National Library of Energy BETA

Sample records for droplet size distribution

  1. ENTRAINMENT AND MIXING AND THEIR EFFECTS ON CLOUD DROPLET SIZE DISTRIBUTIONS OF THE STRATOCUMULUS CLOUDS OBSERVED

    E-Print Network [OSTI]

    ENTRAINMENT AND MIXING AND THEIR EFFECTS ON CLOUD DROPLET SIZE DISTRIBUTIONS OF THE STRATOCUMULUS clouds due to entrainment and mixing of the clear air, which then affect the cloud droplet size distribution. How the entrained clear air mixes with cloudy air has been of great interest for the last several

  2. The effect of turbulence on the stability of liquid jets and the resulting droplet size distributions. Third quarterly technical report, July 1, 1993--September 30, 1993

    SciTech Connect (OSTI)

    Mansour, A.; Chigier, N.

    1993-12-01

    Laminar and turbulent columns of liquids issuing from capillary tubes were studied in order to determine the effects of turbulence on the stability of liquid jets and to establish the influence of liquid turbulence on droplet size distributions after breakup. Two capillary tubes were chosen with diameters D{sub 1}=3.0mm and D{sub 2}=1.2mm; jet Reynolds numbers were 1000--30000, and 400--7200. For water injection into stagnant air, stability curve is bounded by a laminar portion, where a jet radius and {delta}{sub o} initial disturbance amplitude, and a fully developed turbulent portion characterized by high initial disturbance amplitude (ln(a/{delta}{sub o,T}) {approximately} 4.85). In the transition region, ln(a/{delta}{sub o}) is not single valued; it decreases with increasing Reynolds number. In absence of aerodynamic effects, turbulent jets are as stable as laminar jets. For this breakup mode turbulence propagates initial disturbances with amplitudes orders of magnitude larger than laminar jets ({delta}{sub o,T}=28{times}10{sup 6} {delta}{sub o,L}). Growth rates of initial disturbances are same for both laminar and turbulent columns with theoretical Weber values. Droplet size distribution is bi-modal; the number ratio of large (> D/2), to small (< D/2) droplets is 3 and independent of Reynolds number. For laminar flow optimum wavelength ({lambda}{sub opt}) corresponding to fastest growing disturbance is equal to 4.45D, exactly the theoretical Weber value. For turbulent flow conditions, the turbulent column segments. Typically, segments with lengths of one to several wavelengths, detach from the liquid jet. The long ligaments contract under the action of surface tension, resulting in droplet sizes larger than predicted by Rayleigh and Weber. For turbulent flow conditions, {lambda}{sub opt} = 9.2D, about 2 times the optimum Weber wavelength.

  3. ARM - Measurement - Cloud droplet size

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  4. Inhomogeneous distribution of droplets in cloud turbulence

    E-Print Network [OSTI]

    Itzhak Fouxon; Yongnam Park; Roei Harduf; Changhoon Lee

    2014-10-30

    We solve the problem of spatial distribution of inertial particles that sediment in turbulent flow with small ratio of acceleration of fluid particles to acceleration of gravity $g$. The particles are driven by linear drag and have arbitrary inertia. The pair-correlation function of concentration obeys a power-law in distance with negative exponent. Divergence at zero signifies singular distribution of particles in space. Independently of particle size the exponent is ratio of integral of energy spectrum of turbulence times the wavenumber to $g$ times numerical factor. We find Lyapunov exponents and confirm predictions by direct numerical simulations of Navier-Stokes turbulence. The predictions include typical case of water droplets in clouds. This significant progress in the study of turbulent transport is possible because strong gravity makes the particle's velocity at a given point unique.

  5. Continuous growth of droplet size variance due to condensation in turbulent clouds

    E-Print Network [OSTI]

    Sardina, Gaetano; Brandt, Luca; Caballero, Rodrigo

    2015-01-01

    We use a stochastic model and direct numerical simulation to study the impact of turbulence on cloud droplet growth by condensation. We show that the variance of the droplet size distribution increases in time as $t^{1/2}$, with growth rate proportional the large-to-small turbulent scale separation and to the turbulence integral scales but independent of the smallest turbulence scale. Direct numerical simulations confirm this result and produce realistically broad droplet size spectra over time intervals of 20 minutes, comparable with the time of rain formation.

  6. Effects of droplet size on intrusion of sub-surface oil spills

    E-Print Network [OSTI]

    Chan, Godine Kok Yan

    2013-01-01

    This thesis explores the effects of droplet size on droplet intrusion in sub-surface oil spills. Laboratory experiments were performed where glass beads of various sizes, which serve to simulate oil droplets in deepsea oil ...

  7. Combustion characteristics of fuel droplets with addition of nano and micron-sized aluminum particles

    E-Print Network [OSTI]

    Qiao, Li

    Combustion characteristics of fuel droplets with addition of nano and micron-sized aluminum form 27 July 2010 Accepted 3 September 2010 Keywords: High-energy-density fuels Droplet combustion n-decane-based fuels. Five distinctive stages (preheating and ignition, classical combustion

  8. The influence of droplet size on line tension

    E-Print Network [OSTI]

    Pawel Jakubczyk Marek Napiorkowski

    2004-06-21

    Within the effective interfacial Hamiltonian approach we evaluate the excess line free energy associated with cylinder-shaped droplets sessile on a stripe-like chemical inhomogeneity of a planar substrate. In the case of short-range intermolecular forces the droplet morphology and the corresponding expression for the line tension - which includes the inhomogeneity finite width effects - are derived and discussed as functions of temperature and increasing width. The width-dependent contributions to the line tension change their structure at the stripe wetting temperature T_W1: for TT_W1 the decay is algebraic. In addition, a geometric construction of the corresponding contact angle is carried out and its implications are discussed.

  9. Drop-size distribution for crosscurrent breakup of a liquid jet in a convective airstream 

    E-Print Network [OSTI]

    Lyn, Gregory Michael

    1994-01-01

    an apparatus has been designed and constructed. A laser diffraction particle analyzer technique is used to spatially measure the spray Sauter-Mean Diameters. The Rosin-Rammler two parameter model is assumed for the droplet size distribution. Injection pressure...

  10. Generalisation of Levine's prediction for the distribution of freezing temperatures of droplets: A general singular model for ice nucleation

    E-Print Network [OSTI]

    Richard P. Sear

    2013-07-29

    Models without an explicit time dependence, called singular models, are widely used for fitting the distribution of temperatures at which water droplets freeze. In 1950 Levine developed the original singular model. His key assumption was that each droplet contained many nucleation sites, and that freezing occurred due to the nucleation site with the highest freezing temperature. The fact that freezing occurs due to the maximum value out of large number of nucleation temperatures, means that we can apply the results of what is called extreme-value statistics. This is the statistics of the extreme, i.e., maximum or minimum, value of a large number of random variables. Here we use the results of extreme-value statistics to show that we can generalise Levine's model to produce the most general singular model possible. We show that when a singular model is a good approximation, the distribution of freezing temperatures should always be given by what is called the generalised extreme-value distribution. In addition, we also show that the distribution of freezing temperatures for droplets of onesize, can be used to make predictions for the scaling of the median nucleation temperature with droplet size, and vice versa.

  11. Between giant oscillations and uniform distribution of droplets -- the role of varying lumen of channels in microfluidic networks

    E-Print Network [OSTI]

    Olgierd Cybulski; Slawomir Jakiela; Piotr Garstecki

    2015-08-19

    The simplest microfluidic network (a loop) comprises two parallel channels with a common inlet and a common outlet. Recent studies, that assumed constant cross-section of the channels along their length, have shown that the sequence of droplets entering left (L) or right (R) arm of the loop can present either a uniform distribution of choices (e.g. RLRLRL...) or long sequences of repeated choices (RRR...LLL), with all the intermediate permutations being dynamically equivalent and virtually equally probable to be observed. We use experiments and computer simulations to show that even small variation of the cross-section along channels completely shifts the dynamics either into the strong preference for highly grouped patterns (RRR...LLL) that generate system-size oscillations in flow, or just the opposite - to patterns that distribute the droplets homogeneously between the arms of the loop. We also show the importance of noise in the process of self-organization of the spatio-temporal patterns of droplets. Our results provide guidelines for rational design of systems that reproducibly produce either grouped or homogeneous sequences of droplets flowing in microfluidic networks.

  12. High flow rate nozzle system with production of uniform size droplets

    DOE Patents [OSTI]

    Stockel, I.H.

    1990-10-16

    Method steps for production of substantially uniform size droplets from a flow of liquid include forming the flow of liquid, periodically modulating the momentum of the flow of liquid in the flow direction at controlled frequency, generating a cross flow direction component of momentum and modulation of the cross flow momentum of liquid at substantially the same frequency and phase as the modulation of flow direction momentum, and spraying the so formed modulated flow through a first nozzle outlet to form a desired spray configuration. A second modulated flow through a second nozzle outlet is formed according to the same steps, and the first and second modulated flows impinge upon each other generating a liquid sheet. Nozzle apparatus for modulating each flow includes rotating valving plates interposed in the annular flow of liquid. The plates are formed with radial slots. Rotation of the rotating plates is separably controlled at differential angular velocities for a selected modulating frequency to achieve the target droplet size and production rate for a given flow. The counter rotating plates are spaced to achieve a desired amplitude of modulation in the flow direction, and the angular velocity of the downstream rotating plate is controlled to achieve the desired amplitude of modulation of momentum in the cross flow direction. Amplitude of modulation is set according to liquid viscosity. 5 figs.

  13. High flow rate nozzle system with production of uniform size droplets

    DOE Patents [OSTI]

    Stockel, Ivar H. (Bangor, ME)

    1990-01-01

    Method steps for production of substantially uniform size droplets from a flow of liquid include forming the flow of liquid, periodically modulating the momentum of the flow of liquid in the flow direction at controlled frequency, generating a cross flow direction component of momentum and modulation of the cross flow momentum of liquid at substantially the same frequency and phase as the modulation of flow direction momentum, and spraying the so formed modulated flow through a first nozzle outlet to form a desired spray configuration. A second modulated flow through a second nozzle outlet is formed according to the same steps, and the first and second modulated flows impinge upon each other generating a liquid sheet. Nozzle apparatus for modulating each flow includes rotating valving plates interposed in the annular flow of liquid. The plates are formed with radial slots. Rotation of the rotating plates is separably controlled at differential angular velocities for a selected modulating frequency to achieve the target droplet size and production rate for a given flow. The counter rotating plates are spaced to achieve a desired amplitude of modulation in the flow direction, and the angular velocity of the downstream rotating plate is controlled to achieve the desired amplitude of modulation of momentum in the cross flow direction. Amplitude of modulation is set according to liquid viscosity.

  14. Between giant oscillations and uniform distribution of droplets -- the role of varying lumen of channels in microfluidic networks

    E-Print Network [OSTI]

    Cybulski, Olgierd; Garstecki, Piotr

    2015-01-01

    The simplest microfluidic network (a loop) comprises two parallel channels with a common inlet and a common outlet. Recent studies, that assumed constant cross-section of the channels along their length, have shown that the sequence of droplets entering left (L) or right (R) arm of the loop can present either a uniform distribution of choices (e.g. RLRLRL...) or long sequences of repeated choices (RRR...LLL), with all the intermediate permutations being dynamically equivalent and virtually equally probable to be observed. We use experiments and computer simulations to show that even small variation of the cross-section along channels completely shifts the dynamics either into the strong preference for highly grouped patterns (RRR...LLL) that generate system-size oscillations in flow, or just the opposite - to patterns that distribute the droplets homogeneously between the arms of the loop. We also show the importance of noise in the process of self-organization of the spatio-temporal patterns of droplets. Our...

  15. Evolution of droplet size distribution and autoconversion parameterization

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  16. ARM - Measurement - Hydrometeor Size Distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  17. Particle Size Distribution of Gypseous Samples 

    E-Print Network [OSTI]

    Arnett, Morgan P.

    2010-01-16

    Particle size distribution (PSD) of gypseous soils is important in the soil science community. When gypsum constitutes a major portion of the soil, its removal prior to PSD analysis distorts the results and may lead to ...

  18. Modelling for post-dryout heat transfer and droplet sizes at low pressure and low flow conditions

    SciTech Connect (OSTI)

    Jeong, H.Y.; No, H.C. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering] [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering

    1996-10-01

    A correlation describing the initial droplet size just after the CHF position at low mass flux is suggested through regression analysis. The history-dependent post-dryout model of Varone and Rohsenow replaced by the Webb-Chen model for wall-vapor heat transfer is used as a reference model in the analysis. In the post-dryout region at low pressure and low flow, it is found that the suggested one-dimensional mechanistic model is valid only in the churn-turbulent flow regime (j*{sub g} = 0.5 {approximately} 4.5). It is also suggested that the droplet size generated from the churn-turbulent surface is dependent not only on the pressure but also on the vapor velocity. It turns out that the present model can predict the measured cladding and vapor temperatures within 20% and 15%, respectively.

  19. The influence of droplet size and biodegradation on the transport of subsurface oil droplets during the Deepwater Horizon: a model sensitivity study

    E-Print Network [OSTI]

    North, Elizabeth W

    A better understanding of oil droplet formation, degradation, and dispersal in deep waters is needed to enhance prediction of the fate and transport of subsurface oil spills. This research evaluates the influence of initial ...

  20. ARM - Measurement - Aerosol particle size distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  1. Parameterizing Size Distribution in Ice Clouds

    SciTech Connect (OSTI)

    DeSlover, Daniel; Mitchell, David L.

    2009-09-25

    PARAMETERIZING SIZE DISTRIBUTIONS IN ICE CLOUDS David L. Mitchell and Daniel H. DeSlover ABSTRACT An outstanding problem that contributes considerable uncertainty to Global Climate Model (GCM) predictions of future climate is the characterization of ice particle sizes in cirrus clouds. Recent parameterizations of ice cloud effective diameter differ by a factor of three, which, for overcast conditions, often translate to changes in outgoing longwave radiation (OLR) of 55 W m-2 or more. Much of this uncertainty in cirrus particle sizes is related to the problem of ice particle shattering during in situ sampling of the ice particle size distribution (PSD). Ice particles often shatter into many smaller ice fragments upon collision with the rim of the probe inlet tube. These small ice artifacts are counted as real ice crystals, resulting in anomalously high concentrations of small ice crystals (D < 100 µm) and underestimates of the mean and effective size of the PSD. Half of the cirrus cloud optical depth calculated from these in situ measurements can be due to this shattering phenomenon. Another challenge is the determination of ice and liquid water amounts in mixed phase clouds. Mixed phase clouds in the Arctic contain mostly liquid water, and the presence of ice is important for determining their lifecycle. Colder high clouds between -20 and -36 oC may also be mixed phase but in this case their condensate is mostly ice with low levels of liquid water. Rather than affecting their lifecycle, the presence of liquid dramatically affects the cloud optical properties, which affects cloud-climate feedback processes in GCMs. This project has made advancements in solving both of these problems. Regarding the first problem, PSD in ice clouds are uncertain due to the inability to reliably measure the concentrations of the smallest crystals (D < 100 µm), known as the “small mode”. Rather than using in situ probe measurements aboard aircraft, we employed a treatment of ice cloud optical properties formulated in terms of PSD parameters in combination with remote measurements of thermal radiances to characterize the small mode. This is possible since the absorption efficiency (Qabs) of small mode crystals is larger at 12 µm wavelength relative to 11 µm wavelength due to the process of wave resonance or photon tunneling more active at 12 µm. This makes the 12/11 µm absorption optical depth ratio (or equivalently the 12/11 µm Qabs ratio) a means for detecting the relative concentration of small ice particles in cirrus. Using this principle, this project tested and developed PSD schemes that can help characterize cirrus clouds at each of the three ARM sites: SGP, NSA and TWP. This was the main effort of this project. These PSD schemes and ice sedimentation velocities predicted from them have been used to test the new cirrus microphysics parameterization in the GCM known as the Community Climate Systems Model (CCSM) as part of an ongoing collaboration with NCAR. Regarding the second problem, we developed and did preliminary testing on a passive thermal method for retrieving the total water path (TWP) of Arctic mixed phase clouds where TWPs are often in the range of 20 to 130 g m-2 (difficult for microwave radiometers to accurately measure). We also developed a new radar method for retrieving the cloud ice water content (IWC), which can be vertically integrated to yield the ice water path (IWP). These techniques were combined to determine the IWP and liquid water path (LWP) in Arctic clouds, and hence the fraction of ice and liquid water. We have tested this approach using a case study from the ARM field campaign called M-PACE (Mixed-Phase Arctic Cloud Experiment). This research led to a new satellite remote sensing method that appears promising for detecting low levels of liquid water in high clouds typically between -20 and -36 oC. We hope to develop this method in future research.

  2. Pore size distribution and accessible pore size distribution in bituminous coals

    SciTech Connect (OSTI)

    Sakurovs, Richard [ORNL; He, Lilin [ORNL; Melnichenko, Yuri B [ORNL; Radlinski, Andrzej Pawell [ORNL; Blach, Tomasz P [ORNL

    2012-01-01

    The porosity and pore size distribution of coals determine many of their properties, from gas release to their behavior on carbonization, and yet most methods of determining pore size distribution can only examine a restricted size range. Even then, only accessible pores can be investigated with these methods. Small-angle neutron scattering (SANS) and ultra small-angle neutron scattering (USANS) are increasingly used to characterize the size distribution of all of the pores non-destructively. Here we have used USANS/SANS to examine 24 well-characterized bituminous and subbituminous coals: three from the eastern US, two from Poland, one from New Zealand and the rest from the Sydney and Bowen Basins in Eastern Australia, and determined the relationships of the scattering intensity corresponding to different pore sizes with other coal properties. The range of pore radii examinable with these techniques is 2.5 nm to 7 {micro}m. We confirm that there is a wide range of pore sizes in coal. The pore size distribution was found to be strongly affected by both rank and type (expressed as either hydrogen or vitrinite content) in the size range 250 nm to 7 {micro}m and 5 to 10 nm, but weakly in intermediate regions. The results suggest that different mechanisms control coal porosity on different scales. Contrast-matching USANS and SANS were also used to determine the size distribution of the fraction of the pores in these coals that are inaccessible to deuterated methane, CD{sub 4}, at ambient temperature. In some coals most of the small ({approx} 10 nm) pores were found to be inaccessible to CD{sub 4} on the time scale of the measurement ({approx} 30 min - 16 h). This inaccessibility suggests that in these coals a considerable fraction of inherent methane may be trapped for extended periods of time, thus reducing the effectiveness of methane release from (or sorption by) these coals. Although the number of small pores was less in higher rank coals, the fraction of total pores that was inaccessible was not rank dependent. In the Australian coals, at the 10 nm to 50 nm size scales the pores in inertinites appeared to be completely accessible to CD{sub 4}, whereas the pores in the vitrinite were about 75% inaccessible. Unlike the results for total porosity that showed no regional effects on relationships between porosity and coal properties, clear regional differences in the relationships between fraction of closed porosity and coal properties were found. The 10 to 50 nm-sized pores of inertinites of the US and Polish coals examined appeared less accessible to methane than those of the inertinites of Australian coals. This difference in pore accessibility in inertinites may explain why empirical relationships between fluidity and coking properties developed using Carboniferous coals do not apply to Australian coals.

  3. Distribution Effectiveness and Impacts on Equipment Sizing for Residential Thermal Distribution Systems

    E-Print Network [OSTI]

    1 LBNL-43724 Distribution Effectiveness and Impacts on Equipment Sizing for Residential Thermal Distribution Systems Walker, I., Sherman, M., and Siegel, J. Environmental Energy Technologies Division Energy

  4. Grain-size distributions of tsunami sediments 

    E-Print Network [OSTI]

    Spencer, Sarah

    2011-08-08

    tsunamis, Chile 2010 and Peru 2008. The grain-size of the sediment from each tsunami was measured by two common techniques: sieving and digital particle counter. To interpret this real tsunami data, numerical and analytical analysis were used to simulate...

  5. THE COLLISIONAL DIVOT IN THE KUIPER BELT SIZE DISTRIBUTION

    SciTech Connect (OSTI)

    Fraser, Wesley C. [Division of Geological and Planetary Sciences, California Institute of Technology, MC 150-21, 1200 E. California Blvd. Pasadena, CA 91125 (United States)

    2009-11-20

    This paper presents the results of collisional evolution calculations for the Kuiper Belt starting from an initial size distribution similar to that produced by accretion simulations of that region-a steep power-law large object size distribution that breaks to a shallower slope at r approx 1-2 km, with collisional equilibrium achieved for objects r approx< 0.5 km. We find that the break from the steep large object power law causes a divot, or depletion of objects at r approx 10-20 km, which, in turn, greatly reduces the disruption rate of objects with r approx> 25-50 km, preserving the steep power-law behavior for objects at this size. Our calculations demonstrate that the roll-over observed in the Kuiper Belt size distribution is naturally explained as an edge of a divot in the size distribution; the radius at which the size distribution transitions away from the power law, and the shape of the divot from our simulations are consistent with the size of the observed roll-over, and size distribution for smaller bodies. Both the kink radius and the radius of the divot center depend on the strength scaling law in the gravity regime for Kuiper Belt objects. These simulations suggest that the sky density of r approx 1 km objects is approx10{sup 6}-10{sup 7} objects per square degree. A detection of the divot in the size distribution would provide a measure of the strength of large Kuiper Belt objects, and constrain the shape of the size distribution at the end of accretion in the Kuiper Belt.

  6. ARM - Measurement - Cloud particle size distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  7. Pore-size-distribution of cationic polyacrylamide hydrogels. Progress report

    SciTech Connect (OSTI)

    Kremer, M.; Prausnitz, J.M.

    1992-06-01

    The pore size distribution of a AAm/MAPTAC (acrylamide copolymerized with (3-methacrylamidopropyl)trimethylammonium chloride) hydrogel was investigated using Kuga`s mixed-solute-exclusion method, taking into account the wall effect. A Brownian-motion model is also used. Results show the feasibility of determining pore-size distribution of porous materials using the mixed-solute-exclusion method in conjunction with solution of the Fredholm equation; good agreement was obtained with experiment, even for bimodal pore structures. However, different pore size distributions were calculated for the two different probe-solutes (Dextran and poly(ethylene glycol/oxide)). Future work is outlined. 32 figs, 25 refs.

  8. Pore-size-distribution of cationic polyacrylamide hydrogels

    SciTech Connect (OSTI)

    Kremer, M.; Prausnitz, J.M.

    1992-06-01

    The pore size distribution of a AAm/MAPTAC (acrylamide copolymerized with (3-methacrylamidopropyl)trimethylammonium chloride) hydrogel was investigated using Kuga's mixed-solute-exclusion method, taking into account the wall effect. A Brownian-motion model is also used. Results show the feasibility of determining pore-size distribution of porous materials using the mixed-solute-exclusion method in conjunction with solution of the Fredholm equation; good agreement was obtained with experiment, even for bimodal pore structures. However, different pore size distributions were calculated for the two different probe-solutes (Dextran and poly(ethylene glycol/oxide)). Future work is outlined. 32 figs, 25 refs.

  9. INITIAL PLANETESIMAL SIZES AND THE SIZE DISTRIBUTION OF SMALL KUIPER BELT OBJECTS

    SciTech Connect (OSTI)

    Schlichting, Hilke E. [UCLA, Department of Earth and Space Science, 595 Charles E. Young Drive East, Los Angeles, CA 90095 (United States); Fuentes, Cesar I.; Trilling, David E., E-mail: hilke@ucla.edu [Department of Physics and Astronomy, Northern Arizona University, P.O. Box 6010, Flagstaff, AZ 86011 (United States)

    2013-08-01

    The Kuiper Belt is a remnant from the early solar system and its size distribution contains many important constraints that can be used to test models of planet formation and collisional evolution. We show, by comparing observations with theoretical models, that the observed Kuiper Belt size distribution is well matched by coagulation models, which start with an initial planetesimal population with radii of about 1 km, and subsequent collisional evolution. We find that the observed size distribution above R {approx} 30 km is primordial, i.e., it has not been modified by collisional evolution over the age of the solar system, and that the size distribution below R {approx} 30 km has been modified by collisions and that its slope is well matched by collisional evolution models that use published strength laws. We investigate in detail the resulting size distribution of bodies ranging from 0.01 km to 30 km and find that its slope changes several times as a function of radius before approaching the expected value for an equilibrium collisional cascade of material strength dominated bodies for R {approx}< 0.1 km. Compared to a single power-law size distribution that would span the whole range from 0.01 km to 30 km, we find in general a strong deficit of bodies around R {approx} 10 km and a strong excess of bodies around 2 km in radius. This deficit and excess of bodies are caused by the planetesimal size distribution left over from the runaway growth phase, which left most of the initial mass in small planetesimals while only a small fraction of the total mass is converted into large protoplanets. This excess mass in small planetesimals leaves a permanent signature in the size distribution of small bodies that is not erased after 4.5 Gyr of collisional evolution. Observations of the small Kuiper Belt Object (KBO) size distribution can therefore test if large KBOs grew as a result of runaway growth and constrained the initial planetesimal sizes. We find that results from recent KBO occultation surveys and the observed KBO size distribution can be best matched by an initial planetesimal population that contained about equal mass per logarithmic mass bin in bodies ranging from 0.4 km to 4 km in radius. We further find that we cannot match the observed KBO size distribution if most of the planetesimal mass was contained in bodies that were 10 km in radius or larger simply because their resulting size distribution cannot be sufficiently depleted over 4.5 Gyr to match observations.

  10. SELF-CONSISTENT SIZE AND VELOCITY DISTRIBUTIONS OF COLLISIONAL CASCADES

    SciTech Connect (OSTI)

    Pan, Margaret [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Schlichting, Hilke E., E-mail: mpan@astro.berkeley.edu, E-mail: hilke@ucla.edu [Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095 (United States)

    2012-03-10

    The standard theoretical treatment of collisional cascades derives a steady-state size distribution assuming a single constant velocity dispersion for all bodies regardless of size. Here we relax this assumption and solve self-consistently for the bodies' steady-state size and size-dependent velocity distributions. Specifically, we account for viscous stirring, dynamical friction, and collisional damping of the bodies' random velocities in addition to the mass conservation requirement typically applied to find the size distribution in a steady-state cascade. The resulting size distributions are significantly steeper than those derived without velocity evolution. For example, accounting self-consistently for the velocities can change the standard q = 3.5 power-law index of the Dohnanyi differential size spectrum to an index as large as q = 4. Similarly, for bodies held together by their own gravity, the corresponding power-law index range 2.88 < q < 3.14 of Pan and Sari can steepen to values as large as q = 3.26. Our velocity results allow quantitative predictions of the bodies' scale heights as a function of size. Together with our predictions, observations of the scale heights for different-sized bodies for the Kuiper belt, the asteroid belt, and extrasolar debris disks may constrain the mass and number of large bodies stirring the cascade as well as the colliding bodies' internal strengths.

  11. Sedimentation of algae: relationships with biomass and size distribution1

    E-Print Network [OSTI]

    Mazumder, Asit

    Sedimentation of algae: relationships with biomass and size distribution1 Isabelle Larocque, A distribution of epilimnetic algae on patterns of algal sedimentation was determined in lake enclosures under the mean length of algae in fish-free enclosures and reduced the mean length in the enclosures to which

  12. Dispersion of Cloud Droplet Size Distributions, Cloud Parameterizations and Indirect Aerosol Effects

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  13. Influence of defects distribution and specimen size on fracture initiation

    E-Print Network [OSTI]

    Krivtsov, Anton M.

    Influence of defects distribution and specimen size on fracture initiation Anton M. Krivtsov akrivtsov@bk.ru Abstract An analytical model for the scale dependence of the fracture initiation is suggested. The model is based on the idea that fracture is a stochastic process, for the bigger specimens

  14. Snap-off production of monodisperse droplets

    E-Print Network [OSTI]

    Solomon Barkley; Eric R. Weeks; Kari Dalnoki-Veress

    2015-08-13

    We introduce a novel technique to produce monodisperse droplets through the snap-off mechanism. The methodology is simple, versatile, and requires no specialized or expensive components. The droplets produced have polydispersity <1% and can be as small as 2.5 $\\mu$m radius. A convenient feature is that the droplet size is constant over a 100-fold change in flow rate, while at higher flows the droplet size can be continuously adjusted.

  15. Size distribution and structure of Barchan dune fields

    E-Print Network [OSTI]

    Orencio Durán; Veit Schwämmle; Pedro G. Lind; Hans J. Herrmann

    2011-05-19

    Barchans are isolated mobile dunes often organized in large dune fields. Dune fields seem to present a characteristic dune size and spacing, which suggests a cooperative behavior based on dune interaction. In Duran et al. (2009), we propose that the redistribution of sand by collisions between dunes is a key element for the stability and size selection of barchan dune fields. This approach was based on a mean-field model ignoring the spatial distribution of dune fields. Here, we present a simplified dune field model that includes the spatial evolution of individual dunes as well as their interaction through sand exchange and binary collisions. As a result, the dune field evolves towards a steady state that depends on the boundary conditions. Comparing our results with measurements of Moroccan dune fields, we find that the simulated fields have the same dune size distribution as in real fields but fail to reproduce their homogeneity along the wind direction.

  16. Explosive growth of inhomogeneities in the distribution of droplets in a turbulent air

    E-Print Network [OSTI]

    S. A. Derevyanko; G. Falkovich; K. Turitsyn; S. Turitsyn

    2006-04-23

    We study how the spatial distribution of inertial particles evolves with time in a random flow. We describe an explosive appearance of caustics and show how they influence an exponential growth of clusters due to smooth parts of the flow, leading in particular to an exponential growth of the average distance between particles.

  17. Method for measuring the size distribution of airborne rhinovirus

    SciTech Connect (OSTI)

    Russell, M.L.; Goth-Goldstein, R.; Apte, M.G.; Fisk, W.J.

    2002-01-01

    About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor.

  18. Effects of the dynamics of droplet-based laser-produced plasma on angular extreme ultraviolet emission profile

    SciTech Connect (OSTI)

    Giovannini, Andrea Z.; Abhari, Reza S.

    2014-05-12

    The emission distribution of extreme ultraviolet (EUV) radiation from droplet targets is dependent on the dynamics of the laser-produced plasma. The EUV emission is measured on a 2% bandwidth centered at 13.5?nm (in-band). The targets of the laser are small (sub-50 ?m) tin droplets, and the in-band emission distribution is measured for different laser irradiances and droplet sizes at various angular positions. Larger droplets lead to a faster decay of EUV emission at larger angles with respect to the laser axis. A decrease in laser irradiance has the opposite effect. The measurements are used together with an analytical model to estimate plume dynamics. Additionally, the model is used to estimate EUV emission distribution for a desired droplet diameter and laser irradiance.

  19. Fluctuating fitness shapes the clone size distribution of immune repertoires

    E-Print Network [OSTI]

    Desponds, Jonathan; Walczak, Aleksandra M

    2015-01-01

    The adaptive immune system relies on the diversity of receptors expressed on the surface of B and T-cells to protect the organism from a vast amount of pathogenic threats. The proliferation and degradation dynamics of different cell types (B cells, T cells, naive, memory) is governed by a variety of antigenic and environmental signals, yet the observed clone sizes follow a universal power law distribution. Guided by this reproducibility we propose effective models of somatic evolution where cell fate depends on an effective fitness. This fitness is determined by growth factors acting either on clones of cells with the same receptor responding to specific antigens, or directly on single cells with no regards for clones. We identify fluctuations in the fitness acting specifically on clones as the essential ingredient leading to the observed distributions. Combining our models with experiments we characterize the scale of fluctuations in antigenic environments and we provide tools to identify the relevant growth...

  20. Droplet migration characteristics in confined oscillatory microflows

    E-Print Network [OSTI]

    Chaudhury, Kaustav; Chakraborty, Suman

    2015-01-01

    We analyze the migration characteristics of a droplet in an oscillatory flow field in a parallel plate micro-confinement. Using phase filed formalism, we capture the dynamical evolution of the droplet over a wide range of the frequency of the imposed oscillation in the flow field, drop size relative to the channel gap, and the capillary number. The latter two factors imply the contribution of droplet deformability, commonly considered in the study of droplet migration under steady shear flow conditions. We show that the imposed oscillation brings in additional time complexity in the droplet movement, realized through temporally varying drop-shape, flow direction and the inertial response of the droplet. As a consequence, we observe a spatially complicated pathway of the droplet along the transverse direction, in sharp contrast to the smooth migration under a similar yet steady shear flow condition. Intuitively, the longitudinal component of the droplet movement is in tandem with the flow continuity and evolve...

  1. Droplet generation during core reflood. [PWR

    SciTech Connect (OSTI)

    Kocamustafaogullari, G.; De Jarlais, G.; Ishii, M.

    1983-01-01

    The process of entrainment and disintegration of liquid droplets by a flow of steam has considerable practical importance in calculating the effectivenes of the emergency core cooling system. Liquid entrainment is also important in determination of the critical heat flux point in general. Thus the analysis of the reflooding phase of a LOCA requires detailed knowledge of droplet size. Droplet size is mainly determined by the droplet generation mechanisms involved. To study these mechanisms, data generated in the PWR FLECHT SEASET series of experiments was analyzed. In addition, an experiment was performed in which the hydrodynamics of low quality post-CHF flow (inverted annular flow) were simulated in an adiabatic test section.

  2. Sifting attacks in finite-size quantum key distribution

    E-Print Network [OSTI]

    Corsin Pfister; Patrick J. Coles; Stephanie Wehner; Norbert Lütkenhaus

    2015-09-02

    A central assumption in quantum key distribution (QKD) is that Eve has no knowledge about which rounds will be used for parameter estimation or key distillation. Here we show that this assumption is violated for iterative sifting, a commonly used sifting procedure that has been em- ployed in both theoretical and experimental finite-size QKD. We show that iterative sifting leads to two problems: (1) some rounds are more likely to be key rounds than others, (2) the public communication of past measurement choices changes this bias round by round. We analyze these two previously unnoticed problems, present eavesdropping strategies that exploit them, and find that the two problems are independent. We propose corrections to the protocol and prove that the resulting protocol, which we call the fixed round number sifting protocol, is secure and can thus replace iterative sifting in future QKD protocols. It outperforms other recently suggested protocols, increasing the efficiency by a factor of almost two. More generally, we present two formal criteria for a sifting protocol which ensure that they are secure. Our criteria may guide the design of future protocols and inspire a more rigorous QKD analysis, which has neglected sifting-related attacks so far.

  3. Bismuth nano-droplets for group-V based molecular-beam droplet epitaxy

    SciTech Connect (OSTI)

    Li, C.; Zeng, Z. Q.; Hirono, Y.; Morgan, T. A.; Hu, X.; Salamo, G. J.; Fan, D. S.; Wu, J.; Yu, S. Q.; Wang, Zh. M.

    2011-12-12

    Self-assembly of bismuth droplets at nanoscale on GaAs(100) surface using molecular beam epitaxy was demonstrated. Fine control of density and size was achieved by varying growth temperature and total bismuth deposition. Droplet density was tuned by roughly 3 orders of magnitude, and the density-temperature dependence was found to be consistent with classical nucleation theory. These results may extend the flexibility of droplet epitaxy by serving as templates for group V based droplet epitaxy, which is in contrast to conventional group III based droplet epitaxy and may encourage nanostructure formation of bismuth-containing materials.

  4. On the Distribution of Fragment Sizes in the Fragmentation of Polymer Chains.

    E-Print Network [OSTI]

    Hathorn, Bryan C.

    On the Distribution of Fragment Sizes in the Fragmentation of Polymer Chains. B.C. Hathorn, a B of a polymer is calcu­ lated using a simple model based on Transition State Theory to describe the distribution promotes completely random scission, with equal probability distribution for all possible fragment sizes. 1

  5. The size distribution of conspeci c populations: the peoples of New Guinea

    E-Print Network [OSTI]

    The size distribution of conspeci c populations: the peoples of New Guinea Vojtech Novotny1, Department of Biology, Brafova 7, 701 03 Ostrava, Czech Republic The size distribution of the language analogous to the resource division models of species abun- dance distribution in ecological communities

  6. Size-dependent polarization distribution in ferroelectric nanostructures: Phase field simulations

    E-Print Network [OSTI]

    Chen, Long-Qing

    to memory and storage devices, sen- sors, and actuators. The properties of low-dimensional ferro- electricsSize-dependent polarization distribution in ferroelectric nanostructures: Phase field simulations distribution in ferroelectric nanostructures embedded in a nonferroelectric medium. The simulation results

  7. The geographic distribution of mammal body size in Europe

    E-Print Network [OSTI]

    Rodriguez, M A; Lopez-Sanudo, I L; Hawkins, Bradford A.

    2006-01-01

    the mammals of Britain and Europe. Houghton Mif?in, Boston.mammals of Britain and Europe. Collins, London. Cotgreave,of mammal body size in Europe Miguel Á. Rodríguez 1 *, Irene

  8. ARM Evaluation Product : Droplet Number Concentration Value-Added Product

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Riihimaki, Laura

    2014-05-15

    Cloud droplet number concentration is an important factor in understanding aerosol-cloud interactions. As aerosol concentration increases, it is expected that droplet number concentration, Nd, will increase and droplet size decrease, for a given liquid water path (Twomey 1977), which will greatly affect cloud albedo as smaller droplets reflect more shortwave radiation. However, the magnitude and variability of these processes under different environmental conditions is still uncertain. McComiskey et al. (2009) have implemented a method, based on Boers and Mitchell (1994), for calculating Nd from ground-based remote sensing measurements of optical depth and liquid water path. They show that the magnitude of the aerosol-cloud interactions (ACI) varies with a range of factors, including the relative value of the cloud liquid water path (LWP), the aerosol size distribution, and the cloud updraft velocity. Estimates of Nd under a range of cloud types and conditions and at a variety of sites are needed to further quantify the impacts of aerosol cloud interactions.

  9. ARM Evaluation Product : Droplet Number Concentration Value-Added Product

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Riihimaki, Laura

    Cloud droplet number concentration is an important factor in understanding aerosol-cloud interactions. As aerosol concentration increases, it is expected that droplet number concentration, Nd, will increase and droplet size decrease, for a given liquid water path (Twomey 1977), which will greatly affect cloud albedo as smaller droplets reflect more shortwave radiation. However, the magnitude and variability of these processes under different environmental conditions is still uncertain. McComiskey et al. (2009) have implemented a method, based on Boers and Mitchell (1994), for calculating Nd from ground-based remote sensing measurements of optical depth and liquid water path. They show that the magnitude of the aerosol-cloud interactions (ACI) varies with a range of factors, including the relative value of the cloud liquid water path (LWP), the aerosol size distribution, and the cloud updraft velocity. Estimates of Nd under a range of cloud types and conditions and at a variety of sites are needed to further quantify the impacts of aerosol cloud interactions.

  10. Dust size distribution and concentrations with cottonseed oil mills 

    E-Print Network [OSTI]

    Wiederhold, Lee Roy

    1976-01-01

    -VOLUME SAMPLES FOR P. S. D OF PARTICLES & 100 um DIAMETER (MMD) ANALYSIS OF VARIANCE ON HIGH-VOLUME SAMPLES FOR P. S. D. OF PARTICLES & 100 um DIAMETER (og) MULTIPLE RANGE TEST FOR MEAN VALUES OF MMD BY AREA MULTIPLE RANGE TEST OF MMD BY MILL PARTICLE SIZE... TEST OF AREA DUST CONCENTRATIONS = 15 Pm IN DIAMETER MULTIPLE RANGE TEST OF MILL DUST CONCENTRATIONS & 15 um IN DIAMETER ANALYSIS OF VARIANCE ON PARTICLE SIZING HEAD SAMPLES OF CONCENTRATIONS FOR PARTICLES & 100 IJBI DIAMETER . . . . 47 47 54...

