dioxide reaction (C + CO/sub 2/ ..-->.. 2CO). Char was produced by heating the coal at a rate of 25/sup 0/C/min to the reaction temperatures of 800/sup 0/C, 900/sup 0/C, 1000/sup 0/C and 1100/sup 0/C. The changes in surface area and effective diffusivity as a result of devolitization were determined. Changes in effective diffusivity and surface area as a function of conversion have been measured for reactions conducted at 800, 900, 1000 and 1100/sup 0/C for Wyodak coal char. The surface areas exhibit a maximum as a function of conversion in all cases. For the reaction at 1000/sup 0/C the maximum in surface area is greater than the maxima determined at all other reaction temperatures. Thermogravimetric rate data were obtained for five coal chars; Wyodak, Wilcox, Cimmeron, Illinois number 6 and Pittsburgh number 6 over the temperature range 800-1100/sup 0/C. All coal chars exhibit a maximum in reaction rate. Five different models for gas-solid reactions were evaluated. The Bhatia/Perlmutter model seems to best represent the data. 129 references, 67 figures, 37 tables.

  14. Evaluating turbidity and suspended-sediment concentration relations from the North Fork Toutle River basin near Mount St. Helens, Washington; annual, seasonal, event, and particle size variations - a preliminary analysis.

    Science.gov (United States)

    Uhrich, Mark A.; Spicer, Kurt R.; Mosbrucker, Adam; Christianson, Tami

    2015-01-01

    Regression of in-stream turbidity with concurrent sample-based suspended-sediment concentration (SSC) has become an accepted method for producing unit-value time series of inferred SSC (Rasmussen et al., 2009). Turbidity-SSC regression models are increasingly used to generate suspended-sediment records for Pacific Northwest rivers (e.g., Curran et al., 2014; Schenk and Bragg, 2014; Uhrich and Bragg, 2003). Recent work developing turbidity-SSC models for the North Fork Toutle River in Southwest Washington (Uhrich et al., 2014), as well as other studies (Landers and Sturm, 2013, Merten et al., 2014), suggests that models derived from annual or greater datasets may not adequately reflect shorter term changes in turbidity-SSC relations, warranting closer inspection of such relations. In-stream turbidity measurements and suspended-sediment samples have been collected from the North Fork Toutle River since 2010. The study site, U.S. Geological Survey (USGS) streamgage 14240525 near Kid Valley, Washington, is 13 river km downstream of the debris avalanche emplaced by the 1980 eruption of Mount St. Helens (Lipman and Mullineaux, 1981), and 2 river km downstream of the large sediment retention structure (SRS) built from 1987–1989 to mitigate the associated sediment hazard. The debris avalanche extends roughly 25 km down valley from the edifice of the volcano and is the primary source of suspended sediment moving past the streamgage (NF Toutle-SRS). Other significant sources are debris flow events and sand deposits upstream of the SRS, which are periodically remobilized and transported downstream. Also, finer material often is derived from the clay-rich original debris avalanche deposit, while coarser material can derive from areas such as fluvially reworked terraces.

  15. Depth-integrated suspended sediment and geochemical fluxes in large rivers: the Amazon River system

    Science.gov (United States)

    Bouchez, J.; Lupker, M.; Gaillardet, J.; Metivier, F.; France-Lanord, C.; Maurice, L.

    2010-12-01

    Erosion and weathering produce a wide range of residual solid products, in terms of size, density, mineralogy and chemical composition. These solid products are then transported by rivers from the continents to the oceans as suspended particulate matter (SPM) and bedload. Large rivers account for an important part of this transfer of sediments at the global scale. In those rivers, deep channels allow for vertical differentiation, or sorting, of suspended sediment, following their size and density. This hydrodynamic sorting results in vertically heterogeneous depth-profiles in terms of SPM concentration and size distribution (e.g. Garcia, 2008), which in turn likely result in an heterogeneous chemical composition of SPM throughout channel depth (e.g. Galy, 2007), which has to be evaluated. We sampled river water of the main tributaries of the Amazon River system (in the lowland basin), at two distinct water-stages, at various depths following depth-profiles, using a point depth-sampler. After filtration, and SPM recovery, SPM concentration, grain size distribution and chemical composition were determined. River discharge and water velocity throughout the sampled cross-sections were recorded using Acoustic Doppler Current Profiler (ADCP). The large increase in SPM concentration with depth observed at most of the sampled depth-profiles is well accounted for by the Rouse model (e.g. Rouse, 1950). This analysis allows us to reliably infer the SPM concentration and grain size distribution throughout the sampled river cross-section, and thus to estimate the spatially-integrated instantaneous SPM flux using ADCP data (Bouchez et al., 2010). The study also emphasizes the potential role of particle aggregation, within the river system, as a complicating factor regarding the prediction of these depth-integrated SPM fluxes from easily measurable hydrodynamic parameters (surface SPM concentration and grain size, and water velocity). Then, using the previous analysis, combined

  16. Contribution to the study of the behaviour of solid particles in a confined turbulent flow using direct numerical simulation; Contribution a l'etude du comportement de particules solides en ecoulement turbulent confine par simulation numerique directe

    Energy Technology Data Exchange (ETDEWEB)

    Rambaud, P.

    2001-11-01

    The theme of this numerical thesis is on the behavior of solid particles embedded in a non-homogeneous and non-isotropic turbulent gas flow as the one tacking place in a plane channel. The turbulence is generated through the direct numerical simulation of Navier-Stokes equations discretized by formally second order in time and space finite difference operators. This Eulerian vision of the incompressible gas flow is completed by a Lagrangian formulation allowing to follow solid particles. In this formulation, the considered forces are the non-linear drag and the Saffman lift both corrected for wall effects. Furthermore, depending on the test cases studied, particle bouncing forces on the wall, gravity or electrostatic forces are taken into account. A three-dimensional Hermitian interpolation highlight the special care spend on the determination of the fluid velocity at the solid particle location. The first code application is dedicated to solid particles dispersion inside an horizontal channel, or in a channel operated in a weightlessness state. The huge amount of data from the Lagrangian tracking is reduced to the integral times of the turbulence seen by the solid particles on their trajectories. Those times are crucial in Lagrangian methods associated with a low numerical cost compared with the ones used in the present study. Among those methods, the one based on Langevin type equations have the best potential to handle industrial type problems. Nevertheless, this method needs to rebuild the fluid velocity fluctuations seen by the solid particles on their trajectories. This technic is able to reproduce the crossing trajectory effect, the inertial effect and the continuity effect, only if the integral times of the turbulence seen are known. Till now, those times were known thanks to a semi-empirical correlation from direct numerical simulation in homogeneous and isotropic turbulence (Wang and Stock 1993). However, although these conditions, this correlation was

  17. Stability of flocculated particles in concentrated and high hydrophilic solid layer-by-layer (LBL) emulsions formed using whey proteins and gum Arabic.

    Science.gov (United States)

    Lim, Aaron S L; Roos, Yrjö H

    2015-08-01

    The objective of the present study was to investigate flocculation in layer-by-layer (LBL) emulsion systems with high total solids content and deflocculation at various pH conditions, and the effects of whey protein isolate (WPI) concentration and total solids content on the stability of LBL emulsions. WPI (1.96% (1WPI) or 10.71% (10WPI), w/w in water) was prepared in water and high-pressure homogenized with sunflower oil (10%, w/w, of total emulsion). Gum Arabic (0.15%, w/w, in total emulsion) was added to assemble electrostatically on WPI at oil particle interfaces at pH3.5 using aqueous citric acid (10% w/w) forming LBL emulsion. The ζ-potential measurements showed charge reversal upon addition of gum Arabic solution into single layer (SL) emulsion confirming the formation of LBL interface. Trehalose:maltodextrin mixture (1:1, w/w, total emulsion, 28.57% (28) or 57.14% (57), w/w, in water) was used in the continuous phase. The high total solids content of the system results in depletion flocculation of the particles leading to bridging flocculation without coalescence as deflocculation into individual particles occurred with increasing pH from pH3.5 to pH6.5 in 10WPI systems. Deflocculation was evident in 10WPI-28 and 10WPI-57 as found from a decreased ζ-average diameter and visually under microscope. Coalescence was observed in 1WPI systems. Viscosity of the systems was significantly (P<0.05) increased with higher total solids content. Accelerated destabilization test showed that systems at higher WPI and total solids contents exhibited the highest stability against creaming. Deflocculation in LBL systems can be controlled by pH while high solids in the aqueous phase provide stability against creaming. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Direct observation of solid-phase adsorbate concentration profile in powdered activated carbon particle to elucidate mechanism of high adsorption capacity on super-powdered activated carbon.

    Science.gov (United States)

    Ando, Naoya; Matsui, Yoshihiko; Matsushita, Taku; Ohno, Koichi

    2011-01-01

    Decreasing the particle size of powdered activated carbon (PAC) by pulverization increases its adsorption capacities for natural organic matter (NOM) and polystyrene sulfonate (PSS, which is used as a model adsorbate). A shell adsorption mechanism in which NOM and PSS molecules do not completely penetrate the adsorbent particle and instead preferentially adsorb near the outer surface of the particle has been proposed as an explanation for this adsorption capacity increase. In this report, we present direct evidence to support the shell adsorption mechanism. PAC particles containing adsorbed PSS were sectioned with a focused ion beam, and the solid-phase PSS concentration profiles of the particle cross-sections were directly observed by means of field emission-scanning electron microscopy/energy-dispersive X-ray spectrometry (FE-SEM/EDXS). X-ray emission from sulfur, an index of PSS concentration, was higher in the shell region than in the inner region of the particles. The X-ray emission profile observed by EDXS did not agree completely with the solid-phase PSS concentration profile predicted by shell adsorption model analysis of the PSS isotherm data, but the observed and predicted profiles were not inconsistent when the analytical errors were considered. These EDXS results provide the first direct evidence that PSS is adsorbed mainly in the vicinity of the external surface of the PAC particles, and thus the results support the proposition that the increase in NOM and PSS adsorption capacity with decreasing particle size is due to the increase in external surface area on which the molecules can be adsorbed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Direct numerical simulation of gas-solid-liquid flows with capillary effects: An application to liquid bridge forces between spherical particles

    Science.gov (United States)

    Sun, Xiaosong; Sakai, Mikio

    2016-12-01

    In this study, a numerical method is developed to perform the direct numerical simulation (DNS) of gas-solid-liquid flows involving capillary effects. The volume-of-fluid method employed to track the free surface and the immersed boundary method is adopted for the fluid-particle coupling in three-phase flows. This numerical method is able to fully resolve the hydrodynamic force and capillary force as well as the particle motions arising from complicated gas-solid-liquid interactions. We present its application to liquid bridges among spherical particles in this paper. By using the DNS method, we obtain the static bridge force as a function of the liquid volume, contact angle, and separation distance. The results from the DNS are compared with theoretical equations and other solutions to examine its validity and suitability for modeling capillary bridges. Particularly, the nontrivial liquid bridges formed in triangular and tetrahedral particle clusters are calculated and some preliminary results are reported. We also perform dynamic simulations of liquid bridge ruptures subject to axial stretching and particle motions driven by liquid bridge action, for which accurate predictions are obtained with respect to the critical rupture distance and the equilibrium particle position, respectively. As shown through the simulations, the strength of the present method is the ability to predict the liquid bridge problem under general conditions, from which models of liquid bridge actions may be constructed without limitations. Therefore, it is believed that this DNS method can be a useful tool to improve the understanding and modeling of liquid bridges formed in complex gas-solid-liquid flows.

  20. Effect of Variable Solvents on Particle Size of Geranium Oil-Loaded Solid Lipid Nanoparticle (Ge-SLN) For Mosquito Repellent Applications

    Science.gov (United States)

    Asnawi, Syalwati; Aziz, Azila A.; Aziz, Ramlan A.

    2009-06-01

    A new delivery system for insect repellent is proposed by the incorporation of geranium oil into solid lipid nanoparticle (SLN). A variety of solvents which act as co-surfactants, were introduced to increase the particle size of GE-SLN. Ethanol, which has a high boiling point and a long chain alcohol produced larger particle than dichloromethane. The structure of SLN was not stable when methanol and acetone were used as co-solvents. Concentration of solvents can also influence the size of SLN. In vitro release experiments showed that SLN was able to reduce the rapid evaporation of geranium oil.

  1. Investigation of suspended sediment transport using ultrasonic techniques

    DEFF Research Database (Denmark)

    Bjørnø, Irina; Jensen, Leif Bjørnø

    1994-01-01

    The results of the initial experimental studies involving the scattering of ultrasonic signals from canonical and non-canonical shaped suspended particles with known elastical qualities are reported. These results have formed the basis for the development of a numerical model for ultrasound...

  2. Paul Scherrer Institut annual report 1996. Annex I. PSI-F1-Newsletter 1996 nuclear and particle physics. Muons in solid-state physics and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Herlach, D.; Kettle, P.R.; Buechli, C. [eds.] [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-02-01

    This newsletter contains reports from the F1-Department and its Divisions. The contributions are categorized as follows: - activities of the F1-Department of PSI, - nuclear and particle physics supported by the Department, -applications of muons in solid-state physics and chemistry. Groups were asked to present new, preliminary or final results obtained in 1996, as well as a publication list, related to F1-supported work which had appeared in scientific journals during 1996. (author) figs., tabs., refs.

  3. Paul Scherrer Institut annual report 1995. Annex I: PSI-F1-Newsletter 1995. Nuclear and particle physics. Muons in solid-state physics and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Herlach, D.; Kettle, P.R. [eds.

    1996-09-01

    This newsletter contains reports from the F1-Department and its Divisions. The contributions are categorized as follows: - activities of the F1-Department of PSI, - nuclear and particle physics supported by the Department, - applications of muons in solid-state physics and chemistry. Groups were asked to present new, preliminary or final results obtained in 1995, as well as a publication list, related to F1-supported work which had appeared in scientific journals during 1995. (author) figs., tabs., refs.

  4. Advanced Hydraulic Studies on Enhancing Particle Removal

    DEFF Research Database (Denmark)

    He, Cheng

    The removal of suspended solids and attached pollutants is one of the main treatment processes in wastewater treatment. This thesis presents studies on the hydraulic conditions of various particle removal facilities for possible ways to increase their treatment capacity and performance by utilizing...... clarifier. The inlet zone of an existing rectangular storm water clarifier was redesigned to improve the fluid flow conditions and reduce the hydraulic head loss in order to remove the lamellar plates and adapt the clarifier to the needs of high-rate clarification of storm water with flocculant addition...

  5. Effect of modulation of the particle size distributions in the direct solid analysis by total-reflection X-ray fluorescence

    Science.gov (United States)

    Fernández-Ruiz, Ramón; Friedrich K., E. Josue; Redrejo, M. J.

    2018-02-01

    The main goal of this work was to investigate, in a systematic way, the influence of the controlled modulation of the particle size distribution of a representative solid sample with respect to the more relevant analytical parameters of the Direct Solid Analysis (DSA) by Total-reflection X-Ray Fluorescence (TXRF) quantitative method. In particular, accuracy, uncertainty, linearity and detection limits were correlated with the main parameters of their size distributions for the following elements; Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Ba and Pb. In all cases strong correlations were finded. The main conclusion of this work can be resumed as follows; the modulation of particles shape to lower average sizes next to a minimization of the width of particle size distributions, produce a strong increment of accuracy, minimization of uncertainties and limit of detections for DSA-TXRF methodology. These achievements allow the future use of the DSA-TXRF analytical methodology for development of ISO norms and standardized protocols for the direct analysis of solids by mean of TXRF.

  6. Research into the Cleaning Efficiency of 300 m3/h Maintained by the Spiral Multi-Channel Cyclone in the Process of Removing Solid Particles of <20 µm

    Directory of Open Access Journals (Sweden)

    Pranas Baltrėnas

    2014-10-01

    Full Text Available Tests on the cleaning efficiency of an experimental spiral cyclone have been conducted to determine the removal efficiency of the solid particles the dispersion of which makes <20 µm in the streamlined multi-channel cyclone. The introduced device is adapted to removing ultrafine particulate matter from contaminated air (gas flow. A multi-channel cyclone with spiral casing has been designed at the Department of Environmental Protection (DEP of Vilnius Gediminas Technical University. Experimental studies have disclosed that air (gas flow cleaning efficiency of the spiral multi-cyclone (capacity 300 m3 depend on the internal structure of the device, i.e. on the number of channels and air (gas flow distribution ratio of transit and peripheral channels. Also, the treatment efficiency of the applied equipment has been evaluated removing solid particles of different nature. AFA-VP-20 filters have been employed for conducting experimental tests. The obtained results have disclosed that solid granite particles – 95.1%, glass – 91.4% and wood – 92.2% are removed most effectively.

  7. Gas−Solid Turbulent Flow in a Circulating Fluidized Bed Riser: Numerical Study of Binary Particle Systems

    NARCIS (Netherlands)

    He, Y.; Deen, N.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2009-01-01

    Numerical simulations were performed of a turbulent gas-particle multiphase flow in a circulating fluidized bed riser using a hard-sphere discrete particle model (DPM) for the particle phase and the Navier−Stokes equations for the gas phase, where the subgrid scale stresses (SGS) were modeled with

  8. Gas-Solid Turbulent Flow in a Circulating Fluidized Bed Riser; Numerical Study of Binary Particle Mixtures

    NARCIS (Netherlands)

    He, Y; Deen, N.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2008-01-01

    A numerical simulation was performed on a turbulent gas-particle multi-phase flow in a circulating fluidized bed riser based on a hard-sphere discrete particle model (DPM) for the particle phase and the Navier-Stokes equations for the gas phase. The sub-grid scale stresses (SGS) were modeled with

  9. Light scattering by cosmic particles

    NARCIS (Netherlands)

    Hovenier, J.W.; Min, M.

    2008-01-01

    We define cosmic particles as particles outside the Earth. Two types of cosmic particles can be distinguished, namely liquid and solid particles. The solid particles are often called grains or cosmic dust particles. Cosmic particles occur in a great variety of astronomical objects and environments.

  10. Thermally driven metastable solid-solution Li0.5FePO4 in nanosized particles and its phase separation behaviors

    Science.gov (United States)

    Yoo, Sunyoung; Kang, Byoungwoo

    2013-10-01

    Nanosized LiFePO4 particles easily show a fast electrochemical response that can be achieved via a non-equilibrium pathway. To understand this intriguing phase transition behavior in nanosized LiFePO4 particles, the metastable solid-solution phase was prepared by thermal treatment with a chemically delithiated nanosized Li0.5FePO4 sample. Thermal treatment makes all the nanosized particles transform easily to the metastable solid-solution phase because of the large thermal energy while an electrochemical reaction does not. The phase separation behavior of the metastable solid-solution sample (Li0.5FePO4) was investigated under various kinetic conditions to understand critical factors affecting the phase separation behavior of nanosized LiFePO4 particles. The main findings in this study are as follows. The first finding is that the depressed phase separation behavior of the metastable phase may originate from the nanoparticle effect, in which the formation of a second phase inside a nanosized particle is not energetically favored because of the large interfacial energy. Therefore, phase separation in nanosized particles occurs between particles rather than inside a particle. If there was no over-potential, such as in the relaxed pellet experiment or in the relaxed electrode experiment in the electrolyte, the metastable phase was quite stable showing no phase separation behavior even though efficient pathways for lithium ions and electrons were well developed. The second finding is that the phase separation behavior of the metastable phase actually depends on the over-potential. Under open circuit voltage (OCV) conditions, the metastable phase started to exhibit a slight structural change during a long relaxation time, about ten days. The slow change of the metastable phase may be due to the low driving force, less than 10 mV, which comes from the energetic difference between the two-phase state and the metastable phase. This indicates that the phase separation

  11. Measurement of interactions between solid particles, liquid droplets, and/or gas bubbles in a liquid using an integrated thin film drainage apparatus.

    Science.gov (United States)

    Wang, Louxiang; Sharp, David; Masliyah, Jacob; Xu, Zhenghe

    2013-03-19

    A novel device was designed to measure drainage dynamics of thin liquid films confined between a solid particle, an immiscible liquid droplet, and/or gas bubble. Equipped with a bimorph force sensor, a computer-interfaced video capture, and a data acquisition system, the newly designed integrated thin film drainage apparatus (ITFDA) allows for the direct and simultaneous measurements of force barrier, true film drainage time, and bubble/droplet deformation under a well-controlled external force, receding and advancing contact angles, capillary force, and adhesion (detachment) force between an air bubble or oil droplet and a solid, a liquid, or an air bubble in an immiscible liquid. Using the diaphragm of a high-frequency speaker as the drive mechanism for the air bubble or oil droplet attached to a capillary tube, this newly designed device is capable of measuring forces over a wide range of hydrodynamic conditions, including bubble approach and retract velocities up to 50 mm/s and displacement range up to 1 mm. The results showed that the ITFDA was capable of measuring hydrodynamic resistance, film drainage time, and other important physical parameters between air bubbles and solid particles in aqueous solutions. As an example of illustrating the versatility, the ITFDA was also applied to other important systems such as interactions between air bubble and oil droplet, two air bubbles, and two oil droplets in an aqueous solution.

  12. Effect of particle size and microstructure on the hydrogen storage property in a V-Ti-Cr solid solution system

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hanjung; Yoo, Jeong-Hyun; Roh, Ki-Min; Suh, Chang-Yul; Kim, Won-Baek [Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources, 124 Gwahang-no, Yuseong-gu, Daejeon 305-350 (Korea, Republic of); Cho, Sung-Wook, E-mail: cho@kigam.re.kr [Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources, 124 Gwahang-no, Yuseong-gu, Daejeon 305-350 (Korea, Republic of)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer V-Ti-Cr nano-particles were prepared via the electric explosion of wire. Black-Right-Pointing-Pointer Two kinds of particles with different size were formed. Black-Right-Pointing-Pointer Hydrogen storage capacity of nano-particles decreased due to increased surface area. Black-Right-Pointing-Pointer Plateau pressure was higher in the particle with smaller lattice parameter. Black-Right-Pointing-Pointer Hysteresis in P-C isotherm was larger in the particle with lower strain. - Abstract: Nano-particles of V-Ti and V-Ti-Cr alloys with a BCC (Body Centered Cubic) structure were prepared via the EEW (electric explosion of wire) method. However, due to the formation of chromium oxide (CrO{sub 0.87}) and/or vanadium oxide (V{sub 16}O{sub 3}) during the explosion, the exploded particles were deficient in Cr and V content, contrary to the anticipated composition, and micro-particles also formed in addition to the nano-particles. The hydrogen storage capacity of the exploded particles decreased compared to that of mechanically crushed particles from ingots, because the number of interstitial sites for hydrogen in the lattice was reduced due to the increased surface area and also because the BCC phase decreased as a result of the formation of oxide phases. As the lattice parameters of the alloys became small, the plateau pressure in the P-C isotherm increased because it was more difficult for hydrogen to diffuse through the lattice. It was also found that the strain induced by adding other elements in the V lattice reduced the hysteresis in the P-C isotherm.

  13. A comparison between ultraviolet disinfection and copper alginate beads within a vortex bioreactor for the deactivation of bacteria in simulated waste streams with high levels of colour, humic acid and suspended solids.

    Directory of Open Access Journals (Sweden)

    Simon F Thomas

    Full Text Available We show in this study that the combination of a swirl flow reactor and an antimicrobial agent (in this case copper alginate beads is a promising technique for the remediation of contaminated water in waste streams recalcitrant to UV-C treatment. This is demonstrated by comparing the viability of both common and UV-C resistant organisms in operating conditions where UV-C proves ineffective - notably high levels of solids and compounds which deflect UV-C. The swirl flow reactor is easy to construct from commonly available plumbing parts and may prove a versatile and powerful tool in waste water treatment in developing countries.

  14. Suspended animation for delayed resuscitation.

    Science.gov (United States)

    Safar, Peter J; Tisherman, Samuel A

    2002-04-01

    'Suspended animation for delayed resuscitation' is a new concept for attempting resuscitation from cardiac arrest of patients who currently (totally or temporarily) cannot be resuscitated, such as traumatic exsanguination cardiac arrest. Suspended animation means preservation of the viability of brain and organism during cardiac arrest, until restoration of stable spontaneous circulation or prolonged artificial circulation is possible. Suspended animation for exsanguination cardiac arrest of trauma victims would have to be induced within the critical first 5 min after the start of cardiac arrest no-flow, to buy time for transport and resuscitative surgery (hemostasis) performed during no-flow. Cardiac arrest is then reversed with all-out resuscitation, usually requiring cardiopulmonary bypass. Suspended animation has been explored and documented as effective in dogs in terms of long-term survival without brain damage after very prolonged cardiac arrest. In the 1990s, the Pittsburgh group achieved survival without brain damage in dogs after cardiac arrest of up to 90 min no-flow at brain (tympanic) temperature of 10 degrees C, with functionally and histologically normal brains. These studies used emergency cardiopulmonary bypass with heat exchanger or a single hypothermic saline flush into the aorta, which proved superior to pharmacologic strategies. For the large number of normovolemic sudden cardiac death victims, which currently cannot be resuscitated, more research in large animals is needed.

  15. The rotation and translation of non-spherical particles in homogeneous isotropic turbulence

    Science.gov (United States)

    Byron, Margaret

    The motion of particles suspended in environmental turbulence is relevant to many scientific fields, from sediment transport to biological interactions to underwater robotics. At very small scales and simple shapes, we are able to completely mathematically describe the motion of inertial particles; however, the motion of large aspherical particles is significantly more complex, and current computational models are inadequate for large or highly-resolved domains. Therefore, we seek to experimentally investigate the coupling between freely suspended particles and ambient turbulence. A better understanding of this coupling will inform not only engineering and physics, but the interactions between small aquatic organisms and their environments. In the following pages, we explore the roles of shape and buoyancy on the motion of passive particles in turbulence, and allow these particles to serve as models for meso-scale aquatic organisms. We fabricate cylindrical and spheroidal particles and suspend them in homogeneous, isotropic turbulence that is generated via randomly-actuated jet arrays. The particles are fabricated with agarose hydrogel, which is refractive-index-matched to the surrounding fluid (water). Both the fluid and the particle are seeded with passive tracers, allowing us to perform Particle Image Velocimetry (PIV) simultaneously on the particle and fluid phase. To investigate the effects of shape, particles are fabricated at varying aspect ratios; to investigate the effects of buoyancy, particles are fabricated at varying specific gravities. Each particle type is freely suspended at a volume fraction of F=0.1%, for which four-way coupling interactions are negligible. The suspended particles are imaged together with the surrounding fluid and analyzed using stereoscopic PIV, which yields three velocity components in a two-dimensional measurement plane. Using image thresholding, the results are separated into simultaneous fluid-phase and solid-phase velocity

  16. Propagation of a spherical shock wave in mixture of non-ideal gas and small solid particles under gravitational field with conductive and radiative heat fluxes

    Science.gov (United States)

    Nath, Gorakh

    Self-similar solutions are obtained for one-dimensional unsteady adiabatic flow behind a spherical shock wave propagating in a dusty gas with conductive and radiative heat fluxes under a gravitational field. The shock is assumed to be driven out by a moving piston and the dusty gas to be a mixture of non-ideal (or perfect) gas and small solid particles, in which solid particles are continuously distributed. It is assumed that the equilibrium flow-conditions are maintained and variable energy input is continuously supplied by the piston. The heat conduction is express in terms of Fourier’s law and the radiation is considered to be of the diffusion type for an optically thick grey gas model. The thermal conductivity and the absorption coefficient are assumed to vary with temperature and density. The medium is assumed to be under a gravitational field due to heavy nucleus at the origin (Roche Model). The unsteady model of Roche consists of a dusty gas distributed with spherical symmetry around a nucleus having large mass It is assumed that the gravitational effect of the mixture itself can be neglected compared with the attraction of the heavy nucleus. The density of the ambient medium is taken to be constant. Our analysis reveals that after inclusion of gravitational field effect surprisingly the shock strength increases and remarkable difference can be found in the distribution of flow variables. The effects of the variation of the heat transfer parameters, the gravitational parameter and non-idealness of the gas in the mixture are investigated. Also, the effects of an increase in (i) the mass concentration of solid particles in the mixture and (ii) the ratio of the density of solid particles to the initial density of the gas on the flow variables are investigated. It is found that the shock strength is increased with an increase in the value of gravitational parameter. Further, it is investigated that the presence of gravitational field increases the

  17. Batch fabrication of nanotubes suspended between microelectrodes

    DEFF Research Database (Denmark)

    Mateiu, Ramona Valentina; Stöckli, T.; Knapp, H. F.