  11. Determination of pore-size distribution in low-dielectric thin films D. W. Gidleya)

    E-Print Network [OSTI]

    Gidley, David

    -size distribution on pore shape/dimensionality and sample temperature is predicted using a simple quantum mechanicalDetermination of pore-size distribution in low-dielectric thin films D. W. Gidleya) and W. E. Frieze Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 T. L. Dull, J. Sun, and A

  12. Global Patterns of City Size Distributions and Their Fundamental Drivers

    E-Print Network [OSTI]

    Kerkhoff, Andrew J.

    a global perspective on the problem. If we hope to successfully manage urban environmental impacts, we capita environmental impact of humans varies across settlements of different sizes and across regions¤ *, Andrew J. Kerkhoff2 , Melanie E. Moses3 1 Department of Biology, University of New Mexico, Albuquerque

  13. Statistical distributions of water content and sizes for clouds above Europe

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Statistical distributions of water content and sizes for clouds above Europe R. P. H. Berton O and water content (IWC), horizontal and vertical sizes (L and H), and top temperatures (T) of clouds above and water contents) controlling radiation transfer in the cloud, and geo- metrical sizes used

  14. Size distribution of particle systems analyzed with organic photodetectors

    E-Print Network [OSTI]

    Sentis, Matthias

    2015-01-01

    As part of a consortium between academic and industry, this PhD work investigates the interest and capabilities of organic photo-sensors (OPS) for the optical characterization of suspensions and two-phase flows. The principle of new optical particle sizing instruments is proposed to characterize particle systems confined in a cylinder glass (standard configuration for Process Analytical Technologies). To evaluate and optimize the performance of these systems, a Monte-Carlo model has been specifically developed. This model accounts for the numerous parameters of the system: laser beam profile, mirrors, lenses, sample cell, particle medium properties (concentration, mean & standard deviation, refractive indices), OPS shape and positions, etc. Light scattering by particles is treated either by using Lorenz-Mie theory, Debye, or a hybrid model (that takes into account the geometrical and physical contributions). For diluted media (single scattering), particle size analysis is based on the inversion of scatter...

  15. Distribution Network Design: Selection and Sizing of Congested Connections

    E-Print Network [OSTI]

    Nagi, Rakesh

    promotions (i.e., seasonal) and regular demand. In response to this, at the strategic or aggregate level demand. Several multinational companies use distribution center networks in this manner. For example. For most fast moving consumer goods, demand patterns are quite erratic, being a function of both sales

  16. A solvable model of fracture with power-law distribution of fragment sizes

    E-Print Network [OSTI]

    Ken Yamamoto; Yoshihiro Yamazaki

    2011-06-08

    The present paper describes a stochastic model of fracture, whose fragment size distribution can be calculated analytically as a power-law-like distribution. The model is basically cascade fracture, but incorporates the effect that each fragment in each stage of cascade ceases fracture with a certain probability. When the probability is constant, the exponent of the power-law cumulative distribution lies between -1 and 0, depending not only on the probability but the distribution of fracture points. Whereas, when the probability depends on the size of a fragment, the exponent is less than -1, irrespective of the distribution of fracture points.

  17. The dune size distribution and scaling relations of barchan dune fields

    E-Print Network [OSTI]

    Orencio Durán; Veit Schwämmle; Pedro G. Lind; Hans J. Herrmann

    2008-10-27

    Barchan dunes emerge as a collective phenomena involving the generation of thousands of them in so called barchan dune fields. By measuring the size and position of dunes in Moroccan barchan dune fields, we find that these dunes tend to distribute uniformly in space and follow an unique size distribution function. We introduce an analyticalmean-field approach to show that this empirical size distribution emerges from the interplay of dune collisions and sand flux balance, the two simplest mechanisms for size selection. The analytical model also predicts a scaling relation between the fundamental macroscopic properties characterizing a dune field, namely the inter-dune spacing and the first and second moments of the dune size distribution.

  18. Soft substrates suppress droplet splashing

    E-Print Network [OSTI]

    Howland, Christopher J; Style, Robert W; Castrejón-Pita, A A

    2015-01-01

    Droplets splash when they impact dry, flat substrates above a critical velocity that depends on parameters such as droplet size, viscosity and air pressure. We show that substrate stiffness also impacts the splashing threshold by imaging ethanol drops impacting silicone gels of different stiffnesses. Splashing is significantly suppressed: droplets on the softest substrates need over 70% more kinetic energy to splash than they do on rigid substrates. We show that splash suppression is likely to be due to energy losses caused by deformations of soft substrates during the first few microseconds of impact. We find that solids with Youngs modulus $\\lesssim O(10^5)$Pa suppress splashing, in agreement with simple scaling arguments. Thus materials like soft gels and elastomers can be used as simple coatings for effective splash prevention.

  19. THE SIZE DISTRIBUTION OF THE NEPTUNE TROJANS AND THE MISSING INTERMEDIATE-SIZED PLANETESIMALS

    SciTech Connect (OSTI)

    Sheppard, Scott S.; Trujillo, Chadwick A.

    2010-11-10

    We present an ultra-deep survey for Neptune Trojans using the Subaru 8.2 m and Magellan 6.5 m telescopes. The survey reached a 50% detection efficiency in the R band at m{sub R} = 25.7 mag and covered 49 deg{sup 2} of sky. m{sub R} = 25.7 mag corresponds to Neptune Trojans that are about 16 km in radius (assuming an albedo of 0.05). A paucity of smaller Neptune Trojans (radii < 45 km) compared with larger ones was found. The brightest Neptune Trojans appear to follow a steep power-law slope (q = 5 {+-} 1) similar to the brightest objects in the other known stable reservoirs such as the Kuiper Belt, Jupiter Trojans, and main belt asteroids. We find a roll-over for the Neptune Trojans that occurs around a radius of r = 45 {+-} 10 km (m{sub R} = 23.5 {+-} 0.3), which is also very similar to the other stable reservoirs. All the observed stable regions in the solar system show evidence for Missing Intermediate-Sized Planetesimals (MISPs). This indicates a primordial and not collisional origin, which suggests that planetesimal formation proceeded directly from small to large objects. The scarcity of intermediate- and smaller-sized Neptune Trojans may limit them as being a strong source for the short period comets.

  20. Lipid-Protein Interactions Alter Line Tensions and Domain Size Distributions in Lung Surfactant Monolayers

    E-Print Network [OSTI]

    Dhar, Prajnaparamita

    The size distribution of domains in phase-separated lung surfactant monolayers influences monolayer viscoelasticity and compressibility which, in turn, influence monolayer collapse and set the compression at which the ...

  1. A predictive model for particle size distribution and yield for Bayer precipitation and classification 

    E-Print Network [OSTI]

    Kapraun, Christopher Michael

    1996-01-01

    This project implements a dynamic alumina hydrate continuous precipitation and classification model in an alumina refining operation to allow the forecasting of a number of relevant process parameters, such as the particle size distribution...

  2. Network Stability under Alpha Fair Bandwidth Allocation with General File Size Distribution

    E-Print Network [OSTI]

    fair bandwidth allocation, with any positive alpha parameter, a Lyapunov function is constructed1 Network Stability under Alpha Fair Bandwidth Allocation with General File Size Distribution. Cornell University, Ithaca, NY. Swinburne University of Technology, Australia. Abstract--Rate allocation

  3. Notes on representing grain size distributions obtained by electron backscatter diffraction

    SciTech Connect (OSTI)

    Toth, Laszlo S., E-mail: laszlo.metz@univ-lorraine.fr [Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), UMR 7239, CNRS/Université de Lorraine, F-57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine (France); Biswas, Somjeet, E-mail: somjeetbiswas@gmail.com [Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine (France); Gu, Chengfan, E-mail: chengfan.gu@unsw.edu.au [School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Beausir, Benoit, E-mail: benoit.beausir@univ-lorraine.fr [Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), UMR 7239, CNRS/Université de Lorraine, F-57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Université de Lorraine (France)

    2013-10-15

    Grain size distributions measured by electron backscatter diffraction are commonly represented by histograms using either number or area fraction definitions. It is shown here that they should be presented in forms of density distribution functions for direct quantitative comparisons between different measurements. Here we make an interpretation of the frequently seen parabolic tales of the area distributions of bimodal grain structures and a transformation formula between the two distributions are given in this paper. - Highlights: • Grain size distributions are represented by density functions. • The parabolic tales corresponds to equal number of grains in a bin of the histogram. • A simple transformation formula is given to number and area weighed distributions. • The particularities of uniform and lognormal distributions are examined.

  4. The influence of particle-size distribution and moisture levels on the formation of soil hardpans 

    E-Print Network [OSTI]

    Bauer, Herman John

    1963-01-01

    THE INFLUENCE OF PARTICLE-SIZE DISTRIBUTION AND MOISTURE LEVELS ON THE FORMATION OF SOIL HARDPANS A Thesis By HERMAN J. BAUER Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE January, 1963 Major Subject: Soil Physics THE INFLUENCE OF PARTICLE-SIZE DISTRIBUTION AND MOISTURE LEVELS ON THE FORMATION OF SOIL HARDPANS A Thesis By HERMAN J. BAUER Approved as to style and content...

  5. ON CENTRIFUGAL SETTLING OF POLYDISPERSE SUSPENSIONS WITH A CONTINUOUS PARTICLE SIZE DISTRIBUTION

    E-Print Network [OSTI]

    Bürger, Raimund

    ON CENTRIFUGAL SETTLING OF POLYDISPERSE SUSPENSIONS WITH A CONTINUOUS PARTICLE SIZE DISTRIBUTION@ucn.cl ABSTRACT Gravity or centrifugal sedimentation of polydisperse suspensions with a continuous particle size is extended to settling in a rotating tube or basket centrifuge. Numerical simulations are presented

  6. A POSSIBLE DIVOT IN THE SIZE DISTRIBUTION OF THE KUIPER BELT'S SCATTERING OBJECTS

    SciTech Connect (OSTI)

    Shankman, C.; Gladman, B. J. [Department of Physics and Astronomy, University of British Columbia, 6224 Agriculture Road, Vancouver, BC V6T 1Z1 (Canada); Kaib, N. [Department of Physics and Astronomy, Queens University (Canada); Kavelaars, J. J. [National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Petit, J. M. [Institut UTINAM, CNRS-Universite de Franche-Comte, Besancon (France)

    2013-02-10

    Via joint analysis of a calibrated telescopic survey, which found scattering Kuiper Belt objects, and models of their expected orbital distribution, we explore the scattering-object (SO) size distribution. Although for D > 100 km the number of objects quickly rise as diameters decrease, we find a relative lack of smaller objects, ruling out a single power law at greater than 99% confidence. After studying traditional ''knees'' in the size distribution, we explore other formulations and find that, surprisingly, our analysis is consistent with a very sudden decrease (a divot) in the number distribution as diameters decrease below 100 km, which then rises again as a power law. Motivated by other dynamically hot populations and the Centaurs, we argue for a divot size distribution where the number of smaller objects rises again as expected via collisional equilibrium. Extrapolation yields enough kilometer-scale SOs to supply the nearby Jupiter-family comets. Our interpretation is that this divot feature is a preserved relic of the size distribution made by planetesimal formation, now ''frozen in'' to portions of the Kuiper Belt sharing a ''hot'' orbital inclination distribution, explaining several puzzles in Kuiper Belt science. Additionally, we show that to match today's SO inclination distribution, the supply source that was scattered outward must have already been vertically heated to the of order 10 Degree-Sign .

  7. Measurements of Aerosol Charge and Size Distribution for Graphite, Gold, Palladium, and Silver Nanoparticles

    SciTech Connect (OSTI)

    Simones, Matthew P.; Gutti, Veera R.; Meyer, Ryan M.; Loyalka, Sudarshan K.

    2011-11-01

    The role of charge on aerosol evolution and hence the nuclear source term has been an issue of interest, and there is a need for both experimental techniques and modeling for quantifying this role. Our focus here is on further exploration of a tandem differential mobility analyzer (TDMA) technique to simultaneously measure both the size and charge (positive, negative and neutral) dependent aerosol distributions. We have generated graphite, gold, silver, and palladium nanoparticles (aerosol) using a spark generator. We measure the electrical mobility-size distributions for these aerosols using a TDMA, and from these data we deduce the full charge-size distributions. We observe asymmetry in the particle size distributions for negative and positive charges. This asymmetry could have a bearing on the dynamics of charged aerosols, indicating that the assumption of symmetry for size distributions of negatively and positively charged particles in source term simulations may not be always appropriate. Also, the experimental technique should find applications in measurements of aerosol rate processes that are affected by both particle charge and size (e.g. coagulation, deposition, resuspension), and hence in modeling and simulation of the nuclear source term.

  8. Consideration of Grain Size Distribution in the Diffusion of Fission Gas to Grain Boundaries

    SciTech Connect (OSTI)

    Paul C. Millett; Yongfeng Zhang; Michael R. Tonks; S. B. Biner

    2013-09-01

    We analyze the accumulation of fission gas on grain boundaries in a polycrystalline microstructure with a distribution of grain sizes. The diffusion equation is solved throughout the microstructure to evolve the gas concentration in space and time. Grain boundaries are treated as infinite sinks for the gas concentration, and we monitor the cumulative gas inventory on each grain boundary throughout time. We consider two important cases: first, a uniform initial distribution of gas concentration without gas production (correlating with post-irradiation annealing), and second, a constant gas production rate with no initial gas concentration (correlating with in-reactor conditions). The results show that a single-grain-size model, such as the Booth model, over predicts the gas accumulation on grain boundaries compared with a polycrystal with a grain size distribution. Also, a considerable degree of scatter, or variability, exists in the grain boundary gas accumulation when comparing all of the grain boundaries in the microstructure.

  9. Analysis of Dispersive and Distributive Mixing In Terms of Minor Component Size and Spatial Distributions

    E-Print Network [OSTI]

    Distributions In Continuous Polymer Processing Equipment Winston Wang and Ica Manas-Zloczower Department polymer processing opera- tions. Material processability and product properties are highly influenced of the minor component enhances sys- tem homogeneity. In continuous mixing processes, composition uniformity

  10. The effects of deposit thermal history on microstructure produced by uniform droplet spray forming

    E-Print Network [OSTI]

    Cherng, Jean-Pei Jeanie

    2002-01-01

    Uniform droplet spray forming is a process aimed at producing near-net-shape parts directly from the liquid melt by spraying micron-sized droplets onto a movable target. In spray forming, the solidification rate of the ...

  11. Effects of surface properties on solder bump formation by direct droplet deposition

    E-Print Network [OSTI]

    Hsiao, Wen Kai, 1972-

    2004-01-01

    Recent advances in microdroplet generation and deposition processes have made it possible to directly form solder bumps on integrated circuits using micron-sized molten metal droplets. The direct droplet deposition bumping ...

  12. Final Report: Property Improvement in CZT via Modeling and Processing Innovations – Te-particles in vertical gradient freeze CZT: Size and Spatial Distributions and Constitutional Supercooling

    SciTech Connect (OSTI)

    Henager, Charles H.; Alvine, Kyle J.; Bliss, Mary; Riley, Brian J.; Stave, Jean A.

    2014-10-01

    A section of a vertical gradient freeze CZT boule approximately 2100-mm3 with a planar area of 300-mm2 was prepared and examined using transmitted IR microscopy at various magnifications to determine the three-dimensional spatial and size distributions of Te-particles over large longitudinal and radial length scales. The boule section was approximately 50-mm wide by 60-mm in length by 7-mm thick and was doubly polished for TIR work. Te-particles were imaged through the thickness using extended focal imaging to locate the particles in thickness planes spaced 15-µm apart and then in plane of the image using xy-coordinates of the particle center of mass so that a true three dimensional particle map was assembled for a 1-mm by 45-mm longitudinal strip and for a 1-mm by 50-mm radial strip. Te-particle density distributions were determined as a function of longitudinal and radial positions in these strips, and treating the particles as vertices of a network created a 3D image of the particle spatial distribution. Te-particles exhibited a multi-modal log-normal size density distribution that indicated a slight preference for increasing size with longitudinal growth time, while showing a pronounced cellular network structure throughout the boule that can be correlated to dislocation network sizes in CZT. Higher magnification images revealed a typical Rayleigh-instability pearl string morphology with large and small satellite droplets. This study includes solidification experiments in small crucibles of 30:70 mixtures of Cd:Te to reduce the melting point below 1273 K (1000?C). These solidification experiments were performed over a wide range of cooling rates and clearly demonstrated a growth instability with Te-particle capture that is suggested to be responsible for one of the peaks in the size distribution using size discrimination visualization. The results are discussed with regard to a manifold Te-particle genesis history as 1) Te-particle direct capture from melt-solid growth instabilities, 2) Te-particle formation from dislocation core diffusion and the formation and breakup of Te-tubes, and 3) Te-particle formation due to classical nucleation and growth as precipitates.

  13. Low pressure shock initiation of porous HMX for two grain size distributions and two densities

    SciTech Connect (OSTI)

    Gustavsen, R.L.; Sheffield, S.A.; Alcon, R.R.

    1995-09-01

    Shock initiation measurements have been made on granular HMX (octotetramethylene tetranitrainine) for two particle size distributions and two densities. Samples were pressed to either 65% or 73% of crystal density from fine ({approx} 10 {mu}m grain size) and coarse (broad distribution of grain sizes peaking at {approx} 150 {mu}m) powders. Planar shocks of 0.2--1 GPa were generated by impacting gas gun driven projectiles on plastic targets containing the HMX. Wave profiles were measured at the input and output of the {approx} 3.9 mm thick HMX layer using electromagnetic particle velocity gauges. The initiation behavior for the two particle size distributions was very different. The coarse HMX began initiating at input pressures as low as 0.5 GPa. Transmitted wave profiles showed relatively slow reaction with most of the buildup occurring at the shock front. In contrast, the fine particle HMX did not begin to initiate at pressures below 0.9 GPa. When the fine powder did react, however, it did so much faster than the coarse HMX. These observations are consistent with commonly held ideas about bum rates being correlated to surface area, and initiation thresholds being correlated with the size and temperature of the hot spots created by shock passage. For each size, the higher density pressings were less sensitive than the lower density pressings.

  14. Ultrashort laser ablation of bulk copper targets: Dynamics and size distribution of the generated nanoparticles

    SciTech Connect (OSTI)

    Tsakiris, N.; Gill-Comeau, M.; Lewis, L. J.; Anoop, K. K.; Ausanio, G.; Bruzzese, R.; Amoruso, S.

    2014-06-28

    We address the role of laser pulse fluence on expansion dynamics and size distribution of the nanoparticles produced by irradiating a metallic target with an ultrashort laser pulse in a vacuum, an issue for which contrasting indications are present in the literature. To this end, we have carried out a combined theoretical and experimental analysis of laser ablation of a bulk copper target with ?50 fs, 800?nm pulses, in an interval of laser fluencies going from few to several times the ablation threshold. On one side, molecular dynamics simulations, with two-temperature model, describe the decomposition of the material through the analysis of the evolution of thermodynamic trajectories in the material phase diagram, and allow estimating the size distribution of the generated nano-aggregates. On the other side, atomic force microscopy of less than one layer nanoparticles deposits on witness plates, and fast imaging of the nanoparticles broadband optical emission provide the corresponding experimental characterization. Both experimental and numerical findings agree on a size distribution characterized by a significant fraction (?90%) of small nanoparticles, and a residual part (?10%) spanning over a rather large size interval, evidencing a weak dependence of the nanoparticles sizes on the laser pulse fluence. Numerical and experimental findings show a good degree of consistency, thus suggesting that modeling can realistically support the search for experimental methods leading to an improved control over the generation of nanoparticles by ultrashort laser ablation.

  15. PublishedbyManeyPublishing(c)IOMCommunicationsLtd Size distribution of oxides and toughness of

    E-Print Network [OSTI]

    Cambridge, University of

    the size distribution of oxide particles in steel weld metals which have predominantly martensitic of steel weld metals S. Terashima* and H. K. D. H. Bhadeshia Experiments have been conducted to modify microstruc- tures dominated by low carbon martensite. The role of oxide particles introduced into the metal

  16. On the Size-Dependence of the Inclination Distribution of the Main Kuiper Belt

    E-Print Network [OSTI]

    Levison, Harold F.

    On the Size-Dependence of the Inclination Distribution of the Main Kuiper Belt Harold F. Levison We present a new analysis of the currently available orbital elements for the known Kuiper belt objects. In the non-resonant, main Kuiper belt we #12;nd a statistically signi#12;cant relationship

  17. Investigation of the relationship between chemical composition and size distribution of airborne particles by partial least

    E-Print Network [OSTI]

    Stanier, Charlie

    combustion sources, secondary aerosol, and coal-fired power plants. The size distribution, particle identified: secondary nitrate 1 and 2, remote traffic, secondary sulfate, lead, diesel traffic, coal-fired power plant, steel mill, nucleation, local traffic, and coke plant. Citation: Zhou, L., P. K. Hopke, C

  18. EVIDENCE FOR A COLOR DEPENDENCE IN THE SIZE DISTRIBUTION OF MAIN-BELT ASTEROIDS Paul Wiegert

    E-Print Network [OSTI]

    Wiegert, Paul

    EVIDENCE FOR A COLOR DEPENDENCE IN THE SIZE DISTRIBUTION OF MAIN-BELT ASTEROIDS Paul Wiegert ($1 km) main-belt asteroids with the 3.6 m Canada-France-Hawaii Telescope. We observed in two filters axis, the difference between the filters in the inner belt is found to be somewhat less pronounced than

  19. Multiscale modeling and control of crystal shape and size distributions: accounting for crystal aggregation, evaluation of continuous crystallization systems and run-to-run control

    E-Print Network [OSTI]

    Kwon, Joseph Sangil

    2015-01-01

    and Size Distributions: Accounting for Crystal Aggregation,and Size Distributions: Accounting for Crystal Aggregation,steady-state growth rate accounting for the dependence of

  20. Vapor Transport of a Volatile Solvent for a Multicomponent Aerosol Droplet

    E-Print Network [OSTI]

    Feng, James Q

    2015-01-01

    This work presents analytical formulas derived for evaluating vapor transport of a volatile solvent for an isolated multicomponent droplet in a quiescent environment, based on quasi-steady-state approximation. Among multiple solvent components, only one component is considered to be much more volatile than the rest such that other components are assumed to be nonvolatile remaining unchanged in the droplet during the process of (single-component) volatile solvent evaporation or condensation. For evaporating droplet, the droplet size often initially decreases following the familiar "d^2 law" at an accelerated rate. But toward the end, the rate of droplet size change diminishes due to the presence of nonvolatile cosolvent. Such an acceleration-deceleration reversal behavior is unique for evaporating multicomponent droplet, while the droplet of pure solvent has an accelerated rate of size change all the way through the end. This reversal behavior is also reflected in the droplet surface temperature evolution as "...

  1. COLOR DEPENDENCE IN THE SIZE DISTRIBUTION OF MAIN BELT ASTEROIDS REVISITED

    SciTech Connect (OSTI)

    August, Tyler M.; Wiegert, Paul A.

    2013-06-15

    The size distribution of the asteroid belt is examined with 16956 main belt asteroids detected in data taken from the Canada-France-Hawaii Telescope Legacy Survey in two filters (g' and r'). The cumulative H (absolute magnitude) distribution is examined in both filters, and both match well to simple power laws down to H = 17, with slopes in rough agreement with those reported the literature. This implies that disruptive collisions between asteroids are gravitationally dominated down to at least this size, and probably sub-kilometer scales. The slopes of these distributions appear shallower in the outer belt than the inner belt, and the g' distributions appear slightly steeper than the r'. The slope shallowing in the outer belt may reflect a real compositional difference: the inner asteroid belt has been suggested to consist mostly of stony and/or metallic S-type asteroids, whereas carbonaceous C-types are thought to be more prevalent further from the Sun. No waves are seen in the size distribution above H = 15. Since waves are expected to be produced at the transition from gravitationally-dominated to internal strength-dominated collisions, their absence here may imply that the transition occurs at sub-kilometer scales, much smaller than the H = 17 (diameter {approx} 1.6 km) cutoff of this study.

  2. Evidence for a colour dependence in the size distribution of main belt asteroids

    E-Print Network [OSTI]

    Paul Wiegert; David Balam; Andrea Moss; Christian Veillet; Martin Connors; Ian Shelton

    2006-11-09

    We present the results of a project to detect small (~1 km) main-belt asteroids with the 3.6 meter Canada-France-Hawaii Telescope (CFHT). We observed in 2 filters (MegaPrime g' and r') in order to compare the results in each band. Owing to the observational cadence we did not observe the same asteroids through each filter and thus do not have true colour information. However strong differences in the size distributions as seen in the two filters point to a colour-dependence at these sizes, perhaps to be expected in this regime where asteroid cohesiveness begins to be dominated by physical strength and composition rather than by gravity. The best fit slopes of the cumulative size distributions (CSDs) in both filters tend towards lower values for smaller asteroids, consistent with the results of previous studies. In addition to this trend, the size distributions seen in the two filters are distinctly different, with steeper slopes in r' than in g'. Breaking our sample up according to semimajor axis, the difference between the filters in the inner belt is found to be somewhat less pronounced than in the middle and outer belt, but the CSD of those asteroids seen in the r' filter is consistently and significantly steeper than in g' throughout. The CSD slopes also show variations with semimajor axis within a given filter, particularly in r'. We conclude that the size distribution of main belt asteroids is likely to be colour dependent at kilometer sizes and that this dependence may vary across the belt.

  3. SIZE DISTRIBUTION AND RATE OF PRODUCTION OF AIRBORNE PARTICULATE MATTER GENERATED DURING METAL CUTTING

    SciTech Connect (OSTI)

    M.A. Ebadian, Ph.D.; S.K. Dua, Ph.D., C.H.P.; Hillol Guha, Ph.D.

    2001-01-01

    During deactivation and decommissioning activities, thermal cutting tools, such as plasma torch, laser, and gasoline torch, are used to cut metals. These activities generate fumes, smoke and particulates. These airborne species of matter, called aerosols, may be inhaled if suitable respiratory protection is not used. Inhalation of the airborne metallic aerosols has been reported to cause ill health effects, such as acute respiratory syndrome and chromosome damage in lymphocytes. In the nuclear industry, metals may be contaminated with radioactive materials. Cutting these metals, as in size reduction of gloveboxes and tanks, produces high concentrations of airborne transuranic particles. Particles of the respirable size range (size < 10 {micro}m) deposit in various compartments of the respiratory tract, the fraction and the site in the respiratory tract depending on the size of the particles. The dose delivered to the respiratory tract depends on the size distribution of the airborne particulates (aerosols) and their concentration and radioactivity/toxicity. The concentration of airborne particulate matter in an environment is dependent upon the rate of their production and the ventilation rate. Thus, measuring aerosol size distribution and generation rate is important for (1) the assessment of inhalation exposures of workers, (2) the selection of respiratory protection equipment, and (3) the design of appropriate filtration systems. Size distribution of the aerosols generated during cutting of different metals by plasma torch was measured. Cutting rates of different metals, rate of generation of respirable mass, as well as the fraction of the released kerf that become respirable were determined. This report presents results of these studies. Measurements of the particles generated during cutting of metal plates with a plasma arc torch revealed the presence of particles with mass median aerodynamic diameters of particles close to 0.2 {micro}m, arising from condensation of vaporized material and subsequent rapid formation of aggregates. Particles of larger size, resulting from ejection of melted material or fragments from the cutting zone, were also observed. This study presents data regarding the metal cutting rate, particle size distribution, and their generation rate, while using different cutting tools and metals. The study shows that respirable particles constitute only a small fraction of the released kerf.

  4. Ultrahigh throughput plasma processing of free standing silicon nanocrystals with lognormal size distribution

    SciTech Connect (OSTI)

    Dogan, Ilker; Kramer, Nicolaas J.; Westermann, Rene H. J.; Verheijen, Marcel A. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Dohnalova, Katerina; Gregorkiewicz, Tom [Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Smets, Arno H. M. [Photovoltaic Materials and Devices Laboratory, Delft University of Technology, P.O. Box 5031, 2600 GA Delft (Netherlands); Sanden, Mauritius C. M. van de [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Dutch Institute for Fundamental Energy Research (DIFFER), P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

    2013-04-07

    We demonstrate a method for synthesizing free standing silicon nanocrystals in an argon/silane gas mixture by using a remote expanding thermal plasma. Transmission electron microscopy and Raman spectroscopy measurements reveal that the distribution has a bimodal shape consisting of two distinct groups of small and large silicon nanocrystals with sizes in the range 2-10 nm and 50-120 nm, respectively. We also observe that both size distributions are lognormal which is linked with the growth time and transport of nanocrystals in the plasma. Average size control is achieved by tuning the silane flow injected into the vessel. Analyses on morphological features show that nanocrystals are monocrystalline and spherically shaped. These results imply that formation of silicon nanocrystals is based on nucleation, i.e., these large nanocrystals are not the result of coalescence of small nanocrystals. Photoluminescence measurements show that silicon nanocrystals exhibit a broad emission in the visible region peaked at 725 nm. Nanocrystals are produced with ultrahigh throughput of about 100 mg/min and have state of the art properties, such as controlled size distribution, easy handling, and room temperature visible photoluminescence.

  5. Size and spacial distribution of micropores in SBA-15 using CM-SANS

    SciTech Connect (OSTI)

    Pollock, Rachel A; Walsh, Brenna R; Fry, Jason A; Ghampson, Tyrone; Centikol, Ozgul; Melnichenko, Yuri B; Kaiser, Helmut; Pynn, Roger; Frederick, Brian G

    2011-01-01

    Diffraction intensity analysis of small-angle neutron scattering measurements of dry SBA-15 have been combined with nonlocal density functional theory (NLDFT) analysis of nitrogen desorption isotherms to characterize the micropore, secondary mesopore, and primary mesopore structure. The radial dependence of the scattering length density, which is sensitive to isolated surface hydroxyls, can only be modeled if the NLDFT pore size distribution is distributed relatively uniformly throughout the silica framework, not localized in a 'corona' around the primary mesopores. Contrast matching-small angle neutron scattering (CM-SANS) measurements, using water, decane, tributylamine, cyclohexane, and isooctane as direct probes of the size of micropores indicate that the smallest pores in SBA-15 have diameter between 5.7 and 6.2 {angstrom}. Correlation of the minimum pore size with the onset of the micropore size distribution provides direct evidence that the shape of the smallest micropores is cylinderlike, which is consistent with their being due to unraveling of the polymer template.

  6. Scale-free Universal Spectrum for Atmospheric Aerosol Size Distribution for Davos, Mauna Loa and Izana

    E-Print Network [OSTI]

    A. M. Selvam

    2014-08-14

    Atmospheric flows exhibit fractal fluctuations and inverse power law form for power spectra indicating an eddy continuum structure for the selfsimilar fluctuations. A general systems theory for fractal fluctuations developed by the author is based on the simple visualisation that large eddies form by space-time integration of enclosed turbulent eddies, a concept analogous to Kinetic Theory of Gases in Classical Statistical Physics. The ordered growth of atmospheric eddy continuum is in dynamical equilibrium and is associated with Maximum Entropy Production. The model predicts universal (scale-free) inverse power law form for fractal fluctuations expressed in terms of the golden mean. Atmospheric particulates are held in suspension in the fractal fluctuations of vertical wind velocity. The mass or radius (size) distribution for homogeneous suspended atmospheric particulates is expressed as a universal scale-independent function of the golden mean, the total number concentration and the mean volume radius. Model predicted spectrum is in agreement (within two standard deviations on either side of the mean) with total averaged radius size spectra for the AERONET (aerosol inversions) stations Davos and Mauna Loa for the year 2010 and Izana for the year 2009 daily averages. The general systems theory model for aerosol size distribution is scale free and is derived directly from atmospheric eddy dynamical concepts. At present empirical models such as the log normal distribution with arbitrary constants for the size distribution of atmospheric suspended particulates are used for quantitative estimation of earth-atmosphere radiation budget related to climate warming/cooling trends. The universal aerosol size spectrum will have applications in computations of radiation balance of earth-atmosphere system in climate models.

  7. Universal fluid droplet ejector

    DOE Patents [OSTI]

    Lee, E.R.; Perl, M.L.

    1999-08-24

    A droplet generator comprises a fluid reservoir having a side wall made of glass or quartz, and an end cap made from a silicon plate. The end cap contains a micromachined aperture through which the fluid is ejected. The side wall is thermally fused to the end cap, and no adhesive is necessary. This means that the fluid only comes into contact with the side wall and the end cap, both of which are chemically inert. Amplitudes of drive pulses received by reservoir determine the horizontal displacements of droplets relative to the ejection aperture. The drive pulses are varied such that the dropper generates a two-dimensional array of vertically-falling droplets. Vertical and horizontal inter-droplet spacings may be varied in real time. Applications include droplet analysis experiments such as Millikan fractional charge searches and aerosol characterization, as well as material deposition applications. 8 figs.

  8. Supplementary material for "Does the size distribution of mineral dust aerosols depend on the wind speed at emission?"

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    Supplementary material for "Does the size distribution of mineral dust aerosols depend on the wind by truncating those bins. I do so by assuming that the sub-bin distribution follows the power law found by both

  9. THERMAL EFFECTS ON DROPLET TRANSPORT IN DIGITIAL MICROFLUIDICS WITH APPLICATIONS TO CHIP COOLING

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    THERMAL EFFECTS ON DROPLET TRANSPORT IN DIGITIAL MICROFLUIDICS WITH APPLICATIONS TO CHIP COOLING, on a platform we call "digital microfluidics," where nanoliter-sized discrete liquid droplets immersed in oil-dependent system parameters on droplet transport in this digital microfluidic platform. We demonstrate

  10. The effect of fuel and engine design on diesel exhaust particle size distributions

    SciTech Connect (OSTI)

    Baumgard, K.J.; Johnson, J.H. [Michigan Technological Univ., Houghton, MI (United States)

    1996-09-01

    The objective of this research was to obtain diesel particle size distributions from a 1988 and a 1991 diesel engine using three different fuels and two exhaust control technologies (a ceramic particle trap and an oxidation catalytic converter). The particle size distributions from both engines were used to develop models to estimate the composition of the individual size particles. Nucleation theory of the H{sub 2}O and H{sub 2}SO{sub 4} vapor is used to predict when nuclei-mode particles will form in the dilution tunnel. Combining the theory with the experimental data, the conditions necessary in the dilution tunnel for particle formation are predicted. The paper also contains a discussion on the differences between the 1988 and 1991 engine`s particle size distributions. The results indicated that nuclei mode particles (0.0075--0.046 {micro}m) are formed in the dilution tunnel and consist of more than 80% H{sub 2}O-H{sub 2}SO{sub 4} particles when using the 1988 engine and 0.29 wt% sulfur fuel. Nucleation theory indicated that H{sub 2}O-H{sub 2}SO{sub 4} particles may form during dilution at 0.03 wt% fuel sulfur levels and above. The 1991 engine was designed for lower particulate emissions than the 1988 engine and the 1991 engine`s accumulation mode particles (0.046-1.0 {micro}m) were reduced more than 80% by volume compared to the 1988 engine using the same low sulfur fuel. The particle size composition model indicated that using low sulfur fuel and the 1991 engine, the nuclei mode contained more than 45% of the total solid particles and over 85% of the soluble organic fraction.

  11. Wetting kinetics of water nano-droplet containing non-surfactant nanoparticles: A molecular dynamics study

    SciTech Connect (OSTI)

    Lu, Gui; Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, Pennsylvania 19104 ; Hu, Han; Sun, Ying E-mail: ysun@coe.drexel.edu; Duan, Yuanyuan E-mail: ysun@coe.drexel.edu

    2013-12-16

    In this Letter, dynamic wetting of water nano-droplets containing non-surfactant gold nanoparticles on a gold substrate is examined via molecular dynamics simulations. The results show that the addition of non-surfactant nanoparticles hinders the nano-second droplet wetting process, attributed to the increases in both surface tension of the nanofluid and friction between nanofluid and substrate. The droplet wetting kinetics decreases with increasing nanoparticle loading and water-particle interaction energy. The observed wetting suppression and the absence of nanoparticle ordering near the contact line of nano-sized droplets differ from the wetting behaviors reported from nanofluid droplets of micron size or larger.

  12. Oil droplet in alcohol

    E-Print Network [OSTI]

    La Foy, Roderick R.

    The elegant patterns formed by fluid droplets falling through a dissimilar liquid were first studied over a century ago.1 The emerging patterns are driven by hydrodynamic instabilities set up by velocity and density gradients ...

  13. Universal fluid droplet ejector

    DOE Patents [OSTI]

    Lee, Eric R. (Redwood City, CA); Perl, Martin L. (Palo Alto, CA)

    1999-08-24

    A droplet generator comprises a fluid reservoir having a side wall made of glass or quartz, and an end cap made from a silicon plate. The end cap contains a micromachined aperture through which the fluid is ejected. The side wall is thermally fused to the end cap, and no adhesive is necessary. This means that the fluid only comes into contact with the side wall and the end cap, both of which are chemically inert. Amplitudes of drive pulses received by reservoir determine the horizontal displacements of droplets relative to the ejection aperture. The drive pulses are varied such that the dropper generates a two-dimensional array of vertically-falling droplets. Vertical and horizontal interdroplet spacings may be varied in real time. Applications include droplet analysis experiments such as Millikan fractional charge searches and aerosol characterization, as well as material deposition applications.

  14. Evaporation/ Solution Droplet

    E-Print Network [OSTI]

    Suslick, Kenneth S.

    Solvent Evaporation/ Reactions Precursor Solution Droplet Product Densification Product Collection Production of Nano-Materials microporous shell internal macropores Hierarchically Porous Carbons Brandon Ito (20 ppm) Formaldehyde (20 ppm) Control (50% RH) Maryam SayyahKaty Filson Wei Jiang Mechanoluminescence

  15. Nematic droplets at fibres

    E-Print Network [OSTI]

    V. M. O. Batista; N. M. Silvestre; M. M. Telo da Gama

    2015-06-24

    The emergence of new techniques for the fabrication of nematic droplets with nontrivial topology provides new routes for the assembly of responsive devices. Here we perform a numerical study of spherical nematic droplets on fibres. We analyse the equilibrium textures and find that, under certain conditions,the nematic can avoid the nucleation of topological defects. We consider in detail a homeotropic nematic droplet wrapped around a fibre with planar anchoring. We investigate the effect of an electric field on the texture of this droplet such type of system. In the presence of a DC field, the system undergoes a Freederickzs-like transition above a given threshold $E_c$. We also consider AC fields, at high and low frequencies, and find that the textures are similar to those observed for static fields, in contrast with recently reported experiments.

  16. Prediction of the Size Distributions of Methanol-Ethanol Clusters Detected in VUV Laser/Time-of-Flight Mass Spectrometry

    E-Print Network [OSTI]

    Goddard III, William A.

    Prediction of the Size Distributions of Methanol-Ethanol Clusters Detected in VUV Laser distributions and geometries of vapor clusters equilibrated with methanol-ethanol (Me-Et) liquid mixtures were distributions of vapor clusters equilibrated with liquids, ranging from neat alcohols1,2 to methanol-ethanol (Me

  17. Platinum nanoparticle during electrochemical hydrogen evolution: Adsorbate distribution, active reaction species, and size effect

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tan, Teck L.; Wang, Lin -Lin; Zhang, Jia; Johnson, Duane D.; Bai, Kewu

    2015-03-13

    For small Pt nanoparticles (NPs), catalytic activity is, as observed, adversely affected by size in the 1–3 nm range. We elucidate, via first-principles-based thermodynamics, the operation H* distribution and cyclic voltammetry (CV) during the hydrogen evolution reaction (HER) across the electrochemical potential, including the underpotential region (U ? 0) that is difficult to assess in experiment. We consider multiple adsorption sites on a 1 nm Pt NP model and show that the characteristic CV peaks from different H* species correspond well to experiment. We next quantify the activity contribution from each H* species to explain the adverse effect of size.more »From the resolved CV peaks at the standard hydrogen electrode potential (U = 0), we first deduce that the active species for the HER are the partially covered (100)-facet bridge sites and the (111)-facet hollow sites. Upon evaluation of the reaction barriers at operation H* distribution and microkinetic modeling of the exchange current, we find that the nearest-neighbor (100)-facet bridge site pairs have the lowest activation energy and contribute to ~75% of the NP activity. Edge bridge sites (fully covered by H*) per se are not active; however, they react with neighboring (100)-facet H* to account for ~18% of the activity, whereas (111)-facet hollow sites contribute little. As a result, extrapolating the relative contributions to larger NPs in which the ratio of facet-to-edge sites increases, we show that the adverse size effect of Pt NP HER activity kicks in for sizes below 2 nm.« less

  18. Extracting magnetic cluster size and its distributions in advanced perpendicular recording media with shrinking grain size using small angle x-ray scattering

    SciTech Connect (OSTI)

    Mehta, Virat; Ikeda, Yoshihiro; Takano, Ken; Terris, Bruce D.; Hellwig, Olav; Wang, Tianhan; Wu, Benny; Graves, Catherine; Dürr, Hermann A.; Scherz, Andreas; Stöhr, Jo

    2015-05-18

    We analyze the magnetic cluster size (MCS) and magnetic cluster size distribution (MCSD) in a variety of perpendicular magnetic recording (PMR) media designs using resonant small angle x-ray scattering at the Co L{sub 3} absorption edge. The different PMR media flavors considered here vary in grain size between 7.5 and 9.5?nm as well as in lateral inter-granular exchange strength, which is controlled via the segregant amount. While for high inter-granular exchange, the MCS increases rapidly for grain sizes below 8.5?nm, we show that for increased amount of segregant with less exchange the MCS remains relatively small, even for grain sizes of 7.5 and 8?nm. However, the MCSD still increases sharply when shrinking grains from 8 to 7.5?nm. We show evidence that recording performance such as signal-to-noise-ratio on the spin stand correlates well with the product of magnetic cluster size and magnetic cluster size distribution.