    2007-01-01

    We report a fabrication method, which uses standard UV-lithography to pattern the catalyst for the chemical vapour deposition(CVD) of suspended double clamped single walled carbon nanotubes. By using an aqueous solution of Fe(NO3)3 the patterning of the catalyst material onto microelectrodes can...... be done with a simple lift-off process with standard photolithographic resist. An applied electric field is sustained between the microelectrodes during CVD to guide the nanotube growth. Comparison with simulations shows that the location and the orientation of the grown carbon nanotubes (CNT) correspond...... to the regions of maximum electric field, enabling accurate positioning of a nanotube by controlling the shape of the microelectrodes. The CNT bridges are deflected tens of nm when a DC voltage is applied between the nanotube and a gate microelectrode indicating that the clamping through the catalyst particles...

  18. Oscillatory rheology measurements of particle- and bubble-bearing fluids: Solid-like behavior of a crystal-rich basaltic magma

    Science.gov (United States)

    Namiki, Atsuko; Tanaka, Yukie

    2017-09-01

    The rheology of crystal- and bubble-bearing magmas governs the propagation of seismic waves as well as eruption dynamics. Here "rheology" includes viscous and elastic components and their ratio known as attenuation. We perform an oscillatory rheology measurements, which provide storage (elastic component) and loss (viscous component) moduli, and attenuation, with frequency dependence, using particle- and bubble-bearing fluids whose liquid viscosity is in the range of that of a basaltic melt. We find that both the storage and loss moduli dramatically increase with the particle fraction but weakly depend on the bubble fraction. Solid-like behavior, equivalent to attenuation 40 vol %. The shallow conduit of Stromboli volcano, filled by a crystal-rich and low viscosity basaltic magma, may be an example, where shear waves propagate and brittle fractures occur to cause explosive eruptions because of its high crystallinity.

  19. Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

    DEFF Research Database (Denmark)

    Falås, Per; Baillon-Dhumez, Aude; Andersen, Henrik Rasmus

    2012-01-01

    Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct...... and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast...

  20. Scanning electron microscopy applied to the study of solid pollution particles deposited on monumental stone; La microscopia electronica de barrido aplicada al estudio de particulas solidas de contaminacion depositadas sobre la piedra momumental

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Pache, F.; Alonso, F.J.; Esbert, R.M. [Departamento de Geologia, Universidad de Oviedo (Spain)

    1996-06-01

    Solid pollution particles play an important role in the decay of monumental stone. Scanning electron microscopy (SEM) in conjunction with microanalysis (EDX) are a very valuable study tool. In the present paper, particular attention is paid to sample collection and preparation. Examples of particles providing information on the source of decay are submitted. (Author) 9 refs.

  1. Different types of Lagrangian coherent structures formed by solid particles in three-dimensional time-periodic flows

    Science.gov (United States)

    Melnikov, Denis E.; Shevtsova, Valentina

    2017-04-01

    Modeling of the experments on formation of coherent structures (also called particle accumulation structures, or PAS) in a three-dimensional time-periodic flow in a finite-size liquid column driven by a combined effect of thermocapillary stress and buoyancy was performed. The exact experimental conditions were studied. We considered particles 1% denser than the fluid. Aiming at reproducing the observed variety of PAS, double-loop (SL-II) and asymmetric single-loop (ASL-I) structures were obtained along with a "conventional" symmetric single-loop PAS (SL-I). The observations are perfectly in line with the experiments. It is shown that the limit trajectory of a particle is not only a matter of the particle's inertia but also of its initial location. We developed a method to calculate the formation time of a structure. The obtained values are very close to those experimentally measured.

  2. Study on Individual PAHs Content in Ultrafine Particles from Solid Fractions of Diesel and Biodiesel Exhaust Fumes

    Directory of Open Access Journals (Sweden)

    Małgorzata Szewczyńska

    2013-01-01

    Full Text Available In order to characterize PAHs emissions of diesel engine fuelled with diesel and its blend (B20, B40. In the particle phase, PAHs in engine exhausts were collected by fiberglass filters using Electrical Low Pressure Impactor (ELPI and then determined by a high performance liquid chromatography with a fluorimetric detector (HPLC-FL. The main content in exhaust gases from diesel engine, regardless the type of applied fuel, is constituted by the particles fraction of diameter <0.25 μm. Particles sized <0.25 μm constituted on average approximately 68% of particles in diesel exhaust gases and approx. 50% of particles emitted by biodiesel B20 and B40. When the B100 bioester additive was applied, the total emission of particles was reduced thus the volume of toxic substances adsorbed on them was lower. The analysis of chemical composition of <0.25 μm exhaust gas fraction showed that there were mainly 3- and 4-ring aromatic hydrocarbons in the exhaust gas of diesel fuel while in B40 single PAHs with the number of rings of 4 and 5 were detected. An application of ELPI permitted a further separation of <0.25 μm particle’s fraction and a real-time determination of interalia number, mass, and surface concentrations.

  3. Solid-state characterization studies and effect of PEG 20000 and P90G on particle size reduction and stability of complexed glimepiride nanocrystals

    Science.gov (United States)

    Sajeev Kumar, Babasahib; Saraswathi, Raman; Dhanaraj, Sokkalingam Arumugham

    2013-01-01

    Objective The objective of the present study is to formulate and characterize the properties of complexed glimepiride nanocrystals (GLP) by various techniques at different stages of its development, and to study the effect of PEG 20000 and P90G on particle size reduction and stability of nanocrystals. Method Precipitated (GLP-PEG) and complexed NCs (GLP-PEG-P90G) of glimepiride were characterized for particle size, size distribution, zeta potential and stability assessment using photon correlation spectroscopy (PCS). The crystallinity was analyzed using differential scanning calorimetry (DSC) and X-ray powder diffraction spectroscopy (XRPD). The surface morphology and chemical stability were assessed by means of scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). Results A formulation with drug–polymer ratio of 1:1 was most ideal in developing stable NCs as it exhibited smaller particle size and high stability. A high zeta potential was observed in all NCs after complexation indicating improved stability. DSC and XRPD studies showed no change in crystallinity after complexation. SEM analysis of complexed NCs showed presence of spherical shape particles (size below 1 μm) with a lipid coat on the surface. Stability studies on optimized formulation (F1) revealed no change in particle size during 3-month period. FTIR studies prove that the chemical identity of GLP was preserved in the samples and the formulation was stable. Conclusion Solid-state characterization studies reveal that complexed GLP NCs are promising carriers for drug delivery and they can be safely and effectively used in design of various formulations. Also, PEG 20000 and P90G are excellent polymer and lipid for particle size reduction (nanonization) and stabilization of nanocrystals. PMID:24396247

  4. High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T.; Shi, Frank G.

    2004-05-26

    Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.

  5. 7 CFR 1206.21 - Suspend.

    Science.gov (United States)

    2010-01-01

    ... part thereof during a particular period of time specified in the rule. ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MANGO PROMOTION, RESEARCH, AND INFORMATION Mango Promotion, Research, and Information Order Definitions § 1206.21 Suspend. Suspend means to...

  6. Investigation of particle accumulation, chemosensitivity and thermosensitivity for effective solid tumor therapy using thermosensitive liposomes and hyperthermia

    NARCIS (Netherlands)

    W.J.M. Lokerse (Wouter); M. Bolkestein (Michiel); T.L.M. ten Hagen (Timo); M. de Jong (Marcel); A.M.M. Eggermont (Alexander); Grüll, H. (Holger); G.A. Koning (Gerben)

    2016-01-01

    textabstractDoxorubicin (Dox) loaded thermosensitive liposomes (TSLs) have shown promising results for hyperthermia-induced local drug delivery to solid tumors. Typically, the tumor is heated to hyperthermic temperatures (41-42 °C), which induced intravascular drug release from TSLs within the tumor

  7. ASYMPTOTICS OF a PARTICLES TRANSPORT PROBLEM

    Directory of Open Access Journals (Sweden)

    Kuzmina Ludmila Ivanovna

    2017-11-01

    Full Text Available Subject: a groundwater filtration affects the strength and stability of underground and hydro-technical constructions. Research objectives: the study of one-dimensional problem of displacement of suspension by the flow of pure water in a porous medium. Materials and methods: when filtering a suspension some particles pass through the porous medium, and some of them are stuck in the pores. It is assumed that size distributions of the solid particles and the pores overlap. In this case, the main mechanism of particle retention is a size-exclusion: the particles pass freely through the large pores and get stuck at the inlet of the tiny pores that are smaller than the particle diameter. The concentrations of suspended and retained particles satisfy two quasi-linear differential equations of the first order. To solve the filtration problem, methods of nonlinear asymptotic analysis are used. Results: in a mathematical model of filtration of suspensions, which takes into account the dependence of the porosity and permeability of the porous medium on concentration of retained particles, the boundary between two phases is moving with variable velocity. The asymptotic solution to the problem is constructed for a small filtration coefficient. The theorem of existence of the asymptotics is proved. Analytical expressions for the principal asymptotic terms are presented for the case of linear coefficients and initial conditions. The asymptotics of the boundary of two phases is given in explicit form. Conclusions: the filtration problem under study can be solved analytically.

  8. A study of the nature of solid particle impact and shape on the erosion morphology of ductile metals

    Science.gov (United States)

    Rao, P. V.; Young, S. G.; Buckley, D. H.

    1982-01-01

    Impulsive versus steady jet impingement of spherical glass bead particles on metal surfaces was studied using a gas gun facility and a commercial sand blasting apparatus. Crushed glass particles were also used in the sand blasting apparatus as well as glass beads. Comparisons of the different types of erosion patterns were made. Scanning electron microscopy, surface profilometry and energy dispersive X-ray spectroscopy analysis were used to characterize erosion patterns. The nature of the wear can be divided into cutting and deformation, each with its own characteristic features. Surface chemistry analysis indicates the possibility of complex chemical and/or mechanical interactions between erodants and target materials.

  9. Characterization investigations during mechanical alloying and sintering of Ni-W solid solution alloys dispersed with WC and Y{sub 2}O{sub 3} particles

    Energy Technology Data Exchange (ETDEWEB)

    Genc, Aziz, E-mail: agenc@itu.edu.t [Particulate Materials Laboratories, Department of Metallurgical and Materials Engineering, Istanbul Technical University, Maslak, 34469 Istanbul (Turkey); Luetfi Ovecoglu, M. [Particulate Materials Laboratories, Department of Metallurgical and Materials Engineering, Istanbul Technical University, Maslak, 34469 Istanbul (Turkey)

    2010-10-15

    Research highlights: {yields} Characterization investigations on the Ni-W solid solution alloys fabricated via mechanical alloying and the evolution of the properties of the powders with increasing MA durations. {yields} Reinforcement of the selected Ni-W powders with WC and Y{sub 2}O{sub 3} particles and further MA together for 12 h. {yields} There is no reported literature on the development and characterization of Ni-W solid solution alloys matrix composites fabricated via MA. {yields} Sintering of the developed composites and the characterization investigations of the sintered samples. {yields} Identification of new 'pomegranate-like' structures in the bulk of the samples. - Abstract: Blended elemental Ni-30 wt.% W powders were mechanically alloyed (MA'd) for 1 h, 3 h, 6 h, 12 h, 24 h, 36 h and 48 h in a Spex mixer/mill at room temperature in order to investigate the effects of MA duration on the solubility of W in Ni and the grain size, hardness and particle size. Microstructural and phase characterizations of the MA'd powders were carried out using X-ray diffractometer (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). On the basis of achieved saturation on the solid solubility, hardness and particle size, the Ni-30 wt.% W powders MA'd for 48 h were chosen as the matrix which was reinforced with different amounts of WC and/or with 1 wt.% Y{sub 2}O{sub 3} particles. The reinforced powders were further MA'd for 12 h. The MA'd powders were sintered at 1300 {sup o}C for 1 h under Ar and H{sub 2} gas flowing conditions. Microstructural characterizations of the sintered samples were conducted via XRD and SEM. Sintered densities were measured by using the Archimedes' method. Vickers microhardness tests were performed on both MA'd powders and the sintered samples. Sliding wear experiments were done in order to investigate wear behaviors of the sintered samples.