  19. Spontaneous Charging and Crystallization of Water Droplets in Oil

    E-Print Network [OSTI]

    Joost de Graaf; Jos Zwanikken; Markus Bier; Arjen Baarsma; Yasha Oloumi; Mischa Spelt; Rene van Roij

    2008-07-31

    We study the spontaneous charging and the crystallization of spherical micron-sized water-droplets dispersed in oil by numerically solving, within a Poisson-Boltzmann theory in the geometry of a spherical cell, for the density profiles of the cations and anions in the system. We take into account screening, ionic Born self-energy differences between oil and water, and partitioning of ions over the two media. We find that the surface charge density of the droplet as induced by the ion partitioning is significantly affected by the droplet curvature and by the finite density of the droplets. We also find that the salt concentration and the dielectric constant regime in which crystallization of the water droplets is predicted is enhanced substantially compared to results based on the planar oil-water interface, thereby improving quantitative agreement with recent experiments.

  20. Polarized light propagation in highly scattering turbid media with a distribution of the particle size: a Monte Carlo study 

    E-Print Network [OSTI]

    Koh, Wonshill

    2013-02-22

    The light propagation in highly scattering turbid media composed of the particles with different size distribution is studied using a Monte Carlo simulation model implemented in Standard C. Monte Carlo method has been widely utilized to study...

  1. The effect of sand grain size distribution on the minimum oil saturation necessary to support in-situ combustion 

    E-Print Network [OSTI]

    Daniel, William Marvin

    1973-01-01

    THE EFFECT OF SAND GRAIN SIZE DISTRIBUTION ON THE MINIMUM OIL SATURATION NECESSARY TO SUPPORT IN-SITU COMBUSTION A Thesis by WILLIAM MARVIN DANIEL Submitted to the Graduate College of Texas ARM University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 1973 Major Subject: Petroleum. Engineering THE EFFECT OF SAND GRAIN SIZE DISTRIBUTION ON THE MINIMUM OIL SATURATION NECESSARY TO SUPPORT IN-SITU COMBUSTION A Thesis by WILLIAM MARVIN DANIEL Approved...

  2. Chip-based droplet sorting

    DOE Patents [OSTI]

    Beer, Neil Reginald; Lee, Abraham; Hatch, Andrew

    2014-07-01

    A non-contact system for sorting monodisperse water-in-oil emulsion droplets in a microfluidic device based on the droplet's contents and their interaction with an applied electromagnetic field or by identification and sorting.

  3. Distribution approximations for the chemical master equation: comparison of the method of moments and the system size expansion

    E-Print Network [OSTI]

    Alexander Andreychenko; Luca Bortolussi; Ramon Grima; Philipp Thomas; Verena Wolf

    2015-09-30

    The stochastic nature of chemical reactions involving randomly fluctuating population sizes has lead to a growing research interest in discrete-state stochastic models and their analysis. A widely-used approach is the description of the temporal evolution of the system in terms of a chemical master equation (CME). In this paper we study two approaches for approximating the underlying probability distributions of the CME. The first approach is based on an integration of the statistical moments and the reconstruction of the distribution based on the maximum entropy principle. The second approach relies on an analytical approximation of the probability distribution of the CME using the system size expansion, considering higher-order terms than the linear noise approximation. We consider gene expression networks with unimodal and multimodal protein distributions to compare the accuracy of the two approaches. We find that both methods provide accurate approximations to the distributions of the CME while having different benefits and limitations in applications.

  4. Distribution of maximal clique size of the vertices for theoretical small-world networks and real-world networks

    E-Print Network [OSTI]

    Meghanathan, Natarajan

    2015-01-01

    Our primary objective in this paper is to study the distribution of the maximal clique size of the vertices in complex networks. We define the maximal clique size for a vertex as the maximum size of the clique that the vertex is part of and such a clique need not be the maximum size clique for the entire network. We determine the maximal clique size of the vertices using a modified version of a branch-and-bound based exact algorithm that has been originally proposed to determine the maximum size clique for an entire network graph. We then run this algorithm on two categories of complex networks: One category of networks capture the evolution of small-world networks from regular network (according to the wellknown Watts-Strogatz model) and their subsequent evolution to random networks; we show that the distribution of the maximal clique size of the vertices follows a Poisson-style distribution at different stages of the evolution of the small-world network to a random network; on the other hand, the maximal cl...

  5. Oscillatory Flame Response in Acoustically Coupled Fuel Droplet Combustion

    E-Print Network [OSTI]

    Sevilla Esparza, Cristhian Israel

    2013-01-01

    CombustionCombustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Coupled Droplet Combustion . . . . . . . . . . . . Burning

  6. Hovering UFO Droplets

    E-Print Network [OSTI]

    Anand, Sushant; Dhiman, Rajeev; Smith, J David; Varanasi, Kripa K

    2012-01-01

    This fluid dynamics video is an entry for the Gallery of Fluid Motion of the 65th Annual Meeting of the APS-DFD. This video shows behavior of condensing droplets on a lubricant impregnated surface and a comparison with a superhydrophobic surface. On impregnated surfaces, drops appear like UFOs hovering over a surface. The videos were recorded in an Environmental SEM and a specially built condensation rig.

  7. Relationship between Particle Size Distribution of Low-Rank Pulverized Coal and Power Plant Performance

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ganguli, Rajive; Bandopadhyay, Sukumar

    2012-01-01

    The impact of particle size distribution (PSD) of pulverized, low rank high volatile content Alaska coal on combustion related power plant performance was studied in a series of field scale tests. Performance was gauged through efficiency (ratio of megawatt generated to energy consumed as coal), emissions (SO 2 , NO x , CO), and carbon content of ash (fly ash and bottom ash). The study revealed that the tested coal could be burned at a grind as coarse as 50% passing 76 microns, with no deleterious impact on power generation andmore »emissions. The PSD’s tested in this study were in the range of 41 to 81 percent passing 76 microns. There was negligible correlation between PSD and the followings factors: efficiency, SO 2 , NO x , and CO. Additionally, two tests where stack mercury (Hg) data was collected, did not demonstrate any real difference in Hg emissions with PSD. The results from the field tests positively impacts pulverized coal power plants that burn low rank high volatile content coals (such as Powder River Basin coal). These plants can potentially reduce in-plant load by grinding the coal less (without impacting plant performance on emissions and efficiency) and thereby, increasing their marketability. « less

  8. Characterization of Vertical Velocity and Drop Size Distribution Parameters in Widespread Precipitation at ARM Facilities

    SciTech Connect (OSTI)

    Giangrande S. E.; Luke, E. P.; Kollias, P.

    2012-02-01

    Extended, high-resolution measurements of vertical air motion and median volume drop diameter D0 in widespread precipitation from three diverse Atmospheric Radiation Measurement Program (ARM) locations [Lamont, Oklahoma, Southern Great Plains site (SGP); Niamey, Niger; and Black Forest, Germany] are presented. The analysis indicates a weak (0-10 cm{sup -1}) downward air motion beneath the melting layer for all three regions, a magnitude that is to within the typical uncertainty of the retrieval methods. On average, the hourly estimated standard deviation of the vertical air motion is 0.25 m s{sup -1} with no pronounced vertical structure. Profiles of D0 vary according to region and rainfall rate. The standard deviation of 1-min-averaged D0 profiles for isolated rainfall rate intervals is 0.3-0.4 mm. Additional insights into the form of the raindrop size distribution are provided using available dual-frequency Doppler velocity observations at SGP. The analysis suggests that gamma functions better explain paired velocity observations and radar retrievals for the Oklahoma dataset. This study will be useful in assessing uncertainties introduced in the measurement of precipitation parameters from ground-based and spaceborne remote sensors that are due to small-scale variability.

  9. Solitary Dust--Acoustic Waves in a Plasma with Two-Temperature Ions and Distributed Grain Size

    E-Print Network [OSTI]

    V. V. Prudskikh

    2008-12-02

    The propagation of weakly nonlinear dust--acoustic waves in a dusty plasma containing two ion species with different temperatures is explored. The nonlinear equations describing both the quadratic and cubic plasma nonlinearities are derived. It is shown that the properties of dust--acoustic waves depend substantially on the grain size distribution. In particular, for solitary dust--acoustic waves with a positive potential to exist in a plasma with distributed grain size, it is necessary that the difference between the temperatures of two ion species be large that that in the case of unusized grains.

  10. Evolution of soot size distribution in premixed ethylene/air and ethylene/benzene/air flames: Experimental and modeling study

    SciTech Connect (OSTI)

    Echavarria, Carlos A.; Sarofim, Adel F.; Lighty, JoAnn S.; D'Anna, Andrea

    2011-01-15

    The effect of benzene concentration in the initial fuel on the evolution of soot size distribution in ethylene/air and ethylene/benzene/air flat flames was characterized by experimental measurements and model predictions of size and number concentration within the flames. Experimentally, a scanning mobility particle sizer was used to allow spatially resolved and online measurements of particle concentration and sizes in the nanometer-size range. The model couples a detailed kinetic scheme with a discrete-sectional approach to follow the transition from gas-phase to nascent particles and their coagulation to larger soot particles. The evolution of soot size distribution (experimental and modeled) in pure ethylene and ethylene flames doped with benzene showed a typical nucleation-sized (since particles do not actually nucleate in the classical sense particle inception is often used in place of nucleation) mode close to the burner surface, and a bimodal behavior at greater height above burner (HAB). However, major features were distinguished between the data sets. The growth of nucleation and agglomeration-sized particles was faster for ethylene/benzene/air flames, evidenced by the earlier presence of bimodality in these flames. The most significant changes in size distribution were attributed to an increase in benzene concentration in the initial fuel. However, these changes were more evident for high temperature flames. In agreement with the experimental data, the model also predicted the decrease of nucleation-sized particles in the postflame region for ethylene flames doped with benzene. This behavior was associated with the decrease of soot precursors after the main oxidation zone of the flames. (author)

  11. Growth Kinetics of the Homogeneously Nucleated Water Droplets: Simulation Results

    E-Print Network [OSTI]

    Mokshin, Anatolii V; 10.1088/1742-6596/394/1/012023

    2012-01-01

    The growth of homogeneously nucleated droplets in water vapor at the fixed temperatures T=273, 283, 293, 303, 313, 323, 333, 343, 353, 363 and 373 K (the pressure $p=1$ atm.) is investigated on the basis of the coarse-grained molecular dynamics simulation data with the mW-model. The treatment of simulation results is performed by means of the statistical method within the mean-first-passage-time approach, where the reaction coordinate is associated with the largest droplet size. It is found that the water droplet growth is characterized by the next features: (i) the rescaled growth law is unified at all the considered temperatures and (ii) the droplet growth evolves with acceleration and follows the power law.

  12. Controlled Dispensing and Mixing of Pico- to Nanoliter Volumes Using On-Demand Droplet-Based Microfluidics

    SciTech Connect (OSTI)

    Sun, Xuefei; Tang, Keqi; Smith, Richard D.; Kelly, Ryan T.

    2013-07-08

    We present an integrated droplet-on-demand microfluidic platform for dispensing, mixing, incubating, extracting and analyzing by mass spectrometry pico- to nanoliter sized droplets. Droplet generation is accomplished using computer-controlled pneumatic valves. Controlled actuation of valves for different aqueous streams enables controlled dosing and rapid mixing of reagents within droplets in the droplet generation area or in a region with widening channel cross-section. Following incubation, which takes place while droplets travel in the oil stream, the droplet contents are extracted to an aqueous channel for subsequent ionization at an integrated nanoelectrospray emitter. As an initial demonstration of the platform, rapid enzymatic digestions of a model protein are performed in droplets and detected on-line by nanoelectrospray ionization mass spectrometry.

  13. Method development and validation for measuring the particle size distribution of pentaerythritol tetranitrate (PETN) powders.

    SciTech Connect (OSTI)

    Young, Sharissa Gay

    2005-09-01

    Currently, the critical particle properties of pentaerythritol tetranitrate (PETN) that influence deflagration-to-detonation time in exploding bridge wire detonators (EBW) are not known in sufficient detail to allow development of a predictive failure model. The specific surface area (SSA) of many PETN powders has been measured using both permeametry and gas absorption methods and has been found to have a critical effect on EBW detonator performance. The permeametry measure of SSA is a function of particle shape, packed bed pore geometry, and particle size distribution (PSD). Yet there is a general lack of agreement in PSD measurements between laboratories, raising concerns regarding collaboration and complicating efforts to understand changes in EBW performance related to powder properties. Benchmarking of data between laboratories that routinely perform detailed PSD characterization of powder samples and the determination of the most appropriate method to measure each PETN powder are necessary to discern correlations between performance and powder properties and to collaborate with partnering laboratories. To this end, a comparison was made of the PSD measured by three laboratories using their own standard procedures for light scattering instruments. Three PETN powder samples with different surface areas and particle morphologies were characterized. Differences in bulk PSD data generated by each laboratory were found to result from variations in sonication of the samples during preparation. The effect of this sonication was found to depend on particle morphology of the PETN samples, being deleterious to some PETN samples and advantageous for others in moderation. Discrepancies in the submicron-sized particle characterization data were related to an instrument-specific artifact particular to one laboratory. The type of carrier fluid used by each laboratory to suspend the PETN particles for the light scattering measurement had no consistent effect on the resulting PSD data. Finally, the SSA of the three powders was measured using both permeametry and gas absorption methods, enabling the PSD to be linked to the SSA for these PETN powders. Consistent characterization of other PETN powders can be performed using the appropriate sample-specific preparation method, so that future studies can accurately identify the effect of changes in the PSD on the SSA and ultimately model EBW performance.

  14. Gap-Size Distribution Functions of a Random Sequential Adsorption Model of Segments on the Line

    E-Print Network [OSTI]

    N. A. M. Araujo; A. Cadilhe

    2006-04-24

    We performed extensive simulations accompanied by a detailed study of a two-segment size random sequential model on the line. We followed the kinetics towards the jamming state, but we paid particular attention to the characterization of the jamming state structure. In particular, we studied the effect of the size ratio on the mean-gap size, the gap-size dispersion, gap-size skewness, and gap-size kurtosis at the jamming state. We also analyzed the above quantities for the four possible segment-to-segment gap types. We ranged the values of the size ratio from one to twenty. In the limit of a size ratio of one, one recovers the classical car-parking problem. We observed that at low size ratios the jamming state is constituted by short streaks of small and large segments, while at high values of the size ratio the jamming state structure is formed by long streaks of small segments separated by a single large segment. This view of the jamming state structure as a function of the size ratio is supported by the various measured quantities. The present work can help provide insight, for example, on how to minimize the interparticle distance or minimize fluctuations around the mean particle-to-particle distance.

  15. Influence of Cement Particle-Size Distribution on Early Age Autogenous Strains and Stresses in Cement-Based Materials

    E-Print Network [OSTI]

    Bentz, Dale P.

    Influence of Cement Particle-Size Distribution on Early Age Autogenous Strains and Stresses in Cement-Based Materials Dale P. Bentz* Building and Fire Research Laboratory, National Institute-Jochen Haecker* Wilhelm Dyckerhoff Institut, 65203 Wiesbaden, Germany The influence of cement particle

  16. Impaction of spray droplets on leaves: influence of formulation and leaf character on shatter, bounce and adhesion

    E-Print Network [OSTI]

    Dorr, Gary J; Mayo, Lisa C; McCue, Scott W; Forster, W Alison; Hanan, Jim; He, Xiongkui

    2015-01-01

    This paper combines experimental data with simple mathematical models to investigate the influence of spray formulation type and leaf character (wettability) on shatter, bounce and adhesion of droplets impacting with cotton, rice and wheat leaves. Impaction criteria that allow for different angles of the leaf surface and the droplet impact trajectory are presented; their predictions are based on whether combinations of droplet size and velocity lie above or below bounce and shatter boundaries. In the experimental component, real leaves are used, with all their inherent natural variability. Further, commercial agricultural spray nozzles are employed, resulting in a range of droplet characteristics. Given this natural variability, there is broad agreement between the data and predictions. As predicted, the shatter of droplets was found to increase as droplet size and velocity increased, and the surface became harder to wet. Bouncing of droplets occurred most frequently on hard to wet surfaces with high surface ...

  17. Vapor Transport of a Volatile Solvent for a Multicomponent Aerosol Droplet

    E-Print Network [OSTI]

    James Q. Feng

    2015-07-19

    This work presents analytical formulas derived for evaluating vapor transport of a volatile solvent for an isolated multicomponent droplet in a quiescent environment, based on quasi-steady-state approximation. Among multiple solvent components, only one component is considered to be much more volatile than the rest such that other components are assumed to be nonvolatile remaining unchanged in the droplet during the process of (single-component) volatile solvent evaporation or condensation. For evaporating droplet, the droplet size often initially decreases following the familiar "d^2 law" at an accelerated rate. But toward the end, the rate of droplet size change diminishes due to the presence of nonvolatile cosolvent. Such an acceleration-deceleration reversal behavior is unique for evaporating multicomponent droplet, while the droplet of pure solvent has an accelerated rate of size change all the way through the end. This reversal behavior is also reflected in the droplet surface temperature evolution as "S-shaped" curves. However, a closer mathematical examination of conditions for acceleration-deceleration reversal indicates that the acceleration phase may disappear when the amount of nonvolatile cosolvent is relatively small and ambient vapor pressure is relatively high. Because the net effect of adding nonvolatile cosolvent is to reduce the mole fraction of the volatile solvent such that the saturation vapor pressure is lowered, vapor condensation onto the multicomponent droplet is predicted to occur when the ambient vapor pressure is subsaturated with respect to that for the pure volatile solvent. In this case, the droplet will grow asymptotically toward a finite size. But when the ambient vapor pressure becomes supersaturated with respect to that for the pure volatile solvent, the condensation growth of droplet can continue indefinitely without bound.

  18. Droplet Combustion and Non-Reactive Shear-Coaxial Jets with Transverse Acoustic Excitation

    E-Print Network [OSTI]

    Teshome, Sophonias

    2012-01-01

    Related Works in Droplet Combustion . . . . . . . .of Acoustics on Droplet Combustion . . . . . . . . . . . .Fuel Droplet Combustion . . . . . . . . . . . . . . .

  19. Effect of Particle Optical Properties on Size Distribution of Soils Obtained by Laser Diffraction

    E-Print Network [OSTI]

    Ahmad, Sajjad

    ) is essential infor- mation for those in the fields of engineering and environmental geosciences, sedimentology, sedimentology, pedology, etc. (Wen et al., 2002). In geotechnical practices, PSD and clay-size fraction of soils

  20. Ice and water droplets on graphite: A comparison of quantum and classical simulations Rafael Ramrez, Jayant K. Singh, Florian Mller-Plathe, and Michael C. Bhm

    E-Print Network [OSTI]

    Singh, Jayant K.

    to reproduce the macroscopic contact angle of water droplets on graphite. Several energetic and structural compared with the values of ice Ih and liquid water as a function of temperature. The droplet kinetic properties of water droplets with sizes between 102 and 103 molecules were analyzed in a temperature interval

  1. Optimal Placement and Sizing of Distributed Generator Units using Genetic Optimization

    E-Print Network [OSTI]

    and electricity in the distribution grid. A group of DG units can form a virtual power plant, being centrally controlled and behaving as a single power plant towards the grid. The extreme case is an energy island to conventional power plants distributed generation units such as PV cells (depending on solar illumination

  2. Shoreline, grain-size, and total-carbon distribution changes before and after Hurricane Alicia, Galveston Island, Texas, 1983

    SciTech Connect (OSTI)

    Rothammer, C.M.; Morrison, L.R.; Warkentin, S.L.

    1985-02-01

    Shoreline, grain-size, and sediment total-carbon changes were monitored, on a monthly basis, on three Galveston Island beaches, from January through December 1983. The study area included: (1) East Beach, obstructed by groins and a seawall; (2) Galveston Island State Park, obstructed by fences artificially stabilizing the dunes; and (3) West Beach, an unobstructed beach. Beach profiles revealed the effects of beach obstruction, such as erosion and undercutting at East Beach, and truncation of the dunes at Galveston Island State Park. Approximately 20 m of expansional cutback occurred on the beaches after Hurricane Alicia hit on August 18, 1983. Contour maps of grain-size and total-carbon distributions reflect the movement of beach sand by either onshore-offshore transport during low-energy periods, or longshore, edge-wave transport during high-energy periods. Statistical analyses revealed a small variation in grain size throughout the year. There were well-defined times of either no correlation or strong correlation between total carbon vs. mean grain size, skewness vs. mean grain size, kurtosis vs. mean grain size, skewness vs. mean grain size, kurtosis vs. mean grain size, total carbon vs. percent sand, total carbon vs. skewness, and skewness vs. kurtosis. Strong correlation was found in response to high-energy events, whereas no correlation was found in response to low-energy events. Galveston Island is undergoing net erosion and appears to be in a metastable state, still capable of responding to oceanographic conditions. The economic effects of Hurricane Alicia include considerable loss of the shoreline and destruction of property. Beach nourishment appears to be the only economically feasible solution to counteract the extensive erosion.

  3. Environmental Transmission Electron Microscopy Study of the Origins of Anomalous Particle Size Distributions in Supported Metal Catalysts

    SciTech Connect (OSTI)

    Benavidez, Angelica D.; Kovarik, Libor; Genc, Arda; Agrawal, Nitin; Larsson, Elin M.; Hansen, Thomas W.; Karim, Ayman M.; Datye, Abhaya K.

    2012-10-31

    In this Environmental TEM (ETEM) study of supported Pt and Pd model catalysts, individual nanoparticles were tracked during heat treatments at temperatures up to 600°C in H2, O2, and vacuum. We found anomalous growth of nanoparticles occurred during the early stages of catalyst sintering wherein some particles started to grow significantly larger than the mean, resulting in a broadening of the particle size distribution. We can rule out sample non-uniformity as a cause for the growth of these large particles, since images were recorded prior to heat treatments. The anomalous growth of these particles may help explain particle size distributions in heterogeneous catalysts which often show particles that are significantly larger than the mean, resulting in a long tail to the right. It has been suggested that particle migration and coalescence could be the likely cause for the broad size distributions. This study shows that anomalous growth of nanoparticles can occur under conditions where Ostwald ripening is the primary sintering mechanism.

  4. Ising model fog drip: the first two droplets

    E-Print Network [OSTI]

    Dmitry Ioffe; Senya Shlosman

    2007-10-31

    We present here a simple model describing coexistence of solid and vapour phases. The two phases are separated by an interface. We show that when the concentration of supersaturated vapour reaches the dew-point, the droplet of solid is created spontaneously on the interface, adding to it a monolayer of a visible size.

  5. Marine particle dynamics : sinking velocities, size distributions, fluxes, and microbial degradation rates

    E-Print Network [OSTI]

    McDonnell, Andrew M. P

    2011-01-01

    The sinking flux of particulate matter into the ocean interior is an oceanographic phenomenon that fuels much of the metabolic demand of the subsurface ocean and affects the distribution of carbon and other elements ...

  6. Method and apparatus for controlled size distribution of gel microspheres formed from aqueous dispersions. [Patent application

    DOE Patents [OSTI]

    Ryon, A.D.; Haas, P.A.; Vavruska, J.S.

    1982-01-19

    The present invention is directed to a method and apparatus for making a population of dense, closely size-controlled microspheres by sol-gel procedures wherein said microspheres are characterized by a significant percentage of said population being within a predetermined, relatively narrow size range. This is accomplished by subjecting aqueous dispersions of a sol, within a water-immiscible organic liquid to a turbulent flow. Microsphere populations thus provided are useful in vibratory-packed processes for nuclear fuels to be irradiated in LWR- and FBR-type nuclear reactors.

  7. Founding, Foraging, and Fighting: Colony Size and the Spatial Distribution of Harvester Ant Author(s): Deborah M. Gordon and Alan W. Kulig

    E-Print Network [OSTI]

    Gordon, Deborah

    Founding, Foraging, and Fighting: Colony Size and the Spatial Distribution of Harvester Ant Nests of America FOUNDING, FORAGING, AND FIGHTING: COLONY SIZE AND THE SPATIAL DISTRIBUTION OF HARVESTER ANT NESTS meet, most fights are brief, with few resulting in injury or death. These results suggest that the cost

  8. Ice nucleation and droplet formation by bare and coated soot particles

    E-Print Network [OSTI]

    Friedman, Beth

    We have studied ice formation at temperatures relevant to homogeneous and heterogeneous ice nucleation, as well as droplet activation and hygroscopicity, of soot particles of variable size and composition. Coatings of ...

  9. Electrostatic charging of jumping droplets

    E-Print Network [OSTI]

    Miljkovic, Nenad

    With the broad interest in and development of superhydrophobic surfaces for self-cleaning, condensation heat transfer enhancement and anti-icing applications, more detailed insights on droplet interactions on these surfaces ...

  10. LOAD PROFILING IN DISTRIBUTED REAL-TIME SYSTEMS \\One Size Doesn't Fit All"

    E-Print Network [OSTI]

    pro ling, the system attempts to distribute the load amongst its nodes so as to maximize the chances of nding a node that would satisfy the computational needs of incoming real-time tasks. To that end, we on a solid, analytical foundation for real-time resource management. Examples include the Ada RTSIA

  11. LOAD PROFILING IN DISTRIBUTED REALTIME SYSTEMS \\Lambda ``One Size Doesn't Fit All''

    E-Print Network [OSTI]

    . Using load profiling, the system attempts to distribute the load amongst its nodes so as to maximize the chances of finding a node that would satisfy the computational needs of incoming real­time tasks engineering based on a solid, analytical foundation for real­time resource management. Examples include

  12. Determination of plasma frequency, damping constant, and size distribution from the complex dielectric function of noble metal nanoparticles

    SciTech Connect (OSTI)

    Mendoza Herrera, Luis J.; Arboleda, David Muñetón; Schinca, Daniel C.; Scaffardi, Lucía B.

    2014-12-21

    This paper develops a novel method for simultaneously determining the plasma frequency ?{sub P}?? and the damping constant ?{sub free} in the bulk damped oscillator Drude model, based on experimentally measured real and imaginary parts of the metal refractive index in the IR wavelength range, lifting the usual approximation that restricts frequency values to the UV-deep UV region. Our method was applied to gold, silver, and copper, improving the relative uncertainties in the final values for ?{sub p} (0.5%–1.6%) and for ?{sub free} (3%–8%), which are smaller than those reported in the literature. These small uncertainties in ?{sub p} and ?{sub free} determination yield a much better fit of the experimental complex dielectric function. For the case of nanoparticles (Nps), a series expansion of the Drude expression (which includes ?{sub p} and ?{sub free} determined using our method) enables size-dependent dielectric function to be written as the sum of three terms: the experimental bulk dielectric function plus two size corrective terms, one for free electron, and the other for bound-electron contributions. Finally, size distribution of nanometric and subnanometric gold Nps in colloidal suspension was determined through fitting its experimental optical extinction spectrum using Mie theory based on the previously determined dielectric function. Results are compared with size histogram obtained from Transmission Electron Microscopy (TEM)

  13. Copyright c 2006 Tech Science Press FDMP, vol.2, no.2, pp.77-93, 2006 Scalings for Droplet Sizes in Shear-Driven Breakup: Non-Microfluidic Ways to

    E-Print Network [OSTI]

    Renardy, Yuriko

    in Shear-Driven Breakup: Non-Microfluidic Ways to Monodisperse Emulsions V. Cristini1 and Y. Renardy2 to produce monodispersity as an alternative to microfluidic devices. keyword: Drop deformation, drop size

  14. Application of small-angle neutron scattering to the study of forces between magnetically chained monodisperse ferrofluid emulsion droplets

    SciTech Connect (OSTI)

    Jain, Dr Nirmesh [University of Sydney, Australia] [University of Sydney, Australia; Liu, Dr C K [Institute of Materials research and Engineering, A-STAR, Singapore] [Institute of Materials research and Engineering, A-STAR, Singapore; Hawkett, Dr B. S. [University of Sydney, Australia] [University of Sydney, Australia; Warr, G. G. [University of Sydney, Australia] [University of Sydney, Australia; Hamilton, William A [ORNL] [ORNL

    2014-01-01

    The optical magnetic chaining technique (MCT) developed by Leal-Calderon, Bibette and co-workers in the 1990 s allows precise measurements of force profiles between droplets in monodisperse ferrofluid emulsions. However, the method lacks an in-situ determination of droplet size and therefore requires the combination of separately acquired measurements of droplet chain periodicity versus an applied magnetic field from optical Bragg scattering and droplet diameter inferred from dynamic light scattering (DLS) to recover surface force-distance profiles between the colloidal particles. Compound refractive lens (CRL) focussed small-angle scattering (SANS) MCT should result in more consistent measurements of droplet size (form factor measurements in the absence of field) and droplet chaining period (from structure factor peaks when the magnetic field is applied); and, with access to shorter length scales, extend force measurements to closer approaches than possible by optical measurements. We report on CRL-SANS measurements of monodisperse ferrofluid emulsion droplets aligned in straight chains by an applied field perpendicular to the incident beam direction. Analysis of the scattering from the closely spaced droplets required algorithms that carefully treated resolution and its effect on mean scattering vector magnitudes in order to determine droplet size and chain periods to sufficient accuracy. At lower applied fields scattering patterns indicate structural correlations transverse to the magnetic field direction due to the formation of intermediate structures in early chain growth.

  15. Theoretical studies on hydrogen ignition and droplet combustion

    E-Print Network [OSTI]

    Del Álamo, Gonzalo

    2006-01-01

    moving luiquid fuel droplets. Journal of Fluid Mechanics,for a fuel droplet in slow viscous ?ow. Journal of Fluid

  16. Room temperature water Leidenfrost droplets

    E-Print Network [OSTI]

    Franck Celestini; Thomas Frisch; Yves Pomeau

    2013-08-05

    We experimentally investigate the Leidenfrost effect at pressures ranging from 1 to 0.05 atmospheric pressure. As a direct consequence of the Clausius-Clapeyron phase diagram of water, the droplet temperature can be at ambient temperature in a non-sophisticated lab environment. Furthermore, the lifetime of the Leidenfrost droplet is significantly increased in this low pressure environment. The temperature and pressure dependance of the evaporation rate are successfully tested against a recently proposed model. These results may pave a way to reach efficient Leidenfrost micro-fluidic and milli-fluidic applications.

  17. Photoionization Dynamics in Pure Helium Droplets

    E-Print Network [OSTI]

    Peterka, Darcy S.; Kim, Jeong Hyun; Wang, Chia C.; Poisson, Lionel; Neumark, Daniel M.

    2007-01-01

    correlated with production of the largest helium droplets.production Our experiments show that the photoionization of large helium

  18. In-situ droplet monitoring for self-tuning spectrometers

    DOE Patents [OSTI]

    Montaser, Akbar (Potomac, MD); Jorabchi, Kaveh (Arlington, VA); Kahen, Kaveh (Kleinburg, CA)

    2010-09-28

    A laser scattering based imaging technique is utilized in order to visualize the aerosol droplets in an inductively coupled plasma (ICP) torch from an aerosol source to the site of analytical measurements. The resulting snapshots provide key information about the spatial distribution of the aerosol introduced by direct and indirect injection devices: 1) a direct injection high efficiency nebulizer (DIHEN); 2) a large-bore DIHEN (LB-DIHEN); and 3) a PFA microflow nebulizer with a PFA Scott-type spray chamber. Moreover, particle image velocimetry (PIV) is used to study the in-situ behavior of the aerosol before interaction with, for example, plasma, while the individual surviving droplets are explored by particle tracking velocimetry (PTV). Further, the velocity distribution of the surviving droplets demonstrates the importance of the initial droplet velocities in complete desolvation of the aerosol for optimum analytical performance in ICP spectrometries. These new observations are important in the design of the next-generation direct injection devices for lower sample consumption, higher sensitivity, lower noise levels, suppressed matrix effects, and for developing smart spectrometers. For example, a controller can be provided to control the output of the aerosol source by controlling the configuration of the source or the gas flow rate via feedback information concerning the aerosol.

  19. Wetting Transitions of Condensed Droplets on Superhydrophobic Surfaces with Two-Tier Roughness

    E-Print Network [OSTI]

    Lv, Cunjing; Zhang, Xiwen; He, Feng

    2015-01-01

    Although realizing wetting transitions of droplets spontaneously on solid rough surfaces is quite challenging, it is becoming a key research topic in many practical applications which require highly efficient removal of liquid. We report wetting transitions of condensed droplets occurring spontaneously on pillared surfaces with two-tier roughness owing to excellent superhydrophobicity. The phenomenon results from further decreased Laplace pressure on the top side of the individual droplet when its size becomes comparable to the scale of the micropillars, which leads to a surprising robust spontaneous wetting transition, from valleys to tops of the pillars. A simple scaling law is derived theoretically, which demonstrates that the critical size of the droplet is determined by the space of the micropillars. For this reason, highly efficient removal of water benefits greatly from smaller micropillar space. Furthermore, three wetting transition modes exist, in which the in situ wetting behaviors are in good agree...

  20. Tuning Mixing within a Droplet for Digital Microfluidics

    E-Print Network [OSTI]

    R. Chabreyrie; D. Vainchtein; C. Chandre; P. Singh; N. Aubry

    2008-09-02

    The design of strategies to generate efficient mixing is crucial for a variety of applications, particularly digital microfluidic devices that use small "discrete" fluid volumes (droplets) as fluid carriers and microreactors. In recent work, we have presented an approach for the generation and control of mixing inside a translating spherical droplet. This was accomplished by considering Stokes' flow within a droplet proceeding downstream to which we have superimposed time dependent (sinusoidal) rotation. The mixing obtained is the result of the stretching and folding of material lines which increase exponentially the surface contact between reagents. The mixing strategy relies on the generation of resonances between the steady and the unsteady part of the flow, which is achieved by tuning the parameters of the periodic rotation. Such resonances, in our system, offer the possibility of controlling both the location and the size of the mixing region within the droplet, which may be useful to manufacture inhomogeneous particles (such as Janus particles). While the period and amplitude of the periodic rotation play a major role, it is shown here by using a triangular function that the particular shape of the rotation (as a function of time) has a minor influence. This finding demonstrates the robustness of the proposed mixing strategy, a crucial point for its experimental realization.

  1. Shape-shifting droplet networks

    E-Print Network [OSTI]

    T. Zhang; Duanduan Wan; J. M. Schwarz; M. J. Bowick

    2015-05-10

    Many naturally occurring materials can change their shape in response to external stimuli or internal stresses. Inspired by such materials, as well as recent experiments, we consider a three- dimensional network of aqueous droplets joined by single lipid bilayers to form a cohesive, tissue- like material. The droplets in these self-assembled networks can be programmed to have distinct osmolarities. The resultant osmotic gradients generate internal stresses via local fluid flows, causing the network to deform in shape. We study, using molecular dynamics simulations, the formation of a variety of shapes ranging from rings to spirals to tetrahedra and determine the optimal range of parameters for each structure. We also realize a reversible folding-unfolding process by adding an osmotic interaction with the surrounding environment which necessarily evolves dynamically as the shape of the network changes. Such reversible processes may well be important for the development of osmotic robotics in synthetic and bio-inspired materials.

  2. Vortices catapult droplets in atomization

    SciTech Connect (OSTI)

    Jerome, J. John Soundar Zaleski, Stéphane; Hoepffner, Jérôme; Marty, Sylvain; Matas, Jean-Philippe

    2013-11-15

    A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vortex; this reattached flow pushes the liquid film down; by now, a new recirculation vortex is being created in the wake of the wave—just where the liquid film is now located; the liquid film is blown up from below by the newly formed recirculation vortex in a manner similar to a bag-breakup event; the resulting droplets are catapulted by the recirculation vortex.

  3. Intercomparison of Large-eddy Simulations of Arctic Mixed-phase Clouds: Importance of Ice Size Distribution Assumptions

    SciTech Connect (OSTI)

    Ovchinnikov, Mikhail; Ackerman, Andrew; Avramov, Alex; Cheng, Anning; Fan, Jiwen; Fridlind, Ann; Ghan, Steven J.; Harrington, Jerry Y.; Hoose, Corinna; Korolev, Alexei; McFarquhar, Greg; Morrison, H.; Paukert, Marco; Savre, Julien; Shipway, Ben; Shupe, Matthew D.; Solomon, Amy; Sulia, Kara

    2014-03-14

    Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP) and potential cloud dissipation, in agreement with earlier studies. By comparing simulations with the same microphysics coupled to different dynamical cores as well as the same dynamics coupled to different microphysics schemes, it is found that the ice water path (IWP) is mainly controlled by ice microphysics, while the inter-model differences in LWP are largely driven by physics and numerics of the dynamical cores. In contrast to previous intercomparisons, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSD) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case.

  4. Effects of current on droplet generation and arc plasma in gas metal arc welding

    SciTech Connect (OSTI)

    Hu, J.; Tsai, H. L.

    2006-09-01

    In gas metal arc welding (GMAW), a technology using pulsed currents has been employed to achieve the one-droplet-per-pulse (ODPP) metal transfer mode with the advantages of low average currents, a stable and controllable droplet generation, and reduced spatter. In this paper, a comprehensive model was developed to study the effects of different current profiles on the droplet formation, plasma generation, metal transfer, and weld pool dynamics in GMAW. Five types of welding currents were studied, including two constant currents and three wave form currents. In each type, the transient temperature and velocity distributions of the arc plasma and the molten metal, and the shapes of the droplet and the weld pool were calculated. The results showed that a higher current generates smaller droplets, higher droplet frequency, and higher electromagnetic force that becomes the dominant factor detaching the droplet from the electrode tip. The model has demonstrated that a stable ODPP metal transfer mode can be achieved by choosing a current with proper wave form for given welding conditions.

  5. Heavy electrons: Electron droplets generated by photogalvanic and pyroelectric effects

    E-Print Network [OSTI]

    V. Krasnoholovets; N. Kukhtarev; T. Kukhtareva

    2009-11-12

    Electron clusters, X-rays and nanosecond radio-frequency pulses are produced by 100 mW continuous-wave laser illuminating ferroelectric crystal of LiNbO_3. A long-living stable electron droplet with the size of about 100 mcm has freely moved with the velocity 0.5 cm/s in the air near the surface of the crystal experiencing the Earth gravitational field. The microscopic model of cluster stability, which is based on submicroscopic mechanics developed in the real physical space, is suggested. The role of a restraining force plays the inerton field, a substructure of the particles' matter waves, which a solitary one can elastically withstand the Coulomb repulsion of electrons. It is shown that electrons in the droplet are heavy electrons whose mass at least 1 million of times exceeds the rest mass of free electron. Application for X-ray imaging and lithography is discussed.

  6. Evaluation of moist processes during intense precipitation in km-scale NWP models using remote sensing and in-situ data: Impact of microphysics size distribution assumptions

    SciTech Connect (OSTI)

    Van Weverberg, K.; van Lipzig, N. P. M.; Delobbe, L.

    2011-02-01

    This study investigates the sensitivity of moist processes and surface precipitation during three extreme precipitation events over Belgium to the representation of rain, snow and hail size distributions in a bulk one-moment microphysics parameterisation scheme. Sensitivities included the use of empirically derived relations to calculate the slope parameter and diagnose the intercept parameter of the exponential snow and rain size distributions and sensitivities to the treatment of hail/graupel. A detailed evaluation of the experiments against various high temporal resolution and spatially distributed observational data was performed to understand how moist processes responded to the implemented size distribution modifications. Net vapor consumption by microphysical processes was found to be unaffected by snow or rain size distribution modifications, while it was reduced replacing formulations for hail by those typical for graupel, mainly due to intense sublimation of graupel. Cloud optical thickness was overestimated in all experiments and all cases, likely due to overestimated snow amounts. The overestimation slightly deteriorated by modifying the rain and snow size distributions due to increased snow depositional growth, while it was reduced by including graupel. The latter was mainly due to enhanced cloud water collection by graupel and reduced snow depositional growth. Radar reflectivity and cloud optical thickness could only be realistically represented by inclusion of graupel during a stratiform case, while hail was found indispensable to simulate the vertical reflectivity profile and the surface precipitation structure. Precipitation amount was not much altered by any of the modifications made and the general overestimation was only decreased slightly during a supercell convective case.