  10. Development of a microfluidic interface for suspended microchannel resonators

    OpenAIRE

    Maillard, Damien

    2016-01-01

    Suspended microchannel resonators (SMRs) are devices that detect particles in liquid samples. In comparison with similar resonating devices that must be immersed, SMRs allow the fluids to flow through microfluidic resonators. This principle of operation leads to a great reduction of the required sample and to enhanced quality factors. As such, SMRs show great potential for a variety of sensing applications. This thesis reports on the final steps of the microfabrication of SMRs and on the deve...

  11. Dispersive micro-solid phase extraction based on self-assembling, ionic liquid-coated magnetic particles for the determination of clofentezine and chlorfenapyr in environmental water samples.

    Science.gov (United States)

    Peng, Bing; Zhang, Jiaheng; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang

    2013-11-21

    Two ionic liquid-coated-Fe3O4 magnetic particles (IL-Fe3O4 MPs) were developed for use in two types of dispersive micro-solid phase extraction (D-μ-SPE) for the high-performance liquid chromatographic analysis of clofentezine and chlorfenapyr in environmental water samples. Self-assembling IL-Fe3O4 MPs were used in D-μ-SPE as adsorbents. Two D-μ-SPE extraction methods, namely, direct dispersive micro-solid phase extraction (d-D-μ-SPE) and in situ solvent formation-based dispersive micro-solid phase extraction (ISF-D-μ-SPE), were proposed, using [C8MIM][PF6] to extract analytes through two pathways. Lower IL doses were required in the extraction process compared with those in other IL-based methods. Fe3O4 MPs can also be recycled and reused after extraction and are thus environmentally friendly. These newly developed methods were demonstrated to be feasible for use in the quantitation of clofentezine and chlorfenapyr at trace levels, with lower limit of detection values ranging from 0.4 to 0.5 ng mL(-1) for d-D-μ-SPE and 0.4 ng mL(-1) for ISF-D-μ-SPE. Finally, relative standard deviations of less than 6.0% were obtained.

  12. Quantitative suspended sediment mapping using aircraft remotely sensed multispectral data. [in Virginia

    Science.gov (United States)

    Johnson, R. W.

    1975-01-01

    Suspended sediment is an important environmental parameter for monitoring water quality, water movement, and land use. Quantitative suspended sediment determinations were made from analysis of aircraft remotely sensed multispectral digital data. A statistical analysis and derived regression equation were used to determine and plot quantitative suspended sediment concentration contours in the tidal James River, Virginia, on May 28, 1974. From the analysis, a single band, Band 8 (0.70-0.74 microns), was adequate for determining suspended sediment concentrations. A correlation coefficient of 0.89 was obtained with a mean inaccuracy of 23.5 percent for suspended sediment concentrations up to about 50 mg/l. Other water quality parameters - secchi disc depth and chlorophyll - also had high correlations with the remotely sensed data. Particle size distribution had only a fair correlation with the remotely sensed data.

  13. [Polycyclic aromatic hydrocarbons and soluble organic fraction in fine particles from solid fraction of biodiesel exhaust fumes].

    Science.gov (United States)

    Szewczyńska, Małgorzata; Pośniak, Małgorzata

    2012-01-01

    This paper presents the results of investigations into the distribution of fine particles in the biodiesel exhaust fumes (bio-DEP), as well as into the content of polycyclic aromatic hydrocarbons (PAHs) and soluble organic fraction (SOF) in the study fractions. Samples of biodiesel B20 and B40 exhaust combustion fumes were generated at the model station composed of a diesel engine from Diesel TDI 2007 Volkswagen. Sioutas personal cascade impactor (SPCI) with Teflon filters and low-pressure impactor ELIPI (Dekati Low Pressure Impactor) were used for sampling diesel exhaust fine particles. The analysis of PAHs adsorbed on particulate fractions was performed by high performance liquid chromatography with fluorescence detection (HPLC/FL). For the determination of dry residue soluble organic fraction of biodiesel exhaust particles the gravimetric method was used. The combustion exhaust fumes of 100% ON contained mainly naphthalene, acenaphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo(a)anthracene and chrysene, whilst the exhaust of B40-single PAHs of 4 and 5 rings, such as chrysene, benzo(k)fluoranthene, dibenzo (ah)anthracene and benzo(ghi)perylene. The total content of PAHs in diesel exhaust particles averaged 910 ng/m3 for 100% ON and 340 ng/m3 for B40. The concentrations of benzo(a)antarcene were at the levels of 310 ng/m3 (100% ON) and 90 ng/m3 (B40). The investigations indicated that a fraction < 025 microm represents the main component of diesel exhaust particles, regardless of the used fuel. Bioester B 100 commonly added to diesel fuel (ON) causes a reduction of the total particulates emission and thus reduces the amount of toxic substances adsorbed on their surface.

  14. Protein purification using magnetic adsorbent particles

    DEFF Research Database (Denmark)

    Franzreb, M; Siemann-Herzberg, M.; Hobley, Timothy John

    2006-01-01

    of other suspended solids. Thus, it becomes possible to magnetically separate selected target species directly out of crude biological process liquors (e.g. fermentation broths, cell disruptates, plasma, milk, whey and plant extracts) simply by binding them on magnetic adsorbents before application......The application of functionalised magnetic adsorbent particles in combination with magnetic separation techniques has received considerable attention in recent years. The magnetically responsive nature of such adsorbent particles permits their selective manipulation and separation in the presence...... of a magnetic field. By using magnetic separation in this way, the several stages of sample pretreatment (especially centrifugation, filtration and membrane separation) that are normally necessary to condition an extract before its application on packed bed chromatography columns, may be eliminated. Magnetic...

  15. Investigation of Origin of Attached Cu-Ag Droplets to Solid Particles During High-Temperature Slag/Copper/Spinel Interactions

    Science.gov (United States)

    Bellemans, Inge; De Wilde, Evelien; Blanpain, Bart; Moelans, Nele; Verbeken, Kim

    2017-10-01

    This study investigates the origin of mechanically entrained metal droplets in liquid slag due to their interaction with solid spinel particles. Two possible mechanisms were proposed previously: separately formed droplets and spinel particles get attached to each other due to agitation of the slag and metal phases; or the spinel particles form by a chemical reaction together with a new droplet or alongside a droplet that was already present in the system. In this study, an inert tracer element was added to the metallic phase in adapted sessile drop experiments. For this purpose, Cu-Ag alloys, with various Ag-contents, were produced. The results showed that the small entrained metal droplets within the slag droplet contained Ag, but in very low amounts with respect to the amount of Ag in the Cu-Ag alloy. This indicates that the entrained metal droplets are formed due to a sequential combination of the two origins: first, very small metal droplets are dispersed in the slag drop, due to the emulsification process. Then, these metal droplets are nucleation sites for the Cu-spinel reactive formation.

  16. Improving the gas-solids contact efficiency in a fluidized bed of CO2 adsorbent fine particles.

    Science.gov (United States)

    Valverde, J M; Pontiga, F; Soria-Hoyo, C; Quintanilla, M A S; Moreno, H; Duran, F J; Espin, M J

    2011-09-07

    A modified CO(2) adsorbent is obtained by dry mixing of a Ca(OH)(2) fine powder as received with a commercial silica nanopowder. Silica nanoparticles form light agglomerates of size of the order of tens of microns, which are uniformly fluidizable. These agglomerates act as dispersants of the Ca(OH)(2) fine particles, which coat the nanoparticle agglomerates likely due to contact charging. Ca(OH)(2) particles (CO(2) adsorbent) are thus provided with a vehicle for uniform fluidization. In this way, the contact efficiency between the CO(2) adsorbent and CO(2) in the fluidized bed is greatly enhanced. Experimental results show that the improvement of Ca(OH)(2) fluidizability serves to enhance the carbonation reaction in the fluidized bed. This journal is © the Owner Societies 2011

  17. Factors Influencing Quasistatic Modeling of Deformation and Failure in Rock-Like Solids by the Smoothed Particle Hydrodynamics Method

    Directory of Open Access Journals (Sweden)

    X. W. Tang

    2013-01-01

    actual test of marble material. Typical results of the axial stress-strain response from infinitesimal to finite deformation as well as the progressive failure process for the marble tests are given and the influences of various factors are discussed. It is found that only provided proper choices of particle momentum equation and the smoothing length parameter, the SPH method is capable for favorably reproducing the deformation and progressive failure evolution in rock-like materials under quasistatic compression loads.

  18. The rheology of non-suspended sediment transport mediated by a Newtonian fluid

    Science.gov (United States)

    Pähtz, Thomas; Durán, Orencio

    2017-04-01

    Using a coupled DEM/RANS numerical model of non-suspended sediment transport in a Newtonian fluid (Durán et al., POF 103306, 2012), we find that the gas-like part of the granular transport flow can be described by a universal condition that constrains the average geometry of interparticle collisions. We show that this condition corresponds to a constant sliding friction coefficient μ at an appropriately defined bed surface, thus explaining the success of Bagnold's old idea to describe the sediment transport in analogy to sliding friction. We are currently exploring whether this rheology applies to gas-like granular flows in general. We further find a transition of the gas-like flow to either a solid-like flow (solid-to-gas transition), which is typical for aeolian sediment transport ('saltation'), or a liquid-like flow (liquid-to-gas transition), which is typical for subaqueous sediment transport ('bedload'). The transition occurs at about the location of maximal particle collision frequency. If there is a liquid-like flow below the transition, we find that it can be described by a μ(I) rheology, where I is the visco-intertial number, an appropriately defined average of the viscous and intertial number.

  19. Optimization of biological phosphorus and ammonia removal in a combined fixed and suspended growth wastewater treatment system: Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    This project was conducted to optimize design and operational criteria for enhanced biological phosphorus removal and nitrification of ammonia in the fixed growth reactor-suspended growth reactor (FGR-SGR) process. The research completed the investigation of optimum hydraulic retention times for biological phosphorus removal in both the unaerated and aerated phases of the suspended growth components of the FGR-SGR system, including an assessment of the possibility of reducing suspended growth aeration requirements by using oxidized forms of nitrogen rather than dissolved oxygen for biological phosphorus uptake; investigated the effects on biological phosphorus removal and nitrification of varying the internal recycle flow rates; and investigated the optimum solids retention time, or the optimum operating mixed liquor suspended solids concentration, in the suspended growth component of the system for biological phosphorus removal and nitrification-denitrification.

  20. Influence of solid particles to a coriolis mass flow metering; Einfluss von Feststoffen in einer Fluessigkeitsstroemung auf die Coriolis-Massemessung

    Energy Technology Data Exchange (ETDEWEB)

    Goeke, J.; Steffensen, E. [Fachhochschule Koeln (Germany). Fakultaet Anlagen-, Energie- und Maschinensysteme

    2006-07-01

    Since more than 15 years coriolis mass flow meters could be regarded as an extraordinary metering system. Those old mechanical principle could be enhanced by application of new electronic technique. Today high precise technologies are available for the rough industrial application, which are often distorted from enviromental influences. Nevertheless there exist situations, which the rapid chance of parameters affect the state of the swinging metering system. And the algorithm could not react in an suggestive manner. This problem occurs for example at a two phase flow. Within this paper we present the reaction of a coriolis massflow meter in a liquid flow with little solid particles. The result show small deviations between the experimental results and the thoretical calculations. (orig.)

  1. Eulerian multi-fluid models for the simulation of dynamics and coalescence of particles in solid propellant combustion

    Science.gov (United States)

    Doisneau, F.; Laurent, F.; Murrone, A.; Dupays, J.; Massot, M.

    2013-02-01

    The accurate simulation of polydisperse sprays undergoing coalescence in unsteady gaseous flows is a crucial issue. In solid rocket motors, the internal flow depends strongly on the alumina droplet size distribution, which spreads up with coalescence. Yet solving for unsteady two-phase flows with high accuracy on the droplet sizes is a challenge for both modeling and scientific computing. As an alternative to Lagrangian approaches, a wide range of Eulerian models have been recently developed to describe the disperse liquid phase at a lower cost, with an easier coupling to the gaseous phase and with massively parallel codes. Among these models, the multi-fluid model allows the detailed description of polydispersity and size/velocity correlations by separately solving fluids of size-sorted droplets, the so-called sections. The existing one size moment method, which describes the size distribution with one size moment per section, provides simple and fast resolution for coalescence. On the other hand, a two size moment method has been suggested to reduce the number of sections but it lacks an efficient coalescence resolution method. After introducing a new strategy for two size moment coalescence, the two methods are compared on various configurations in a research code and an industrial-oriented code, in order to conclude on computational accuracy and cost. Then the paper aims at describing the most efficient approach for multi-dimensional unsteady and eventually coalescing rocket chamber simulations. Its objective is threefold: first, to validate the two size moment method by comparing simulations to reference solutions and dedicated experimental measurements conducted at ONERA, second to study the efficiency and robustness of both methods, third, to draw some firm conclusions about the necessity to use the one size moment or two size moment method to simulate solid propellant alumina sprays. We finally perform the first simulations of coalescence in realistic 2D

  2. Rippling instabilities in suspended nanoribbons

    Science.gov (United States)

    Wang, Hailong; Upmanyu, Moneesh

    2012-11-01

    Morphology mediates the interplay between the structure and electronic transport in atomically thin nanoribbons such as graphene as the relaxation of edge stresses occurs preferentially via out-of-plane deflections. In the case of end-supported suspended nanoribbons that we study here, past experiments and computations have identified a range of equilibrium morphologies, in particular, for graphene flakes, yet a unified understanding of their relative stability remains elusive. Here, we employ atomic-scale simulations and a composite framework based on isotropic elastic plate theory to chart out the morphological stability space of suspended nanoribbons with respect to intrinsic (ribbon elasticity) and engineered (ribbon geometry) parameters, and the combination of edge and body actuation. The computations highlight a rich morphological shape space that can be naturally classified into two competing shapes, bendinglike and twistlike, depending on the distribution of ripples across the interacting edges. The linearized elastic framework yields exact solutions for these rippled shapes. For compressive edge stresses, the body strain emerges as a key variable that controls their relative stability and in extreme cases stabilizes coexisting transverse ripples. Tensile edge stresses lead to dimples within the ribbon core that decay into the edges, a feature of obvious significance for stretchable nanoelectronics. The interplay between geometry and mechanics that we report should serve as a key input for quantifying the transport along these ribbons.