  7. Oil droplet behavior at a pore entrance in the presence of crossflow: Implications for microfiltration of oil-water dispersions

    E-Print Network [OSTI]

    Darvishzadeh, Tohid; Priezjev, Nikolai V

    2013-01-01

    The behavior of an oil droplet pinned at the entrance of a micropore and subject to clossflow-induced shear is investigated numerically by solving the Navier-Stokes equation. We found that in the absence of crossflow, the critical transmembrane pressure required to force the droplet into the pore is in excellent agreement with a theoretical prediction based on the Young-Laplace equation. With increasing shear rate, the critical pressure of permeation increases, and at sufficiently high shear rates the oil droplet breaks up into two segments. The results of numerical simulations indicate that droplet breakup at the pore entrance is facilitated at lower surface tension, higher oil-to-water viscosity ratio and larger droplet size but is insensitive to the value of the contact angle. Using simple force and torque balance arguments, an estimate for the increase in critical pressure due to crossflow and the breakup capillary number is obtained and validated for different viscosity ratios, surface tension coefficien...

  8. Binary-Fluid Turbulence: Signatures of Multifractal Droplet Dynamics and Dissipation Reduction

    E-Print Network [OSTI]

    Pal, Nairita; Gupta, Anupam; Pandit, Rahul

    2016-01-01

    We present an extensive direct numerical simulation of statistically steady, homogeneous, isotropic turbulence in two-dimensional, binary-fluid mixtures with air-drag-induced friction by using the Cahn-Hilliard-Navier-Stokes equations. We choose parameters, e.g., the surface tension, such that we have a droplet of the minority phase moving inside a turbulent background of the majority phase. We characterize the deformation of the droplet and show that it displays multifractal dynamics. The probability distribution functions of the components of the acceleration of the center of mass of the droplet exhibit wide, non-Gaussian tails. Our study reveals that the droplet enhances the energy spectrum $E(k)$ when the wavenumber $k$ is large; this enhancement leads to dissipation reduction.

  9. Simultaneous Measurements of Droplet Size and Transient Temperature Within Surface Water Droplets

    E-Print Network [OSTI]

    Hu, Hui

    be impossible [2]. Ice can also cause engine stoppage by either icing up the carburetor or, in the case of a fuel-injected engine, blocking the engine's air source. Advancing the technology for safe and efficient

  10. Cement and Concrete Research, Vol. 42 (2), 404-409, 2012. Influence of Particle Size Distributions on Yield Stress and Viscosity of

    E-Print Network [OSTI]

    Bentz, Dale P.

    on Yield Stress and Viscosity of Cement-Fly Ash Pastes Dale P. Bentz Chiara F. Ferraris Michael A. Galler of three variables (cement particle size distribution (PSD), fly ash PSD, and ratio of fly ash to cement of either total (cement + fly ash) particle surface area or total particle density. Keywords: Cement; fly

  11. Length Scale of Leidenfrost Ratchet Switches Droplet Directionality...

    Office of Scientific and Technical Information (OSTI)

    Length Scale of Leidenfrost Ratchet Switches Droplet Directionality Citation Details In-Document Search Title: Length Scale of Leidenfrost Ratchet Switches Droplet Directionality...

  12. Sub-millimeter sized methyl butanoate droplet combustion: Microgravity experiments

    E-Print Network [OSTI]

    Walter, M.Todd

    grown and deployed onto the intersection of two 14 lm silicon carbide fibers in a cross agreement with the measurements. The average burning rates and flame temperatures for both fuels were found to the presence of additional oxygen atoms in the parent fuel. Important differences in the diffusion flame

  13. Kinetics of complex plasma with liquid droplets

    SciTech Connect (OSTI)

    Misra, Shikha; Sodha, M. S. [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India)] [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India); Mishra, S. K. [Institute for Plasma Research (IPR), Gandhinagar 382428 (India)] [Institute for Plasma Research (IPR), Gandhinagar 382428 (India)

    2013-12-15

    This paper provides a theoretical basis for the reduction of electron density by spray of water (or other liquids) in hot plasma. This phenomenon has been observed in a hypersonic flight experiment for relief of radio black out, caused by high ionization in the plasma sheath of a hypersonic vehicle, re-entering the atmosphere. The analysis incorporates a rather little known phenomenon for de-charging of the droplets, viz., evaporation of ions from the surface and includes the charge balance on the droplets and number cum energy balance of electrons, ions, and neutral molecules; the energy balance of the evaporating droplets has also been taken into account. The analysis has been applied to a realistic situation and the transient variations of the charge and radius of water droplets, and other plasma parameters have been obtained and discussed. The analysis through made in the context of water droplets is applicable to all liquids.

  14. Active polar fluid flow in finite droplets

    E-Print Network [OSTI]

    Carl A. Whitfield; Davide Marenduzzo; Raphaël Voituriez; Rhoda J. Hawkins

    2014-02-19

    We present a continuum level analytical model of a droplet of active contractile fluid consisting of filaments and motors. We calculate the steady state flows that result from a splayed polarisation of the filaments. We account for the interaction with an arbitrary external medium by imposing a viscous friction at the fixed droplet boundary. We then show that the droplet has non-zero force dipole and quadrupole moments, the latter of which is essential for self-propelled motion of the droplet at low Reynolds' number. Therefore, this calculation describes a simple mechanism for the motility of a droplet of active contractile fluid embedded in a 3D environment, which is relevant to cell migration in confinement (for example, embedded within a gel or tissue). Our analytical results predict how the system depends on various parameters such as the effective friction coefficient, the phenomenological activity parameter and the splay of the imposed polarisation.

  15. Droplet-Based Microfluidics DOI: 10.1002/anie.200601554

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    Droplet-Based Microfluidics DOI: 10.1002/anie.200601554 Reactions in Droplets in Microfluidic · interfaces · microfluidics · microreactors · plugs R. F. Ismagilov et al.Reviews 7336 www;1. Introduction: Reactions in Droplets This Review discusses the use of droplets in microfluidic channels

  16. Theoretical studies on hydrogen ignition and droplet combustion

    E-Print Network [OSTI]

    Del Álamo, Gonzalo

    2006-01-01

    1.2 Droplet Combustion . . . . . . . . . . . . .Combustion . . . . . . . . . . . . . . . . . . . . . . . . . .Lewis, B. and von Elbe, G. Combustion, Flames and Explosions

  17. Laser induced rotation of trapped chiral and achiral nematic droplets

    E-Print Network [OSTI]

    Marjan Mosallaeipour; Yashodhan Hatwalne; N. V. Madhusudana; Sharath Ananthamurthy

    2010-02-05

    We study the response of optically trapped achiral and chiralised nematic liquid crystal droplets to linear as well as circular polarised light. We find that there is internal dissipation in rotating achiral nematic droplets trapped in glycerine. We also demonstrate that some chiralised droplets rotate under linearly polarised light. The best fit to our data on chiralised droplets indicates that rotational frequency of these droplets with radius R is approximately proportional to1/R^2, rather than to 1/R^3.

  18. Measuring droplet impact with piezoelectric film 

    E-Print Network [OSTI]

    Basahi, Jalal M. Al-Badry M.

    1993-01-01

    The objective of this research was to develop a measurement system for determining droplet impact in the field with piezoelectric film. The piezoelectric film generates an output signal when it is deformed. The signals ...

  19. The role of precipitation size distributions in km-scale NWP simulations of intense precipitation: Evaluation of cloud properties and surface precipitation

    SciTech Connect (OSTI)

    Van Weverberg K.; Vogelmann A.; van Lipzig, N. P. M.; Delobbec, L.

    2012-04-01

    We investigate the sensitivity of simulated cloud properties and surface precipitation to assumptions regarding the size distributions of the precipitating hydrometeors in a one-moment bulk microphysics scheme. Three sensitivity experiments were applied to two composites of 15 convective and 15 frontal stratiform intense precipitation events observed in a coastal midlatitude region (Belgium), which were evaluated against satellite-retrieved cloud properties and radar-rain-gauge derived surface precipitation. It is found that the cloud optical thickness distribution was well captured by all experiments, although a significant underestimation of cloudiness occurred in the convective composite. The cloud-top-pressure distribution was improved most by more realistic snow size distributions (including a temperature-dependent intercept parameter and non-spherical snow for the calculation of the slope parameter), due to increased snow depositional growth at high altitudes. Surface precipitation was far less sensitive to whether graupel or hail was chosen as the rimed ice species, as compared to previous idealized experiments. This smaller difference in sensitivity could be explained by the stronger updraught velocities and higher freezing levels in the idealized experiments compared to typical coastal midlatitude environmental conditions.

  20. Physica Medica -Vol. XVII, Supplement 1, 2001 Monte Carlo Predictions of DNA Fragment-Size Distributions for

    E-Print Network [OSTI]

    Brenner, David Jonathan

    to low-LET radiation. DSB induction due to track interaction with the DNA volume depends on the radiation us to give biophysically based extrapolations of high-dose DNA fragment-size data to low doses on Space Radiation Research and 11th Annual NASA Space Radiation Health Investigators' Workshop Arona

  1. Journal of Power Sources 135 (2004) 7987 Predicting water and current distributions in a commercial-size PEMFC

    E-Print Network [OSTI]

    Van Zee, John W.

    2004-01-01

    in a commercial-size PEMFC S. Shimpaleea, S. Greenwaya, D. Spucklerb, J.W. Van Zeea, a Department of Chemical have experimentally studied small (10­50 cm2), single cell PEMFC systems to understand the behavior and electro- chemistry of PEMFC. Also, three-dimensional electrochemical models have been used to predict

  2. System Size, Energy and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy Ion Collisions

    E-Print Network [OSTI]

    B. Alver; B. B. Back; M. D. Baker; M. Ballintijn; D. S. Barton; R. R. Betts; R. Bindel; W. Busza; Z. Chai; V. Chetluru; E. García; T. Gburek; K. Gulbrandsen; J. Hamblen; I. Harnarine; C. Henderson; D. J. Hofman; R. S. Hollis; R. Ho?y?ski; B. Holzman; A. Iordanova; J. L. Kane; P. Kulinich; C. M. Kuo; W. Li; W. T. Lin; C. Loizides; S. Manly; A. C. Mignerey; R. Nouicer; A. Olszewski; R. Pak; C. Reed; E. Richardson; C. Roland; G. Roland; J. Sagerer; I. Sedykh; C. E. Smith; M. A. Stankiewicz; P. Steinberg; G. S. F. Stephans; A. Sukhanov; A. Szostak; M. B. Tonjes; A. Trzupek; G. J. van Nieuwenhuizen; S. S. Vaurynovich; R. Verdier; G. I. Veres; P. Walters; E. Wenger; D. Willhelm; F. L. H. Wolfs; B. Wosiek; K. Wo?niak; S. Wyngaardt; B. Wys?ouch

    2007-09-25

    We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, \\sqrtsnn = 22.4, 62.4 and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. Making a global comparison of Cu+Cu and Au+Au results, we find that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same Npart/2A value rather than the same Npart value. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.

  3. Monodisperse alginate microgel formation in a three-dimensional microfluidic droplet generator

    SciTech Connect (OSTI)

    Lian, Meng; Collier, Pat; Doktycz, Mitchel John; Retterer, Scott T

    2012-01-01

    Droplet based microfluidic systems provide an ideal platform for partitioning and manipulating aqueous samples for analysis. Identifying stable operating conditions under which droplets are generated is challenging yet crucial for real-world applications. A novel three-dimensional microfluidic platform that facilitates the consistent generation and gelation of alginate-calcium hydrogel microbeads for microbial encapsulation, over a broad range of backing pressures, in the absence of surfactants, is described. The unique three-dimensional design of the fluidic network utilizes a height difference at the junction between the aqueous sample injection and organic carrier channels to induce droplet formation via a surface tension enhanced self-shearing mechanism. Combined within a flow-focusing geometry, under constant pressure control, this arrangement facilitates predictable generation of droplets over a much broader range of operating conditions than conventional two-dimensional systems. The impact of operating pressures and geometry on droplet gelation, aqueous and organic material flow rates, microbead size and bead generation frequency are described. The system presented provides a robust platform for encapsulating single microbes in complex mixtures into individual hydrogel beads, and provides the foundation for the development of a complete system for sorting and analyzing microbes at the single cell level.

  4. THE IMPORTANCE OF PHYSICAL MODELS FOR DERIVING DUST MASSES AND GRAIN SIZE DISTRIBUTIONS IN SUPERNOVA EJECTA. I. RADIATIVELY HEATED DUST IN THE CRAB NEBULA

    SciTech Connect (OSTI)

    Temim, Tea; Dwek, Eli, E-mail: tea.temim@nasa.gov [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-09-01

    Recent far-infrared (IR) observations of supernova remnants (SNRs) have revealed significantly large amounts of newly condensed dust in their ejecta, comparable to the total mass of available refractory elements. The dust masses derived from these observations assume that all the grains of a given species radiate at the same temperature, regardless of the dust heating mechanism or grain radius. In this paper, we derive the dust mass in the ejecta of the Crab Nebula, using a physical model for the heating and radiation from the dust. We adopt a power-law distribution of grain sizes and two different dust compositions (silicates and amorphous carbon), and calculate the heating rate of each dust grain by the radiation from the pulsar wind nebula. We find that the grains attain a continuous range of temperatures, depending on their size and composition. The total mass derived from the best-fit models to the observed IR spectrum is 0.019-0.13 M{sub Sun }, depending on the assumed grain composition. We find that the power-law size distribution of dust grains is characterized by a power-law index of 3.5-4.0 and a maximum grain size larger than 0.1 {mu}m. The grain sizes and composition are consistent with what is expected for dust grains formed in a Type IIP supernova (SN). Our derived dust mass is at least a factor of two less than the mass reported in previous studies of the Crab Nebula that assumed more simplified two-temperature models. These models also require a larger mass of refractory elements to be locked up in dust than was likely available in the ejecta. The results of this study show that a physical model resulting in a realistic distribution of dust temperatures can constrain the dust properties and affect the derived dust masses. Our study may also have important implications for deriving grain properties and mass estimates in other SNRs and for the ultimate question of whether SNe are major sources of dust in the Galactic interstellar medium and in external galaxies.

  5. A hemispherical Langmuir probe array detector for angular resolved measurements on droplet-based laser-produced plasmas

    SciTech Connect (OSTI)

    Gambino, Nadia Brandstätter, Markus; Rollinger, Bob; Abhari, Reza

    2014-09-15

    In this work, a new diagnostic tool for laser-produced plasmas (LPPs) is presented. The detector is based on a multiple array of six motorized Langmuir probes. It allows to measure the dynamics of a LPP in terms of charged particles detection with particular attention to droplet-based LPP sources for EUV lithography. The system design permits to temporally resolve the angular and radial plasma charge distribution and to obtain a hemispherical mapping of the ions and electrons around the droplet plasma. The understanding of these dynamics is fundamental to improve the debris mitigation techniques for droplet-based LPP sources. The device has been developed, built, and employed at the Laboratory for Energy Conversion, ETH Zürich. The experimental results have been obtained on the droplet-based LPP source ALPS II. For the first time, 2D mappings of the ion kinetic energy distribution around the droplet plasma have been obtained with an array of multiple Langmuir probes. These measurements show an anisotropic expansion of the ions in terms of kinetic energy and amount of ion charge around the droplet target. First estimations of the plasma density and electron temperature were also obtained from the analysis of the probe current signals.

  6. Jumping-Droplet-Enhanced Condensation on Scalable Superhydrophobic Nanostructured Surfaces

    E-Print Network [OSTI]

    Miljkovic, Nenad

    When droplets coalesce on a superhydrophobic nanostructured surface, the resulting droplet can jump from the surface due to the release of excess surface energy. If designed properly, these superhydrophobic nanostructured ...

  7. A reproducible and low-cost piezoelectric droplet generator

    E-Print Network [OSTI]

    Liu, Tanya

    2014-01-01

    This thesis presents the design for a piezoelectric droplet generator capable of producing highly repeatable droplets ranging from 0.60 mm to 1.60 mm in diameter. The generator is low cost, simple to fabricate, and easily ...

  8. Electrowetting study of jumping droplets on hydrophobic surfaces

    E-Print Network [OSTI]

    Tio, Evelyn

    2014-01-01

    Recent studies have shown that jumping-droplet-enhanced condensation has higher heat transfer than state-of-the-art dropwise condensing surfaces by -30-40%. Jumping-droplet condensation occurs due to the conversion of ...

  9. The pilot-wave dynamics of walking droplets in confinement

    E-Print Network [OSTI]

    Harris, Daniel Martin

    2015-01-01

    A decade ago, Yves Couder and coworkers discovered that millimetric droplets can walk on a vibrated fluid bath, and that these walking droplets or "walkers" display several features reminiscent of quantum particles. We ...

  10. Net Metering Policy Development and Distributed Solar Generation in Minnesota: Overview of Trends in Nationwide Policy Development and Implications of Increasing the Eligible System Size Cap

    SciTech Connect (OSTI)

    Doris, E.; Busche, S.; Hockett, S.

    2009-12-01

    The goal of the Minnesota net metering policy is to give the maximum possible encouragement to distributed generation assets, especially solar electric systems (MN 2008). However, according to a published set of best practices (NNEC 2008) that prioritize the maximum development of solar markets within states, the Minnesota policy does not incorporate many of the important best practices that may help other states transform their solar energy markets and increase the amount of grid-connected distributed solar generation assets. Reasons cited include the low system size limit of 40kW (the best practices document recommends a 2 MW limit) and a lack of language protecting generators from additional utility fees. This study was conducted to compare Minnesota's policies to national best practices. It provides an overview of the current Minnesota policy in the context of these best practices and other jurisdictions' net metering policies, as well as a qualitative assessment of the impacts of raising the system size cap within the policy based on the experiences of other states.

  11. Shock-Wave Heating Model for Chondrule Formation: Hydrodynamic Simulation of Molten Droplets exposed to Gas Flows

    E-Print Network [OSTI]

    Hitoshi Miura; Taishi Nakamoto

    2006-11-09

    Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. One of the most plausible scenarios is that the chondrule precursor dust particles are heated and melt in the high-velocity gas flow (shock-wave heating model). We developed the non-linear, time-dependent, and three-dimensional hydrodynamic simulation code for analyzing the dynamics of molten droplets exposed to the gas flow. We confirmed that our simulation results showed a good agreement in a linear regime with the linear solution analytically derived by Sekiya et al. (2003). We found that the non-linear terms in the hydrodynamical equations neglected by Sekiya et al. (2003) can cause the cavitation by producing negative pressure in the droplets. We discussed that the fragmentation through the cavitation is a new mechanism to determine the upper limit of chondrule sizes. We also succeeded to reproduce the fragmentation of droplets when the gas ram pressure is stronger than the effect of the surface tension. Finally, we compared the deformation of droplets in the shock-wave heating with the measured data of chondrules and suggested the importance of other effects to deform droplets, for example, the rotation of droplets. We believe that our new code is a very powerful tool to investigate the hydrodynamics of molten droplets in the framework of the shock-wave heating model and has many potentials to be applied to various problems.

  12. An interface tracking model for droplet electrocoalescence.

    SciTech Connect (OSTI)

    Erickson, Lindsay Crowl

    2013-09-01

    This report describes an Early Career Laboratory Directed Research and Development (LDRD) project to develop an interface tracking model for droplet electrocoalescence. Many fluid-based technologies rely on electrical fields to control the motion of droplets, e.g. microfluidic devices for high-speed droplet sorting, solution separation for chemical detectors, and purification of biodiesel fuel. Precise control over droplets is crucial to these applications. However, electric fields can induce complex and unpredictable fluid dynamics. Recent experiments (Ristenpart et al. 2009) have demonstrated that oppositely charged droplets bounce rather than coalesce in the presence of strong electric fields. A transient aqueous bridge forms between approaching drops prior to pinch-off. This observation applies to many types of fluids, but neither theory nor experiments have been able to offer a satisfactory explanation. Analytic hydrodynamic approximations for interfaces become invalid near coalescence, and therefore detailed numerical simulations are necessary. This is a computationally challenging problem that involves tracking a moving interface and solving complex multi-physics and multi-scale dynamics, which are beyond the capabilities of most state-of-the-art simulations. An interface-tracking model for electro-coalescence can provide a new perspective to a variety of applications in which interfacial physics are coupled with electrodynamics, including electro-osmosis, fabrication of microelectronics, fuel atomization, oil dehydration, nuclear waste reprocessing and solution separation for chemical detectors. We present a conformal decomposition finite element (CDFEM) interface-tracking method for the electrohydrodynamics of two-phase flow to demonstrate electro-coalescence. CDFEM is a sharp interface method that decomposes elements along fluid-fluid boundaries and uses a level set function to represent the interface.

  13. Oil droplet behavior at a pore entrance in the presence of crossflow: Implications for microfiltration of oil-water dispersions

    E-Print Network [OSTI]

    Tohid Darvishzadeh; Volodymyr V. Tarabara; Nikolai V. Priezjev

    2013-06-10

    The behavior of an oil droplet pinned at the entrance of a micropore and subject to clossflow-induced shear is investigated numerically by solving the Navier-Stokes equation. We found that in the absence of crossflow, the critical transmembrane pressure required to force the droplet into the pore is in excellent agreement with a theoretical prediction based on the Young-Laplace equation. With increasing shear rate, the critical pressure of permeation increases, and at sufficiently high shear rates the oil droplet breaks up into two segments. The results of numerical simulations indicate that droplet breakup at the pore entrance is facilitated at lower surface tension, higher oil-to-water viscosity ratio and larger droplet size but is insensitive to the value of the contact angle. Using simple force and torque balance arguments, an estimate for the increase in critical pressure due to crossflow and the breakup capillary number is obtained and validated for different viscosity ratios, surface tension coefficients, contact angles, and drop-to-pore size ratios.

  14. A novel coarsening mechanism of droplets in immiscible fluid mixtures

    E-Print Network [OSTI]

    Ryotaro Shimizu; Hajime Tanaka

    2015-09-11

    In our daily lives, after shaking a salad dressing, we see the coarsening of oil droplets suspended in vinegar. Such a demixing process is observed everywhere in nature and also of technological importance. For a case of high droplet density, domain coarsening proceeds with interdroplet collisions and the resulting coalescence. This phenomenon has been explained primarily by the so-called Brownian coagulation mechanism: stochastic thermal forces exerted by molecules induce random motion of individual droplets, causing accidental collisions and subsequent interface-tension driven coalescence. Contrary to this, we demonstrate that the droplet motion is not random, but hydrodynamically driven by the composition Marangoni force due to an interfacial tension gradient produced in each droplet as a consequence of composition correlation among droplets. This alters our physical understanding of droplet coarsening in immiscible liquid mixtures on a fundamental level.

  15. ARM - Measurement - Particle size distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Roomparticlecontentnumber concentration ARM Datasize

  16. Collective waves in dense and confined microfluidic droplet arrays

    E-Print Network [OSTI]

    Ulf D. Schiller; Jean-Baptiste Fleury; Ralf Seemann; Gerhard Gompper

    2015-02-19

    Excitation mechanisms for collective waves in confined dense one-dimensional microfluidic droplet arrays are investigated by experiments and computer simulations. We demonstrate that distinct modes can be excited by creating specific `defect' patterns in flowing droplet trains. Excited longitudinal modes exhibit a short-lived cascade of pairs of laterally displacing droplets. Transversely excited modes obey the dispersion relation of microfluidic phonons and induce a coupling between longitudinal and transverse modes, whose origin is the hydrodynamic interaction of the droplets with the confining walls. Moreover, we investigate the long-time behaviour of the oscillations and discuss possible mechanisms for the onset of instabilities. Our findings demonstrate that the collective dynamics of microfluidic droplet ensembles can be studied particularly well in dense and confined systems. Experimentally, the ability to control microfluidic droplets may allow to modulate the refractive index of optofluidic crystals which is a promising approach for the production of dynamically programmable metamaterials.

  17. Phospholipid demixing and the birth of a lipid droplet

    E-Print Network [OSTI]

    J. Zanghellini; F. Wodlei; H. -H. von Gruenberg

    2009-10-30

    The biogenesis of lipid droplets (LD) in the yeast Saccharomyces cerevisiae was theoretically investigated on basis of a biophysical model. In accordance with the prevailing model of LD formation, we assumed that neutral lipids oil-out between the membrane leaflets of the endoplasmic reticulum (ER), resulting in LD that bud-off when a critical size is reached. Mathematically, LD were modeled as spherical protuberances in an otherwise planar ER membrane. We estimated the local phospholipid composition, and calculated the change in elastic free energy of the membrane caused by nascent LD. Based on this model calculation, we found a gradual demixing of lipids in the membrane leaflet that goes along with an increase in surface curvature at the site of LD formation. During demixing, the phospholipid monolayer was able to gain energy during LD growth, which suggested that the formation of curved interfaces was supported by or even driven by lipid demixing. In addition, we show that demixing is thermodynamically necessary as LD cannot bud-off otherwise. In the case of Saccharomyces cerevisiae our model predicts a LD bud-off diameter of about 13 nm. This diameter is far below the experimentally determined size of typical yeast LD. Thus, we concluded that if the standard model of LD formation is valid, LD biogenesis is a two step process. Small LD are produced from the ER, which subsequently ripe within the cytosol through a series of fusions.

  18. Whispering Gallery Mode Resonators for Rapid Label-Free Biosensing in Small Volume Droplets

    E-Print Network [OSTI]

    Wildgen, Sarah M.; Dunn, Robert C.

    2015-03-23

    WGM resonators as label-free sensors in 10 ?L sample droplets. Droplet evaporation leads to potentially useful convective mixing, but also limits the time over which analysis can be completed. We show that active droplet mixing combined with initial...

  19. Dependence of fluid flows in an evaporating sessile droplet on the characteristics of the substrate

    E-Print Network [OSTI]

    Barash, L Yu

    2014-01-01

    Temperature distributions and the corresponding vortex structures in an evaporating sessile droplet are obtained by performing detailed numerical calculations. A Marangoni convection induced by thermal conduction processes in the drop and the substrate is demonstrated to be able to result not only in a single vortex, but also in two or three vortices, depending on the ratio of substrate to fluid thermal conductivities, on the substrate thickness and the contact angle. The "phase diagrams" containing information on the number, orientation and spatial location of the vortices for quasistationary fluid flows are presented and analysed. The results obtained demonstrate that the fluid flow structure in evaporating droplets can be influenced in a controlled manner by selecting substrates with appropriate properties.

  20. Enhanced Cooling for High Heat Flux Applications Using Droplet Impact and Optical Cavitation

    E-Print Network [OSTI]

    Banks, Darren

    2015-01-01

    angle and center thickness of each droplet on the PTFEof a water droplet impacting a PTFE surface at increasedment a. Aluminum surface c. PTFE surface with hydrophobic

  1. OIL DROPLET MANIPULATION USING LIQUID DIELECTROPHORESIS ON ELECTRET WITH SUPERLYOPHOBIC

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    OIL DROPLET MANIPULATION USING LIQUID DIELECTROPHORESIS ON ELECTRET WITH SUPERLYOPHOBIC SURFACES flow friction for water and oil. Charge stability of electret in liquid is much improved with new hysteresis of SLS for oil droplets are experimentally demonstrated, indicating low motion resistance

  2. Ultralocalized thermal reactions in subnanoliter droplets-in-air

    E-Print Network [OSTI]

    Bashir, Rashid

    -on-chip systems promise rapid, sensitive, and multiplexed detection of biological samples for medical diag subnanoliter screening techniques used droplets-in-oil, micromachined chambers, and other strategies (2­4). Encapsulating droplets with mineral oil, capping them with polydimethylsiloxane (PDMS), or covering and sealing

  3. Optical switch using a deformable liquid droplet Hongwen Ren1,

    E-Print Network [OSTI]

    Wu, Shin-Tson

    . As the voltage increases, the dielectric force reshapes the droplet by uplifting its dome. As the dome touches developed a di- electric liquid droplet whose dome can be deformed from a spherical shape to flat, the dielectric force uplifts the dro- plet. As soon as the dome touches the top substrate, a clear channel

  4. Cooling of Integrated Circuits Using Droplet-Based Microfluidics

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    Cooling of Integrated Circuits Using Droplet-Based Microfluidics Vamsee K. Pamula Duke University and microfluidics-based solutions were proposed in the past. We present a cooling method based on high General Terms Measurement, Design, Experimentation. Keywords Microfluidics, Droplet, Electrowetting, Hot

  5. Resuspension by droplets STUART B. DALZIEL & MARTIN D. SEATON

    E-Print Network [OSTI]

    Dalziel, Stuart

    , but the hydrodynamics of the droplet also plays a sub- stantial role, leading to a more efficient resuspension thanResuspension by droplets STUART B. DALZIEL & MARTIN D. SEATON Department of Applied Mathematics.dalziel@damtp.cam.ac.uk 1. Introduction Most of the work on hydrodynamic resuspension has concentrated on the lift (and drag

  6. Cloud droplet sedimentation, entrainment efficiency, and subtropical stratocumulus albedo

    E-Print Network [OSTI]

    Bretherton, Chris

    Cloud droplet sedimentation, entrainment efficiency, and subtropical stratocumulus albedo C. S December 2006; published 9 February 2007. [1] The effect of cloud droplet sedimentation on the entrainment), sedimentation is found to decrease entrainment rate and thereby increase liquid water path. They suggested

  7. Growth of Cloud Droplets in a Turbulent Environment

    E-Print Network [OSTI]

    Wang, Lian-Ping

    Growth of Cloud Droplets in a Turbulent Environment Wojciech W. Grabowski1 and Lian-Ping Wang2 1 Keywords condensational growth, turbulent collision-coalescence, particle-laden flow, cloud microphysical concerning the growth of cloud droplets by water-vapor diffu- sion and by collision

  8. METHANE GAS STABILIZES SUPERCOOLED ETHANE DROPLETS IN TITAN'S CLOUDS

    SciTech Connect (OSTI)

    Wang, Chia C.; Lang, E. Kathrin; Signorell, Ruth

    2010-03-20

    Strong evidence for ethane clouds in various regions of Titan's atmosphere has recently been found. Ethane is usually assumed to exist as ice particles in these clouds, although the possible role of liquid and supercooled liquid ethane droplets has been recognized. Here, we report on infrared spectroscopic measurements of ethane aerosols performed in the laboratory under conditions mimicking Titan's lower atmosphere. The results clearly show that liquid ethane droplets are significantly stabilized by methane gas which is ubiquitous in Titan's nitrogen atmosphere-a phenomenon that does not have a counterpart for water droplets in Earth's atmosphere. Our data imply that supercooled ethane droplets are much more abundant in Titan's clouds than previously anticipated. Possibly, these liquid droplets are even more important for cloud processes and the formation of lakes than ethane ice particles.

  9. Effect of Engine-Out NOx Control Strategies on PM Size Distribution in Heavy-Duty Diesel Engines Developed for 2010

    Office of Energy Efficiency and Renewable Energy (EERE)

    A distinct relationship was found between engine-out and SCR-out PM distributions for single-mode testing.

  10. Technical Letter Report Development of Flaw Size Distribution Tables Including Effects of Flaw Depth Sizing Errors for Draft 10CFR 50.61a (Alternate PTS Rule) JCN-N6398, Task 4

    SciTech Connect (OSTI)

    Simonen, Fredric A.; Gosselin, Stephen R.; Doctor, Steven R.

    2013-04-22

    This document describes a new method to determine whether the flaws in a particular reactor pressure vessel are consistent with the assumptions regarding the number and sizes of flaws used in the analyses that formed the technical justification basis for the new voluntary alternative Pressurized Thermal Shock (PTS) rule (Draft 10 CFR 50.61a). The new methodology addresses concerns regarding prior methodology because ASME Code Section XI examinations do not detect all fabrication flaws, they have higher detection performance for some flaw types, and there are flaw sizing errors always present (e.g., significant oversizing of small flaws and systematic under sizing of larger flaws). The new methodology allows direct comparison of ASME Code Section XI examination results with values in the PTS draft rule Tables 2 and 3 in order to determine if the number and sizes of flaws detected by an ASME Code Section XI examination are consistent with those assumed in the probabilistic fracture mechanics calculations performed in support of the development of 10 CFR 50.61a.

  11. Synchronization of Washing Operations with Droplet Routing for Cross-Contamination Avoidance in Digital Microfluidic

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    Synchronization of Washing Operations with Droplet Routing for Cross-Contamination Avoidance in many areas of biochemistry and biomedical sciences. Since cross-contamination between droplets-droplet routing with sample/reagent drop- let-routing steps by controlling the arrival order of droplets at cross-contamination

  12. Evolution of neutral and charged droplets in an electric field M. A. Fontelos, 2

    E-Print Network [OSTI]

    Fontelos, Marco

    , such as the breakup of water droplets in thunderstorms, electrospraying, nanoencapsulation, electrospinning

  13. Direct numerical simulation and subgrid analysis of a transitional droplet laden mixing layer

    E-Print Network [OSTI]

    Miller, Richard S.

    and liquid droplet flows; e.g., pulverized coal combustion, spray painting, spray combustion, atomization

  14. Surfactant-driven flow transitions in evaporating droplets

    E-Print Network [OSTI]

    Marin, Alvaro; Rossi, Massimiliano; Kähler, Christian J

    2015-01-01

    An evaporating droplet is a dynamic system in which flow is spontaneously generated to minimize the surface energy, dragging particles to the borders and ultimately resulting in the so-called "coffee-stain effect". The situation becomes more complex at the droplet's surface, where surface tension gradients of different nature can compete with each other yielding different scenarios. With careful experiments and with the aid of 3D particle tracking techniques, we are able to show that different types of surfactants turn the droplet's surface either rigid or elastic, which alters the evaporating fluid flow, either enhancing the classical coffee-stain effect or leading to a total flow inversion. Our measurements lead to unprecedented and detailed measurements of the surface tension difference along an evaporating droplet's surface with good temporal and spatial resolution.

  15. Transient growth of droplet instabilities in a stream

    SciTech Connect (OSTI)

    Jalaal, M., E-mail: mazi@mech.ubc.ca, E-mail: m-jalaal@yahoo.com [Department of Mechanical Engineering, The University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Mehravaran, K. [School of Engineering, The University of British Columbia, Kelowna, British Columbia V1V 1V7 (Canada)] [School of Engineering, The University of British Columbia, Kelowna, British Columbia V1V 1V7 (Canada)

    2014-01-15

    Droplet deformation is the first stage of all aerodynamically induced-breakups, considerably affecting the characteristics of the atomization. In the present study, using an adaptive volume of fluid method, two and three-dimensional direct numerical simulations have been performed to understand droplet deformation. A high Reynolds number and a range of relatively high Weber numbers are chosen, addressing the shear breakup of droplets in a stream. The study is focused on the initiation and growth of instabilities over the droplet. The role of Kelvin-Helmholtz and Rayleigh-Taylor instabilities in wave formation and azimuthal transverse modulation are shown and the obtained results for the most amplified wave-numbers are compared with instability theories for zero and non-zero vorticity layers. The present results for the most amplified wave-numbers and deformation topologies are in good agreement with the previous experimental results.

  16. Droplet Bouncing Behavior in the Direct Solder Bumping Process

    E-Print Network [OSTI]

    Hsiao, Wayne

    This paper presents the results of an ongoing effort to develop a direct solder bumping process for electronics packaging. The proposed process entails delivering molten droplets onto specific locations on electronic devices ...

  17. Recent Progress in Droplet-Based Manufacturing Research

    E-Print Network [OSTI]

    Kim, H.-Y.

    This article reports the recent progress of re-search made in the Droplet-Based Manufacturing Laboratory at MIT. The study has been focused on obtaining a fundamental understanding of microdroplet deposition and applying ...

  18. Determination of lateral size distribution of type-II ZnTe/ZnSe stacked submonolayer quantum dots via spectral analysis of optical signature of the Aharanov-Bohm excitons

    SciTech Connect (OSTI)

    Ji, Haojie; Dhomkar, Siddharth; Roy, Bidisha; Kuskovsky, Igor L.; Shuvayev, Vladimir; Deligiannakis, Vasilios; Tamargo, Maria C.; Ludwig, Jonathan; Smirnov, Dmitry; Wang, Alice

    2014-10-28

    For submonolayer quantum dot (QD) based photonic devices, size and density of QDs are critical parameters, the probing of which requires indirect methods. We report the determination of lateral size distribution of type-II ZnTe/ZnSe stacked submonolayer QDs, based on spectral analysis of the optical signature of Aharanov-Bohm (AB) excitons, complemented by photoluminescence studies, secondary-ion mass spectroscopy, and numerical calculations. Numerical calculations are employed to determine the AB transition magnetic field as a function of the type-II QD radius. The study of four samples grown with different tellurium fluxes shows that the lateral size of QDs increases by just 50%, even though tellurium concentration increases 25-fold. Detailed spectral analysis of the emission of the AB exciton shows that the QD radii take on only certain values due to vertical correlation and the stacked nature of the QDs.

  19. The impact of size distribution assumptions in a bulk one-moment microphysics scheme on simulated surface precipitation and storm dynamics during a low-topped supercell case in Belgium

    SciTech Connect (OSTI)

    Van Weverberg, K.; Van Lipzig, N. P. M.; Delobbe, L.

    2011-04-01

    In this research the impact of modifying the size distribution assumptions of the precipitating hydrometeors in a bulk one-moment microphysics scheme on simulated surface precipitation and storm dynamics has been explored for long-lived low-topped supercells in Belgium. It was shown that weighting the largest precipitating ice species of the microphysics scheme to small graupel results in an increase of surface precipitation because of counteracting effects. On the one hand, the precipitation formation process slowed down, resulting in lower precipitation efficiency. On the other hand, latent heat release associated with freezing favored more intense storms. In contrast to previous studies finding decreased surface precipitation when graupel was present in the microphysics parameterization, storms were rather shallow in the authors simulations. This left little time for graupel sublimation. The impact of size distribution assumptions of snow was found to be small, but more realistic size distribution assumptions of rain led to the strongest effect on surface precipitation. Cold pools shrunk because of weaker rain evaporation at the cold pool boundaries, leading to a decreased surface rain area.

  20. Supersolid Droplet Crystal in a Dipole-Blockaded Gas

    SciTech Connect (OSTI)

    Cinti, F.; Jain, P.; Boninsegni, M. [Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2J1 (Canada); Micheli, A.; Zoller, P.; Pupillo, G. [IQOQI and Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck (Austria)

    2010-09-24

    A novel supersolid phase is predicted for an ensemble of Rydberg atoms in the dipole-blockade regime, interacting via a repulsive dipolar potential softened at short distances. Using exact numerical techniques, we study the low-temperature phase diagram of this system, and observe an intriguing phase consisting of a crystal of mesoscopic superfluid droplets. At low temperature, phase coherence throughout the whole system, and the ensuing bulk superfluidity, are established through tunnelling of identical particles between neighboring droplets.

  1. Study of the Physics of Droplet Impingement Cooling 

    E-Print Network [OSTI]

    Soriano, Guillermo Enrique

    2012-07-16

    ??? Mass flux rate n Refractive index Nu Nusselt number ((hd)/kf ) Oh Ohnesorge number (?/???d) P Power q Heat q?? Heat flux q??c Critical heat flux Q?? Volumetric flow rate Re Reynolds number ((?vd)/?) s Droplet spacing S Jet spacing St... viscosity ? Density ? Critical angle ? Transmissivity vii Subscripts: avg Average atm Atmosphere c Impact zone crown d Droplet diff Difference eq Equivalent htr Heater in Input j Jet l Liquid loss Losses ref Reference o Initial obj Object...

  2. Material forming apparatus using a directed droplet stream

    DOE Patents [OSTI]

    Holcomb, David E. (Oak Ridge, TN); Viswanathan, Srinath (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Wilgen, John B. (Oak Ridge, TN)

    2000-01-01

    Systems and methods are described for rapidly forming precision metallic and intermetallic alloy net shape parts directly from liquid metal droplets. A directed droplet deposition apparatus includes a crucible with an orifice for producing a jet of material, a jet destabilizer, a charging structure, a deflector system, and an impact zone. The systems and methods provide advantages in that fully dense, microstructurally controlled parts can be fabricated at moderate cost.

  3. Human serum activates CIDEB-mediated lipid droplet enlargement in hepatoma cells

    SciTech Connect (OSTI)

    Singaravelu, Ragunath; National Research Council of Canada, Ottawa, Ontario K1A 0R6 ; Lyn, Rodney K.; National Research Council of Canada, Ottawa, Ontario K1A 0R6 ; Srinivasan, Prashanth; Delcorde, Julie; National Research Council of Canada, Ottawa, Ontario K1A 0R6 ; Steenbergen, Rineke H.; Tyrrell, D. Lorne; Li Ka Shing Institute of Virology, Katz Centre for Pharmacy and Health Research, Edmonton, Alberta T6G 2S2 ; Pezacki, John P.

    2013-11-15

    Highlights: •Human serum induced differentiation of hepatoma cells increases cellular lipid droplet (LD) size. •The observed increase in LD size correlates with increased PGC-1? and CIDEB expression. •Induction of CIDEB expression correlates with rescue of VLDL secretion and loss of ADRP. •siRNA knockdown of CIDEB impairs the human serum mediated increase in LD size. •This system represents a cost-efficient model to study CIDEB’s role in lipid biology. -- Abstract: Human hepatocytes constitutively express the lipid droplet (LD) associated protein cell death-inducing DFFA-like effector B (CIDEB). CIDEB mediates LD fusion, as well as very-low-density lipoprotein (VLDL) maturation. However, there are limited cell culture models readily available to study CIDEB’s role in these biological processes, as hepatoma cell lines express negligible levels of CIDEB. Recent work has highlighted the ability of human serum to differentiate hepatoma cells. Herein, we demonstrate that culturing Huh7.5 cells in media supplemented with human serum activates CIDEB expression. This activation occurs through the induced expression of PGC-1?, a positive transcriptional regulator of CIDEB. Coherent anti-Stokes Raman scattering (CARS) microscopy revealed a correlation between CIDEB levels and LD size in human serum treated Huh7.5 cells. Human serum treatment also resulted in a rapid decrease in the levels of adipose differentiation-related protein (ADRP). Furthermore, individual overexpression of CIDEB was sufficient to down-regulate ADRP protein levels. siRNA knockdown of CIDEB revealed that the human serum mediated increase in LD size was CIDEB-dependent. Overall, our work highlights CIDEB’s role in LD fusion, and presents a new model system to study the PGC-1?/CIDEB pathway’s role in LD dynamics and the VLDL pathway.

  4. Correlating size and composition-dependent effects with magnetic, Mössbauer, and pair distribution function measurements in a family of catalytically active ferrite nanoparticles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wong, Stanislaus; Papaefthymiou, Georgia C.; Lewis, Crystal S.; Han, Jinkyu; Zhang, Cheng; Li, Qiang; Shi, Chenyang; Abeykoon, A. M.Milinda; Billinge, Simon J.L.; Stach, Eric; et al

    2015-05-06

    The magnetic spinel ferrites, MFe?O? (wherein 'M' = a divalent metal ion such as but not limited to Mn, Co, Zn, and Ni), represent a unique class of magnetic materials in which the rational introduction of different 'M's can yield correspondingly unique and interesting magnetic behaviors. Herein we present a generalized hydrothermal method for the synthesis of single-crystalline ferrite nanoparticles with 'M' = Mg, Fe, Co, Ni, Cu, and Zn, respectively, which can be systematically and efficaciously produced simply by changing the metal precursor. Our protocol can moreover lead to reproducible size control by judicious selection of various surfactants. Asmore »such, we have probed the effects of both (i) size and (ii) chemical composition upon the magnetic properties of these nanomaterials using complementary magnetometry and Mössbauer spectroscopy techniques. The structure of the samples was confirmed by atomic PDF analysis of X-ray and electron powder diffraction data as a function of particle size. These materials retain the bulk spinel structure to the smallest size (i.e., 3 nm). In addition, we have explored the catalytic potential of our ferrites as both (a) magnetically recoverable photocatalysts and (b) biological catalysts, and noted that many of our as-prepared ferrite systems evinced intrinsically higher activities as compared with their iron oxide analogues.« less

  5. Surface Tension Estimates for Droplet Formation in Slurries with Low Concentrations of Hydrophobic Particles, Polymer Flocculants or Surface-Active Contaminants

    SciTech Connect (OSTI)

    Gauglitz, Phillip A.; Mahoney, Lenna A.; Blanchard, Jeremy; Bamberger, Judith A.

    2011-06-10

    In support of the K-Basin project, Pacific Northwest National Laboratory (PNNL) was requested to evaluate the appropriate surface tension value to use in models predicting the formation of droplets from spray leaks of K-Basin slurries. The specific issue was whether it was more appropriate to use the surface tension of pure water in model predictions for all plausible spray leaks or to use a lower value. The surface tension of K-Basin slurries is potentially affected not only by particles but by low concentrations of nonionic polyacrylamide flocculant and perhaps by contaminants with surfactant properties, which could decrease the surface tension below that of water. A lower surface tension value typically results in smaller droplets being formed with a larger fraction of droplets in the respirable size range, so using the higher surface tension value of pure water is not conservative and thus needs a strong technical basis.

  6. Inverse modelling of cloud-aerosol interactions - Part 2: Sensitivity tests on liquid phase clouds using a Markov chain Monte Carlo based simulation approach

    E-Print Network [OSTI]

    Partridge, D. G; Vrugt, J. A; Tunved, P.; Ekman, A. M. L; Struthers, H.; Sorooshian, A.

    2012-01-01

    Seinfeld, J. H. : Aerosol, cloud drop concentration closureof aerosol composition on cloud droplet size distribution –aerosol properties on warm cloud droplet activation, At-

  7. Breaking anchored droplets in a microfluidic Hele-Shaw cell

    E-Print Network [OSTI]

    Amselem, Gabriel; Gallaire, François; Baroud, Charles N

    2015-01-01

    We study microfluidic self digitization in Hele-Shaw cells using pancake droplets anchored to surface tension traps. We show that above a critical flow rate, large anchored droplets break up to form two daughter droplets, one of which remains in the anchor. Below the critical flow velocity for breakup the shape of the anchored drop is given by an elastica equation that depends on the capillary number of the outer fluid. As the velocity crosses the critical value, the equation stops admitting a solution that satisfies the boundary conditions; the drop breaks up in spite of the neck still having finite width. A similar breaking event also takes place between the holes of an array of anchors, which we use to produce a 2D array of stationary drops in situ.

  8. Air-stable droplet interface bilayers on oil-infused surfaces

    SciTech Connect (OSTI)

    Boreyko, Jonathan B [ORNL] [ORNL; Polizos, Georgios [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Datskos, Panos G [ORNL] [ORNL; Sarles, Stephen A [ORNL] [ORNL; Collier, Pat [ORNL] [ORNL

    2014-01-01

    Droplet interface bilayers (DIBs) are versatile model membranes useful for synthetic biology and biosensing; however, to date they have always been confined to fluid reservoirs. Here, we demonstrate that when two or more water droplets collide on an oil-infused substrate, they exhibit non-coalescence due to the formation of a thin oil film that gets squeezed between the droplets from the bottom-up. We show that when phospholipids are included in the water droplets, a stable droplet interface bilayer forms between the non-coalescing water droplets. As with traditional oil-submerged DIBs, we were able to characterize ion channel transport by incorporating peptides into each droplet. Our findings reveal that droplet interface bilayers can function in air environments, which could potentially enable biosensing of atmospheric particulates.

  9. Relationship between Cloud Condensation Nuclei and Satellite Retrievals of Cloud Droplet Effective Radius

    E-Print Network [OSTI]

    Delene, David J.

    ` Relationship between Cloud Condensation Nuclei and Satellite Retrievals of Cloud Droplet is the relationship between below cloud base cloud condensation nuclei (CCN) and satellite retrievals of cloud droplet cloud effective radius; however, satellites can not measure cloud condensation nuclei (CCN

  10. Programmable active droplet generation enabled by integrated pneumatic micropumps

    E-Print Network [OSTI]

    Zeng, Yong; Shin, Mimi; Wang, Tanyu

    2013-01-01

    Cite this: Lab Chip, 2013, 13, 267 Programmable active droplet generation enabled by integrated pneumatic micropumps Received 8th August 2012, Accepted 19th October 2012 DOI: 10.1039/c2lc40906b www.rsc.org/loc Yong Zeng,*abc Mimi Shinab and Tanyu... susceptibility to the physical properties of samples and devices (e.g. capacitance and dielectric strength).38 Pneumatic valves fabricated by soft lithography have been demonstrated to be a promising technique for controlled droplet forma- a...

  11. Dynamics of lipid droplets induced by the hepatitis C virus core protein

    SciTech Connect (OSTI)

    Lyn, Rodney K.; Department of Chemistry, University of Ottawa, Ottawa ; Kennedy, David C.; Stolow, Albert; Ridsdale, Andrew; Pezacki, John Paul

    2010-09-03

    Research highlights: {yields} Hepatitis C virus uses lipid droplets (LD) onto which HCV core proteins bind. {yields} HCV core proteins on LDs facilitate viral particle assembly. {yields} We used a novel combination of CARS, two-photon fluorescence, and DIC microscopies. {yields} Particle tracking experiments show that core slowly affects LD localization. {yields} Particle tracking measured the change in speed and directionality of LD movement. -- Abstract: The hepatitis C virus (HCV) is a global health problem, with limited treatment options and no vaccine available. HCV uses components of the host cell to proliferate, including lipid droplets (LD) onto which HCV core proteins bind and facilitate viral particle assembly. We have measured the dynamics of HCV core protein-mediated changes in LDs and rates of LD movement on microtubules using a combination of coherent anti-Stokes Raman scattering (CARS), two-photon fluorescence (TPF), and differential interference contrast (DIC) microscopies. Results show that the HCV core protein induces rapid increases in LD size. Particle tracking experiments show that HCV core protein slowly affects LD localization by controlling the directionality of LD movement on microtubules. These dynamic processes ultimately aid HCV in propagating and the molecules and interactions involved represent novel targets for potential therapeutic intervention.

  12. Dilution-Free Analysis from Picoliter Droplets by Nano-Electrospray Ionization Mass Spectrometry

    SciTech Connect (OSTI)

    Kelly, Ryan T.; Page, Jason S.; Marginean, Ioan; Tang, Keqi; Smith, Richard D.

    2009-09-01

    The expanding role of microfluidics for chemical and biochemical analysis is due to factors including the favorable scaling of separation performance with reduced channel dimensions,[1] flexibility afforded by computer-aided device design, and the ability to integrate multiple sample handling and analysis steps into a single platform.[2] Such devices enable smaller liquid volumes and sample sizes to be handled than can be achieved on the benchtop, where sub-microliter volumes are difficult to work with and where sample losses to the surfaces of multiple reaction vessels become prohibitive. A particularly attractive microfluidic platform for sample-limited analyses employs aqueous droplets or plugs encapsulated by an immiscible oil.[3,4] Each droplet serves as a discrete compartment or reaction chamber enabling, e.g., high throughput screening[5,6] and kinetic studies[7-9] of femto- to nanoliter samples, as well as the encapsulation[10-12] and lysis[10] of individual cells with limited dilution of the cellular contents

  13. Cross-Contamination Avoidance for Droplet Routing in Digital Microfluidic Biochips

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    Cross-Contamination Avoidance for Droplet Routing in Digital Microfluidic Biochips Yang Zhao- contamination between droplets of different biomolecules can lead to erroneous outcomes for bioassays, the avoidance of cross- contamination during droplet routing is a key design challenge for biochips. We propose

  14. Entropic Aspects of Supercooled Droplet Freezing ALEXANDER KOSTINSKI AND WILL CANTRELL

    E-Print Network [OSTI]

    Kostinski, Alex

    Entropic Aspects of Supercooled Droplet Freezing ALEXANDER KOSTINSKI AND WILL CANTRELL Department, in final form 27 December 2007) ABSTRACT The freezing of supercooled water droplets in the atmosphere to establish a lower bound on the amount of latent heat that can be liberated by the freezing droplets

  15. DIGITAL CHROMATOGRAPHY AND THE FORMA-TION OF HETEROGENEOUS DROPLET LIBRARIES

    E-Print Network [OSTI]

    Basu, Amar S.

    by a droplet generator placed immediately after the column. A prototype, comprised of a C18 cartridge, showing a C18 cartridge loaded with red and yellow dyes, and a plastic cross-junction droplet generator components: a C18 sep-pak cartridge, a droplet generator, and two fiber-optic absorbance detectors. The C18

  16. Droplet microfluidic technology for single-cell high-throughput screening

    E-Print Network [OSTI]

    Perrimon, Norbert

    Droplet microfluidic technology for single-cell high-throughput screening Eric Brouzesa,b,1 (received for review March 31, 2009) We present a droplet-based microfluidic technology that enables high our droplet microfluidic platform is modular, robust, uses no moving parts, and has a wide range

  17. DROPLET-BASED HOT SPOT COOLING USING TOPLESS DIGITAL MICROFLUIDICS ON A PRINTED CIRCUIT BOARD

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    DROPLET-BASED HOT SPOT COOLING USING TOPLESS DIGITAL MICROFLUIDICS ON A PRINTED CIRCUIT BOARD Phil demonstrated a cooling method on a "digital microfluidics" platform whereby discrete droplets are manipulated and the effective flow rate of the droplets. The results presented here suggest that digital microfluidics

  18. The recoiling of liquid droplets upon collision with solid surfaces H.-Y. Kima)

    E-Print Network [OSTI]

    Kim, Ho-Young

    solid surfaces polycarbonate and silicon oxide . The droplet dynamics are experimentally studied using of different liquid droplets water, ink, and silicone oil on different solid surfaces polycarbonate and silicon. Fukai et al.14,15 conducted a theoretical study on the spreading and recoiling of a liquid droplet upon

  19. Investigation of thermochemical biorefinery sizing and environmental sustainability impacts for conventional supply system and distributed pre-processing supply system designs

    SciTech Connect (OSTI)

    David J. Muth, Jr.; Matthew H. Langholtz; Eric C. D. Tan; Jacob J. Jacobson; Amy Schwab; May M. Wu; Andrew Argo; Craig C. Brandt; Kara G. Cafferty; Yi-Wen Chiu; Abhijit Dutta; Laurence M. Eaton; Erin M. Searcy

    2014-08-01

    The 2011 US Billion-Ton Update estimates that by 2030 there will be enough agricultural and forest resources to sustainably provide at least one billion dry tons of biomass annually, enough to displace approximately 30% of the country's current petroleum consumption. A portion of these resources are inaccessible at current cost targets with conventional feedstock supply systems because of their remoteness or low yields. Reliable analyses and projections of US biofuels production depend on assumptions about the supply system and biorefinery capacity, which, in turn, depend upon economic value, feedstock logistics, and sustainability. A cross-functional team has examined combinations of advances in feedstock supply systems and biorefinery capacities with rigorous design information, improved crop yield and agronomic practices, and improved estimates of sustainable biomass availability. A previous report on biochemical refinery capacity noted that under advanced feedstock logistic supply systems that include depots and pre-processing operations there are cost advantages that support larger biorefineries up to 10 000 DMT/day facilities compared to the smaller 2000 DMT/day facilities. This report focuses on analyzing conventional versus advanced depot biomass supply systems for a thermochemical conversion and refinery sizing based on woody biomass. The results of this analysis demonstrate that the economies of scale enabled by advanced logistics offsets much of the added logistics costs from additional depot processing and transportation, resulting in a small overall increase to the minimum ethanol selling price compared to the conventional logistic supply system. While the overall costs do increase slightly for the advanced logistic supply systems, the ability to mitigate moisture and ash in the system will improve the storage and conversion processes. In addition, being able to draw on feedstocks from further distances will decrease the risk of biomass supply to the conversion facility.

  20. Jumping-Droplet-Enhanced Condensation on Scalable Superhydrophobic Nanostructured Surfaces

    SciTech Connect (OSTI)

    Miljkovic, N; Enright, R; Nam, Y; Lopez, K; Dou, N; Sack, J; Wang, E

    2012-01-01

    When droplets coalesce on a superhydrophobic nanostructured surface, the resulting droplet can jump from the surface due to the release of excess surface energy. If designed properly, these superhydrophobic nanostructured surfaces can not only allow for easy droplet removal at micrometric length scales during condensation but also promise to enhance heat transfer performance. However, the rationale for the design of an ideal nanostructured surface as well as heat transfer experiments demonstrating the advantage of this jumping behavior are lacking. Here, we show that silanized copper oxide surfaces created via a simple fabrication method can achieve highly efficient jumping-droplet condensation heat transfer. We experimentally demonstrated a 25% higher overall heat flux and 30% higher condensation heat transfer coefficient compared to state-of-the-art hydrophobic condensing surfaces at low supersaturations (<1.12). This work not only shows significant condensation heat transfer enhancement but also promises a low cost and scalable approach to increase efficiency for applications such as atmospheric water harvesting and dehumidification. Furthermore, the results offer insights and an avenue to achieve high flux superhydrophobic condensation.

  1. Length Scale Selects Directionality of Droplets on Vibrating Pillar Ratchet

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Agapov, Rebecca L.; Boreyko, Jonathan B.; Briggs, Dayrl P.; Srijanto, Bernadeta R.; Retterer, Scott T.; Collier, Pat; Lavrik, Nickolay V.

    2014-09-22

    Directional control of droplet motion at room temperature is of interest for applications such as microfluidic devices, self-cleaning coatings, and directional adhesives. Here, arrays of tilted pillars ranging in height from the nanoscale to the microscale are used as structural ratchets to directionally transport water at room temperature. Water droplets deposited on vibrating chips with a nanostructured ratchet move preferentially in the direction of the feature tilt while the opposite directionality is observed in the case of microstructured ratchets. This remarkable switch in directionality is consistent with changes in the contact angle hysteresis. To glean further insights into the lengthmore »scale dependent asymmetric contact angle hysteresis, the contact lines formed by a nonvolatile room temperature ionic liquid placed onto the tilted pillar arrays were visualized and analyzed in situ in a scanning electron microscope. The ability to tune droplet directionality by merely changing the length scale of surface features all etched at the same tilt angle would be a versatile tool for manipulating multiphase flows and for selecting droplet directionality in other lap-on-chip applications.« less

  2. Effect of droplet size on the behavior and characteristics of emulsified acid 

    E-Print Network [OSTI]

    Almutairi, Saleh Haif

    2008-10-10

    Emulsified acids have been extensively used in the oil industry since 1933. Most of the available research and publications discussed mainly the application of emulsified acid in the field. A fair number of the published ...

  3. 1 INTRODUCTION 1.1 Optical sizing

    E-Print Network [OSTI]

    Maerz, Norbert H.

    mining operation, from the drilling and blasting to the final product; the material size dictates all downstream operating costs. Previously, the only way to measure a size distribution was to stop production

  4. Composition profiling of GaAs/AlGaAs quantum dots grown by droplet epitaxy

    SciTech Connect (OSTI)

    Bocquel, J.; Koenraad, P. M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Giddings, A. D.; Prosa, T. J.; Larson, D. J. [CAMECA Instruments, Inc., 5500 Nobel Drive, Madison, Wisconsin 53711 (United States); Mano, T. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2014-10-13

    Droplet epitaxy (DE) is a growth method which can create III-V quantum dots (QDs) whose optoelectronic properties can be accurately controlled through the crystallisation conditions. In this work, GaAs/AlGaAs DE-QDs have been analyzed with the complimentary techniques of cross-sectional scanning tunneling microscopy and atom probe tomography. Structural details and a quantitative chemical analysis of QDs of different sizes are obtained. Most QDs were found to be pure GaAs, while a small proportion exhibited high intermixing caused by a local etching process. Large QDs with a high aspect ratio were observed to have an Al-rich crown above the GaAs QD. This structure is attributed to differences in mobility of the cations during the capping phase of the DE growth.

  5. Dynamics of a dielectric droplet suspended in a magnetic fluid in electric and magnetic fields

    E-Print Network [OSTI]

    Arthur Zakinyan; Elena Tkacheva; Yury Dikansky

    2012-03-24

    The behavior of a microdrop of dielectric liquid suspended in a magnetic fluid and exposed to the action of electric and magnetic fields is studied experimentally. With increasing electric field, the deformation of droplets into oblate ellipsoid, toroid and curved toroid was observed. At the further increase in the electric field, the bursting of droplets was also revealed. The electrorotation of deformed droplets was observed and investigated. The influence of an additional magnetic field on the droplet dynamics was studied. The main features of the droplet dynamics were interpreted and theoretically examined.

  6. Transient direct-contact condensation on liquid droplets

    SciTech Connect (OSTI)

    Pasamehmetoglu, K.O.; Nelson, R.A.

    1987-01-01

    In this paper, direct-contact condensation on subcooled liquid droplets is studied in two parts. In the first part, simple design correlations for the condensation in a steady environment are developed based upon a conduction model. These correlations include the convective heat-transfer coefficient, condensation rate, total condensation, and the droplet-thermalization time. In the second part of the paper, the effect of a time-dependent saturation temperature on the condensation process is investigated. A rapid decrease in saturation temperature is typical of condensation environments in which the steam-supply rate is limited and condensation-induced depressurization becomes important. Design correlations are developed for condensation in an environment in which the saturation temperature decreases linearly with time. These correlations are graphically compared to the design correlations of the first part through a quasi-steady approach. The error associated with this approach is quantified as a function of the rate of change of the saturation temperature.

  7. Characterizing Uncertainties in Ice Particle Size Distributions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene Network ShapingDate:Characterization ofArcticUncertainties in

  8. In-service Inspection Ultrasonic Testing of Reactor Pressure Vessel Welds for Assessing Flaw Density and Size Distribution per 10 CFR 50.61a, Alternate Fracture Toughness Requirements

    SciTech Connect (OSTI)

    Sullivan, Edmund J.; Anderson, Michael T.; Norris, Wallace

    2012-09-17

    Pressurized thermal shock (PTS) events are system transients in a pressurized water reactor (PWR) in which there is a rapid operating temperature cool-down that results in cold vessel temperatures with or without repressurization of the vessel. The rapid cooling of the inside surface of the reactor pressure vessel (RPV) causes thermal stresses that can combine with stresses caused by high pressure. The aggregate effect of these stresses is an increase in the potential for fracture if a pre-existing flaw is present in a material susceptible to brittle failure. The ferritic, low alloy steel of the reactor vessel beltline adjacent to the core, where neutron radiation gradually embrittles the material over the lifetime of the plant, can be susceptible to brittle fracture. The PTS rule, described in the Code of Federal Regulations, Title 10, Section 50.61 (§50.61), “Fracture Toughness Requirements for Protection against Pressurized Thermal Shock Events,” adopted on July 23, 1985, establishes screening criteria to ensure that the potential for a reactor vessel to fail due to a PTS event is deemed to be acceptably low. The U.S. Nuclear Regulatory Commission (NRC) completed a research program that concluded that the risk of through-wall cracking due to a PTS event is much lower than previously estimated. The NRC subsequently developed a rule, §50.61a, published on January 4, 2010, entitled “Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events” (75 FR 13). Use of the new rule by licensees is optional. The §50.61a rule differs from §50.61 in that it requires licensees who choose to follow this alternate method to analyze the results from periodic volumetric examinations required by the ASME Code, Section XI, Rules for Inservice Inspection (ISI) of Nuclear Power Plants. These analyses are intended to determine if the actual flaw density and size distribution in the licensee’s reactor vessel beltline welds are bounded by the flaw density and size distribution values used in the PTS technical basis. Under a contract with the NRC, Pacific Northwest National Laboratory (PNNL) has been working on a program to assess the ability of current inservice inspection (ISI)-ultrasonic testing (UT) techniques, as qualified through ASME Code, Appendix VIII, Supplements 4 and 6, to detect small fabrication or inservice-induced flaws located in RPV welds and adjacent base materials. As part of this effort, the investigators have pursued an evaluation, based on the available information, of the capability of UT to provide flaw density/distribution inputs for making RPV weld assessments in accordance with §50.61a. This paper presents the results of an evaluation of data from the 1993 Browns Ferry Nuclear Plant, Unit 3, Spirit of Appendix VIII reactor vessel examination, a comparison of the flaw density/distribution from this data with the distribution in §50.61a, possible reasons for differences, and plans and recommendations for further work in this area.

  9. Shock-Wave Heating Model for Chondrule Formation: Hydrodynamic Simulation of Molten Droplets exposed to Gas Flows

    E-Print Network [OSTI]

    Miura, H; Miura, Hitoshi; Nakamoto, Taishi

    2006-01-01

    Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. One of the most plausible scenarios is that the chondrule precursor dust particles are heated and melt in the high-velocity gas flow (shock-wave heating model). We developed the non-linear, time-dependent, and three-dimensional hydrodynamic simulation code for analyzing the dynamics of molten droplets exposed to the gas flow. We confirmed that our simulation results showed a good agreement in a linear regime with the linear solution analytically derived by Sekiya et al. (2003). We found that the non-linear terms in the hydrodynamical equations neglected by Sekiya et al. (2003) can cause the cavitation by producing negative pressure in the droplets. We discussed that the fragmentation through the cavitation is a new mechanism to determine the upper limit of chondrule sizes. We also succeeded t...

  10. ON-DEMAND SERIAL DILUTION USING QUANTIZED NANO/PICOLITER-SCALE DROPLETS

    SciTech Connect (OSTI)

    Jambovane, Sachin R.; Prost, Spencer A.; Sheen, Allison M.; Magnuson, Jon K.; Kelly, Ryan T.

    2014-10-29

    This paper describes a fully automated droplet-based microfluidic device for on-demand serial dilution that is capable of achieving a dilution ratio of >6000 (concentration ranges from 1 mM to 160nM) over 35 nanoliter-scale droplets. This serial diluter can be applied to high throughput and label-free kinetic assays by integrating with our previously developed on-demand droplet-based microfluidic with mass spectrometry detection.

  11. Natural discharge after pulse and cooperative electrodes to enhance droplet velocity in digital microfluidics

    SciTech Connect (OSTI)

    Chen, Tianlan; Dong, Cheng; Gao, Jie; Jia, Yanwei; Mak, Pui-In, E-mail: pimak@umac.mo; Vai, Mang-I; Martins, Rui P. [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)] [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)

    2014-04-15

    Digital Microfluidics (DMF) is a promising technology for biological/chemical micro-reactions due to its distinct droplet manageability via electronic automation, but the limited velocity of droplet transportation has hindered DMF from utilization in high throughput applications. In this paper, by adaptively fitting the actuation voltages to the dynamic motions of droplet movement under real-time feedback monitoring, two control-engaged electrode-driving techniques: Natural Discharge after Pulse (NDAP) and Cooperative Electrodes (CE) are proposed. They together lead to, for the first time, enhanced droplet velocity with lower root mean square voltage value.

  12. Self-propelled motion of a fluid droplet under chemical reaction

    E-Print Network [OSTI]

    Shunsuke Yabunaka; Takao Ohta; Natsuhiko Yoshinaga

    2012-03-03

    We study self-propelled dynamics of a droplet due to a Marangoni effect and chemical reactions in a binary fluid with a dilute third component of chemical product which affects the interfacial energy of a droplet. The equation for the migration velocity of the center of mass of a droplet is derived in the limit of an infinitesimally thin inter- face. We found that there is a bifurcation from a motionless state to a propagating state of droplet by changing the strength of the Marangoni effect.

  13. Robust Extraction Interface for Coupling Droplet-Based and Continuous Flow Microfluidics

    SciTech Connect (OSTI)

    Sun, Xuefei; Tang, Keqi; Smith, Richard D.; Kelly, Ryan T.

    2012-03-07

    Reliable and highly efficient extraction of droplets from oil to aqueous phase is key for downstream coupling with chemical separations and nonoptical detection methods such as amperometry and mass spectrometry. This paper presents an improved interface providing robust extraction for droplet-based poly(dimethylsiloxane) (PDMS) microfluidic devices. The extraction interface consists of an array of cylindrical posts with narrow apertures in between. The aqueous flow channel into which droplets coalesced was simply and selectively modified to be hydrophilic, while the continuous oil phase flow channel that contained encapsulated aqueous droplets retained a hydrophobic surface. The different surfaces on both sides of the extraction region form a highly stable liquid interface between the two immiscible phases, allowing rapid droplet transfer to the aqueous stream. Entire droplets could be completely extracted within broad ranges of aqueous and oil flow rates (0 - 1 and 0.1 - 1 uL/min, respectively). After extraction, the droplet contents could be transported electrophoretically or by pressure-driven flow to a monolithically integrated emitter for nano-electrospray ionization mass spectrometry (nanoESI-MS) analysis. This interface should be amenable to the separation and identification of droplet contents and on-line monitoring of in-droplet reactions.

  14. Project Sponsor: Siemens Power GenerationUCI Combustion Laboratory www.ucicl.uci.edu

    E-Print Network [OSTI]

    Mease, Kenneth D.

    in ultra low sulfur diesel fuel (DF2), its discrete water droplet size distribution and the injection

  15. A simple technique to reduce evaporation of crystallization droplets by using plate lids with apertures for adding liquids

    SciTech Connect (OSTI)

    Zipper, Lauren E.; Aristide, Xavier; Bishop, Dylan P.; Joshi, Ishita; Kharzeev, Julia; Patel, Krishna B.; Santiago, Brianna M.; Joshi, Karan; Dorsinvil, Kahille; Sweet, Robert M.; Soares, Alexei S.

    2014-11-28

    This article describes the use of evaporation control lids that are fitted to crystallization plates to improve the reproducibility of trials using as little as 5 nl. The plate lids contain apertures which are large enough for the transfer of protein containing droplets, but small enough to greatly reduce the rate of evaporation during the time needed to prepare the plate. A method is described for using plate lids to reduce evaporation in low-volume vapor-diffusion crystallization experiments. The plate lids contain apertures through which the protein and precipitants were added to different crystallization microplates (the reservoir was filled before fitting the lids). Plate lids were designed for each of these commonly used crystallization microplates. This system minimizes the dehydration of crystallization droplets containing just a few nanolitres of protein and precipitant, and results in more reproducible diffraction from the crystals. For each lid design, changes in the weight of the plates were used to deduce the rate of evaporation under different conditions of temperature, air movement, droplet size and precipitant. For comparison, the state of dehydration was also visually assessed throughout the experiment. Finally, X-ray diffraction methods were used to compare the diffraction of protein crystals that were conventionally prepared against those that were prepared on plates with plate lids. The measurements revealed that the plate lids reduced the rate of evaporation by 63–82%. Crystals grown in 5 nl drops that were set up with plate lids diffracted to higher resolution than similar crystals from drops that were set up without plate lids. The results demonstrate that plate lids can be instrumental for improving few-nanolitre crystallizations.

  16. Aerosol mobility size spectrometer

    DOE Patents [OSTI]

    Wang, Jian (Port Jefferson, NY); Kulkarni, Pramod (Port Jefferson Station, NY)

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  17. Cavitation within a dropletCavitation within a droplet G. L. Heijnen1,2, P. A. Quinto-Su2, X. Zhao2, C. D. Ohl1,2

    E-Print Network [OSTI]

    Ohl, Claus-Dieter

    . The droplet is illuminated from behind with a high power light emitting diode (Seoul Semiconductor, P7

  18. Droplet impingement and breakup on a dry surface Amit Gupta, Ranganathan Kumar *

    E-Print Network [OSTI]

    Gupta, Amit

    solution for breakup based on the conservation of energy is provided. Criteria for three to a rebound of the droplet from the surface. For the case where there is no rebound of the liquid film from rebound on a dry surface for low density ratios [12]. However, an analytical investigation of the droplet

  19. Droplet motion with phase change in a temperature gradient Akira Onuki and Kentaro Kanatani

    E-Print Network [OSTI]

    2005 We examine the droplet motion in one-component fluids in a small temperature gradient by solving changes the hydro- dynamic flow around the droplet. As a result, the temperature becomes almost the Reynolds number Re=vgR/ gR3 1- / / 2 is small. Here = / is the exterior kinematic viscosity. As another

  20. Formation of Droplets and Mixing in Multiphase Microfluidics at Low Values of the Reynolds and the

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    Formation of Droplets and Mixing in Multiphase Microfluidics at Low Values of the Reynolds, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 Received March 4, 2003. In Final Form formation of droplets, or plugs, of multiple aqueous reagents without bringing reagents into contact prior

  1. Formation of Droplets of Alternating Composition in Microfluidic Channels and Applications to

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    Formation of Droplets of Alternating Composition in Microfluidic Channels and Applications* Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 and caused formation of droplets that were smaller than the cross-sectional dimension of the channel

  2. Molecular tagging thermometry for transient temperature mapping within a water droplet

    E-Print Network [OSTI]

    Hu, Hui

    temperature measurements within a small water droplet over a solid surface. For MTT measurement, a pulsed-induced phosphorescence is imaged at two successive times after the same laser excitation pulse. The temperature measurements of liquid droplets for combustion applications [1­3]. Laser- induced phosphorescence (LIP

  3. Confined Dissipative Droplet Solitons in Spin-Valve Nanowires with Perpendicular Magnetic Anisotropy

    E-Print Network [OSTI]

    Hoefer, Mark

    in nanoscale structures for magnetic storage and computation, but dissipative droplet studies have so far been possibilities for the study of low-dimensional solitons and droplet applications in nanostructures. DOI: 10 is achieved in devices known as spin valves (SVs) [5­8], where two magnetic layers are separated

  4. Experimental test of scaling of mixing by chaotic advection in droplets moving through microfluidic channels

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    Experimental test of scaling of mixing by chaotic advection in droplets moving through microfluidic that predicts the scaling of chaotic mixing in a droplet moving through a winding microfluidic channel microfluidic channels.1 In microfluidic systems2,3 operating at low values of the Reynolds number Re, streams

  5. Fatty Acid Chemistry at the Oil-Water Interface: Self-Propelled Oil Droplets

    E-Print Network [OSTI]

    Ikegami, Takashi

    Fatty Acid Chemistry at the Oil-Water Interface: Self-Propelled Oil Droplets Martin M. Hanczyc transitions. Here we have explored the possibility that fatty acid systems also demonstrate movement. An oil solution. The oil droplets showed autonomous, sustained movement through the aqueous media. Internal

  6. Effects of nonreacting solid particle and liquid droplet loading on an exothermic reacting mixing layer

    E-Print Network [OSTI]

    Miller, Richard S.

    of natural and practical applications; including, liquid fueled combustion, solid propellant combustion or liquid droplets smaller than the smallest length scale of the corresponding single-phase gas flowEffects of nonreacting solid particle and liquid droplet loading on an exothermic reacting mixing

  7. The interaction of liquid reacting droplets with the pulsating flow in a Rijke-tube combustor

    SciTech Connect (OSTI)

    Carvalho, J.A.; Gotac, P.R. [Inst. Nacional de Pesquisas Espaciais, Cachoeira Paulista, Sao Paulo (Brazil). Lab. Associado de Combustao e Propulsao] [Inst. Nacional de Pesquisas Espaciais, Cachoeira Paulista, Sao Paulo (Brazil). Lab. Associado de Combustao e Propulsao; McQuay, M.Q. [Brigham Young Univ., Provo, UT (United States). Mechanical Engineering Dept.] [Brigham Young Univ., Provo, UT (United States). Mechanical Engineering Dept.

    1997-01-01

    This paper presents the results of a theoretical investigation on the characteristics of a reacting liquid droplet in the self-generated oscillatory flow of a Rijke-pulse combustor. The droplet motion equation, accounting for droplet evaporation due to combustion, was solved using a fourth-order, Runge-Kutta method. The model was applied to a Rijke-type, alcohol-fired combustor for which experimental data exist to be used as entrance parameters. The main conclusions derived from this study are (1) for a range of droplet initial velocity, pulsating flames of liquid fuels are shorter than the corresponding steady flames because of a reduction in lifetime of droplets with the same initial diameter in the pulsating flow, (2) for a range of droplet initial diameter, time-resolved heat generation rates from pulsating sprays exhibit a preferred frequency equal to twice the frequency of the pulsating flow, and (3) droplet initial diameter, droplet initial velocity, and location of the spray in the tube influence the excitation and maintenance of acoustic oscillations in a Rijke-type combustor based on evaluation of the Rayleigh integral over time and volume in the combustor. The theoretical results presented and discussed herein are supported by experimental observations.

  8. Spraying Mode Effect on Droplet Formation and Ion Chemistry in Electrosprays

    E-Print Network [OSTI]

    Vertes, Akos

    release of gas-phase ions18,19 are interconnected steps that have been studied separately. To better on the liquid jet emerging from the Taylor cone, whereas secondary droplets are formed by fission. Dramatic observed at different emitter voltages and liquid flow rates. We demonstrate that droplet fission can

  9. On the physics of fizzing: How bubble bursting controls droplets ejection

    E-Print Network [OSTI]

    Cessi, Paola

    ­12 . For example, this latter mechanism accounts for the majority of sea-spray aerosol particles in the atmosphere, the tiny droplets ejected during bursting are crucial for champagne tasting as their evaporation highly and atmosphere5,6 . Two distinct types of droplets are involved, lying on two different mechanisms appearing

  10. Defect-Aware Synthesis of Droplet-Based Microfluidic Biochips* , Krishnendu Chakrabarty

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    " droplet-based microfluidic platforms, system integration, design complexity, and the need for defect is referred to as "digital microfluidics" [1]. Because each droplet can be controlled independently adapt more bioassays for concurrent execution on a digital microfluidic platform, system integration

  11. Physics/Mathematics double degree BSc project: Adhesive Force of Droplets with Increasingly Realistic

    E-Print Network [OSTI]

    Vuik, Kees

    Physics/Mathematics double degree BSc project: Adhesive Force of Droplets with Increasingly to predict how the adhesive force depends on the droplet properties. What is this project about? In this project you theoretically and numerically investigate how the adhesive force depends on two key parameters

  12. Transport of expiratory droplets in an aircraft cabin Jitendra K. Guptaa

    E-Print Network [OSTI]

    Chen, Qingyan "Yan"

    disease such as influenza or Tuberculosis may be the carriers of contagious agents. Indoor environments such as the airliner cabins may be susceptible to infection from such airborne contagious agents. The present of the droplets exhaled by an index passenger in an aircraft cabin. These droplets may contain active contagious

  13. Microfluidic droplet encapsulation of highly motile single zoospores for phenotypic screening of an antioomycete chemical

    E-Print Network [OSTI]

    Bhattacharyya, Madan Kumar

    Microfluidic droplet encapsulation of highly motile single zoospores for phenotypic screening for re-usable 3D polydimethylsiloxane (PDMS) microfluidic networks Biomicrofluidics 5, 036502 (2011://bmf.aip.org/about/rights_and_permissions #12;Microfluidic droplet encapsulation of highly motile single zoospores for phenotypic screening

  14. Photoelectron Imaging of Helium Droplets Darcy S. Peterka,1,2

    E-Print Network [OSTI]

    Neumark, Daniel M.

    crossed the helium droplet beam perpendicular to the axis of the electron detection system, comprisingPhotoelectron Imaging of Helium Droplets Darcy S. Peterka,1,2 Albrecht Lindinger,2 Lionel Poisson,1.40.­c, 33.20.Ni, 33.60.Cv, 33.80.Eh Helium nanodroplets have been shown to be a novel spectroscopic

  15. Sminaire du Groupe N2IS Manipulation of chemicals in droplet-based microfluidics

    E-Print Network [OSTI]

    Ingrand, François

    Séminaire du Groupe N2IS Manipulation of chemicals in droplet-based microfluidics Le 06 Septembre TOULOUSE Cedex 4 Résumé Droplet-based microfluidics has a tremendous potential for the miniaturization of chemicals in microfluidic systems is therefore a key to reliably downscale the assays from microtiter plates

  16. Journal of Power Sources 161 (2006) 333345 Liquid droplet behavior and instability in a polymer

    E-Print Network [OSTI]

    Mench, Matthew M.

    2006-01-01

    droplet removal where practical. © 2006 Elsevier B.V. All rights reserved. Keywords: Flooding; PolymerJournal of Power Sources 161 (2006) 333­345 Liquid droplet behavior and instability in a polymer local channel flooding. However, at low flow rates, hydrophobicity of the DM surface has only a minimal

  17. High speed flow cytometer droplet formation system and method

    DOE Patents [OSTI]

    Van den Engh, Ger (Seattle, WA)

    2000-01-01

    A droplet forming flow cytometer system allows high speed processing without the need for high oscillator drive powers through the inclusion of an oscillator or piezoelectric crystal such as within the nozzle volume or otherwise unidirectionally coupled to the sheath fluid. The nozzle container continuously converges so as to amplify unidirectional oscillations which are transmitted as pressure waves through the nozzle volume to the nozzle exit so as to form droplets from the fluid jet. The oscillator is directionally isolated so as to avoid moving the entire nozzle container so as to create only pressure waves within the sheath fluid. A variation in substance concentration is achieved through a movable substance introduction port which is positioned within a convergence zone to vary the relative concentration of substance to sheath fluid while still maintaining optimal laminar flow conditions. This variation may be automatically controlled through a sensor and controller configuration. A replaceable tip design is also provided whereby the ceramic nozzle tip is positioned within an edge insert in the nozzle body so as to smoothly transition from nozzle body to nozzle tip. The nozzle tip is sealed against its outer surface to the nozzle body so it may be removable for cleaning or replacement.

  18. Detachment of Liquid-Water Droplets from Gas-Diffusion Layers

    SciTech Connect (OSTI)

    Das, Prodip K.; Grippin, Adam; Weber, Adam Z.