  3. Turbulence control of suspended matter aggregate size

    Science.gov (United States)

    Jago, C. F.; Jones, S. E.; Rippeth, T. P.; Simpson, J. H.

    2003-04-01

    The size and properties of the aggregates which comprise suspended particulate matter (SPM) change on short time and length scales in shelf seas. There is experimental and theoretical evidence to suggest that turbulence plays a key role in aggregation but there is contradictory evidence with respect to disaggregation: it has been proposed that sinking stresses, rather than turbulent stresses, are the dominant control of disaggregation. But there is little observational evidence for turbulence control of particle properties. New observations are presented which provide compelling evidence for turbulence control of both aggregation and disaggregation. TKE dissipation and particle size were measured in situ at stratified sites in the northern North Sea in 110 m water depth during the period of weakening of the seasonal thermocline (in October/November) and in the Clyde Sea in 55 m water depth (April). There were similar vertical distributions of TKE dissipation E, SPM concentration C, and particle size D at both sites. At the base of the thermocline, there were minima in E and C, but a maximum in D, indicating that enhanced aggregation was occurring in this region of low turbulent stress. In the bottom mixed layer, E and C increased, while D decreased due to disaggregation in this region of increasing turbulent stress towards the seabed. Particles settling out of the low stress region at the base of the thermocline began to disaggregate when E increased to 3.2x10-6 watts m-2. D did not correlate directly with E because aggregation is a function of collision frequency (and hence of both C and E): this can be accounted for using a simplified theoretical aggregation model which treats flocs as self-similar fractal entities and allows simultaneous floc formation and break up, specified as functions of C and E. It was found that in the northern North Sea the measured D represents an equilibrium size predicted by the model, while in the Clyde Sea tidal variation in both C

  4. Assessment of suspended particulate matters and their heavy metal content in the ambient air of Mobarakeh city, Isfahan, Iran

    OpenAIRE

    Avazali Saririan Mobarakeh; Bibi Fatemeh Nabavi; Mahnaz Nikaeen; Mohammad Mehdi Amin; Akbar Hassanzadeh; Kazem Nadafi

    2014-01-01

    Aim: This study was carried out to investigate the quality of Mobarakeh ambient air in terms of suspended particles and heavy metals. Material and Methods: The current study was carried out in Mobarakeh city, Isfahan, Iran. Air sampling was performed in three sites for a 1-year period (in 2007). Measurement of total suspended particles (TSP) and heavy metals was achieved using high volume air sampler with fiberglass filter. The concentration of heavy metals, including Pb, Ni, Zn, Fe, and ...

  5. Suspended matter in surface waters of the Atlantic continental margin from Cape Cod to the Florida keys

    Science.gov (United States)

    Manheim, F. T.; Meade, R.H.; Bond, G.C.

    1970-01-01

    Appreciable amounts of suspended matter (> 1.0 milligram per liter) in surface waters are restricted to within a few kilometers of the Atlantic coast. Particles that escape estuaries or are discharged by rivers into the shelf region tend to travel longshoreward rather than seaward. Suspended matter farther offshore, chiefly amorphous organic particles, totals 0.1 milligram per liter or less. Soot, fly ash, processed cellulose, and other pollutants are widespread.

  6. Elevated Temperature Solid Particle Erosion Performance of Plasma-Sprayed Co-based Composite Coatings with Additions of Al2O3 and CeO2

    Science.gov (United States)

    Nithin, H. S.; Desai, Vijay; Ramesh, M. R.

    2017-09-01

    In this paper, investigation into solid particle erosion behavior of atmospheric plasma-sprayed composite coating of CoCrAlY reinforced with Al2O3 and CeO2 oxides on Superni 76 at elevated temperature of 600 °C is presented. Alumina particles are used as erodent at two impact angles of 30° and 90°. The microstructure, porosity, hardness, toughness and adhesion properties of the as-sprayed coatings are studied. The effects of temperature and phase transformation in the coatings during erosion process are analyzed using XRD and EDS techniques. Optical profilometer is used for accurate elucidation of erosion volume loss. CoCrAlY/CeO2 coating showed better erosion resistance with a volume loss of about 50% of what was observed in case of CoCrAlY/Al2O3/YSZ coating. Lower erosion loss is observed at 90° as compared to 30° impact angle. The erosion mechanism evaluated using SEM micrograph revealed that the coatings experienced ductile fracture exhibiting severe deformation with unusual oxide cracks. Reinforced metal oxides provide shielding effect for erodent impact, enabling better erosion resistance. The oxidation of the coating due to high-temperature exposure reforms erosion process into oxidation-modified erosion process.

  7. Elevated Temperature Solid Particle Erosion Performance of Plasma-Sprayed Co-based Composite Coatings with Additions of Al2O3 and CeO2

    Science.gov (United States)

    Nithin, H. S.; Desai, Vijay; Ramesh, M. R.

    2017-11-01

    In this paper, investigation into solid particle erosion behavior of atmospheric plasma-sprayed composite coating of CoCrAlY reinforced with Al2O3 and CeO2 oxides on Superni 76 at elevated temperature of 600 °C is presented. Alumina particles are used as erodent at two impact angles of 30° and 90°. The microstructure, porosity, hardness, toughness and adhesion properties of the as-sprayed coatings are studied. The effects of temperature and phase transformation in the coatings during erosion process are analyzed using XRD and EDS techniques. Optical profilometer is used for accurate elucidation of erosion volume loss. CoCrAlY/CeO2 coating showed better erosion resistance with a volume loss of about 50% of what was observed in case of CoCrAlY/Al2O3/YSZ coating. Lower erosion loss is observed at 90° as compared to 30° impact angle. The erosion mechanism evaluated using SEM micrograph revealed that the coatings experienced ductile fracture exhibiting severe deformation with unusual oxide cracks. Reinforced metal oxides provide shielding effect for erodent impact, enabling better erosion resistance. The oxidation of the coating due to high-temperature exposure reforms erosion process into oxidation-modified erosion process.

  8. Shear Rheology of a Suspension of Deformable Solids in Viscoelastic Fluid via Immersed Boundary Techniques

    Science.gov (United States)

    Guido, Christopher; Shaqfeh, Eric

    2017-11-01

    The simulation of fluids with suspended deformable solids is important to the design of microfluidic devices with soft particles and the examination of blood flow in complex channels. The fluids in these applications are often viscoelastic, motivating the development of a high-fidelity simulation tool with general constitutive model implementations for both the viscoelastic fluid and deformable solid. The Immersed Finite Element Method (IFEM) presented by Zhang et al. (2007) allows for distinct fluid and solid grids to be utilized reducing the need for costly re-meshing when particles translate. We discuss a modified version of the IFEM that allows for the simulation of deformable particles in viscoelastic flows. This simulation tool is validated for simple Newtonian shear flows with elastic particles that obey a Neo-Hookean Law. The tool is used to further explore the rheology of a dilute suspension of Neo-Hookean particles in a Giesekus fluid. The results show that dilute suspensions of soft particles have viscosities that decrease as the Capillary number becomes higher in both the case of a Newtonian and viscoelastic fluid. A discussion of multiple particle results will be included. NSF CBET-1066263 and 1066334.

  9. Modelling of air flows in pleated filters and of their clogging by solid particles; Modelisation des ecoulements d'air et du colmatage des filtres plisses par des aerosols solides

    Energy Technology Data Exchange (ETDEWEB)

    Del Fabbro, L

    2002-07-01

    The devices of air cleaning against particles are widely spread in various branches of industry: nuclear, motor, food, electronic,...; among these devices, numerous are constituted by pleated porous media to increase the surface of filtration and thus to reduce the pressure drop, for given air flow. The objective of our work is to compensate a lack evident of knowledge on the evolution of the pressure drop of pleated filter during the clogging and to deduct a modelling from it, on the basis of experiments concerning industrial filters of nuclear and car types. The obtained model is a function of characteristics of the filtering medium and pleats, of the characteristics of solid particles deposited on the filter, of the mass of particles and of the aeraulic conditions of air flow. It also depends on data on the clogging of flat filters of equivalent medium. To elaborate this model of pressure drop, an initial stage was carried out in order to characterize, experimentally and numerically, the pressure drop and the distribution of air flow in clean pleated filters of nuclear (high efficiency particulate air filter, in fiberglasses) and car (mean efficiency filter, in fibers of cellulose) types. The numerical model allowed to understand the fundamental role played by the aeraulic resistance of the filtering medium. From an non-dimensional approach, we established a semi-empirical model of pressure drop for a clean pleated filter valid for both studied types of medium; this model is used of first base for the development of the final model of clogging. The study of the clogging of the filters showed the complexity of the phenomenon dependent mainly on a reduction of the surface of filtration. This observation brings us to propose a clogging of pleated filters in three phases. Both first phases are similar in those observed for flat filters, while last phase corresponds to a reduction of the surface of filtration and leads a strong increase of the filter pressure drop

  10. Surface tension of Nanofluid-type fuels containing suspended nanomaterials.

    Science.gov (United States)

    Tanvir, Saad; Qiao, Li

    2012-04-18

    The surface tension of ethanol and n-decane based nanofluid fuels containing suspended aluminum (Al), aluminum oxide (Al2O3), and boron (B) nanoparticles as well as dispersible multi-wall carbon nanotubes (MWCNTs) were measured using the pendant drop method by solving the Young-Laplace equation. The effects of nanoparticle concentration, size and the presence of a dispersing agent (surfactant) on surface tension were determined. The results show that surface tension increases both with particle concentration (above a critical concentration) and particle size for all cases. This is because the Van der Waals force between particles at the liquid/gas interface increases surface free energy and thus increases surface tension. At low particle concentrations, however, addition of particles has little influence on surface tension because of the large distance between particles. An exception is when a surfactant was used or when (MWCNTs) was involved. For such cases, the surface tension decreases compared to the pure base fluid. The hypothesis is the polymer groups attached to (MWCNTs) and the surfactant layer between a particle and the surround fluid increases the electrostatic force between particles and thus reduce surface energy and surface tension.

  11. Surface tension of Nanofluid-type fuels containing suspended nanomaterials

    Science.gov (United States)

    2012-01-01

    The surface tension of ethanol and n-decane based nanofluid fuels containing suspended aluminum (Al), aluminum oxide (Al2O3), and boron (B) nanoparticles as well as dispersible multi-wall carbon nanotubes (MWCNTs) were measured using the pendant drop method by solving the Young-Laplace equation. The effects of nanoparticle concentration, size and the presence of a dispersing agent (surfactant) on surface tension were determined. The results show that surface tension increases both with particle concentration (above a critical concentration) and particle size for all cases. This is because the Van der Waals force between particles at the liquid/gas interface increases surface free energy and thus increases surface tension. At low particle concentrations, however, addition of particles has little influence on surface tension because of the large distance between particles. An exception is when a surfactant was used or when (MWCNTs) was involved. For such cases, the surface tension decreases compared to the pure base fluid. The hypothesis is the polymer groups attached to (MWCNTs) and the surfactant layer between a particle and the surround fluid increases the electrostatic force between particles and thus reduce surface energy and surface tension. PMID:22513039

  12. Detection of nano- and micro-sized particles in routine biopsy material - pilot study.

    Science.gov (United States)

    Dvorackova, Jana; Bielnikova, Hana; Kukutschova, Jana; Peikertova, Pavlina; Filip, Peter; Zelenik, Karol; Kominek, Pavel; Uvirova, Magdalena; Pradna, Jana; Cermakova, Zuzana; Dvoracek, Igor

    2015-03-01

    Nanotechnology is receiving enormous funding. Very little however is known about the health dangers of this technology so far. Chronic tonsillitis is one of a number of diseases called idiopathic. Among other factors, the tonsils are exposed to suspended particles in inhaled air including nano particles. The objective of this study was to detect and evaluate metallic particles in human tonsil tissue diagnosed with chronic tonsillitis and in amniotic fluid as a comparison. . Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) was used for identification of solid particles in a total of 64 samples of routinely analyzed biopsy and cytologic material. Almost all samples were found to contain solid particles of various metals. The most frequent, regardless of diagnosis, were iron, chromium, nickel and aluminium. The size, determined using SEM, varied from around 500 nm to 25 µm. The majority formed aggregates of several micrometers in size but there were a significant number of smaller (sub-micrometer or nano-sized) particles present. The incidence of metallic particles was similar in child and adult tissues. The difference was in composition: the presence of several metals in adults was due to occupational exposure. The presence of metallic particles in pathologically altered tissues may signal an alternative causation of some diseases. The ethiopathogenic explanation of these diseases associated with the presence of nano-sized particles in the organism has emerged into a new field of pathology, nanopathology.

  13. Combined dispersive solid-phase extraction-dispersive liquid-liquid microextraction-derivatization for gas chromatography-mass spectrometric determination of aliphatic amines on atmospheric fine particles.

    Science.gov (United States)

    Majedi, Seyed Mohammad; Lee, Hian Kee

    2017-02-24

    Short-chain aliphatic amines are ubiquitous in the atmospheric environment. They play an important role in the formation and growth of atmospheric particles. As such, there is a pressing need to monitor these particle-bound compounds present at trace quantities. The present work describes an efficient, one-step microextraction technique for the preconcentration and detection of trace levels of 10 aliphatic amines on fine particles (particulate matter of 2.5μm or less (PM2.5)) in the atmosphere. After extraction of amines from particles in acidified water samples, carbon-based sorbents (in dispersive solid-phase extraction mode), and vortex agitation were utilized for simultaneous derivatization-extraction and dispersive liquid-liquid microextraction. The approach significantly increased the recoveries and enrichment of the amine derivatives. This one-step, combined technique is proposed for the first time. Several influential factors including type and concentration of derivatization reagent (for gas chromatographic separation), type of buffer, sample pH, types and volumes of extraction and disperser solvents, type and amount of sorbent, vortex time and temperature, desorption solvent type and volume, and salt content were investigated and optimized. Under the optimum conditions, high enrichment factors (in the range of between 307 and 382) and good reproducibility (relative standard deviations, below 7.0%, n=5) were achieved. The linearity ranged from 0.1μg/L-100μg/L, and from 0.5μg/L-100μg/L, depending on the analytes. The limits of detection were between 0.02μg/L (corresponding to ∼0.01ng/m(3) in air) and 0.09μg/L (corresponding to ∼0.04ng/m(3) in air). The developed method was successfully applied to the analysis of PM2.5 samples collected by air sampling through polytetrafluoroethylene filters. The concentration levels of amines ranged from 1.04 to 4.16ng/m(3) in the air sampled. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Abrasion properties of self-suspended hairy titanium dioxide nanomaterials

    Science.gov (United States)

    Zhang, Jiao-xia; Liu, Si; Yan, Chao; Wang, Xiao-jing; Wang, Lei; Yu, Ya-ming; Li, Shi-yun

    2017-10-01

    Considering the excellent solubility of pyrrolidone ring organic compounds, the synthesized N-(trimethoxysilyl) propyl-N-methyl-2-pyrrolidone chlorides was tethered onto titanium dioxide (TiO2) nanoparticles to improve dispersion of TiO2, and then polyethylene oxide (PEO) oligomer through ion exchange embraced the tethered TiO2 to obtain a novel self-suspended hairy TiO2 nanomaterials without any solvent. A variety of techniques were carried out to illustrate the structure and properties of the self-suspended hairy TiO2 nanomaterials. It was found that TiO2 nanoparticles embody monodispersity in the hybrid system though the "false reunion" phenomenon occurring due to nonpermanent weak physical cross-linking. Remarkably, self-suspended hairy TiO2 nanomaterials exhibit lower viscosity, facilitating maneuverable and outstanding antifriction and wear resistance properties, due to the synergistic lubricating effect between spontaneously forming lubricating film and nano-lubrication of TiO2 cores, overcoming the deficiency of both solid and liquid lubricants. This make them promising candidates for the micro-electromechanic/nano-electromechanic systems (MEMS/NEMS).

  15. 23 Elemental Composition of Suspended Particulate Matter ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    Elemental Composition of Suspended Particulate Matter Collected at Two Different. Heights above the Ground in A Sub-Urban Site in Kenya. Gitari W. M1, Kinyua A. M. 2, Kamau G. N3 and C. K. Gatebe C. K4. Abstract. Suspended particulate matter samples were collected in a sub-urban area in Nairobi over a 12 month ...

  16. Co-grinding significance for calcium carbonate-calcium phosphate mixed cement. Part I: effect of particle size and mixing on solid phase reactivity.

    Science.gov (United States)

    Tadier, S; Le Bolay, N; Rey, C; Combes, C

    2011-04-01

    In part I of this study we aim to evaluate and control the characteristics of the powders constituting the solid phase of a vaterite CaCO(3)-dicalcium phosphate dihydrate cement using a co-grinding process and to determine their impact on cement setting ability. An original methodology involving complementary analytical techniques was implemented to thoroughly investigate the grinding mechanism of separated or mixed reactive powders and the effects on solid phase reactivity. We showed that the association of both reactive powders during co-grinding improves the efficiency of this process in terms of the particle size decrease, thus making co-grinding adaptable to industrial development of the cement. For the first time the usefulness of horizontal attenuated total reflection Fourier transform infrared spectroscopy to follow the chemical setting reaction at 37°C in real time has been demonstrated. We point out the antagonist effects that co-grinding can have on cement setting: the setting time is halved; however, progress of the chemical reaction involving dissolution-reprecipitation is delayed by 30 min, probably due to the increased contact area between the reactive powders, limiting their hydration. More generally, we can take advantage of the co-grinding process to control powder mixing, size and reactivity and this original analytical methodology to better understand its effect on the phenomena involved during powder processing and cement setting, which is decisive for the development of multi-component cements. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Effects of continuous flow centrifugation on measurements of trace elements in river water: intrinsic contamination and particle fragmentation

    Science.gov (United States)

    Rossé, Patrick; Vignati, Davide; Dominik, Janusz

    2006-08-01

    Continuous flow centrifugation (CFC) is a well-established technique used in natural surface water studies to collect large amounts of suspended solids, thus allowing a broad spectrum of measurements. However, a potential contamination or changes in the particle size distribution during the centrifugation may restrain the use of CFC effluents for element analysis in the colloidal and dissolved fractions. In this paper we evaluate the possibility of using the effluent of a Westfalia centrifuge (type KA2-06-075, 9700 rpm) for such analysis. This evaluation is based on two laboratory experiments with deionized and tap water and two field experiments in rivers. Elemental concentration changes across the CFC were assessed from the CFC influent and effluent after a filtration at 0.45 μm. Significant increases were found, mainly in the field experiments at a high suspended solids level and a slightly acid pH. A hypothesis was made on the origin of these increases as a superposition of a centrifuge intrinsic contamination and a particle fragmentation effect. A numerical model based on elemental concentration measurements (inductively coupled plasma mass spectrometry) gave a particle fragmentation level of 0.55% (mass percentage of particles broken up into smaller fragments during centrifugation). In another experiment, a direct particle counting (single particle counter) shows an excess of particles smaller than 500 nm in the CFC effluent, corresponding to a fragmentation level of 0.11%. In consequence, the use of CFC effluent for element analysis is possible in low-turbidity river or lake waters, but should be carefully considered in waters with high suspended matter contents.

  18. Modeled summer background concentration nutrients and suspended sediment in the mid-continent (USA) great rivers

    Science.gov (United States)

    We used regression models to predict background concentration of four water quality indictors: total nitrogen (N), total phosphorus (P), chloride, and total suspended solids (TSS), in the mid-continent (USA) great rivers, the Upper Mississippi, the Lower Missouri, and the Ohio. F...

  19. Influence of near-bottom re-suspended sediment on benthic light availability

    DEFF Research Database (Denmark)

    Pedersen, Troels Møller; Gallegos, Charles L.; Nielsen, Søren Laurentius

    2012-01-01

    Increased light attenuation in the water column is a common consequence of the increased organic loading that accompanies anthropogenic eutrophication in coastal systems. Frequently, the best water quality correlate of the light attenuation coefficient is the total suspended solids, even in syste...

  20. Species sensitivity distributions for suspended clays, sediment burial and grain size change in the marine environment

    NARCIS (Netherlands)

    Smit, M.G.D.; Holthaus, K.I.E.; Trannum, H.C.; Neff, J.M.; Kjeilen-Eilertsen, G.; Jak, R.G.; Singsaas, I.; Huijbregts, M.A.J.; Hendriks, A.J.

    2008-01-01

    Assessment of the environmental risk of discharges, containing both chemicals and suspended solids (e.g., drilling discharges to the marine environment), requires an evaluation of the effects of both toxic and nontoxic pollutants. To date, a structured evaluation scheme that can be used for

  1. Pulse Jet Mixing Tests With Noncohesive Solids

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro; Bailey, Sharon A.; Bower, John C.; Denslow, Kayte M.; Eakin, David E.; Elmore, Monte R.; Gauglitz, Phillip A.; Guzman, Anthony D.; Hatchell, Brian K.; Hopkins, Derek F.; Hurley, David E.; Johnson, Michael D.; Kirihara, Leslie J.; Lawler, Bruce D.; Loveland, Jesse S.; Mullen, O Dennis; Pekour, Mikhail S.; Peters, Timothy J.; Robinson, Peter J.; Russcher, Michael S.; Sande, Susan; Santoso, Christian; Shoemaker, Steven V.; Silva, Steve M.; Smith, Devin E.; Su, Yin-Fong; Toth, James J.; Wiberg, John D.; Yu, Xiao-Ying; Zuljevic, Nino

    2009-05-11

    This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants. The test data were used to independently develop mixing models that can be used to predict full-scale WTP vessel performance and to rate current WTP mixing system designs against two specific performance requirements. One requirement is to ensure that all solids have been disturbed during the mixing action, which is important to release gas from the solids. The second requirement is to maintain a suspended solids concentration below 20 weight percent at the pump inlet. The models predict the height to which solids will be lifted by the PJM action, and the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate we can calculate the concentration of solids at the pump inlet. The velocity needed to lift the solids is slightly more demanding than "disturbing" the solids, and is used as a surrogate for this metric. We applied the models to assess WTP mixing vessel performance with respect to the two perform¬ance requirements. Each mixing vessel was evaluated against these two criteria for two defined waste conditions. One of the wastes was defined by design limits and one was derived from Hanford waste characterization reports. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy

  2. The Ages in a Self-Suspended Nanoparticle Liquid

    KAUST Repository

    Agarwal, Praveen

    2010-01-13

    Telomers ionically tethered to nanometer-sized particles yield self-suspended, nanoparticle-Iaden liquids with unusual dynamical features. By subjecting these suspensions to controlled, modest shear strains, we find that their flow behaviors observed using experiments performed on time scales of tens of seconds can be projected to obtain maps of their dynamical response on geological time scales. That such extraordinarily slow dynamic processes can be uncovered from real-time measurements by simply stretching a system provides a simple but powerful tool for interrogating extremely slow motions in other jammed physical states. © 2010 American Chemical Society.

  3. Mucous Secretion and Cilia Beating Defend Developing Coral Larvae from Suspended Sediments.

    Directory of Open Access Journals (Sweden)

    Gerard F Ricardo

    Full Text Available Suspended sediments produced from dredging activities, or added to the sediment budget via river runoff, are a concern for marine resource managers. Understanding the impact of suspended sediments on critical life history stages of keystone species like corals is fundamental to effective management of coastlines and reefs. Coral embryos (Acropora tenuis and A. millepora and larvae (A. tenuis, A. millepora and Pocillopora acuta were subjected to a range of suspended sediment concentrations of different sediment types (siliciclastic and carbonate to assess concentration-response relationships on ecologically relevant endpoints, including survivorship and ability to metamorphose. Embryos were subjected to short (12 h suspended sediment exposures from ages of 3-12 hours old or a long (30 h exposure at 6 hours old. Neither the survivorship nor metamorphosis function of embryos were significantly affected by realistic sediment exposures to ~1000 mg L-1. However, some embryos exhibited a previously undescribed response to dynamically suspended sediments, which saw 10% of the embryos form negatively buoyant cocoons at siliciclastic suspended sediment concentrations ≥35 mg L-1. Scanning electron and optical microscopy confirmed the presence of a coating on these embryos, possibly mucus with incorporated sediment particles. Cocoon formation was common in embryos but not in larvae, and occurred more often after exposure to siliciclastic rather than carbonate sediments. Once transferred into sediment-free seawater, functional ~36-h-old embryos began emerging from the cocoons, coinciding with cilia development. Ciliated (> 36-h-old larvae exposed to suspended sediments for 60 h were also observed to secrete mucus and were similarly unaffected by suspended sediment concentrations to ~800 mg L-1. This study provides evidence that mucous secretion and cilia beating effectively protect coral embryos and larvae from suspended sediment and that these mechanisms

  4. Heavy metal ions adsorption by suspended particle and sediment of ...

    African Journals Online (AJOL)

    GREGORY

    2012-01-10

    Jan 10, 2012 ... samples in the laboratory, standard metals including Pb, Cu, Zn and Fe (15, 5, 5, and 5 mg/l, respectively) and sediments from the three stations, both arranged in the .... process, lead is separated from gold, silver, zinc and iron but much lead is deposited in waste. Figure 1 shows the situation of the Sorb ...

  5. Suspended particle transport through constriction channel with Brownian motion

    DEFF Research Database (Denmark)

    Hanasaki, Itsuo; Walther, Jens Honore

    2017-01-01

    It is well known that translocation events of a polymer or rod through pores or narrower parts of micro- and nanochannels have a stochastic nature due to the Brownian motion. However, it is not clear whether the objects of interest need to have a larger size than the entrance to exhibit the devia...

  6. Heavy metal ions adsorption by suspended particle and sediment of ...

    African Journals Online (AJOL)

    Nowadays, it is important to evaluate the self-purifying capacity of rivers because of the different kinds of pollutants discharged into them. Important kind of pollutants and heavy metals exist in wastewaters industries. When the Sorb Dona mine is placed in Upper Chalus River, in the west of Mazandaran, products of mine ...