    2011-07-01

    A critical issue for optimal water management in proton-exchange-membrane fuel cells at lower temperatures is the removal of liquid water from the cell. This pathway is intimately linked with the phenomena of liquid-water droplet removal from surface of the gas-diffusion layer and into the flow channel. Thus, a good understanding of liquid-water transport and droplet growth and detachment from the gas-diffusion layer is critical. In this study, liquid-water droplet growth and detachment on the gas-diffusion layer surfaces are investigated experimentally to improve the understating of water transport through and removal from gas-diffusion layers. An experiment using a sliding-angle measurement is designed and used to quantify and directly measure the adhesion force for liquid-water droplets, and to understand the droplets? growth and detachment from the gas-diffusion layers.

  19. Droplet-Based Segregation and Extraction of Concentrated Samples

    SciTech Connect (OSTI)

    Buie, C R; Buckley, P; Hamilton, J; Ness, K D; Rose, K A

    2007-02-23

    Microfluidic analysis often requires sample concentration and separation techniques to isolate and detect analytes of interest. Complex or scarce samples may also require an orthogonal separation and detection method or off-chip analysis to confirm results. To perform these additional steps, the concentrated sample plug must be extracted from the primary microfluidic channel with minimal sample loss and dilution. We investigated two extraction techniques; injection of immiscible fluid droplets into the sample stream (''capping'''') and injection of the sample into an immiscible fluid stream (''extraction''). From our results we conclude that capping is the more effective partitioning technique. Furthermore, this functionality enables additional off-chip post-processing procedures such as DNA/RNA microarray analysis, realtime polymerase chain reaction (RT-PCR), and culture growth to validate chip performance.

  20. On-Demand Generation of Monodisperse Femtoliter Droplets by Shape-Induced Shear

    SciTech Connect (OSTI)

    Collier, Pat [ORNL; Retterer, Scott T [ORNL; Jung, Seung-Yong [ORNL

    2010-01-01

    We describe a method for creating discrete femtoliter-scale water-in-oil droplets on demand, based solely on a geometrically induced reduction in oil/water interfacial area at microfabricated junction orifices. This on-demand generation method is driven by self-shear of droplets due to interfacial tension induced forces resulting from a localized transition in microchannel height. The magnitudes of shear stresses involved appear to be significantly less than the shearing instabilities used to split off daughter droplets from aqueous mother plugs at microfabricated junctions in continuous water-in-oil segmented flows, which implies that this method may be better suited for studying biochemical reactions and reaction kinetics in droplets of decreased volume without loss of chemical reactivity due to redistribution of surfactant density used to passivate the oil/water interface. Predictable droplet generation rates under constant pressure conditions or the gated formation of one, two or more droplets at a time with fixed pressure pulses have been demonstrated in a similar manner to active on-demand droplet generation strategies, but with a simpler system not needing actuation and sensing equipment beyond a pressure regulator.

  1. Self-propelled running droplets on solid substrates driven by chemical reactions

    E-Print Network [OSTI]

    K. John; M. Baer; U. Thiele

    2006-11-17

    We study chemically driven running droplets on a partially wetting solid substrate by means of coupled evolution equations for the thickness profile of the droplets and the density profile of an adsorbate layer. Two models are introduced corresponding to two qualitatively different types of experiments described in the literature. In both cases an adsorption or desorption reaction underneath the droplets induces a wettability gradient on the substrate and provides the driving force for droplet motion. The difference lies in the behavior of the substrate behind the droplet. In case I the substrate is irreversibly changed whereas in case II it recovers allowing for a periodic droplet movement (as long as the overall system stays far away from equilibrium). Both models allow for a non-saturated and a saturated regime of droplet movement depending on the ratio of the viscous and reactive time scales. In contrast to model I, model II allows for sitting drops at high reaction rate and zero diffusion along the substrate. The transition from running to sitting drops in model II occurs via a super- or subcritical drift-pitchfork bifurcation and may be strongly hysteretic implying a coexistence region of running and sitting drops.

  2. Oscillation and collective conveyor of water-in-oil droplets by microfluidic bolus flow

    E-Print Network [OSTI]

    Ohmura, Takuya; Kamei, Ken-ichiro; Maeda, Yusuke T

    2015-01-01

    Microfluidic techniques have been extensively developed to realize micro-total analysis systems in a small chip. For microanalysis, the trapping or arranging of objects in a line is a critical step. Physical effects such as inertial lift force have been utilized so far, however, hydrodynamic interaction in a many body system is yet to be explored despite its relevance to pattern formation. Here, we report water-in-oil (W/O) droplets can be transported with sequential order in the grid of one-dimensional array of another large W/O droplets. As each droplet comes close to an interspace of the large droplet array, while exhibiting persistent back-and-forth motion, it is conveyed at a velocity equal to the droplet array. The droplet also makes asymmetric orbit to and from the large droplet behind, suggesting vortex like stream was involved. We confirm the appearance of closed streamlines, which called bolus flow, in numerical simulation based on lattice Boltzmann method. The existence region of bolus flow account...

  3. Droplet shattering, vaporization and recondensation in cloud clearing with long pulse infrared chemical lasers

    SciTech Connect (OSTI)

    Caramana, E.J.; Kindel, J.L.; Morse, R.L.; Quigley, G.P.; Webster, R.B.; York, G.W.

    1990-01-01

    Results of experimental attempts to produce an optically clear channel in a water cloud by evaporating the cloud droplets with a CO{sub 2} laser are presented. Using scattered light it is possible to visualize the clear channel produced. Measurements of the fraction of power transmitted through the channel at visible wavelengths give insight into the clearing mechanisms. The present data suggest that the water droplets explode in the process of clearing. A theoretical explanation of why this should occur is presented and predictions of the onset of droplet explosions are made. 4 refs., 5 figs.

  4. Quantized vortices in {sup 4}He droplets: A quantum Monte Carlo study

    SciTech Connect (OSTI)

    Sola, E.; Casulleras, J.; Boronat, J.

    2007-08-01

    We present a diffusion Monte Carlo study of a vortex line excitation attached to the center of a {sup 4}He droplet at zero temperature. The vortex energy is estimated for droplets of increasing number of atoms, from N=70 up to 300, showing a monotonous increase with N. The evolution of the core radius and its associated energy, the core energy, is also studied as a function of N. The core radius is {approx}1 A in the center and increases when approaching the droplet surface; the core energy per unit volume stabilizes at a value 2.8 K{sigma}{sup -3} ({sigma}=2.556 A) for N{>=}200.

  5. Table I: Distribution Functions for Fuel Fractions Group 2L0 FL0 ( wL0

    E-Print Network [OSTI]

    Hallett, William L.H.

    Table I: Distribution Functions for Fuel Fractions Group 2L0 FL0 ( wL0 alcohols 55 20 0 0: Distribution fun ctions used to mod el the oil. Evaporation of Biomass Pyrolysis Oil Droplets - II W), and the composition of each of these groups is described by a gamma distribution function with mean 2L0, standard

  6. Effects of Induced Acoustic Vibrations on Droplet Shedding on Hybrid Micro-structured Surfaces 

    E-Print Network [OSTI]

    Lai, Chen-Ling

    2014-04-28

    during condensation. However, use of hybrid surfaces in condensation leads to a strong pinning effect that takes place between the condensing droplets and the hydrophobic-hydrophillic edge, leading to a significant contact angle hysteresis effect...

  7. Monte Carlo computer simulations and electron microscopy of colloidal cluster formation via emulsion droplet evaporation

    E-Print Network [OSTI]

    Schmidt, Matthias

    . The arrangement of the particles on the surface of the droplets was analyzed with cryogenic field emission with respect to freezing for suffi- ciently short range of attraction.1­4 While the addition of a short

  8. Studies on the ion-droplet mixed regime in colloid thrusters

    E-Print Network [OSTI]

    Lozano-Tovar, Paulo César, 1970-

    2003-01-01

    Colloid thrusters working with mixtures of ions and droplets are gradually becoming an alternative technology for space micro-propulsion needs in missions requiring high position controllability, compactness and low power ...

  9. Osmotic compression of droplets of hard rods: A computer simulation study

    E-Print Network [OSTI]

    Y. Trukhina; S. Jungblut; P. van der Schoot; T. Schilling

    2009-02-12

    By means of computer simulations we study how droplets of hard, rod-like particles optimize their shape and internal structure under the influence of the osmotic compression caused by the presence of spherical particles that act as depletion agents. At sufficiently high osmotic pressures the rods that make up the drops spontaneously align to turn them into uniaxial nematic liquid crystalline droplets. The nematic droplets or "tactoids" that are formed this way are not spherical but elongated, resulting from the competition between the anisotropic surface tension and the elastic deformation of the director field. In agreement with recent theoretical predictions we find that sufficiently small tactoids have a uniform director field, whilst large ones are characterized by a bipolar director field. From the shape and director-field transformation of the droplets we are able to estimate the surface anchoring strength and an average of the elastic constants of the hard-rod nematic.

  10. Tunable spatial heterogeneity in structure and composition within aqueous microfluidic droplets

    E-Print Network [OSTI]

    Hui, Sophia Lee Su

    In this paper, we demonstrate biphasic microfluidic droplets with broadly tunable internal structures, from simple near-equilibrium drop-in-drop morphologies to complex yet uniform non-equilibrium steady-state structures. ...

  11. Physico-chemical hydrodynamics of droplets on textured surfaces with engineered micro/nanostructures

    E-Print Network [OSTI]

    Park, Kyoo Chul

    2013-01-01

    Understanding physico-chemical hydrodynamics of droplets on textured surfaces is of fundamental and practical significance for designing a diverse range of engineered surfaces such as low-reflective, self-cleaning or ...

  12. Wetting hysteresis and droplet roll off behavior on superhydrophobic surfaces by Katherine Marie Smyth.

    E-Print Network [OSTI]

    Smyth, Katherine Marie

    2010-01-01

    Various states of hydrophobic wetting and hysteresis are observed when water droplets are deposited on micro-post surfaces of different post densities. Hysteresis is commonly defined as the difference between the advancing ...

  13. Self-propulsion of pure water droplets by spontaneous Marangoni stress driven motion

    E-Print Network [OSTI]

    Ziane Izri; Marjolein N. van der Linden; Sébastien Michelin; Olivier Dauchot

    2014-11-12

    We report spontaneous motion in a fully bio-compatible system consisting of pure water droplets in an oil-surfactant medium of squalane and monoolein. Water from the droplet is solubilized by the reverse micellar solution, creating a concentration gradient of swollen reverse micelles around each droplet. The strong advection and weak diffusion conditions allow for the first experimental realization of spontaneous motion in a system of isotropic particles at sufficiently large P\\'eclet number according to a straightforward generalization of a recently proposed mechanism. Experiments with a highly concentrated solution of salt instead of water, and tetradecane instead of squalane, confirm the above mechanism. The present swimming droplets are able to carry external bodies such as large colloids, salt crystals, and even cells.

  14. Modelin combustion of multicomponent fuel droplets: formulation and application to transportation fuels 

    E-Print Network [OSTI]

    Vittilapuram Subramanian, Kannan

    2006-04-12

    The quasi-steady, spherically symmetric combustion of multicomponent isolated fuel droplets has been modeled using modified Shvab-Zeldovich variable mechanism. Newly developed modified Shvab-Zeldovich equations have been used to describe the gas...

  15. Oscillation of a Rotating Levitated Droplet: Analysis with a Mechanical Model

    E-Print Network [OSTI]

    Kitahata, Hiroyuki; Koyano, Yuki; Matsumoto, Satoshi; Nishinari, Katsuhiro; Watanabe, Tadashi; Hasegawa, Koji; Kanagawa, Tetsuya; Kaneko, Akiko; Abe, Yutaka

    2015-01-01

    A droplet of millimeter-to-centimeter scale can exhibit electrostatic levitation, and such levitated droplets can be used for the measurement of the surface tension of the liquids by observing the characteristic frequency of oscillatory deformation. In the present study, a simple mechanical model is proposed by considering a single mode of oscillation in the ellipsoidal deformation of a levitated rotating droplet. By measuring the oscillation frequency with respect to the rotational speed and oscillation amplitude, it is expected that the accuracy of the surface tension measurement could be improved. Using the proposed model, the dependences of the characteristic frequency of oscillatory deformation and the averaged aspect ratio are calculated with respect to the rotational angular velocity of a rotating droplet. These dependences are found to be consistent with the experimental observations.

  16. Study of the Effects of Single and Double Droplets Impingement on Surface Cooling 

    E-Print Network [OSTI]

    Tsai, Hsin-Min

    2012-10-19

    Spray cooling is a promising technique which is used to remove large amounts of heat from surfaces. It is characterized by uniform heat removal, low droplet impact velocity and better cooling efficiency when compared to ...

  17. Magnetic detection of underground pipe using timed-release marking droplets

    DOE Patents [OSTI]

    Powell, James R. (Shoreham, NY); Reich, Morris (Kew Garden Hills, NY)

    1996-12-17

    A system 10 and method of detecting an underground pipe 12 injects magnetic marking droplets 16 into the underground pipe 12 which coat the inside of the pipe 12 and may be detected from aboveground by a magnetometer 28. The droplets 16 include a non-adhesive cover 32 which allows free flow thereof through the pipe 12, with the cover 32 being ablatable for the timed-release of a central core 30 containing magnetic particles 30a which adhere to the inside of the pipe 12 and are detectable from aboveground. The rate of ablation of the droplet covers 32 is selectively variable to control a free flowing incubation zone 12a for the droplets 16 and a subsequent deposition zone 12b in which the magnetic particles 30a are released for coating the pipe 12.

  18. An Investigation on Heat Transfer During the Freezing of Condensate Droplets 

    E-Print Network [OSTI]

    Gong, Ying

    1996-01-01

    The heat transfer and the freezing process of condensate droplets resting on a cold metal plate have been studied both experimentally and numerically. The experimental part of the investigation dealt with the measurements ...

  19. Dynamic Response of Quartz Crystal Microbalances in contact with Silicone Oil Droplets

    E-Print Network [OSTI]

    Zhuang, Han

    Quartz crystal microbalances (QCMs) in contact with liquid droplets have been used to investigate the rheological properties of liquids and the diverse solid-liquid interfacial phenomena. In this article, we first report ...

  20. Development of a uniform-droplet spray apparatus for high melting temperature metals

    E-Print Network [OSTI]

    Joumaa, Hady K

    2005-01-01

    The building and operation of a high-temperature uniform droplet spraying (UDS) apparatus extend the performance and capabilities of powder based manufacturing processes. Although the main concepts of operation of the ...

  1. Energy Exchange Analysis in Droplet Dynamics via the Navier-Stokes-Cahn-Hilliard Model

    E-Print Network [OSTI]

    Espath, LFR; Vignal, P; Varga, BON; Cortes, AMA; Dalcin, L; Calo, VM

    2015-01-01

    We develop the energy budget equation of the coupled Navier-Stokes-Cahn-Hilliard (NSCH) system. We use the NSCH equations to model the dynamics of liquid droplets in a liquid continuum. Buoyancy effects are accounted for through the Boussinesq assumption. We physically interpret each quantity involved in the energy exchange to further insight into the model. Highly resolved simulations involving density-driven flows and merging of droplets allow us to analyze these energy budgets. In particular, we focus on the energy exchanges when droplets merge, and describe flow features relevant to this phenomenon. By comparing our numerical simulations to analytical predictions and experimental results available in the literature, we conclude that modeling droplet dynamics within the framework of NSCH equations is a sensible approach worth further research.

  2. Conglomeration of kilometre-sized planetesimals

    E-Print Network [OSTI]

    Shannon, Andrew; Wu, Yanqin; Lithwick, Yoram

    2015-02-25

    out of ? 104M? of primordial solids. The total disk mass, if supplemented with the missing hydro- gen gas, would then reach of order a solar mass. This is very surprising and, in our view, invalidates the low-efficiency conglomeration model. Moreover... . This corresponds to a dis- ruption velocity of v ? 100 cm/ s, or e ? 10?3 at 40 AU. When bodies of size s1 are catastrophically disrupted, we re-distribute their masses to smaller size bins with a number distribution that is power-law in size, dn/ds ? sq? for s < s...

  3. Impact of picolitre droplets on superhydrophobic surfaces with ultra-low spreading ratios

    E-Print Network [OSTI]

    Brown, P.S.; Berson, A.; Talbot, E.L.; Wood, T.J.; Schofield, W.C.E.; Bain, C.D.; Badyal, J.P.S.

    2011-01-01

    :24 1 IMPACT OF PICOLITRE DROPLETS ON SUPERHYDROPHOBIC SURFACES WITH ULTRA-LOW SPREADING RATIOS P. S. Brown, A. Berson, E. L. Talbot, T. J. Wood, W. C. E. Schofield, C. D. Bain†, and J. P. S. Badyal†* Department of Chemistry Science... the dynamics of wetting to be precisely controlled. Final spreading ratios as low as 0.63 can be achieved. Comparison of the maximum spreading ratio and droplet oscillation frequencies with models described in the literature shows that both are found...

  4. On-chip real-time single-copy polymerase chain reaction in picoliter droplets

    SciTech Connect (OSTI)

    Beer, N R; Hindson, B; Wheeler, E; Hall, S B; Rose, K A; Kennedy, I; Colston, B

    2007-04-20

    The first lab-on-chip system for picoliter droplet generation and PCR amplification with real-time fluorescence detection has performed PCR in isolated droplets at volumes 10{sup 6} smaller than commercial real-time PCR systems. The system utilized a shearing T-junction in a silicon device to generate a stream of monodisperse picoliter droplets that were isolated from the microfluidic channel walls and each other by the oil phase carrier. An off-chip valving system stopped the droplets on-chip, allowing them to be thermal cycled through the PCR protocol without droplet motion. With this system a 10-pL droplet, encapsulating less than one copy of viral genomic DNA through Poisson statistics, showed real-time PCR amplification curves with a cycle threshold of {approx}18, twenty cycles earlier than commercial instruments. This combination of the established real-time PCR assay with digital microfluidics is ideal for isolating single-copy nucleic acids in a complex environment.

  5. System for sensing droplet formation time delay in a flow cytometer

    DOE Patents [OSTI]

    Van den Engh, Ger (Seattle, WA); Esposito, Richard J. (Seattle, WA)

    1997-01-01

    A droplet flow cytometer system which includes a system to optimize the droplet formation time delay based on conditions actually experienced includes an automatic droplet sampler which rapidly moves a plurality of containers stepwise through the droplet stream while simultaneously adjusting the droplet time delay. Through the system sampling of an actual substance to be processed can be used to minimize the effect of the substances variations or the determination of which time delay is optimal. Analysis such as cell counting and the like may be conducted manually or automatically and input to a time delay adjustment which may then act with analysis equipment to revise the time delay estimate actually applied during processing. The automatic sampler can be controlled through a microprocessor and appropriate programming to bracket an initial droplet formation time delay estimate. When maximization counts through volume, weight, or other types of analysis exists in the containers, the increment may then be reduced for a more accurate ultimate setting. This may be accomplished while actually processing the sample without interruption.

  6. The structure of mixed {sup 3}He-{sup 4}He droplets doped with OCS: A density functional approach

    SciTech Connect (OSTI)

    Leal, Antonio; Mateo, David; Pi, Martí; Barranco, Manuel [Departament ECM, Facultat de Física and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain)] [Departament ECM, Facultat de Física and IN2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Navarro, Jesús [IFIC (CSIC-Universidad de Valencia), P.O. Box 22085, E-46071 Valencia (Spain)] [IFIC (CSIC-Universidad de Valencia), P.O. Box 22085, E-46071 Valencia (Spain)

    2013-11-07

    We have investigated the structure and energetics of mixed {sup 3}He-{sup 4}He droplets doped with a carbonyl sulfide molecule within a density functional approach considering a small but finite temperature of 0.1 K. The molecule is treated as an external field to which the helium droplet is attached. The energetics and appearance of these droplets are discussed for selected numbers of helium atoms, identifying the first magic numbers of the fermionic component.

  7. THE LIFETIME OF AEROSOL DROPLETS IN AMBIENT AIR: CONSIDERATION OF THE EFFECTS OF SURFACTANTS AND CHEMICAL REACTIONS

    E-Print Network [OSTI]

    Toossi, R.

    2013-01-01

    OF SURFACTANT$ AND CHEMICAL REACTIONS R. Toossi and T.Absorption of gases and chemical reactions within theno catalyst, no chemical reaction) Droplet containing l0- gr

  8. Axisymmetric oscillation modes of a double droplet system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ramalingam, Santhosh K.; Basaran, Osman A.

    2010-01-01

    A double droplet system (DDS) consists of a sessile and a pendant drop that are coupled through a liquid filled cylindrical hole in a plate of thickness d. For a small hole radius R, equilibrium shapes of both drops are sections of spheres. While DDSs have a number of applications in microfluidics, a DDS oscillating about its equilibrium state can be used as a fast focusing liquid lens. Here, a DDS consisting of an isothermal, incompressible Newtonian fluid of constant density p and constant viscosity u that is surrounded by a gas is excited by oscillating in time (a) the pressure in the gas surrounding either drop (pressure excitation), (b) the plate perpendicular to its plane (axial excitation), and (c) the hole radius (radial excitation). In contrast to previous works that assumed transient drop shapes are spherical, they are determined here by simulation and used to identify the natural modes of axisymmetric oscillations from resonances observed during frequency sweeps with DDSs for which the combined volume V of the two drops is less than (4/3)?R3. Pressure and axial excitations are found to have identical responses but axial and radial excitations are shown to excite different modes. These modes are compared to those exhibited by single pendant (sessile) drop systems. In particular, while a single pendant (sessile) drop has one additional oscillation mode compared to a free drop, a DDS is found to exhibit roughly twice as many oscillation modes as a pendant (sessile) drop. The effects of dimensionless volume V/R3, dimensionless plate thickness d/R, and Ohnesorge number Oh =?/??R? , where ? is the surface tension of the DDS-gas interface, on the resonance frequencies are also investigated.

  9. Axisymmetric oscillation modes of a double droplet system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ramalingam, Santhosh K.; Basaran, Osman A.

    2010-11-15

    A double droplet system (DDS) consists of a sessile and a pendant drop that are coupled through a liquid filled cylindrical hole in a plate of thickness d. For a small hole radius R, equilibrium shapes of both drops are sections of spheres. While DDSs have a number of applications in microfluidics, a DDS oscillating about its equilibrium state can be used as a fast focusing liquid lens. Here, a DDS consisting of an isothermal, incompressible Newtonian fluid of constant density p and constant viscosity u that is surrounded by a gas is excited by oscillating in time (a) themore »pressure in the gas surrounding either drop (pressure excitation), (b) the plate perpendicular to its plane (axial excitation), and (c) the hole radius (radial excitation). In contrast to previous works that assumed transient drop shapes are spherical, they are determined here by simulation and used to identify the natural modes of axisymmetric oscillations from resonances observed during frequency sweeps with DDSs for which the combined volume V of the two drops is less than (4/3)?R3. Pressure and axial excitations are found to have identical responses but axial and radial excitations are shown to excite different modes. These modes are compared to those exhibited by single pendant (sessile) drop systems. Specifically, while a single pendant (sessile) drop has one additional oscillation mode compared to a free drop, a DDS is found to exhibit roughly twice as many oscillation modes as a pendant (sessile) drop. The effects of dimensionless volume V/R3, dimensionless plate thickness d/R, and Ohnesorge number Oh =?/??R? , where ? is the surface tension of the DDS-gas interface, on the resonance frequencies are also investigated.« less

  10. Axisymmetric oscillation modes of a double droplet system

    SciTech Connect (OSTI)

    Ramalingam, Santhosh K.; Basaran, Osman A.

    2010-11-15

    A double droplet system (DDS) consists of a sessile and a pendant drop that are coupled through a liquid filled cylindrical hole in a plate of thickness d. For a small hole radius R, equilibrium shapes of both drops are sections of spheres. While DDSs have a number of applications in microfluidics, a DDS oscillating about its equilibrium state can be used as a fast focusing liquid lens. Here, a DDS consisting of an isothermal, incompressible Newtonian fluid of constant density p and constant viscosity u that is surrounded by a gas is excited by oscillating in time (a) the pressure in the gas surrounding either drop (pressure excitation), (b) the plate perpendicular to its plane (axial excitation), and (c) the hole radius (radial excitation). In contrast to previous works that assumed transient drop shapes are spherical, they are determined here by simulation and used to identify the natural modes of axisymmetric oscillations from resonances observed during frequency sweeps with DDSs for which the combined volume V of the two drops is less than (4/3)?R3. Pressure and axial excitations are found to have identical responses but axial and radial excitations are shown to excite different modes. These modes are compared to those exhibited by single pendant (sessile) drop systems. In particular, while a single pendant (sessile) drop has one additional oscillation mode compared to a free drop, a DDS is found to exhibit roughly twice as many oscillation modes as a pendant (sessile) drop. The effects of dimensionless volume V/R3, dimensionless plate thickness d/R, and Ohnesorge number Oh =?/??R? , where ? is the surface tension of the DDS-gas interface, on the resonance frequencies are also investigated.

  11. Controlled emulsion droplet solvent evaporation for particle production

    E-Print Network [OSTI]

    Chang, Emily P

    2013-01-01

    In this work, we are motivated by the need to produce particles of well-controlled size, shape and morphology for general application in catalysis, environmental remediation, nanomedicine, pharmaceuticals, the development ...

  12. Bright tunable femtosecond x-ray emission from laser irradiated micro-droplets

    SciTech Connect (OSTI)

    Yu, Tong-Pu Hu, Li-Xiang; Yin, Yan; Shao, Fu-Qiu; Zhuo, Hong-Bin; Ma, Yan-Yun; Yang, Xiao-Hu; Luo, Wen; Pukhov, Alexander

    2014-09-15

    It is demonstrated that bright femtosecond X-rays can be obtained by irradiating a moderate laser onto a helium micro-droplet. The laser ponderomotive force continuously sweeps electrons from the droplets and accelerates them forward. The electrons exposed in the outrunning laser field oscillate transversely and emit photons in the forward direction. The total flux of photons with energies above 1?keV is as high as 10{sup 9}/shot which is about 10-fold enhancement compared with betatron oscillation under similar laser conditions. The maximum achieved peak brightness is up to 10{sup 21} photons/s/mm{sup 2}/mrad{sup 2}/0.1%BW. By adjusting laser and droplet parameters, we can get tunable X-rays with required brightness and energy.

  13. Measurements of Droplet Pinch-Off In Liquid Sodium

    E-Print Network [OSTI]

    Anlage, Steven

    than Mercury ­ 10X BETTER RESOLUTION · Study Effect of Magnetic Fields #12;Experimental Design SHIELDING · Reduces Electrical Noise · Coaxial Ground · Distributes Heat · Containment/ Structural Support #12;Running the Experiment · Sodium Melting? · Sodium Purity · Contact Wetting · Sampling Rate Gah

  14. Sensors and Actuators B 98 (2004) 319327 Automated on-chip droplet dispensing with volume control by

    E-Print Network [OSTI]

    Fair, Richard

    2004-01-01

    ). scribed an approach to droplet metering by introducing a hydrophobic patch in a microcapillary channel of the air/liquid interface was achieved. Then by pneumatic actuation with an exter- nal or on-chip pressure with existing droplet manipulation methods, such as pneumatic handling [10], dielectrophoresis [11

  15. The spherically symmetric droplet burning characteristics of Jet-A and biofuels derived from camelina and tallow

    E-Print Network [OSTI]

    Walter, M.Todd

    The spherically symmetric droplet burning characteristics of Jet-A and biofuels derived from the biofuels due to its higher aromatic content. " Droplet burning rates of camelina and tallow HRJ fuel Available online 1 March 2013 Keywords: Alternative jet fuel Hydroprocessed biofuel Spherically symmetric

  16. Oxidation Behavior of In-Flight Molten Aluminum Droplets in the Twin-Wire Electric Arc Thermal Spray Process

    SciTech Connect (OSTI)

    Donna Post Guillen; Brian G. Williams

    2005-05-01

    This paper examines the in-flight oxidation of molten aluminum sprayed in air using the twin-wire electric arc (TWEA) thermal spray process. The oxidation reaction of aluminum in air is highly exothermic and is represented by a heat generation term in the energy balance. Aerodynamic shear at the droplet surface enhances the amount of in-flight oxidation by: (1) promoting entrainment and mixing of the surface oxides within the droplet, and (2) causing a continuous heat generation effect that increases droplet temperature over that of a droplet without internal circulation. This continual source of heat input keeps the droplets in a liquid state during flight. A linear rate law based on the Mott-Cabrera theory was used to estimate the growth of the surface oxide layer formed during droplet flight. The calculated oxide volume fraction of an average droplet at impact agrees well with the experimentally determined oxide content for a typical TWEA-sprayed aluminum coating, which ranges from 3.3 to 12.7%. An explanation is provided for the elevated, nearly constant surface temperature (~ 2000 oC) of the droplets during flight to the substrate and shows that the majority of oxide content in the coating is produced during flight, rather than after deposition.

  17. Microfluidic production of monodisperse functional o/w droplets and study of their reversible pH dependent aggregation behavior

    E-Print Network [OSTI]

    Cicuta, Pietro

    Microfluidic production of monodisperse functional o/w droplets and study of their reversible p DOI: 10.1039/c1sm05087g We report the use of microfluidics for the production of monodisperse oil of individual droplets. Introduction Microdroplets in microfluidics have attracted enormous atten- tion

  18. The entrainment of oil droplets in flow beneath an oil slick 

    E-Print Network [OSTI]

    Chao, Chien-Hwa

    1973-01-01

    THE ENTRAINMENT OF OIL DROPLETS IN PLOW BENEATH AN OIL SLICK A Thesis by CHIEN-HWA CHAO Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OP SCIENCE August 1973 Ma...)or Sub)ect: Mechanical Engineering THE ENTRAINMENT OF OIL DROPLETS IN FLOW BENEATH AN OIL SLICK A Thesis CHIEN-HWA CHAD Approved as to style and content by: ( hairman o Committee) (Head of De tment) C ( (Member) ber) (Member) August 1973...

  19. Chemical Characterization of Individual Particles and Residuals of Cloud Droplets and Ice Crystals Collected On Board Research Aircraft in the ISDAC 2008 Study

    SciTech Connect (OSTI)

    Hiranuma, Naruki; Brooks, Sarah D.; Moffet, Ryan C.; Glen, Andrew; Laskin, Alexander; Gilles, Marry K.; Liu, Peter; MacDonald, A. M.; Strapp, J. Walter; McFarquhar, Greg

    2013-06-24

    Although it has been shown that size of atmospheric particles has a direct correlation with their ability to act as cloud droplet and ice nuclei, the influence of composition of freshly emitted and aged particles in nucleation processes is poorly understood. In this work we combine data from field measurements of ice nucleation with chemical imaging of the sampled particles to link aerosol composition with ice nucleation ability. Field measurements and sampling were conducted during the Indirect and Semidirect Aerosols Campaign (ISDAC) over Barrow, Alaska, in the springtime of 2008. In-situ ice nucleation measurements were conducted using a Continuous Flow Diffusion Chamber (CFDC). Measured number concentrations of ice nuclei (IN) varied from frequent values of 0.01 per liter to more than 10 per liter. Residuals of airborne droplets and ice crystals were collected through a counterflow virtual impactor (CVI). The compositions of individual atmospheric particles and the residuals were studied using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis (CCSEM/EDX) and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy (STXM/NEXAFS). Chemical analysis of cloud particle residuals collected during an episode of high ice nucleation suggests that both size and composition may influence aerosol's ability to act as IN. The STXM/NEXAFS chemical composition maps of individual residuals have characteristic structures of either inorganic or black carbon cores coated by organic materials. In a separate flight, particle samples from a biomass burning plume were collected. Although it has previously been suggested that episodes of biomass burning contribute to increased numbers of highly effective ice nuclei, in this episode we observed that only a small fraction were effective ice nuclei. Most of the particles from the biomass plume episode were smaller in size and were composed of homogeneous organic material without identifiable cores.

  20. On-chip single-copy real-time reverse-transcription PCR in isolated picoliter droplets

    SciTech Connect (OSTI)

    Beer, N R; Wheeler, E; Lee-Houghton, L; Watkins, N; Nasarabadi, S; Hebert, N; Leung, P; Arnold, D; Bailey, C; Colston, B

    2007-12-19

    The first lab-on-chip system for picoliter droplet generation and RNA isolation, followed by reverse transcription, and PCR amplification with real-time fluorescence detection in the trapped droplets has been developed. The system utilized a shearing T-junction in a fused silica device to generate a stream of monodisperse picoliter-scale droplets that were isolated from the microfluidic channel walls and each other by the oil phase carrier. An off-chip valving system stopped the droplets on-chip, allowing thermal cycling for reverse transcription and subsequent PCR amplification without droplet motion. This combination of the established real-time reverse transcription-PCR assay with digital microfluidics is ideal for isolating single-copy RNA and virions from a complex environment, and will be useful in viral discovery and gene-profiling applications.

  1. In-flight thermal control of molten metal droplet streams B. Matthew Michaelis *, Derek Dunn-Rankin, Robert F. Smith Jr., James E. Bobrow

    E-Print Network [OSTI]

    Bobrow, James E.

    with previously deposited mate- rial, new droplets should arrive with enough thermal energy to re-melt a thinIn-flight thermal control of molten metal droplet streams B. Matthew Michaelis *, Derek Dunn Available online 19 June 2007 Abstract Precision droplet manufacturing (PDM) is a process that builds

  2. Photoionization Dynamics in Pure Helium Droplets Darcy S. Peterka, Jeong Hyun Kim, Chia C. Wang, Lionel Poisson, and Daniel M. Neumark*

    E-Print Network [OSTI]

    Neumark, Daniel M.

    helium droplets in which ion mass spectrometry was used as the detection method. An essential featurePhotoionization Dynamics in Pure Helium Droplets Darcy S. Peterka, Jeong Hyun Kim, Chia C. Wang This paper presents a study of the photoionization of pure helium droplets above the ionization energy

  3. Does size matter?

    SciTech Connect (OSTI)

    Carreras, B. A.; Physics Department, College of Natural Science and Mathematics and Geophysical Institute, University of Alaska, Fairbanks, Alaska 99775; Physics Department, Universidad Carlos III de Madrid, Madrid ; Newman, D. E.; Dobson, Ian

    2014-06-15

    Failures of the complex infrastructures society depends on having enormous human and economic cost that poses the question: Are there ways to optimize these systems to reduce the risks of failure? A dynamic model of one such system, the power transmission grid, is used to investigate the risk from failure as a function of the system size. It is found that there appears to be optimal sizes for such networks where the risk of failure is balanced by the benefit given by the size.

  4. Supplementary Material for Interdroplet bilayer arrays in millifluidic droplet traps from 3D printed moulds

    E-Print Network [OSTI]

    Southampton, University of

    on an Objet Connex350TM 3D printer. One block was baked for 24 hours at 80 °C, causing a colour change fromSupplementary Material for Interdroplet bilayer arrays in millifluidic droplet traps from 3D. Untreated 3D-printed moulds were found to inhibit the curing of PDMS; baking the moulds eliminates

  5. Under consideration for publication in J. Fluid Mech. 1 Field-induced motion of ferrofluid droplets

    E-Print Network [OSTI]

    Renardy, Yuriko

    of the viscous drag force. The time taken by the droplet to travel through the medium and the deformations al. 2005). By treating the sphere as a magnetic particle, the magnetic force acting on it can with respect to the distance x from the permanent magnet. This magnetic force is balanced with the viscous drag

  6. IEEE SENSORS JOURNAL, VOL. 13, NO. 12, DECEMBER 2013 4733 Droplet-Based Sensing: Optical Microresonator

    E-Print Network [OSTI]

    Fair, Richard

    ) microfluidics is an emerging platform for practical applications such as water quality testing and medical detection of proteins, DNA, and other biologically relevant mole- cules while tolerating a droplet oil sensors were tested, and the effect of a conventional filler medium, silicone oil, on the sensor

  7. Droplet microfluidics for high-throughput biological assays Mira T. Guo,a

    E-Print Network [OSTI]

    developed over the past several decades have greatly impacted medical research, therapeutics signal-to-noise ratios restrict the possible targets of medical diagnostics, and thus limit their medical sensitivities by using water-in-oil emulsion droplets to compartmentalize reactants into picolitre volumes,3

  8. Droplet microfluidic technology for single-cell high-throughput screening

    E-Print Network [OSTI]

    Higgins, Darren

    , Lexington, MA 02421; and bGenetics Department, Harvard Medical School and cHoward Hughes Medical Institute oil and enables the digital manipulation of these reactors at a very high-throughput. Here, we by an immiscible oil. The advantages of this droplet- based technique include the physical and chemical isolation

  9. Thermally enhanced solubility for the shrinking of a nanoink droplet in a surrounding liquid

    E-Print Network [OSTI]

    Daraio, Chiara

    the large range of potential applications in thermal nano-manufacturing and life science, the fundamentalThermally enhanced solubility for the shrinking of a nanoink droplet in a surrounding liquid Magnus, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich

  10. Communications Aqueous droplets of 250 pL formed in a microfluidic channel in a

    E-Print Network [OSTI]

    Ismagilov, Rustem F.

    Angewandte Chemie Communications Aqueous droplets of 250 pL formed in a microfluidic channel-7851/03/4207-0767 $ 20.00+.50/0 #12;High-Throughput Measurements A Microfluidic System for Controlling Reaction Networks in Time** Helen Song, Joshua D. Tice, and Rustem F. Ismagilov* We present here a microfluidic system

  11. Vol. 122 (2012) ACTA PHYSICA POLONICA A No. 4 Evaporation of Micro-Droplets

    E-Print Network [OSTI]

    2012-01-01

    -Square-Law Revisited D. Jakubczyk , M. Kolwas, G. Derkachov, K. Kolwas and M. Zientara Institute of Physics, Polish. The continuous- -medium descriptions of evaporation/condensation phe- nomena (see e.g. [3, 4]) cannot grasp valuable information, if they are carefully applied. As far as the evaporation/condensation of droplets

  12. Determination of mass and thermal accommodation coefficients from evolution of evaporating water droplet

    E-Print Network [OSTI]

    droplet M. Zientara, D. Jakubczyk, G. Derkachov, K. Kolwas and M. Kolwas Institute of Physics, Polish of evaporation and condensation are in the very heart of various fields of science. Cloud and aerosol called evaporation (condensation) or mass accommodation coefficient C and thermal conductivity

  13. Effects of temporally varying liquid-phase mass diffusivity in multicomponent droplet gasification

    SciTech Connect (OSTI)

    Zhang, Huiqiang [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Department of Engineering Mechanics, Tsinghua University, Beijing, 100084 (China); Law, Chung K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

    2008-06-15

    The relative roles of liquid-phase diffusional resistance and volatility differential in multicomponent droplet gasification are revisited, recognizing that liquid-phase mass diffusivities can be substantially increased as the droplet is progressively heated upon initiation of gasification, leading to a corresponding substantial weakening of the diffusional resistance. Calculations performed using realistic and temperature-dependent thermal and mass diffusivities indeed substantiate this influence. In particular, the calculated results agree with the literature experimental data, indicating that the gasification mechanism of multicomponent fuels is intermediate between diffusion and distillation limits. Investigation was also performed on gasification at elevated pressures, recognizing that the liquid boiling point and hence the attainable droplet temperature would increase with increasing pressure, causing further weakening of the liquid-phase diffusional resistance. This possibility was again verified through calculated results, suggesting further departure from diffusion limit toward distillation limit behavior for gasification at high pressures. The study also found that diffusional resistance is stronger for the lighter, gasoline-like fuels as compared to the heavier, diesel-like fuels because the former have overall lower boiling points, lower attainable droplet temperatures, and hence lower mass diffusivities in spite of their lower molecular weights. (author)

  14. Macroscopic erosion of plasma facing and nearby components during plasma instabilities: the droplet shielding phenomenon

    E-Print Network [OSTI]

    Harilal, S. S.

    shielding phenomenon A. Hassanein *, I. Konkashbaev 1 Argonne National Laboratory, Bldg 362, 9700 South Cass. This will result in further reduction of net radiation power to the surface, i.e., `droplet shielding' eect; Shielding; Lifetime; HEIGHTS package 1. Introduction During plasma disruptions, the power ¯ux reaching

  15. Two dimensional thermoelectric platforms for thermocapillary droplet Man-Chi Liu,ac

    E-Print Network [OSTI]

    Lin, Pei-Chun

    Two dimensional thermoelectric platforms for thermocapillary droplet actuation Man-Chi Liu,ac Jin the cooling function relies on the natural conduction and/or convection. A thermoelectric (TE) chip a novel approach utilizing a 5 6 5 array of thermoelectric (TE) chips. The advantage of using TE chips

  16. Fire Size in Tunnels 

    E-Print Network [OSTI]

    Carvel, Ricky O

    In recent years, a number of high profile accidental fires have occurred in several road and rail tunnels throughout the world. Many of these fires grew rapidly to catastrophic size and claimed many lives. The processes ...