  7. Oral Delivery of Bovine Lactoferrin Using Pectin- and Chitosan-Modified Liposomes and Solid Lipid Particles: Improvement of Stability of Lactoferrin.

    Science.gov (United States)

    Yao, Xudong; Bunt, Craig; Cornish, Jillian; Quek, Siew-Young; Wen, Jingyuan

    2015-10-01

    A critical problem associated with delivery of bovine lactoferrin (bLf) by the oral route is low bioavailability, which is derived from the enzymatic degradation in the gastrointestinal tract and poor permeation across the intestinal epitheliums. Particulate carrier systems have been identified to protect bLf against proteolysis via encapsulation. This study aimed to evaluate the physico-chemical stability of bLf-loaded liposomes and solid lipid particles (SLPs) modified by pectin and chitosan when exposed to various stress conditions. Transmission electron microscopy results showed liposomes and SLPs had a classic shell-core structure with polymer layers surrounded on surface, but the structure appeared to be partially broken after digestion in simulated intestinal fluid (SIF). Although HPLC and sodium dodecyl sulphate-polyacrylamide gel electrophoresis methods qualitatively and quantitatively described either liposomes or SLPs could retain intact bLf against proteolysis in SIF to some extent, all liposome formulations showed rapid rate of lipolysis mediated by pancreatic enzymes. On the other hand, all SLP formulations showed higher heat resistance and greater electrolyte tolerance compared to liposome formulations. After 180 days storage time, liposome-loaded bLf was completely degraded, whereas almost 30% of intact bLf still remained in SLP formulations. Overall, SLPs are considered as primary choice for oral bLf delivery. © 2015 John Wiley & Sons A/S.

  8. Effect of particle presence on the incompressible inviscid flow through a two dimensional compressor cascade

    Science.gov (United States)

    Balan, C.; Tabakoff, W.

    1983-01-01

    A computational model is developed for calculating the flow field, in the presence of solid particles, through a two-dimensional compressor cascade. Results show that the effect of solid particles on the flow field contributes to the bending of the streamlines toward the blade suction surface. It is determined that the difference in the pressure coefficient for particulate flow, with 165 micron diameter for the particles, is of the order of 3 percent over the air only flow. The change in the pressure coefficients is shown to be much larger for very small particles. It was found that the total pressure loss associated with the particulate flow is very high for very small particles as compared with large particles. The total pressure loss is also shown to be higher for accelerating flow than for decelerating flow. The total pressure loss is shown to be directly proportional to the particle concentration. It is concluded that significant reductions in performance can occur in a real multistage machine due to the changes in the pressure ratios, particularly if the suspended matter is small particles.

  9. Technological advances in suspended-sediment surrogate monitoring

    Science.gov (United States)

    Gray, John R.; Gartner, Jeffrey W.

    2009-01-01

    Surrogate technologies to continuously monitor suspended sediment show promise toward supplanting traditional data collection methods requiring routine collection and analysis of water samples. Commercially available instruments operating on bulk optic (turbidity), laser optic, pressure difference, and acoustic backscatter principles are evaluated based on cost, reliability, robustness, accuracy, sample volume, susceptibility to biological fouling, and suitable range of mass concentration and particle size distribution. In situ turbidimeters are widely used. They provide reliable data where the point measurements can be reliably correlated to the river's mean cross section concentration value, effects of biological fouling can be minimized, and concentrations remain below the sensor's upper measurement limit. In situ laser diffraction instruments have similar limitations and can cost 6 times the approximate $5000 purchase price of a turbidimeter. However, laser diffraction instruments provide volumetric-concentration data in 32 size classes. Pressure differential instruments measure mass density in a water column, thus integrating substantially more streamflow than a point measurement. They are designed for monitoring medium-to-large concentrations, are generally unaffected by biological fouling, and cost about the same as a turbidimeter. However, their performance has been marginal in field applications. Acoustic Doppler profilers use acoustic backscatter to measure suspended sediment concentrations in orders of magnitude more streamflow than do instruments that rely on point measurements. The technology is relatively robust and generally immune to effects of biological fouling. Cost of a single-frequency device is about double that of a turbidimeter. Multifrequency arrays also provide the potential to resolve concentrations by clay silt versus sand size fractions. Multifrequency hydroacoustics shows the most promise for revolutionizing collection of continuous

  10. Net transport of suspended matter due to tidal straining

    Science.gov (United States)

    Jones, S. E.; Jago, C. F.; Simpson, J. H.; Rippeth, T. P.

    2003-04-01

    Net transport of suspended particulate matter (SPM) is well-known in tidal regions where there is time-velocity asymmetry due to frictional modification of the tide in shallow water. We present here observations which show a new mechanism for net flux of SPM in response to tidal straining in a region of freshwater influence (ROFI). In situ measurements of the particle size of suspended particulate matter (SPM) and turbulent energy dissipation have been made at a site in Liverpool Bay (Irish Sea) where there is significant resuspension of particles from the muddy sand substrate during spring tides. This is a ROFI where tidal straining dominates the temporal development of turbulence. On a spring tide the water column tries to stratify on the ebb and destratify on the flood, but these tendencies are masked by mixing due to tidal stirring. Nevertheless, there is a marked excess of TKE dissipation rate E on the flood, especially in the upper part of the water column. Resuspension occurs on both flood and ebb, but SPM flux is strongly asymmetric with a net shorewards component. Asymmetry is most pronounced for the larger particles which comprise most of the mass. Enhanced ? on the flood mixes large particles upwards into faster flowing water, which increases the flux. Comparable upwards mixing of large particles does not occur on the ebb where enhanced E is confined to slower bottom waters. The net flux is not seen on neap tides because, although there is more stratification due to tidal straining, there is essentially no resuspension. The net flux on springs is undoubtedly an important component of SPM transport (and any comparable particulates) in coastal regions.

  11. Magnetically suspended virtual divergent channel

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Ryuichiro [Kokushikan University, 4-28-1 Setagaya, Setagaya-ku, Tokyo 154-8515 (Japan)]. E-mail: yamane@kokushikan.ac.jp; Oshiama, Shuzo [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Park, Myeong-Kwan [Pusan National University, 30 Changjeon-dong, Kumjeong-ku, Pusan 609-735 (Korea, Republic of)

    2005-03-15

    Two permanent magnets are set face-to-face and inclined with each other to produce the long cuspidal magnetic field. The diamagnetic liquid is levitated and flows through it without contact with the solid walls as if it is in the virtual divergent channel. Analysis is made on the shape of the virtual channel, and the results are compared with the experimental ones. The divergence angle increases with the increase in the inclination of the magnets.

  12. Formation of fine particles in co-combustion of coal and solid recovered fuel in a pulverized coal-fired power station

    DEFF Research Database (Denmark)

    Wu, Hao; Pedersen, Anne Juul; Glarborg, Peter

    2011-01-01

    appear to be an important formation mechanism. The elemental composition of the particles from coal combustion showed that S and Ca were significantly enriched in ultrafine particles and P was also enriched considerably. However, compared with supermicron particles, the contents of Al, Si and K were...... showed an ultrafine mode centered at approximately 0.1 μm. Compared with coal combustion, co-combustion of coal and SRF increased the formation of submicron particles, especially ultrafine particles below 0.2 μm. The morphology of the particles indicated that supermicron particles were primarily formed...

  13. Basic hydraulic experiment on the saturated concentration of suspended load due to tsunamis

    Science.gov (United States)

    Takahashi, Tomoyuki; Somekawa, Shiho

    2016-04-01

    When tsunamis arrive in the shallow sea, a huge amount of suspended load is generated by large velocity and strong turbulence. The suspended load causes the geomorphic processes of erosion and deposition. Because the suspended load cannot be increased endlessly, it should have the saturated concentration. Many numerical models of sediment transport due to tsunamis have assumed a constant value of 1% for the saturated concentration empirically. However, it is supposed as a function of velocity. In this study, a hydraulic experiment was carried out to investigate a relationship between velocity and the saturated concentration of suspended load when tsunamis attack. A water circulation pipe used in the experiment was 10 cm in a diameter, 260 cm in length and 50 cm in width. A velocity of water flow in the pipe had been controlled by two pumps and two valves. It was changed from 0.24 to 1.22 m/s. Various amounts of sand was spread on the bottom of pipe. The amount of sand was changed from 0.1 to 10% as converted in the concentration of suspended load if all sand suspended. A diameter and a density of the sand were 0.267 mm and 2.64 x 103 kg/m^3. A condition of sediment transport in the pipe was recorded by video camera from a transparent window at the side of pipe. The condition was judged as all sand particles were suspended or not. The former condition indicates that the concentration of suspended load is saturated and the latter does it is not saturated. When velocity was smaller than 0.47 m/s, there was no suspended load because of a weak tractive force. When velocity became larger, the suspended load was generated and the concentration also became higher. However, the concentration had the upper limit and surplus sand appeared on the bed of pipe when velocity became much larger. The condition gave the saturated concentration of suspended load. When velocity was 0.665 m/s, the saturated concentration was smaller than 1% which is used in many numerical simulations

  14. Numerical Modelling of Suspended Transport and Deposition of Highway Deposited Sediments

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Bach, Christine

    Good data for calibration and validation of numerical models are of high importance. In the natural environment data can be hard to archive and the stochastic nature have governing influence on the data archived. Hence for modelling of suspended transport and deposition of particles, originating...

  15. Observations of suspended sediment from ADCP and OBS measurements in a mud-dominated environment

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Hoekstra, P.

    2005-01-01

    The ability of a 1.2-MHz Acoustic Doppler Current Profiler (ADCP) to measure suspended sediment concentration (SSC) and particle size variation in a mud-dominated environment has been investigated. Experiments were conducted in the Bay of Banten, Indonesia, where clays and silts in the range of 3-55

  16. Remote Laser Diffraction Particle Size Distribution Analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Batcheller, Thomas Aquinas; Huestis, Gary Michael; Bolton, Steven Michael

    2001-03-01

    In support of a radioactive slurry sampling and physical characterization task, an “off-the-shelf” laser diffraction (classical light scattering) particle size analyzer was utilized for remote particle size distribution (PSD) analysis. Spent nuclear fuel was previously reprocessed at the Idaho Nuclear Technology and Engineering Center (INTEC—formerly recognized as the Idaho Chemical Processing Plant) which is on DOE’s INEEL site. The acidic, radioactive aqueous raffinate streams from these processes were transferred to 300,000 gallon stainless steel storage vessels located in the INTEC Tank Farm area. Due to the transfer piping configuration in these vessels, complete removal of the liquid can not be achieved. Consequently, a “heel” slurry remains at the bottom of an “emptied” vessel. Particle size distribution characterization of the settled solids in this remaining heel slurry, as well as suspended solids in the tank liquid, is the goal of this remote PSD analyzer task. A Horiba Instruments Inc. Model LA-300 PSD analyzer, which has a 0.1 to 600 micron measurement range, was modified for remote application in a “hot cell” (gamma radiation) environment. This technology provides rapid and simple PSD analysis, especially down in the fine and microscopic particle size regime. Particle size analysis of these radioactive slurries down in this smaller range was not previously achievable—making this technology far superior than the traditional methods used. Successful acquisition of this data, in conjunction with other characterization analyses, provides important information that can be used in the myriad of potential radioactive waste management alternatives.

  17. Large-eddy simulation and Lagrangian stochastic modelling of solid particle and droplet dispersion and mixing. Application to atmospheric pollution; Dispersion et melange turbulents de particules solides et de gouttelettes par une simulation des grandes echelles et une modelisation stochastique lagrangienne. Application a la pollution de l'atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Vinkovic, I.

    2005-07-15

    In order to study atmospheric pollution and the dispersion of industrial stack emissions, a large eddy simulation with the dynamic Smagorinsky-Germano sub-grid-scale model is coupled with Lagrangian tracking of fluid particles containing scalar, solid particles and droplets. The movement of fluid particles at a sub-grid level is given by a three-dimensional Langevin model. The stochastic model is written in terms of sub-grid-scale statistics at a mesh level. By introducing a diffusion model, the coupling between the large-eddy simulation and the modified three-dimensional Langevin model is applied to passive scalar dispersion. The results are validated by comparison with the wind-tunnel experiments of Fackrell and Robins (1982). The equation of motion of a small rigid sphere in a turbulent flow is introduced. Solid particles and droplets are tracked in a Lagrangian way. The velocity of solid particles and droplets is considered to have a large scale component (directly computed by the large-eddy simulation) and a sub-grid scale part. Because of inertia and gravity effects, solid particles and droplets, deviate from the trajectories of the surrounding fluid particles. Therefore, a modified Lagrangian correlation timescale is introduced into the Langevin model previously developed for the sub-grid velocity of fluid particles. Two-way coupling and collisions are taken into account. The results of the large-eddy simulation with solid particles are compared with the wind-tunnel experiments of Nalpanis et al. (1993) and of Taniere et al. (1997) on sand particles in saltation and in modified saltation, respectively. A model for droplet coalescence and breakup is implemented which allows to predict droplet interactions under turbulent flow conditions in the frame of the Euler/Lagrange approach. Coalescence and breakup are considered as a stochastic process with simple scaling symmetry assumption for the droplet radius, initially proposed by Kolmogorov (1941). At high

  18. Solid-solid contacts due to surface roughness and their effects on suspension behaviour.

    Science.gov (United States)

    Davis, Robert H; Zhao, Yu; Galvin, Kevin P; Wilson, Helen J

    2003-05-15

    Solid-solid contacts due to microscopic surface roughness in viscous fluids were examined by observing the translational and rotational behaviours of a suspended sphere falling past a lighter sphere or down an inclined surface. In both cases, a roll-slip behaviour was observed, with the gravitational forces balanced by not only hydrodynamic forces but also normal and tangential solid-solid contact forces. Moreover, the nominal separation between the surfaces due to microscopic surface roughness elements is not constant but instead varies due to multiple roughness scales. By inverting the system, so that the heavy sphere fell away from the lighter sphere or the plane, it was found that the average nominal separation increases with increasing angle of inclination of the plane or the surface of the lighter sphere from horizontal; the larger asperities lift the sphere up from the opposing surface and then gravity at large angles of inclination is too weak to pull the sphere back down to the opposing surface before another large asperity is encountered. The existence of microscopic surface roughness and solid-solid contacts is shown to modify the rheological properties of suspensions. For example, the presence of compressive, but not tensile, contact forces removes the reversibility of sphere-sphere interactions and breaks the symmetry of the particle trajectories. As a result, suspensions of rough spheres exhibit normal stress differences that are absent for smooth spheres. For the conditions studied, surface roughness reduces the effective viscosity of a suspension by limiting the lubrication resistance during near-contact motion, and it also modifies the suspension microstructure and hydrodynamic diffusivity.