  17. Sensitivity of Tropospheric Chemical Composition to Halogen-Radical Chemistry Using a Fully Coupled Size-Resolved Multiphase Chemistry-Global Climate System: Halogen Distributions, Aerosol Composition, and Sensitivity of Climate-Relevant Gases

    SciTech Connect (OSTI)

    Long, M.; Keene, W. C.; Easter, Richard C.; Sander, Rolf; Liu, Xiaohong; Kerkweg, A.; Erickson, D.

    2014-04-07

    Observations and model studies suggest a significant but highly non-linear role for halogens, primarily Cl and Br, in multiphase atmospheric processes relevant to tropospheric chemistry and composition, aerosol evolution, radiative transfer, weather, and climate. The sensitivity of global atmospheric chemistry to the production of marine aerosol and the associated activation and cycling of inorganic Cl and Br was tested using a size-resolved multiphase coupled chemistry/global climate model (National Center for Atmospheric Research’s Community Atmosphere Model (CAM); v3.6.33). Simulation results showed strong meridional and vertical gradients in Cl and Br species. The simulation reproduced most available observations with reasonable confidence permitting the formulation of potential mechanisms for several previously unexplained halogen phenomena including the enrichment of Br- in submicron aerosol, and the presence of a BrO maximum in the polar free troposphere. However, simulated total volatile Br mixing ratios were generally high in the troposphere. Br in the stratosphere was lower than observed due to the lack of long-lived organobromine species in the simulation. Comparing simulations using chemical mechanisms with and without reactive Cl and Br species demonstrated a significant temporal and spatial sensitivity of primary atmospheric oxidants (O3, HOx, NOx), CH4, and non-methane hydrocarbons (NMHC’s) to halogen cycling. Simulated O3 and NOx were globally lower (65% and 35%, respectively, less in the planetary boundary layer based on median values) in simulations that included halogens. Globally, little impact was seen in SO2 and non-sea-salt SO42- processing due to halogens. Significant regional differences were evident: The lifetime of nss-SO42- was extended downwind of large sources of SO2. The burden and lifetime of DMS (and its oxidation products) were lower by a factor of 5 in simulations that included halogens, versus those without, leading to a 20% reduction in nss-SO42- in the southern hemisphere planetary boundary layer based on median values.

  18. Sizing and burn time measurements of micron-sized metal powders

    SciTech Connect (OSTI)

    Gill, Robert J.; Mohan, Salil; Dreizin, Edward L. [New Jersey Institute of Technology Newark, New Jersey 07102 (United States)

    2009-06-15

    Detailed ignition and combustion mechanisms are needed to develop optimized propellant and energetic formulations using micron-sized metal powders, such as aluminum. Combustion researchers have traditionally used relatively coarse metal particles to characterize the burn time dependence on particle size. However, measurements of burn times for particles below 10 {mu}m in diameter are still needed for aluminum powders and other metal fuels. The apparatus described here sizes the particles just before the ignition event, providing a direct correlation between individual particle size and its burn time. Two lasers were utilized: a 785 nm laser diode for sizing the particles and a 125 W CO{sub 2} laser for particle ignition. The particles crossed the 785 nm laser beam just before crossing the CO{sub 2} laser beam. The particle size was determined from the amplitude of the scattered 785 nm light pulse. The burn time was determined from the duration of the visible light emission produced from the ignited particle. The in situ measured particle size distributions compared well with the size distributions measured for the same powders by a commercial instrument using low angle laser light scattering. Our measurements with two nominally spherical aluminum powders, suggest that the burn times increase from 0.5 to {approx}2.5 ms as the particle diameters increase from 3 to 8 {mu}m.

  19. Distributed Estimation Distributed Estimation

    E-Print Network [OSTI]

    Gupta, Vijay

    with a Star Topology 2 2.1 Static Sensor Fusion . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.1 Combining Estimators . . . . . . . . . . . . . . . . . . . . 3 2.1.2 Static Sensor Fusion for Star Topology;Distributed Estimation 3 Non-Ideal Networks with Star Topology 10 3.1 Sensor Fusion in Presence of Message

  20. Angular Size in a Static Universe

    E-Print Network [OSTI]

    David F. Crawford

    1994-07-11

    In principle the geometry of the universe can be investigated by measuring the angular size of known objects as a function of distance. Thus the distribution of angular sizes provides a critical test of the stable and static model of the universe described by Crawford (1991,1993) that has a simple and explicit relationship between the angular size of an object and its redshift. The result is that the agreement with observations of galactic diameters and the size of double radio sources with the static model is much better than the standard (Big Bang) theory without evolution. However there is still a small discrepancy at large redshifts that could be due to selection effects.

  1. identification Distributed

    E-Print Network [OSTI]

    Schenato, Luca

    Networked Control Systems Clock Sync Channel identification in WSN Distributed control of Smart. Sandro Zampieri #12;Networked Control Systems Clock Sync Channel identification in WSN Distributed Systems Clock Sync Channel identification in WSN Distributed control of Smart Grids Conclusions Issues

  2. Control of pore size in epoxy systems.

    SciTech Connect (OSTI)

    Sawyer, Patricia Sue; Lenhart, Joseph Ludlow (North Dakota State University, Fargo, ND); Lee, Elizabeth (North Dakota State University, Fargo, ND); Kallam, Alekhya (North Dakota State University, Fargo, ND); Majumdar, Partha (North Dakota State University, Fargo, ND); Dirk, Shawn M.; Gubbins, Nathan; Chisholm, Bret J. (North Dakota State University, Fargo, ND); Celina, Mathias Christopher; Bahr, James (North Dakota State University, Fargo, ND); Klein, Robert J.

    2009-01-01

    Both conventional and combinatorial approaches were used to study the pore formation process in epoxy based polymer systems. Sandia National Laboratories conducted the initial work and collaborated with North Dakota State University (NDSU) using a combinatorial research approach to produce a library of novel monomers and crosslinkers capable of forming porous polymers. The library was screened to determine the physical factors that control porosity, such as porogen loading, polymer-porogen interactions, and polymer crosslink density. We have identified the physical and chemical factors that control the average porosity, pore size, and pore size distribution within epoxy based systems.

  3. The interaction of radio frequency electromagnetic fields with atmospheric water droplets and application to aircraft ice prevention

    E-Print Network [OSTI]

    Hansman, Robert John

    1982-01-01

    In this work the physics of advanced microwave anti-icing systems, which pre-heat impinging supercooled water droplets prior to impact, is studied by means of a computer simulation and is found to be feasible. In order to ...

  4. A Lattice Boltzmann study of the effects of viscoelasticity on droplet formation in microfluidic cross-junctions

    E-Print Network [OSTI]

    Gupta, Anupam

    2015-01-01

    Based on mesoscale lattice Boltzmann (LB) numerical simulations, we investigate the effects of viscoelasticity on the break-up of liquid threads in microfluidic cross-junctions, where droplets are formed by focusing a liquid thread of a dispersed (d) phase into another co-flowing continuous (c) immiscible phase. Working at small Capillary numbers, we investigate the effects of non-Newtonian phases in the transition from droplet formation at the cross-junction (DCJ) to droplet formation downstream of the cross-junction (DC) (Liu $\\&$ Zhang, ${\\it Phys. ~Fluids.}$ ${\\bf 23}$, 082101 (2011)). We will analyze cases with ${\\it Droplet ~Viscoelasticity}$ (DV), where viscoelastic properties are confined in the dispersed phase, as well as cases with ${\\it Matrix ~Viscoelasticity}$ (MV), where viscoelastic properties are confined in the continuous phase. Moderate flow-rate ratios $Q \\approx {\\cal O}(1)$ of the two phases are considered in the present study. Overall, we find that the effects are more pronounced in ...

  5. Spatially resolved temperature and heat flux measurements for slow evaporating droplets heated by a microfabricated heater array 

    E-Print Network [OSTI]

    Paik, Sokwon

    2006-08-16

    The evaporation phenomenon of a liquid droplet was investigated by using microfabricated heaters. All 32 microheaters were designed to have the same resistance. Gold microheaters worked both as temperature indicators and as heaters. The first...

  6. Uniform Distribution

    E-Print Network [OSTI]

    randomly and equally likely a point in that interval), the uniform distribution ... Roughly speaking, this means that from any distribution we can create the uniform.

  7. Experimental investigation of the impact, spreading, and drying of picolitre droplets onto substrates with a broad range of wettabilities

    E-Print Network [OSTI]

    Berson, A.

    2011-10-02

    flows In this section, we present preliminary results concerning the development of advanced measurement techniques for the charac- terization of internal flows during the drying of inkjet droplets. Experimental Picolitre droplets of water are generated... ’s University in Kingston, ON, Canada, before joining Durham University, UK, in 2010 as a post-doctoral fellow. His interests include sustainable energy systems (thermoacoustic devices, fuel cells), the development of advanced flow diagnostic techniques...

  8. Droplet traffic in microfluidic networks: A simple model for understanding and designing

    E-Print Network [OSTI]

    M. Schindler; A. Ajdari

    2007-12-20

    We propose a simple model to analyze the traffic of droplets in microfluidic ``dual networks''. Such functional networks which consist of two types of channels, namely those accessible or forbidden to droplets, often display a complex behavior characteristic of dynamical systems. By focusing on three recently proposed configurations, we offer an explanation for their remarkable behavior. Additionally, the model allows us to predict the behavior in different parameter regimes. A verification will clarify fundamental issues, such as the network symmetry, the role of the driving conditions, and of the occurrence of reversible behavior. The model lends itself to a fast numerical implementation, thus can help designing devices, identifying parameter windows where the behavior is sufficiently robust for a devices to be practically useful, and exploring new functionalities.

  9. Injectable Spontaneous Generation of Tremendous Self-Fueled Liquid Metal Droplet Motors in a Moment

    E-Print Network [OSTI]

    Yao, You-You; Liu, Jing

    2015-01-01

    Micro motors that could run in liquid environment is very important for a variety of practices such as serving as pipeline robot, soft machine, drug delivery, or microfluidics system etc. However, fabrication of such tiny motors is generally rather time and cost consumptive and has been a tough issue due to involve too many complicated procedures and tools. Here, we show a straightforward injectable way for spontaneously generating autonomously running soft motors in large quantity. A basic fabrication strategy thus enabled is established and illustrated. It was found that, injecting the GaIn alloy pre-fueled with aluminum into electrolyte would automatically split in seconds into tremendous droplet motors swiftly running here and there. The driving force originated from the galvanic cell reaction among alloy, aluminum and surrounding electrolyte which offers interior electricity and hydrogen gas as motion power. This finding opens the possibility to develop injectable tiny-robots, droplet machines or microfl...

  10. Gallium surface diffusion on GaAs (001) surfaces measured by crystallization dynamics of Ga droplets

    SciTech Connect (OSTI)

    Bietti, Sergio, E-mail: sergio.bietti@mater.unimib.it; Somaschini, Claudio; Esposito, Luca; Sanguinetti, Stefano [L–NESS and Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 55, I–20125 Milano (Italy); Fedorov, Alexey [L–NESS and CNR–IFN, via Anzani 42, I-22100 Como (Italy)

    2014-09-21

    We present accurate measurements of Ga cation surface diffusion on GaAs surfaces. The measurement method relies on atomic force microscopy measurement of the morphology of nano–disks that evolve, under group V supply, from nanoscale group III droplets, earlier deposited on the substrate surface. The dependence of the radius of such nano-droplets on crystallization conditions gives direct access to Ga diffusion length. We found an activation energy for Ga on GaAs(001) diffusion E{sub A}=1.31±0.15 eV, a diffusivity prefactor of D?=0.53(×2.1±1) cm² s?¹ that we compare with the values present in literature. The obtained results permit to better understand the fundamental physics governing the motion of group III ad–atoms on III–V crystal surfaces and the fabrication of designable nanostructures.

  11. Radio-frequency capacitive discharge with non-flow-type and droplet-jet electrolytic electrodes

    SciTech Connect (OSTI)

    Gaisin, A. F.; Abdullin, I. Sh.; Basyrov, R. Sh.; Khaziev, R. M.; Samitova, G. T.; Shakirova, E. F.

    2014-12-15

    Results are presented from experimental studies of the shape, structure, and spectral characteristics of an RF capacitive discharge operating between a droplet-jet electrolytic electrode and an electrolytic cell in air at pressures of P = 10{sup 3}–10{sup 5} Pa, as well as of a discharge burning between a copper rod and the surface of non-flow electrolyte at atmospheric pressure. It is found that, at voltages of U ? 3500 V, the multichannel discharge burning between the rod and the electrolyte (saturated solution of NaCl in technical water) surface transforms into a torch discharge. Specific features of the burning of a discharge with a droplet electrolytic electrode are investigated. Different forms of discharges burning on the surface of a copper tube and an electrolyte jet are revealed.

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

    DOE Patents [OSTI]

    Huber, Dale L. (Albuquerque, NM)

    2011-07-05

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

  13. Nuclear mass systematics by complementing the Finite Range Droplet Model with neural networks

    E-Print Network [OSTI]

    S. Athanassopoulos; E. Mavrommatis; K. A. Gernoth; J. W. Clark

    2005-11-30

    A neural-network model is developed to reproduce the differences between experimental nuclear mass-excess values and the theoretical values given by the Finite Range Droplet Model. The results point to the existence of subtle regularities of nuclear structure not yet contained in the best microscopic/phenomenological models of atomic masses. Combining the FRDM and the neural-network model, we create a hybrid model with improved predictive performance on nuclear-mass systematics and related quantities.

  14. Contrasting size evolution in marine and freshwater diatoms

    E-Print Network [OSTI]

    carbon cycle and most aquatic ecosystems. Their cell sizes impact carbon sequestration and en- ergy carbon cycle and the structure and functioning of aquatic ecosystems. evolutionarily stable strategy and forming the basis of many aquatic food webs (6). Diatom size distributions greatly influence carbon

  15. Computational insights of water droplet transport on graphene sheet with chemical density

    SciTech Connect (OSTI)

    Zhang, Liuyang; Wang, Xianqiao, E-mail: xqwang@uga.edu [College of Engineering and NanoSEC, University of Georgia, Athens, Georgia 30602 (United States)

    2014-05-21

    Surface gradient has been emerging as an intriguing technique for nanoscale particle manipulation and transportation. Owing to its outstanding and stable chemical properties, graphene with covalently bonded chemical groups represents extraordinary potential for the investigation of nanoscale transport in the area of physics and biology. Here, we employ molecular dynamics simulations to investigate the fundamental mechanism of utilizing a chemical density on a graphene sheet to control water droplet motions on it. Simulation results have demonstrated that the binding energy difference among distinct segment of graphene in terms of interaction between the covalently bonded oxygen atoms on graphene and the water molecules provides a fundamental driving force to transport the water droplet across the graphene sheet. Also, the velocity of the water droplet has showed a strong dependence on the relative concentration of oxygen atoms between successive segments. Furthermore, a multi-direction channel provides insights to guide the transportation of objects towards a targeted position, separating the mixtures with a system of specific chemical functionalization. Our findings shed illuminating lights on the surface gradient method and therefore provide a feasible way to control nanoscale motion on the surface and mimic the channelless microfluidics.

  16. Droplet minimizers for the Gates-Lebowitz-Penrose free energy functional

    E-Print Network [OSTI]

    E. A. Carlen; M. C. Carvalho; R. Esposito; J. L. Lebowitz; R. Marra

    2009-05-21

    We study the structure of the constrained minimizers of the Gates-Lebowitz-Penrose free-energy functional ${\\mathcal F}_{\\rm GLP}(m)$, non-local functional of a density field $m(x)$, $x\\in {\\mathcal T}_L$, a $d$-dimensional torus of side length $L$. At low temperatures, ${\\mathcal F}_{\\rm GLP}$ is not convex, and has two distinct global minimizers, corresponding to two equilibrium states. Here we constrain the average density $L^{-d}\\int_{{\\cal T}_L}m(x)\\dd x$ to be a fixed value $n$ between the densities in the two equilibrium states, but close to the low density equilibrium value. In this case, a "droplet" of the high density phase may or may not form in a background of the low density phase, depending on the values $n$ and $L$. We determine the critical density for droplet formation, and the nature of the droplet, as a function of $n$ and $L$. The relation between the free energy and the large deviations functional for a particle model with long-range Kac potentials, proven in some cases, and expected to be true in general, then provides information on the structure of typical microscopic configurations of the Gibbs measure when the range of the Kac potential is large enough.

  17. Sample sizes for confidence limits for reliability.

    SciTech Connect (OSTI)

    Darby, John L.

    2010-02-01

    We recently performed an evaluation of the implications of a reduced stockpile of nuclear weapons for surveillance to support estimates of reliability. We found that one technique developed at Sandia National Laboratories (SNL) under-estimates the required sample size for systems-level testing. For a large population the discrepancy is not important, but for a small population it is important. We found that another technique used by SNL provides the correct required sample size. For systems-level testing of nuclear weapons, samples are selected without replacement, and the hypergeometric probability distribution applies. Both of the SNL techniques focus on samples without defects from sampling without replacement. We generalized the second SNL technique to cases with defects in the sample. We created a computer program in Mathematica to automate the calculation of confidence for reliability. We also evaluated sampling with replacement where the binomial probability distribution applies.

  18. Modeling and Control of Ibuprofen Crystal Growth and Size Distribution

    E-Print Network [OSTI]

    Tran, Anh Tuan

    2015-01-01

    time evolution of coupled chemical reactions. J. Comput.stochastic simulation of chemical kinetics. Annu. Rev. Phys.title for publication in Chemical Engineering Science and is

  19. Concentrations and Size Distributions of Particulate Matter Emissions...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    on the Emission Profiles of Trucks and Buses ARB's Study of Emissions from Diesel and CNG Heavy-duty Transit Buses Measurement of Real-World Emissions from Heavy-Duty Diesel...

  20. Modeling and Control of Ibuprofen Crystal Growth and Size Distribution

    E-Print Network [OSTI]

    Tran, Anh Tuan

    2015-01-01

    ethanol and aqueous ethanolic mixtures. In Proceedings of Chemica 2008, pages 1393– 1401, Newcastle, Australia,

  1. Population growth, distribution, and size in Latin America

    E-Print Network [OSTI]

    Lopez-Carr, David

    timber harvesting oil exploration/extraction population growth? degradation of lands in source areas history in Amazonia · Early extractive uses Rubber Forestry #12;Development history in Amazonia forests in the world 2) 45% of all the fresh water on the Earth 3) the planet's largest carbon sink 4

  2. Profiling of Adrenocorticotropic Hormone and Arginine Vasopressin in Human Pituitary Gland and Tumor Thin Tissue Sections using Droplet-Based Liquid Microjunction Surface Sampling-HPLC-ESI-MS/MS

    SciTech Connect (OSTI)

    Kertesz, Vilmos; Van Berkel, Gary J; Calligaris, David; Feldman, Daniel R; Changelian, Armen; Laws, Edward R; Santagata, Sandro; Agar, Nathalie YR

    2015-01-01

    Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections using a fully automated droplet-based liquid microjunction surface sampling-HPLC-ESI-MS/MS system for spatially resolved sampling, HPLC separation, and mass spectral detection. Excellent correlation was found between the protein distribution data obtained with this droplet-based liquid microjunction surface sampling-HPLC-ESI-MS/MS system and those data obtained with matrix assisted laser desorption ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland. AVP was most abundant in the posterior pituitary gland region (neurohypophysis) and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH secreting and non-secreting pituitary adenomas correlated with histopathological evaluation. ACTH was readily detected at significantly higher levels in regions of ACTH secreting adenomas and in normal anterior adenohypophysis compared to non-secreting adenoma and neurohypophysis. AVP was mostly detected in normal neurohypophysis as anticipated. This work demonstrates that a fully automated droplet-based liquid microjunction surface sampling system coupled to HPLC-ESI-MS/MS can be readily used for spatially resolved sampling, separation, detection, and semi-quantitation of physiologically-relevant peptide and protein hormones, such as AVP and ACTH, directly from human tissue. In addition, the relative simplicity, rapidity and specificity of the current methodology support the potential of this basic technology with further advancement for assisting surgical decision-making.

  3. Edison Job Size Charts

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES Science Network RequirementsEdison ElectrifiesJob Size Charts

  4. Aerosol measurements at a high-elevation site: composition, size, and cloud condensation nuclei activity

    E-Print Network [OSTI]

    Friedman, Beth

    Measurements of cloud condensation nuclei (CCN) concentrations, single particle composition and size distributions at a high-elevation research site from March 2011 are presented.

  5. Hardware Sizing for Software Application

    E-Print Network [OSTI]

    Swaminathan, Ganesh

    2009-05-15

    Hardware sizing is an approximation of the hardware resources required to support a software implementation. Just like any theoretical model, hardware sizing model is an approximation of the reality. Depending on the infrastructure needs, workload...

  6. Structure of droplet-epitaxy-grown InAs/GaAs quantum dots

    SciTech Connect (OSTI)

    Cohen, Eyal; Yochelis, Shira; Westreich, Ohad; Shusterman, Sergey; Kumah, Divine P.; Clarke, Roy; Yacoby, Yizhak; Paltiel, Yossi

    2011-09-06

    We have used a direct x-ray phasing method, coherent Bragg rod analysis, to obtain sub-angstrom resolution electron density maps of the InAs/GaAs dot system. The dots were grown by the droplet heteroepitaxy (DHE) technique and their structural and compositional properties are compared with those of dots grown by the strain-driven Stranski-Krastanov method. Our results show that the Ga diffusion into the DHE-grown dots is somewhat larger; however, other characteristics such as the composition of the dots uppermost layers, the interlayer spacing, and the bowing of the atomic layers are similar.

  7. A microfluidic device based on droplet storage for screening solubility diagrams

    E-Print Network [OSTI]

    P. Laval; N. Lisai; J. -B. Salmon; M. Joanicot

    2007-04-04

    This work describes a new microfluidic device developed for rapid screening of solubility diagrams. In several parallel channels, hundreds of nanoliter-volume droplets of a given solution are first stored with a gradual variation in the solute concentration. Then, the application of a temperature gradient along these channels enables us to read directly and quantitatively phase diagrams, concentration vs. temperature. We show, using a solution of adipic acid, that we can measure ten points of the solubility curve in less than 1 hr and with only 250 $\\mu$L of solution.

  8. Freezing a Droplet to Stop the Ice | U.S. DOE Office of Science (SC)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journal Article)Forthcoming Upgrades toFreezing a Droplet to Stop the Ice

  9. Cell detachment and label-free cell sorting using modulated surface acoustic waves (SAW) in droplet-based microfluidics

    E-Print Network [OSTI]

    Bussonnière, Adrien; Baudoin, Michael; Bou-Matar, Olivier; Grandbois, Michel; Charette, Paul; Renaudin, Alan

    2014-01-01

    We present a droplet-based surface acoustic wave (SAW) system designed to viably detach biological cells from a surface and sort cell types based on differences in adhesion strength (adhesion contrast), without the need to label cells with molecular markers. The system uses modulated SAW to generate pulsatile flows in the droplets and efficiently detach the cells, thereby minimizing SAW excitation power and exposure time. As a proof-of-principle, the system is shown to efficiently sort HEK 293 from A7r5 cells based on adhesion contrast. Results are obtained in minutes with sorting purity and efficiency reaching 97 % and 95 %, respectively.

  10. Strategic Petroleum Reserve: Analysis of size options

    SciTech Connect (OSTI)

    Not Available

    1990-02-01

    This report presents the results of the deliberations of the interagency group formed to study the costs and benefits of expanding the size of the SPR. The study concentrated on severe oil supply disruptions involving sharp reductions in world oil production that were 2 to 4 times larger than the largest 1970s interruption. The disruption sizes and estimated probability of occurrence of these scenarios were supplied by the CIA. The most critical part of the CIA's analysis was the assessment of likelihood of these cases occurring. The CIA approached the likelihood problem by combining an examination of past oil supply disruptions with qualitative analysis of important oil market and regional trends. The study group then used statistical techniques and probability distributions to synthesize the historical data with CIA evaluations of as yet unobserved events. The SPR size study assumed direct purchases of SPR oil and did not assume the use of alternative financing mechanisms. Members of the working group with foreign policy and national security responsibilities provided an in-depth review of strategic considerations affecting SPR size. A number of prior studies, some classified, have addressed the strategic importance and insurance value of the SPR to the US and its allies. The results of these studies have also been incorporated in the current effort. 10 refs., 5 figs.

  11. Finite element thermomechanical simulation of droplets impacting on a rigid substrate

    SciTech Connect (OSTI)

    Bertagnolli, M.; Marchese, M.; Jacucci, G.; St. Doltsinis, I.; Noelting, S.

    1994-12-31

    The plasma spray process is a convenient way to coat a piece of material with a layer of another material, to protect the first from thermal shock or environmental degradation. Finite Element simulation techniques (FEM) for the spreading process of a ceramic liquid droplet impacting on a flat cold surface have been developed. The goal of the present investigation is (1) to predict the geometrical form of the splat as a function of process parameters, such as initial temperature and velocity, and (2) to follow the thermal field developing in the droplet up to solidification. A non-linear finite element procedure has been extended in order to model the complex physical phenomena involved in the impact process. The dynamic motion of the viscous melt in the drops as constrained by elastic surface tensions in interaction with the developing contact with the target, ultimately has been coupled to transient thermal phenomena accounting also for the solidification of the material. In a first model description, spherical particles of liquid ceramic of given temperature and velocity impact on a flat, cool rigid surface. The deformation of the splat geometry as well as the evolution of the thermal field within the splat are followed up to the final state and require adaptive discretization techniques. The authors discuss an utilization of the proposed model in correlating flattening degrees with the initial process parameters.

  12. Azeotropic Distillation as a Technique for Emulsion Size Reduction

    E-Print Network [OSTI]

    Petta, Jason

    : A solvent with HA Boiling point with water Heptane or Hexane Low vapor pressure viscosifying oil Technique for producing uniform picoliter droplets by manipulating two phase fluid flows at low Reynolds such as chloroform, ethanol, and polymers. Microfluidic Generation of Droplets #12;Materials for Emulsions Oil Phase

  13. Accepted for publication in GEOPHYSICAL RESEARCH LETTERS, doi:10.1029/2010GL044689 1/10 Simulations of underwater plumes of dissolved

    E-Print Network [OSTI]

    to small droplet sizes. Subsea injection of dispersants will also create tiny droplets and encourage

  14. Distributed Generation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Electricity, US Data. 6. Distributed Generation: Standby Generation and Cogeneration Ozz Energy Solutions, Inc. February 28 th , 2005. For more information about...

  15. Distributed generation

    SciTech Connect (OSTI)

    Ness, E.

    1999-09-02

    Distributed generation, locating electricity generators close to the point of consumption, provides some unique benefits to power companies and customers that are not available from centralized electricity generation. Photovoltaic (PV) technology is well suited to distributed applications and can, especially in concert with other distributed resources, provide a very close match to the customer demand for electricity, at a significantly lower cost than the alternatives. In addition to augmenting power from central-station generating plants, incorporating PV systems enables electric utilities to optimize the utilization of existing transmission and distribution.

  16. Wide size range fast integrated mobility spectrometer

    SciTech Connect (OSTI)

    Wang, Jian

    2013-10-29

    A mobility spectrometer to measure a nanometer particle size distribution is disclosed. The mobility spectrometer includes a conduit and a detector. The conduit is configured to receive and provide fluid communication of a fluid stream having a charged nanometer particle mixture. The conduit includes a separator section configured to generate an electrical field of two dimensions transverse to a dimension associated with the flow of the charged nanometer particle mixture through the separator section to spatially separate charged nanometer particles of the charged nanometer particle mixture in said two dimensions. The detector is disposed downstream of the conduit to detect concentration and position of the spatially-separated nanometer particles.

  17. Gravitational effects on the deformation of a droplet adhering to a horizontal solid surface in shear flow

    E-Print Network [OSTI]

    Dimitrakopoulos, Panagiotis

    flows at low Reynolds number. This regime has relevance in coating operations, enhanced oil recovery is monotonically decreased owing to the monotonic decrease of the droplets' height and thus the exerted pressure- dimensional interfaces at both low- and finite-Reynolds num- bers, e.g., Refs. 8­12. Recently, Dimitrakopoulos

  18. A study of ignition and combustion characteristics of isolated coal water slurry droplet using digital image processing technique 

    E-Print Network [OSTI]

    Bhadra, Tanmoy

    1998-01-01

    on the premise that ignitability of a spray of coal water slurry must depend on the ignition characteristic of an isolated coal water slurry droplet. A flat flame burner is used for optical accessibility and also for simulating vitiated gases as existing...

  19. Droplet-Trace-Based Array Partitioning and a Pin Assignment Algorithm for the Automated Design of Digital

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    of a system clock; this microfludic system is similar in operation to a digital microprocessor. Thus assays for drug discovery [8], design tools are needed to map and execute them on the digital micofludicDroplet-Trace-Based Array Partitioning and a Pin Assignment Algorithm for the Automated Design

  20. Numerical investigation of interfacial transport resistance due to water droplets in proton exchange membrane fuel cell air channels

    E-Print Network [OSTI]

    Kandlikar, Satish

    (GDL) interface is needed in modelling the performance of a proton exchange membrane fuel cell (PEMFC representative case of a PEMFC air flow channel. The results show that the droplets significantly increase Sh of a proton exchange membrane fuel cell (PEMFC) is an active area of research. The O2 transport loss becomes

  1. Experimental and numerical investigation of phonon mean free path distribution

    E-Print Network [OSTI]

    Zeng, Lingping

    2013-01-01

    Knowledge of phonon mean free path (MFP) distribution is critically important to engineering size effects. Phenomenological models of phonon relaxation times can give us some sense about the mean free path distribution, ...

  2. Normal Distribution

    E-Print Network [OSTI]

    User

    NORMAL DlSTRlBUTION TABLE. Entries represent the area under the standardized normal distribution from -w to z, Pr(Z

  3. Water droplet behavior on superhydrophobic SiO{sub 2} nanocomposite films during icing/deicing cycles

    SciTech Connect (OSTI)

    Lazauskas, A.; Guobien?, A.; Prosy?evas, I.; Baltrušaitis, V.; Grigali?nas, V.; Narmontas, P.; Baltrusaitis, J.

    2013-08-15

    This work investigates water droplet behavior on superhydrophobic (water contact angle value of 162 ± 1°) SiO{sub 2} nanocomposite films subjected to repetitive icing/deicing treatments, changes in SiO{sub 2} nanocomposite film surface morphology and their non-wetting characteristics. During the experiment, water droplets on SiO{sub 2} nanocomposite film surface are subjected to a series of icing and deicing cycles in a humid (? 70% relative humidity) atmosphere and the resulting morphological changes are monitored and characterized using atomic force microscopy (AFM) and contact angle measurements. Our data show that the formation of the frozen or thawed water droplet, with no further shape change, on superhydrophobic SiO{sub 2} nanocomposite film, is obtained faster within each cycle as the number of the icing/deicing cycles increases. After 10 icing and deicing cycles, the superhydrophobic SiO{sub 2} nanocomposite film had a water contact angle value of 146 ± 2° which is effectively non-superhydrophobic. AFM analysis showed that the superhydrophobic SiO{sub 2} nanocomposite film surface area under the water droplet undergoes gradual mechanical damage during the repetitive icing/deicing cycles. We propose a possible mechanism of the morphological changes to the film surface that take place during the consecutive icing/deicing experiments. - Highlights: • Superhydrophobic film is subjected to repetitive icing/deicing treatments. • Water droplet shape transition is recorded and characterized thereafter. • Atomic force microscopy and contact angle measurements are performed. • The surface undergoes gradual mechanical damage during repetitive icing/deicing. • Mechanism for the observed surface morphological changes is suggested.

  4. Mapping Biomass Distribution Potential

    E-Print Network [OSTI]

    Schaetzel, Michael

    2010-11-18

    stream_size 1487 stream_content_type text/plain stream_name ku_gis_day_2010_schaetzel.pdf.txt stream_source_info ku_gis_day_2010_schaetzel.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Mapping Biomass... Distribution Potential Michael Schaetzel Undergraduate ? Environmental Studies ? University of Kansas L O C A T S I O N BIOMASS ENERGY POTENTIAL o According to DOE, Biomass has the potential to provide 14% of the nation’s power o Currently 1% of...

  5. Equilibrium distribution

    E-Print Network [OSTI]

    Ashot Vagharshakyan

    2015-08-29

    In the paper discusses the interaction between two charged balls in equilibrium state. It is shown that, depending of the sizes, charges and distance, the balls can move in the same or opposite direction. They can repulse and attract. It is proved, that one of the balls may vibrate.

  6. Does semantic size affect size constancy scaling using lexical stimuli? 

    E-Print Network [OSTI]

    Beveridge, Madeleine

    2010-11-24

    Binocular disparity allows us to perceive the world in 3-dimensions through the process of stereopsis. In this study, we used binocular disparity to induce the size constancy illusion in lexical stimuli. 47 undergraduate ...

  7. How Focal Adhesion Size Depends on Integrin Affinity Tong Zhao,,

    E-Print Network [OSTI]

    Dinner, Aaron

    How Focal Adhesion Size Depends on Integrin Affinity Tong Zhao,, Ying Li,, and Aaron R. Dinner the thermodynamics and kinetics of integrin receptor binding and clustering impact the formation of focal adhesions in their environment. Cells on chemically well-defined surfaces were observed to have distributions of focal adhesions

  8. Children's Clothes - Size and Selection. 

    E-Print Network [OSTI]

    Vanderpoorten, Ann; Kerbel, Claudia

    1980-01-01

    , children's clothing should fit well, allow for growth and be durable and easy to care for. Children's Sizes The age of a child does not determine size. Chil dren of the same age may vary greatly in height, weight and body measurements. Clothing... and pants provide room for growth. Durability Because growing children are active and vigorous in play, select clothing that will withstand stress and strain. Clothing that wears out or falls apart before the child outgrows it is frustrating as well...

  9. Molecular behavior of DNA in a cell-sized compartment coated by lipids

    E-Print Network [OSTI]

    T. Hamada; R. Fujimoto; S. F. Shimobayashi; M. Ichikawa; M. Takagi

    2015-04-13

    The behavior of long DNA molecules in a cell-sized confined space was investigated. We prepared water-in-oil droplets covered by phospholipids, which mimic the inner space of a cell, following the encapsulation of DNA molecules with unfolded coil and folded globule conformations. Microscopic observation revealed that the adsorption of coiled DNA onto the membrane surface depended on the size of the vesicular space. Globular DNA showed a cell-size-dependent unfolding transition after adsorption on the membrane. Furthermore, when DNA interacted with a two-phase membrane surface, DNA selectively adsorbed on the membrane phase, such as an ordered or disordered phase, depending on its conformation. We discuss the mechanism of these trends by considering the free energy of DNA together with a polyamine in the solution. The free energy of our model was consistent with the present experimental data. The cooperative interaction of DNA and polyamines with a membrane surface leads to the size-dependent behavior of molecular systems in a small space. These findings may contribute to a better understanding of the physical mechanism of molecular events and reactions inside a cell.

  10. Molecular behavior of DNA in a cell-sized compartment coated by lipids

    E-Print Network [OSTI]

    Hamada, T; Shimobayashi, S F; Ichikawa, M; Takagi, M

    2015-01-01

    The behavior of long DNA molecules in a cell-sized confined space was investigated. We prepared water-in-oil droplets covered by phospholipids, which mimic the inner space of a cell, following the encapsulation of DNA molecules with unfolded coil and folded globule conformations. Microscopic observation revealed that the adsorption of coiled DNA onto the membrane surface depended on the size of the vesicular space. Globular DNA showed a cell-size-dependent unfolding transition after adsorption on the membrane. Furthermore, when DNA interacted with a two-phase membrane surface, DNA selectively adsorbed on the membrane phase, such as an ordered or disordered phase, depending on its conformation. We discuss the mechanism of these trends by considering the free energy of DNA together with a polyamine in the solution. The free energy of our model was consistent with the present experimental data. The cooperative interaction of DNA and polyamines with a membrane surface leads to the size-dependent behavior of molec...

  11. Synchronized droplet size measurements of intermittent coal-water slurry diesel sprays from an electronically-controlled accumulator fuel injection system 

    E-Print Network [OSTI]

    Terracina, Dwayne Paul

    1993-01-01

    .6 mm, four axial measurement locations from 60 to 120 mm downstream of the nozzle tip were studied. Measurements were made for both pressurized (2.07 MPa, 300 psig) and unpressurized (ambient, 0 gage) chamber conditions. The spray tip SMD showed...

  12. Occurrence and Management of Glyphosate Resistant Amaranthus Weed Species in Central Texas Cotton and Evaluation of Spray Droplet Size Spectra as Affected by Nozzle Design and Herbicide Formulation 

    E-Print Network [OSTI]

    McGinty, Joshua Allan

    2014-08-28

    , also a member of the dioecious subgenus Acnida, is native to North America and is currently found in the Midwestern United States from Illinois and southern Michigan in the north, to Texas and Louisiana in the south (Horak et al. 1994; Pratt et al... be influenced by environmental conditions. Ellis and Griffin (2002) found that sublethal rates of 140 g ha-1 glyphosate and 53 g ha-1 glufosinate applied at several growth stages from 3-leaf to early bloom resulted in maximum visual injury values of 16...

  13. A simple grand canonical approach to compute the vapor pressure of bulk and finite size systems

    SciTech Connect (OSTI)

    Factorovich, Matías H.; Scherlis, Damián A.

    2014-02-14

    In this article we introduce a simple grand canonical screening (GCS) approach to accurately compute vapor pressures from molecular dynamics or Monte Carlo simulations. This procedure entails a screening of chemical potentials using a conventional grand canonical scheme, and therefore it is straightforward to implement for any kind of interface. The scheme is validated against data obtained from Gibbs ensemble simulations for water and argon. Then, it is applied to obtain the vapor pressure of the coarse-grained mW water model, and it is shown that the computed value is in excellent accord with the one formally deduced using statistical thermodynamics arguments. Finally, this methodology is used to calculate the vapor pressure of a water nanodroplet of 94 molecules. Interestingly, the result is in perfect agreement with the one predicted by the Kelvin equation for a homogeneous droplet of that size.

  14. Empirical distribution Theoretical2distribution

    E-Print Network [OSTI]

    Reich, David

    2 distribution. #12;Supplementary Table 1: Simulations using K axes of variation K = 1 K = 2 K = 5 K SNPs 0.4923 0.4916 0.4891 0.4860 Proportion of associations reported as significant by EIGENSTRAT adjusting along the top K axes of variation, for various values of K. #12;Page 2 Supplementary Table 2

  15. Chapter 6 Continuous Distribution: The Normal Distribution

    E-Print Network [OSTI]

    Hong, Don

    Chapter 6 Continuous Distribution: The Normal Distribution 6.1 Introduction 6.2 Properties of a Normal Distribution 6.3 The Standard Normal Distribution 6.4 Applications of Normal Distribution 6.5 The Central Limit Theorem 6.6 The Normal Approximation to the Binomial Distribution Definition. A continuous

  16. probability distributions

    E-Print Network [OSTI]

    Heller, Barbara

    probabilities in the standard normal table What is the area to the left of Z=1.51 in a standard normal curve? Z=1.51 Z=1.51 Area is 93.45% #12;Exercises · If scores are normally distributed with a mean of 30 beauty of the normal curve: No matter what and are, the area between - and + is about 68%; the area

  17. Splashing phenomena of room temperature liquid metal droplet striking on the pool of the same liquid under ambient air environment

    E-Print Network [OSTI]

    Haiyan Li; Shengfu Mei; Lei Wang; Yunxia Gao; Jing Liu

    2013-09-04

    In this article, the fluid dynamics of room temperature liquid metal (RTLM) droplet impacting onto a pool of the same liquid in ambient air was investigated. A series of experiments were conducted in order to disclose the influence of the oxidation effect on the impact dynamics. The droplet shape and impact phenomenology were recorded with the aid of a high-speed digital camera. The impact energy stored in the splash structures was estimated via a theoretical model and several morphological parameters obtained from instantaneous images of the splash. It was observed that the droplet shape and the splashing morphology of RTLM were drastically different from those of water, so was the impact dynamics between room temperature LM pool and high temperature LM pool. The energy analysis disclosed that the height of the jet is highly sensitive to the viscosity of the fluid, which is subjected to the oxidation effect and temperature effect simultaneously, and thus perfectly explained the phenomena. These basic findings are important for the application of RTLM in a series of newly emerging technologies such as liquid metal based spray cooling, ink-jet printed electronics, interface material painting and coating, metallurgy, and 3D packages, etc.