  19. Carrier particle design for stabilization and isolation of drug nanoparticles.

    Science.gov (United States)

    Tierney, Teresa; Bodnár, Katalin; Rasmuson, Åke; Hudson, Sarah

    2017-02-25

    Nanoparticles of poorly water-soluble drugs were prepared in suspension via antisolvent precipitation in order to improve their dissolution behaviour. Insoluble, surface-functionalized, micron-range, clay carrier particles were employed for the dual purpose of stabilizing the nanoparticles in suspended state, and facilitating their unhindered isolation to solid state; often a challenging step in nanoparticle production. The carrier particles, which were functionalized with an optimal level of cationic polymer (protamine), attracted negatively-charged nanoparticles to their surface as a uniform and segregated nanoparticle layer, at drug loadings up to 9% w/w. By using carrier particles to stabilise the nanoparticles on their surface, the traditionally used solubilised nanosuspension stabilisers could be eliminated, thus avoiding time-consuming stabiliser screening tests. The carrier particle system facilitated stabilisation of nanoparticles in suspension, isolation of nanoparticles to the solid state via filtration, and preservation of fast nanoparticle-induced dissolution rates of the dried nanoparticle-carrier composites, indicating preservation of their high surface area during drying. The process was validated with two poorly water-soluble BCS Class II drugs, fenofibrate and mefenamic acid, both of which demonstrated negative surface charge in aqueous suspension. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Analysis of the Reduction Rate of Hematite Concentrate Particles in the Solid State by H2 or CO in a Drop-Tube Reactor Through CFD Modeling

    Science.gov (United States)

    Fan, De-Qiu; Sohn, H. Y.; Elzohiery, Mohamed

    2017-10-01

    The kinetic analysis of the reduction of hematite concentrate particles by individual reducing gas H2 or CO was performed using a computational fluid dynamics (CFD)-based approach in this paper. The particle residence time was calculated through the integration of the equation of particle motion. Non-uniform particle temperature profiles inside the reactor were obtained, and were taken into consideration for the kinetic analysis. The calculated reduction degrees based on this approach are in good agreement with the experimental values.

  1. Continuous-flow centrifugation to collect suspended sediment for chemical analysis

    Science.gov (United States)

    Conn, Kathleen E.; Dinicola, Richard S.; Black, Robert W.; Cox, Stephen E.; Sheibley, Richard W.; Foreman, James R.; Senter, Craig A.; Peterson, Norman T.

    2016-12-22

    polychlorinated biphenyls. The particle-size distribution of the captured sediment changes to a more fine-grained sample during centrifugation, and the necessity to account for this change when extrapolating chemical concentrations on the centrifuged sediment sample to the environmental water system is discussed.The data produced using this method will help eliminate a data gap of suspended sediment-bound chemical concentrations, and will support management decisions, such as chemical source-control efforts or in-stream restoration activities. When coupled with streamflow and sediment flux data, it will improve estimates of riverine chemical fluxes, and will aid in assessing the importance and impacts of suspended sediment-bound chemicals to downstream freshwater and coastal marine ecosystems.

  2. Gas-solid turbulent flow in a circulating fluidized bed riser: experimental and numerical study of mono-disperse particle systems

    NARCIS (Netherlands)

    He, Y.; Deen, N.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2009-01-01

    Numerical simulations were performed of a turbulent gas-particle multiphase flow in a circulating fluidized bed riser using a hard-sphere discrete particle model (DPM) for the particle phase and the Navier−Stokes equations for the gas phase, where the subgrid scale stresses (SGS) were modeled with

  3. Controls on suspended aggregate size in partially mixed estuaries

    Science.gov (United States)

    Fugate, David C.; Friedrichs, Carl T.

    2003-10-01

    Knowledge of aggregate size in estuaries is important to determining the fate and transport of suspended sediment and particle adherent contaminants. We have used a suite of in situ instruments to determine the controls of aggregate size distributions in three muddy, partially mixed estuaries in the mid-Atlantic USA. A novel method is presented to estimate turbulent kinetic energy (TKE) production and the resulting Kolmogorov microscale ( λK) using a profiling acoustic Doppler velocimeter that has been contaminated by boat motion. The physical processes that control particle size distribution differ in the three estuaries due to the different hydrodynamics and benthic characteristics. Controls within each estuary also vary with different depth regimes. Surface particle size dynamics in all the studied estuaries are affected by irregular advection events. In the hydrodynamically energetic York River, mid-depth regions are controlled tidally by the combined processes of small λK decreasing particle size at high TKE and differential settling increasing particle size during lower TKE, more stratified conditions. Mid-depth regions in the lower energy Elizabeth River are controlled by irregular resuspension and trapping at the pycnocline of large low density particles. Bottom regions in all estuaries are most strongly influenced by resuspension, tidally in the energetic estuaries and irregularly in the low energy estuary. Near-bed particle size distributions are controlled by both λK and the distribution of particles in the bed in the higher energy estuaries. Just above the bed, large porous particles survive resuspension in the lower energy Elizabeth River, particles become smaller with decreased λK in the more energetic York River, and biological aggregation causes large dense particles to resist turbulent breakup in the Chesapeake Bay, which has a more active benthic community. The net result just above the bed is that particle size and settling velocity are

  4. Stormwater solids removal characteristics of a catch basin insert using geotextile.

    Science.gov (United States)

    Alam, Md Zahanggir; Anwar, A H M Faisal; Heitz, Anna

    2018-03-15

    Suspended solids in urban runoff have multiple adverse environmental impacts and create a wide range of water quality problems in receiving water bodies. Geotextile filtration systems inserted within catch basins have the potential to mitigate these effects, through flow attenuation and pollutant removal. This study modelled a catch basin in a column and assessed the hydraulic and solids removal characteristics of a new type of non-woven geotextile (NWG1) in the capture of solids from stormwater runoff. The new geotextile was compared with two others readily available on the market (NWG2, NWG3). Synthetic stormwater containing TSS (200mg/L) was used with two particle size distributions of 0-180μm (P1; D50:106μm) and 0-300μm (P2; D50:150μm). The results revealed that the desired stormwater TSS concentration (<30mg/L; ANZECC, 2000) could be achieved with a short ripening process (e.g., 1-2kg/m2 of suspended solids loading) for trials using the larger particle size distribution (P2). In addition, 36% more suspended solids were captured in trials using the soil with the larger range of particle sizes (P2) than for the soil with smaller particle sizes (P1). Geotextile fibre pattern appeared to have a significant influence on the TSS removal capacity. The NWG1 has higher permittivity than NWG3 but similar to NWG2. NWG1 could capture overall more TSS (which also resulted in earlier clogging) than NWG2 and NWG3 because of the special fibre structure of NWG1. The experimental data shows that these geotextiles may start to clog when the hydraulic conductivity reaches below 1.36×10-5m/s. The overall hydraulic performances of geotextiles showed that the NWG1 has better potential for use in CBIs because of its higher strength and multiple reuse capability. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Natural radionuclides in the environment. A contribution for the localization and characterization of natural hot particles in solid samples; Natuerliche Radionuklide in der Umwelt. Ein Beitrag zur Lokalisierung und Charakterisierung natuerlicher Heisser Teilchen in festen Proben

    Energy Technology Data Exchange (ETDEWEB)

    Boehnke, A.

    2006-07-01

    In the present thesis appearance, spreading, origin, and mineralogical properties of natural hot particles are studied and the radioecological relevance of these particles judged. For this first relevent quaestions on radioactivity in the environment and on hot particles are theoretically treated. In the following detailedly the method of the autoradiography and solid-state track detectors is considered, which make possible to quote the precise position, the number and distribution of radioactive particles on the cutting area or surface of a sample. Basing on these methodical considerations by laboratory experiments determined track pattern formations of alpha emitters are documentated and interpreted. Starting from the knowledge obtained from this in the further part of the thesis a detection technique is developed, by means of which it is possible, to determine and mark the position of natural hot particles in sold samples. Thereafter follows a description of the electron-microscopical studies for the identification of the localized natural hot particles. Using the developed detection technique, as well as the electron-microscopical methods, a broad spectrum of samples - anthropogeneous depositions (industrial residues, industry products, by-products) and natural depositions (rocks, sediments, minerals) - is studied.

  6. Self-suspended permanent magnetic FePt ferrofluids

    KAUST Repository

    Dallas, Panagiotis

    2013-10-01

    We present the synthesis and characterization of a new class of self-suspended ferrofluids that exhibit remanent magnetization at room temperature. Our system relies on the chemisorption of a thiol-terminated ionic liquid with very low melting point on the surface of L10 FePt nanoparticles. In contrast, all types of ferrofluids previously reported employ either volatile solvents as the suspending media or superparamagnetic iron oxide nanoparticles (that lacks permanent magnetization) as the inorganic component. The ferrofluids do not show any sign of flocculation or phase separation, despite the strong interactions between the magnetic nanoparticles due to the strong chemisorption of the ionic liquid as evidenced by Raman spectroscopy and thermal analysis. Composites with high FePt loading (40 and 70. wt%) exhibit a pseudo solid-like rheological behavior and high remanent magnetization values (10.1 and 12.8. emu/g respectively). At lower FePt loading (12. wt%) a liquid like behavior is observed and the remanent and saturation magnetization values are 3.5 and 6.2. emu/g, respectively. The magnetic and flow properties of the materials can be easily fine tuned by controlling the type and amount of FePt nanoparticles used. © 2013 Elsevier Inc.

  7. Estuarine Suspended Sediment Dynamics: Observations Derived from over a Decade of Satellite Data

    Directory of Open Access Journals (Sweden)

    Anthony Reisinger

    2017-12-01

    Full Text Available Suspended sediment dynamics of Corpus Christi Bay, Texas, USA, a shallow-water wind-driven estuary, were investigated by combining field and satellite measurements of total suspended solids (TSS. An algorithm was developed to transform 500-m Moderate Resolution Imaging Spectroradiometer (MODIS Aqua satellite reflectance data into estimated TSS values. The algorithm was developed using a reflectance ratio regression of MODIS Band 1 (red and Band 3 (green with TSS measurements (n = 54 collected by the Texas Commission on Environmental Quality for Corpus Christi Bay and other Texas estuaries. The algorithm was validated by independently collected TSS measurements during the period of 2011–2014 with an uncertainty estimate of 13%. The algorithm was applied to the period of 2002–2014 to create a synoptic time series of TSS for Corpus Christi Bay. Potential drivers of long-term variability in suspended sediment were investigated. Median and IQR composites of suspended sediments were generated for seasonal wind regimes. From this analysis it was determined that long-term, spatial patterns of suspended sediment in the estuary are related to wind-wave resuspension during the predominant northerly and prevalent southeasterly seasonal wind regimes. The impact of dredging is also apparent in long-term patterns of Corpus Christi Bay as concentrations of suspended sediments over dredge spoil disposal sites are higher and more variable than surrounding areas, which is most likely due to their less consolidated sediments and shallower depths requiring less wave energy for sediment resuspension. This study highlights the advantage of how long-synoptic time series of TSS can be used to elucidate the major drivers of suspended sediments in estuaries.

  8. The effects of colloidal SiO2 and inhibitor on the solid deposit formation in geothermal water of low hardness

    Directory of Open Access Journals (Sweden)

    Stanković Novica J.

    2011-01-01

    Full Text Available Low solubility of SiO2 and its occurrence in geothermal waters in the form of ionic, colloidal and suspended state are the main cause of the solid deposit occurrence. Certain chemical types of silica, under the influence of Fe2+, Al3+, F−, OH- ions and other micro-constituents, and due to significantly decreased solubility of SiO2, stimulate nucleation, particle growth and solid deposit formation. The aim of this paper is to inhibit the process of nucleation and solid deposit formation by adding originally designed inhibitor in the form of an emulsion, when the total concentration of the present and added colloidal SiO2 is beyond the solubility limit (120 mg/dm3. By turbidimetric, SEM, EDS and XRD analysis, the processes of solid deposit formation were investigated in Vranjska Banja (Serbia spa geothermal water source (water hardness of 4ºdH, and theoretical and practical conclusions were made.

  9. Physical theory for near-bed turbulent particle suspension capacity

    Science.gov (United States)

    Eggenhuisen, Joris T.; Cartigny, Matthieu J. B.; de Leeuw, Jan