  18. Control of membrane permeability in air-stable droplet interface bilayers

    SciTech Connect (OSTI)

    Mruetusatorn, Prachya [ORNL; Polizos, Georgios [Oak Ridge National Laboratory (ORNL); Datskos, Panos G [ORNL; Taylor, Graham [University of Tennessee (UT); Sarles, Stephen A [ORNL; Boreyko, Jonathan [Virginia Polytechnic Institute and State University; Hayes, Douglas G [ORNL; Collier, Pat [ORNL

    2015-01-01

    Air-stable droplet interface bilayers (airDIBs) on oil-infused surfaces are versatile model membranes for synthetic biology applications, including biosensing of airborne species. However, air-DIBs are subject to evaporation, which can, over time, destabilize them and reduce their useful lifetime compared to traditional DIBs that are fully submerged in oil. Here, we show that lifetimes of air-DIBs can be extended by as much as an order of magnitude by maintaining them at a temperature just above the dew point. We find that raising the temperature from near the dew point (7 C at 38.5 % relative humidity) to room temperature results in loss of water molecules of hydration from the polar head groups of the lipid bilayer membrane due to evaporation in an irreversible process that increases the overall entropy of the system. This dehydration transition affects primarily the bilayer resistance, by increasing ion permeability through the increasingly disordered polar head group region of the bilayer. Temperature and/or relative humidity are conveniently tunable parameters for controlling the stability and composition of air-DIBs membranes, while still allowing for operation in ambient environments.

  19. Acoustic Droplet Vaporization, Cavitation, and Therapeutic Properties of Copolymer-Stabilized Perfluorocarbon Nanoemulsions

    SciTech Connect (OSTI)

    Nam, Kweon-Ho; Christensen, Douglas A.; Rapoport, Natalya; Kennedy, Anne M.

    2009-04-14

    Acoustic and therapeutic properties of Doxorubicin (DOX) and paclitaxel (PTX)-loaded perfluorocarbon nanoemulsions have been investigated in a mouse model of ovarian cancer. The nanoemulsions were stabilized by two biodegradable amphiphilic block copolymers that differed in the structure of the hydrophobic block. Acoustic droplet vaporization (ADV) and cavitation parameters were measured as a function of ultrasound frequency, pressure, duty cycles, and temperature. The optimal parameters that induced ADV and inertial cavitation of the formed microbubbles were used in vivo in the experiments on the ultrasound-mediated chemotherapy of ovarian cancer. A combination tumor treatment by intravenous injections of drug-loaded perfluoropentane nanoemulsions and tumor-directed 1-MHz ultrasound resulted in a dramatic decrease of ovarian or breast carcinoma tumor volume and sometimes complete tumor resolution. However, tumors often recurred three to six weeks after the treatment indicating that some cancer cells survived the treatment. The recurrent tumors proved more aggressive and resistant to the repeated therapy than initial tumors suggesting selection for the resistant cells during the first treatment.

  20. Concentration of measures via size biased couplings

    E-Print Network [OSTI]

    Ghosh, Subhankar

    2009-01-01

    Let $Y$ be a nonnegative random variable with mean $\\mu$ and finite positive variance $\\sigma^2$, and let $Y^s$, defined on the same space as $Y$, have the $Y$ size biased distribution, that is, the distribution characterized by E[Yf(Y)]=\\mu E f(Y^s) for all functions $f$ for which these expectations exist. Under a variety of conditions on the coupling of Y and $Y^s$, including combinations of boundedness and monotonicity, concentration of measure inequalities hold. Examples include the number of relatively ordered subsequences of a random permutation, sliding window statistics including the number of m-runs in a sequence of coin tosses, the number of local maximum of a random function on a lattice, the number of urns containing exactly one ball in an urn allocation model, the volume covered by the union of $n$ balls placed uniformly over a volume n subset of d diml Euclidean space, the number of bulbs switched on at the terminal time in the so called lightbulb process, the number of isolated vertices in the ...

  1. Metal oxide porous ceramic membranes with small pore sizes

    DOE Patents [OSTI]

    Anderson, Marc A. (Madison, WI); Xu, Qunyin (Madison, WI)

    1991-01-01

    A method is disclosed for the production of metal oxide ceramic membranes of very small pore size. The process is particularly useful in the creation of titanium and other transition metal oxide membranes. The method utilizes a sol-gel process in which the rate of particle formation is controlled by substituting a relatively large alcohol in the metal alkoxide and by limiting the available water. Stable, transparent metal oxide ceramic membranes are created having a narrow distribution of pore size, with the pore diameter being manipulable in the range of 5 to 40 Angstroms.

  2. Size exclusion deep bed filtration: Experimental and modelling uncertainties

    SciTech Connect (OSTI)

    Badalyan, Alexander You, Zhenjiang; Aji, Kaiser; Bedrikovetsky, Pavel; Carageorgos, Themis; Zeinijahromi, Abbas

    2014-01-15

    A detailed uncertainty analysis associated with carboxyl-modified latex particle capture in glass bead-formed porous media enabled verification of the two theoretical stochastic models for prediction of particle retention due to size exclusion. At the beginning of this analysis it is established that size exclusion is a dominant particle capture mechanism in the present study: calculated significant repulsive Derjaguin-Landau-Verwey-Overbeek potential between latex particles and glass beads is an indication of their mutual repulsion, thus, fulfilling the necessary condition for size exclusion. Applying linear uncertainty propagation method in the form of truncated Taylor's series expansion, combined standard uncertainties (CSUs) in normalised suspended particle concentrations are calculated using CSUs in experimentally determined parameters such as: an inlet volumetric flowrate of suspension, particle number in suspensions, particle concentrations in inlet and outlet streams, particle and pore throat size distributions. Weathering of glass beads in high alkaline solutions does not appreciably change particle size distribution, and, therefore, is not considered as an additional contributor to the weighted mean particle radius and corresponded weighted mean standard deviation. Weighted mean particle radius and LogNormal mean pore throat radius are characterised by the highest CSUs among all experimental parameters translating to high CSU in the jamming ratio factor (dimensionless particle size). Normalised suspended particle concentrations calculated via two theoretical models are characterised by higher CSUs than those for experimental data. The model accounting the fraction of inaccessible flow as a function of latex particle radius excellently predicts normalised suspended particle concentrations for the whole range of jamming ratios. The presented uncertainty analysis can be also used for comparison of intra- and inter-laboratory particle size exclusion data.

  3. Published as Europhys. Lett. 110:36001, (2015) Direct observation of size scaling and elastic

    E-Print Network [OSTI]

    Nordlund, Kai

    2015-01-01

    provide direct evidence for a power-law size distribution of nano-scale defects formed in high-energy cascades, with an upper size limit independent of the incident ion energy, as predicted by Sand et al. [Eur and high thermal conductivity [?, ?], is expected to be significantly affected by neu- trons produced from

  4. Optimization of cement and fly ash particle sizes to produce sustainable concretes Dale P. Bentz a,

    E-Print Network [OSTI]

    Bentz, Dale P.

    Optimization of cement and fly ash particle sizes to produce sustainable concretes Dale P. Bentz a of experiment Fly ash Hydration Particle size distribution Strength Sustainability a b s t r a c t In the drive. High volume fly ash concretes have been proposed as one potential approach for achieving substantial

  5. Broad-scale patterns of body size in squamate reptiles of Europe and

    E-Print Network [OSTI]

    Rodríguez, Miguel Ángel

    ORIGINAL ARTICLE Broad-scale patterns of body size in squamate reptiles of Europe and North America and western Europe. Methods We processed distribution maps for native species of squamate reptiles to document by the data. Results Europe is characterized by clear latitudinal trends in body size, whereas geographical

  6. Asymptotic Interference Alignment for Exact Repair in Distributed Storage Systems

    E-Print Network [OSTI]

    Jafar, Syed A.

    Asymptotic Interference Alignment for Exact Repair in Distributed Storage Systems Viveck R. Cadambe consider a distributed storage system where a file of size M is stored in n distributed storage nodes using of this paper is to repair failed nodes in the storage system, by replacing them by their replicas (exact repair

  7. light-Scattering and Size-Exclusion Chromatographic.' Characterization of Hydroxyethyl Cellulose Acetate

    E-Print Network [OSTI]

    Wu, Chi

    light-Scattering and Size-Exclusion Chromatographic.' Characterization of Hydroxyethyl Cellulose to investigate a set of moderately distributed hydroxyethyl cellulose acetate{~ECA) samples'in tetrahydrofuran- Cellulose constitutes a ubiquitous and r~newable ular weight~ndcm9l~cular weight distribution:"". natural

  8. Distributed Theorem Proving for Distributed Hybrid Systems

    E-Print Network [OSTI]

    Platzer, André

    system with a varying number of arbitrarily many cars. 1 Introduction Hybrid systems with joint discrete a multi-agent system, e.g., distributed car control systems. Such systems form distributed hybrid systemsDistributed Theorem Proving for Distributed Hybrid Systems David W. Renshaw, Sarah M. Loos

  9. Seasonal Run Distribution Seasonal Run Distribution

    E-Print Network [OSTI]

    . The term "total run" defines the number of adult sockeye salmon that home to the Karluk River before197 Seasonal Run Distribution CHAPTER 6 Seasonal Run Distribution They arrived from the sea in one, what was the seasonal run distribution of its sockeye salmon? Was the original run distribution which

  10. Bivariate Generalized Exponential Distribution

    E-Print Network [OSTI]

    Kundu, Debasis

    Bivariate Generalized Exponential Distribution Debasis Kundu and Rameshwar D. Gupta Abstract Recently it is observed that the generalized exponential distribution can be used quite effectively exponential distribution so that the marginals have generalized exponential distributions. It is observed

  11. Introduction Constrained distribution

    E-Print Network [OSTI]

    Nuel, Gregory

    Introduction Constrained distribution Observed pattern distribution Counting patterns-9 September 2009 G. Nuel Counting patterns in degenerated sequences #12;Introduction Constrained distribution Observed pattern distribution Outline 1 Introduction Special letters in biological sequences Counting

  12. Discrete multivariate distributions

    E-Print Network [OSTI]

    Oleg Yu. Vorobyev; Lavrentiy S. Golovkov

    2011-02-22

    This article brings in two new discrete distributions: multidimensional Binomial distribution and multidimensional Poisson distribution. Those distributions were created in eventology as more correct generalizations of Binomial and Poisson distributions. Accordingly to eventology new laws take into account full distribution of events. Also, in article its characteristics and properties are described

  13. Direct in situ measurement of specific capacitance, monolayer tension, and bilayer tension in a droplet interface bilayer

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Taylor, Graham J.; Venkatesan, Guru A.; Collier, C. Patrick; Sarles, Stephen A.

    2015-08-05

    In this study, thickness and tension are important physical parameters of model cell membranes. However, traditional methods to measure these quantities require multiple experiments using separate equipment. This work introduces a new multi-step procedure for directly accessing in situ multiple physical properties of droplet interface bilayers (DIB), including specific capacitance (related to thickness), lipid monolayer tension in the Plateau-Gibbs border, and bilayer tension. The procedure employs a combination of mechanical manipulation of bilayer area followed by electrowetting of the capacitive interface to examine the sensitivities of bilayer capacitance to area and contact angle to voltage, respectively. These data allow formore »determining the specific capacitance of the membrane and surface tension of the lipid monolayer, which are then used to compute bilayer thickness and tension, respectively. The use of DIBs affords accurate optical imaging of the connected droplets in addition to electrical measurements of bilayer capacitance, and it allows for reversibly varying bilayer area. After validating the accuracy of the technique with diphytanoyl phosphatidylcholine (DPhPC) DIBs in hexadecane, the method is applied herein to quantify separately the effects on membrane thickness and tension caused by varying the solvent in which the DIB is formed and introducing cholesterol into the bilayer. Because the technique relies only on capacitance measurements and optical images to determine both thickness and tension, this approach is specifically well-suited for studying the effects of peptides, biomolecules, natural and synthetic nanoparticles, and other species that accumulate within membranes without altering bilayer conductance.« less

  14. A high-speed beam of lithium droplets for collecting diverted energy and particles in ITER (International Thermonuclear Experimental Reactor)

    SciTech Connect (OSTI)

    Werley, K.A.

    1989-01-01

    A high-speed (160m/s) beam (0.14 {times} 0.86m) of liquid-lithium droplets passing through the divertor region(s) below (and above) the main plasma has the potential to replace and out-perform conventional'' solid divertor plates in both heat and particle removal. In addition to superior heat-collection properties, the lithium beam would: remove impurities; require low power to circulate the lithium; exhibit low-recycle divertor operation compatible with lower-hybrid current drive, H-mode plasma confinement, and no flow reversal in the edge plasma; be insensitive to plasma shifts; and finally protect solid structures from the plasma thermal energy for those disruptions that deposit energy preferentially into the divertor while simultaneously being rapidly re-established after a major disruption. Scoping calculations identifying the beam configuration and the droplet dynamics, including formation, MHD effects, gravitational effects, thermal response and hydrodynamics, are presented. Limitations and uncertainties are also discussed. 20 refs., 6 figs., 3 tabs.

  15. Hydrocracking process using disparate catalyst particle sizes

    SciTech Connect (OSTI)

    Kukes, S.G.; Miller, J.T.; Gutberlet, L.C.; Kelterboro, J.C

    1989-05-30

    This patent describes a process for the hydrocracking of a hydrocarbon feedstock which comprises reacting the feedstock with hydrogen at hydrocracking conversion conditions in a plurality of reaction zones in series containing hydrocracking catalyst wherein at least one of the reaction zones contains a small nominal size hydrocracking catalyst wherein the small nominal size catalyst has a U.S. sieve mesh size ranging from about 10 to about 16, and wherein at least one reaction zone upstream of the reaction zone containing the small nominal size hydrocracking catalyst having a particle size greater than the small nominal size hydrocracking catalyst.

  16. GASIFICATION FOR DISTRIBUTED GENERATION

    SciTech Connect (OSTI)

    Ronald C. Timpe; Michael D. Mann; Darren D. Schmidt

    2000-05-01

    A recent emphasis in gasification technology development has been directed toward reduced-scale gasifier systems for distributed generation at remote sites. The domestic distributed power generation market over the next decade is expected to be 5-6 gigawatts per year. The global increase is expected at 20 gigawatts over the next decade. The economics of gasification for distributed power generation are significantly improved when fuel transport is minimized. Until recently, gasification technology has been synonymous with coal conversion. Presently, however, interest centers on providing clean-burning fuel to remote sites that are not necessarily near coal supplies but have sufficient alternative carbonaceous material to feed a small gasifier. Gasifiers up to 50 MW are of current interest, with emphasis on those of 5-MW generating capacity. Internal combustion engines offer a more robust system for utilizing the fuel gas, while fuel cells and microturbines offer higher electric conversion efficiencies. The initial focus of this multiyear effort was on internal combustion engines and microturbines as more realistic near-term options for distributed generation. In this project, we studied emerging gasification technologies that can provide gas from regionally available feedstock as fuel to power generators under 30 MW in a distributed generation setting. Larger-scale gasification, primarily coal-fed, has been used commercially for more than 50 years to produce clean synthesis gas for the refining, chemical, and power industries. Commercial-scale gasification activities are under way at 113 sites in 22 countries in North and South America, Europe, Asia, Africa, and Australia, according to the Gasification Technologies Council. Gasification studies were carried out on alfalfa, black liquor (a high-sodium waste from the pulp industry), cow manure, and willow on the laboratory scale and on alfalfa, black liquor, and willow on the bench scale. Initial parametric tests evaluated through reactivity and product composition were carried out on thermogravimetric analysis (TGA) equipment. These tests were evaluated and then followed by bench-scale studies at 1123 K using an integrated bench-scale fluidized-bed gasifier (IBG) which can be operated in the semicontinuous batch mode. Products from tests were solid (ash), liquid (tar), and gas. Tar was separated on an open chromatographic column. Analysis of the gas product was carried out using on-line Fourier transform infrared spectroscopy (FT-IR). For selected tests, gas was collected periodically and analyzed using a refinery gas analyzer GC (gas chromatograph). The solid product was not extensively analyzed. This report is a part of a search into emerging gasification technologies that can provide power under 30 MW in a distributed generation setting. Larger-scale gasification has been used commercially for more than 50 years to produce clean synthesis gas for the refining, chemical, and power industries, and it is probable that scaled-down applications for use in remote areas will become viable. The appendix to this report contains a list, description, and sources of currently available gasification technologies that could be or are being commercially applied for distributed generation. This list was gathered from current sources and provides information about the supplier, the relative size range, and the status of the technology.

  17. The Colloidal State A colloidal dispersion comprises a collection of small particles, droplets, or bubbles

    E-Print Network [OSTI]

    Schramm, Laurier L.

    , or an ultrasound generator. The resulting suspension may have considerable stability as a metastable dispersion1 1.1 The Colloidal State A colloidal dispersion comprises a collection of small particles of colloidal size, just above atomic dimensions and overlapping with the emerging regime of nanotechnology

  18. Concurrent Testing of Droplet-Based Microfluidic Systems for Multiplexed Biomedical Assays*

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    ) of microfluidic systems and makes them less dependent on costly manual maintenance on a regular basis. Next flexibility, smaller size, lower cost, and higher sensitivity. They enable controlling small amounts (e, most microfluidic systems, consisting of micro-pumps, micro-valves, and micro-channels, are based

  19. Phase-retrieval X-ray microscopy by Wigner-distribution deconvolution

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Chapman, Henry, N.

    2014-10-30

    64x64 scan of a group of latex spheres with 45 nm step size, used for demonstrating Wigner-distribution deconvolution.

  20. Top 9 Things You Didn't Know About Distributed Wind Power | Department...

    Broader source: Energy.gov (indexed) [DOE]

    by households, schools, farms, industrial facilities and municipalities, distributed wind doesn't only refer to small-scale turbines; it includes any size turbine or array of...

  1. Top 10 Things You Didn't Know About Distributed Wind Power |...

    Energy Savers [EERE]

    by households, schools, farms, industrial facilities and municipalities, distributed wind doesn't only refer to small-scale turbines; it includes any size turbine or array of...

  2. Experimental comparison of various techniques for spot size measurement of high-energy x-ray source

    E-Print Network [OSTI]

    Wang, Yi; Chen, Nan; Cheng, Jinming; Li, Chenggang; Dai, Wenhua; Li, Hong; Long, Quanhong; Shi, Jinshui; Deng, Jianjun

    2015-01-01

    In the experiment of flash-radiography, the quality of acquired image strongly depends on the focal size of the x-ray source spot. A variety of techniques based on imaging of pinhole, slit and rollbar are adopted to measure the focal spot size of the Dragon-I linear induction accelerator. The image of pinhole provides a two-dimensional distribution of the x-ray spot, while those of slit and rollbar give a line-spread distribution and an edge-spread distribution, respectively. The spot size characterized by full-width at half-maximum and that characterized by the LANL definition are calculated for comparison.

  3. Software implemented fault-tolernace on distributed-memory MIMD architectures 

    E-Print Network [OSTI]

    Holland, Gavin D

    1995-01-01

    Large multicomputer systems are inherently unreliable because of their enormous complexity. This has a direct impact on distributed computations performed on these systems. As the size and execution time of these distributed computations grows, so...

  4. Distributed anonymous function computation in information fusion and multiagent systems

    E-Print Network [OSTI]

    Hendrickx, Julien

    We propose a model for deterministic distributed function computation by a network of identical and anonymous nodes, with bounded computation and storage capabilities that do not scale with the network size. Our goal is ...

  5. 2012 Market Report on Wind Technologies in Distributed Applications

    SciTech Connect (OSTI)

    Orrell, Alice C.

    2013-08-01

    An annual report on U.S. wind power in distributed applications – expanded to include small, mid-size, and utility-scale installations – including key statistics, economic data, installation, capacity, and generation statistics, and more.

  6. Areas of contact and pressure distribution in bolted joints

    E-Print Network [OSTI]

    Gould, Herbert Hirsch

    1970-01-01

    When two plates are bolted (or riveted) together these will be in contact in the immediate vicinity of the bolt heads and separated beyond it. The pressure distribution and size of the contact zone is of considerable ...

  7. Grain size dependence of barchan dune dynamics

    E-Print Network [OSTI]

    C. Groh; N. Aksel; I. Rehberg; C. Kruelle

    2008-11-28

    The dependence of the barchan dune dynamics on the size of the grains involved is investigated experimentally. Downsized barchan dune slices are observed in a narrow water flow tube. The relaxation time from an initial symmetric triangular heap towards an asymmetric shape attractor increases with dune mass and decreases with grain size. The dune velocity increases with grain size. In contrast, the velocity scaling and the shape of the barchan dune is independent of the size of the grains.

  8. Semicontinuous Sized Types and Termination Andreas Abel #

    E-Print Network [OSTI]

    Abel, Andreas

    , and classical applications are total correctness and termination of partial evaluation. In languagesSemi­continuous Sized Types and Termination Andreas Abel # Institut für Informatik Ludwig to termination uses sized types: an ordinal bound for the size of a data structure is stored in its type

  9. Prior distribution Andrew Gelman

    E-Print Network [OSTI]

    Gelman, Andrew

    Prior distribution Andrew Gelman Volume 3, pp 1634­1637 in Encyclopedia of Environmetrics (ISBN, 2002 #12;Prior distribution The prior distribution is a key part of Bayesian infer- ence (see Bayesian with the probability distribution of new data to yield the posterior distribution, which in turn is used for future

  10. J. Europ. Opt. Soc. Rap. Public. 9, 14056 (2014) www.jeos.org Digital in-line holography in a droplet with cavitation

    E-Print Network [OSTI]

    2014-01-01

    in a droplet with cavitation air bubbles S. Co¨etmellec coetmellec@coria.fr D´epartement d'optique, UMR-6614, and in industrial applications. Sometimes bubbles are used to seed a fluid flow to study the hydrodynamics around

  11. Hazards of explosives dusts: Particle size effects

    SciTech Connect (OSTI)

    Cashdollar, K L; Hertzberg, M; Green, G M

    1992-02-01

    At the request of the Department of Energy, the Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. In this report, the effect of particle size for HMX, HNS, RDX, TATB, and TNT explosives dusts is studied in detail. The explosibility data for these dusts are also compared to those for pure fuel dusts. The data show that all of the sizes of the explosives dusts that were studied were capable of sustaining explosions as dust clouds dispersed in air. The finest sizes (<10 [mu]m) of explosives dusts were less reactive than the intermediate sizes (20 to 60 [mu]m); this is opposite to the particle size effect observed previously for the pure fuel dusts. At the largest sizes studied, the explosives dusts become somewhat less reactive as dispersed dust clouds. The six sizes of the HMX dust were also studied as dust clouds dispersed in nitrogen.

  12. Simultaneous regulation of cell size and chromosome replication in bacteria

    E-Print Network [OSTI]

    Po-Yi Ho; Ariel Amir

    2015-07-24

    Bacteria are able to maintain a narrow distribution of cell sizes by regulating the timing of cell divisions. In rich nutrient conditions, cells divide much faster than their chromosomes replicate. This implies that cells maintain multiple rounds of chromosome replication per cell division by regulating the timing of chromosome replications. Here, we show that both cell size and chromosome replication may be simultaneously regulated by the long-standing initiator accumulation strategy. The strategy proposes that initiators are produced in proportion to the volume increase and is accumulated at each origin of replication, and chromosome replication is initiated when a critical amount per origin has accumulated. We show that this model maps to the incremental model of size control, which was previously shown to reproduce experimentally observed correlations between various events in the cell cycle and explains the exponential dependence of cell size on the growth rate of the cell. Furthermore, we show that this model also leads to the efficient regulation of the timing of initiation and the number of origins consistent with existing experimental results.

  13. Integrated Transmission and Distribution Control

    SciTech Connect (OSTI)

    Kalsi, Karanjit; Fuller, Jason C.; Tuffner, Francis K.; Lian, Jianming; Zhang, Wei; Marinovici, Laurentiu D.; Fisher, Andrew R.; Chassin, Forrest S.; Hauer, Matthew L.

    2013-01-16

    Distributed, generation, demand response, distributed storage, smart appliances, electric vehicles and renewable energy resources are expected to play a key part in the transformation of the American power system. Control, coordination and compensation of these smart grid assets are inherently interlinked. Advanced control strategies to warrant large-scale penetration of distributed smart grid assets do not currently exist. While many of the smart grid technologies proposed involve assets being deployed at the distribution level, most of the significant benefits accrue at the transmission level. The development of advanced smart grid simulation tools, such as GridLAB-D, has led to a dramatic improvement in the models of smart grid assets available for design and evaluation of smart grid technology. However, one of the main challenges to quantifying the benefits of smart grid assets at the transmission level is the lack of tools and framework for integrating transmission and distribution technologies into a single simulation environment. Furthermore, given the size and complexity of the distribution system, it is crucial to be able to represent the behavior of distributed smart grid assets using reduced-order controllable models and to analyze their impacts on the bulk power system in terms of stability and reliability. The objectives of the project were to: • Develop a simulation environment for integrating transmission and distribution control, • Construct reduced-order controllable models for smart grid assets at the distribution level, • Design and validate closed-loop control strategies for distributed smart grid assets, and • Demonstrate impact of integrating thousands of smart grid assets under closed-loop control demand response strategies on the transmission system. More specifically, GridLAB-D, a distribution system tool, and PowerWorld, a transmission planning tool, are integrated into a single simulation environment. The integrated environment allows the load flow interactions between the bulk power system and end-use loads to be explicitly modeled. Power system interactions are modeled down to time intervals as short as 1-second. Another practical issue is that the size and complexity of typical distribution systems makes direct integration with transmission models computationally intractable. Hence, the focus of the next main task is to develop reduced-order controllable models for some of the smart grid assets. In particular, HVAC units, which are a type of Thermostatically Controlled Loads (TCLs), are considered. The reduced-order modeling approach can be extended to other smart grid assets, like water heaters, PVs and PHEVs. Closed-loop control strategies are designed for a population of HVAC units under realistic conditions. The proposed load controller is fully responsive and achieves the control objective without sacrificing the end-use performance. Finally, using the T&D simulation platform, the benefits to the bulk power system are demonstrated by controlling smart grid assets under different demand response closed-loop control strategies.

  14. Probabilistic Precipitation Forecast Skill as a Function of Ensemble Size and Spatial Scale in a Convection-Allowing Ensemble

    E-Print Network [OSTI]

    Xue, Ming

    Probabilistic Precipitation Forecast Skill as a Function of Ensemble Size and Spatial Scale decreases. These results appear to reflect the broadening of the forecast probability distribution function lead time. They also illustrate that efficient allocation of computing resources for convection

  15. Distribution Grid Integration

    Broader source: Energy.gov [DOE]

    The DOE Systems Integration team funds distribution grid integration research and development (R&D) activities to address the technical issues that surround distribution grid planning,...

  16. About Industrial Distributed Energy

    Broader source: Energy.gov [DOE]

    The Advanced Manufacturing Office's (AMO's) Industrial Distributed Energy activities build on the success of predecessor DOE programs on distributed energy and combined heat and power (CHP) while...

  17. THE MASSIVE SATELLITE POPULATION OF MILKY-WAY-SIZED GALAXIES

    SciTech Connect (OSTI)

    Rodriguez-Puebla, Aldo; Avila-Reese, Vladimir; Drory, Niv, E-mail: apuebla@astro.unam.mx [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, A. P. 70-264, 04510 Mexico, DF (Mexico)

    2013-08-20

    Several occupational distributions for satellite galaxies more massive than m{sub *} Almost-Equal-To 4 Multiplication-Sign 10{sup 7} M{sub Sun} around Milky-Way (MW)-sized hosts are presented and used to predict the internal dynamics of these satellites as a function of m{sub *}. For the analysis, a large galaxy group mock catalog is constructed on the basis of (sub)halo-to-stellar mass relations fully constrained with currently available observations, namely the galaxy stellar mass function decomposed into centrals and satellites, and the two-point correlation functions at different masses. We find that 6.6% of MW-sized galaxies host two satellites in the mass range of the Small and Large Magellanic Clouds (SMC and LMC, respectively). The probabilities of the MW-sized galaxies having one satellite equal to or larger than the LMC, two satellites equal to or larger than the SMC, or three satellites equal to or larger than Sagittarius (Sgr) are Almost-Equal-To 0.26, 0.14, and 0.14, respectively. The cumulative satellite mass function of the MW, N{sub s} ({>=}m{sub *}) , down to the mass of the Fornax dwarf is within the 1{sigma} distribution of all the MW-sized galaxies. We find that MW-sized hosts with three satellites more massive than Sgr (as the MW) are among the most common cases. However, the most and second most massive satellites in these systems are smaller than the LMC and SMC by roughly 0.7 and 0.8 dex, respectively. We conclude that the distribution N{sub s} ({>=}m{sub *}) for MW-sized galaxies is quite broad, the particular case of the MW being of low frequency but not an outlier. The halo mass of MW-sized galaxies correlates only weakly with N{sub s} ({>=}m{sub *}). Then, it is not possible to accurately determine the MW halo mass by means of its N{sub s} ({>=}m{sub *}); from our catalog, we constrain a lower limit of 1.38 Multiplication-Sign 10{sup 12} M{sub Sun} at the 1{sigma} level. Our analysis strongly suggests that the abundance of massive subhalos should agree with the abundance of massive satellites in all MW-sized hosts, i.e., there is not a missing (massive) satellite problem for the {Lambda}CDM cosmology. However, we confirm that the maximum circular velocity, v{sub max}, of the subhalos of satellites smaller than m{sub *} {approx} 10{sup 8} M{sub Sun} is systematically larger than the v{sub max} inferred from current observational studies of the MW bright dwarf satellites; different from previous works, this conclusion is based on an analysis of the overall population of MW-sized galaxies. Some pieces of evidence suggest that the issue could refer only to satellite dwarfs but not to central dwarfs, then environmental processes associated with dwarfs inside host halos combined with supernova-driven core expansion should be on the basis of the lowering of v{sub max}.

  18. Sex, Size and Gender Roles evolutionary studies of sexual size dimorphism

    E-Print Network [OSTI]

    Saltzman, Wendy

    , John L. Gittleman and Kate E. Jones 3. Sexual Size Dimorphism in Birds , Tamás Székely, Terje Lislevand in the Hartebeest, Isabella Capellini 13. Sexual Size Dimorphism and Offspring Vulnerability in Birds, EllenSex, Size and Gender Roles evolutionary studies of sexual size dimorphism Edited by Daphne J

  19. Combustion characteristics of alternative liquid fuels

    E-Print Network [OSTI]

    Chong, Cheng Tung

    2011-11-08

    atomizer are investigated using a phase Doppler anemometry (PDA) under non-reacting conditions. The droplet size and velocity distribution of biodiesels are compared to conventional fuels. For spray combustion investigations, a generic gas turbine...

  20. Ground-state energy and stability limit of {sup 3}He droplets

    SciTech Connect (OSTI)

    Sola, E.; Casulleras, J.; Boronat, J.

    2006-03-01

    Small and stable drops of {sup 3}He atoms can only exist above a minimum number of particles, due to the combination of the {sup 3}He atom Fermi statistics and its light mass. An accurate estimation of this minimum number using microscopic theory has been difficult due to the inhomogeneous and fermionic nature of these systems. We present a diffusion Monte Carlo calculation of {sup 3}He drops with sizes near the minimum in order to determine the stability threshold. The results show that the minimum self-bound drop is formed by N=30 atoms with preferred orbitals for open shells corresponding to maximum value of the spin.

  1. Stochastic Programming Formulation for Integrating Renewables into the Distribution Grid

    E-Print Network [OSTI]

    Ernst, Damien

    #12;Distribution Networks Distribution networks had been designed to carry power from the transmis. The set of scenarios sizing the network infrastructure might not be frequent. Much more kilometers of electricity markets : .... Day-ahead market Intraday market Time ... Period 1 Period 2 Period T ... Real

  2. Dynamically Adaptive Partition-based Data Distribution Management* Bora . Kumova

    E-Print Network [OSTI]

    Kumova, Bora

    Dynamically Adaptive Partition-based Data Distribution Management* Bora . Kumova zmir Institute-size partitioning shared data. Based on this technique, a novel DDM algorithm is introduced that is dynamically of the employed data distribution management (DDM) algorithm, which aims at reducing the overall computational

  3. Extrapolating Oceanic Age Distributions: Lessons from the Pacific Region

    E-Print Network [OSTI]

    Extrapolating Oceanic Age Distributions: Lessons from the Pacific Region David B. Rowley Department plate reconstructions. An area equal in size to the Pacific Basin oceanic lithosphere must-mail: rowley@geosci.uchicago.edu) A B S T R A C T Extrapolation of the age distribution of oceanic lithosphere

  4. ON A POSSIBLE SIZE/COLOR RELATIONSHIP IN THE KUIPER BELT

    SciTech Connect (OSTI)

    Pike, R. E.; Kavelaars, J. J., E-mail: repike@uvic.ca [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6 (Canada)

    2013-10-01

    Color measurements and albedo distributions introduce non-intuitive observational biases in size-color relationships among Kuiper Belt Objects (KBOs) that cannot be disentangled without a well characterized sample population with systematic photometry. Peixinho et al. report that the form of the KBO color distribution varies with absolute magnitude, H. However, Tegler et al. find that KBO color distributions are a property of object classification. We construct synthetic models of observed KBO colors based on two B-R color distribution scenarios: color distribution dependent on H magnitude (H-Model) and color distribution based on object classification (Class-Model). These synthetic B-R color distributions were modified to account for observational flux biases. We compare our synthetic B-R distributions to the observed ''Hot'' and ''Cold'' detected objects from the Canada-France Ecliptic Plane Survey and the Meudon Multicolor Survey. For both surveys, the Hot population color distribution rejects the H-Model, but is well described by the Class-Model. The Cold objects reject the H-Model, but the Class-Model (while not statistically rejected) also does not provide a compelling match for data. Although we formally reject models where the structure of the color distribution is a strong function of H magnitude, we also do not find that a simple dependence of color distribution on orbit classification is sufficient to describe the color distribution of classical KBOs.

  5. A Master equation for force distributions in polydisperse frictional particles

    E-Print Network [OSTI]

    Kuniyasu Saitoh; Vanessa Magnanimo; Stefan Luding

    2015-05-28

    An incremental evolution equation, i.e. a Master equation in statistical mechanics, is introduced for force distributions in polydisperse frictional particle packings. As basic ingredients of the Master equation, the conditional probability distributions of particle overlaps are determined by molecular dynamics simulations. Interestingly, tails of the distributions become much narrower in the case of frictional particles than frictionless particles, implying that correlations of overlaps are strongly reduced by microscopic friction. Comparing different size distributions, we find that the tails are wider for the wider distribution.

  6. On measures of size for convex cones

    E-Print Network [OSTI]

    2015-05-18

    Section 2 presents a battery of examples of size indices disseminated in the literature. For each ...... ferent measures of conditioning for conic linear systems.

  7. Interfacial Studies of Sized Carbon Fiber

    SciTech Connect (OSTI)

    Shahrul, S. N.; Hartini, M. N.; Hilmi, E. A.; Nizam, A. [Nanomaterials Program, Advance Materials Centre (AMREC), SIRIM Berhad, Lot 34, Jalan Hi-Tech Park, 09000, Kulim, Kedah (Malaysia)

    2010-03-11

    This study was performed to investigate the influence of sizing treatment on carbon fiber in respect of interfacial adhesion in composite materials, Epolam registered 2025. Fortafil unsized carbon fiber was used to performed the experiment. The fiber was commercially surface treated and it was a polyacrylonitrile based carbon fiber with 3000 filament per strand. Epicure registered 3370 was used as basic sizing chemical and dissolved in two types of solvent, ethanol and acetone for the comparison purpose. The single pull out test has been used to determine the influence of sizing on carbon fiber. The morphology of carbon fiber was observed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The apparent interfacial strength IFSS values determined by pull out test for the Epicure registered 3370/ethanol sized carbon fiber pointed to a good interfacial behaviour compared to the Epicure registered 3370/acetone sized carbon fiber. The Epicure registered 3370/ethanol sizing agent was found to be effective in promoting adhesion because of the chemical reactions between the sizing and Epolam registered 2025 during the curing process. From this work, it showed that sized carbon fiber using Epicure registered 3370 with addition of ethanol give higher mechanical properties of carbon fiber in terms of shear strength and also provided a good adhesion between fiber and matrix compared to the sizing chemical that contain acetone as a solvent.

  8. AMO Industrial Distributed Energy: Industrial Distributed Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    in owning and operating costs, thereby improving the economics of distributed power generation using reciprocating gas engines. Caterpillar's Phase I technologies have...

  9. The role of stochastic processes in producing nested patterns of species distributions

    E-Print Network [OSTI]

    Strauss, Richard E.

    that underlie species distributions on island systems, then null models might be better determined on the basis of species. Island size and abundance had less of an effect on nestedness in systems dominated by only a few (uniform, dominance-decay, random-assortment, and dominance-preemption), island-size distributions (uniform

  10. Multimedia Environmental Distribution of Nanomaterials

    E-Print Network [OSTI]

    Liu, Haoyang Haven

    2015-01-01

    6. ! Multimedia Environmental Distribution of Engineeredon Simulations of the Multimedia Distribution of ParticulateCohen, Multimedia Environmental Distribution of Engineered

  11. Assessment of Available Particle Size Data to Support an Analysis of the Waste Feed Delivery System Transfer System

    SciTech Connect (OSTI)

    JEWETT, J.R.

    2000-08-10

    Available data pertaining to size distribution of the particulates in Hanford underground tank waste have been reviewed. Although considerable differences exist between measurement methods, it may be stated with 95% confidence that the median particle size does not exceed 275 {micro}m in at least 95% of the ten tanks selected as sources of HLW feed for Phase 1 vitrification in the RPP. This particle size is recommended as a design basis for the WFD transfer system.

  12. Definition of a Random Variable Distribution Functions Properties of Distribution Functions Random Variables and Distribution Functions

    E-Print Network [OSTI]

    Watkins, Joseph C.

    Definition of a Random Variable Distribution Functions Properties of Distribution Functions Topic 7 Random Variables and Distribution Functions Distribution Functions 1 / 11 #12;Definition of a Random Variable Distribution Functions Properties of Distribution Functions Outline Definition of a Random

  13. The Thermal Phase Transition in Nuclear Multifragmentation: The Role of Coulomb Energy and Finite Size

    E-Print Network [OSTI]

    EOS Collaboration; B. K. Srivastava

    2001-07-30

    A systematic analysis of the moments of the fragment size distribution has been carried out for the multifragmentation (MF)of 1A GeV Au, La, and Kr on carbon. The breakup of Au and La is consistent with a continuous thermal phase transition. The data indicate that the excitation energy per nucleon and isotopic temperature at the critical point decrease with increasing system size. This trend is attributed primarily to the increasing Coulomb energy with finite size effects playing a smaller role.

  14. Morphological changes in ultrafast laser ablation plumes with varying spot size

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Harilal, S. S.; Diwakar, P. K.; Polek, M. P.; Phillips, M. C.

    2015-06-04

    We investigated the role of spot size on plume morphology during ultrafast laser ablation of metal targets. Our results show that the spatial features of fs LA plumes are strongly dependent on the focal spot size. Two-dimensional self-emission images showed that the shape of the ultrafast laser ablation plumes changes from spherical to cylindrical with an increasing spot size from 100 to 600 ?m. The changes in plume morphology and internal structures are related to ion emission dynamics from the plasma, where broader angular ion distribution and faster ions are noticed for the smallest spot size used. The present resultsmore »clearly show that the morphological changes in the plume with spot size are independent of laser pulse width.« less

  15. Useful Probability Distributions Standard Normal Distribution

    E-Print Network [OSTI]

    the proportion t as a variable which is continuous over the interval (0,1) For small consignments, say N Consignment of tablets, a proportion of which are suspected drugs. For large consignments, probability distribution of the proportion t which are drugs can be modeled with a beta distribution, which treats

  16. Squibs and Discussions Pipelines and Size Constraints

    E-Print Network [OSTI]

    Squibs and Discussions Pipelines and Size Constraints Ehud Reiter* University of Aberdeen Some. This can be a difficult constraint to enforce in a pipelined natural language generation (NLG) system of the pipeline, but size cannot be accurately measured until the document has been completely processed

  17. Spatially DistributedSpatially Distributed Experimentation toExperimentation to

    E-Print Network [OSTI]

    Rubloff, Gary W.

    : Spatially distributed atomic layer deposition Spatially Distributed Atomic LayerSpatially Distributed Atomic properties Significance Atomic layer deposition (ALD) is widely sought for its atomic-scale thickness control, MKS Instruments #12;Rubloff: Spatially distributed atomic layer deposition Spatially Distributed

  18. Single photon emission of a charge-tunable GaAs/Al{sub 0.25}Ga{sub 0.75}As droplet quantum dot device

    SciTech Connect (OSTI)

    Langer, Fabian Plischke, David; Kamp, Martin; Höfling, Sven

    2014-08-25

    In this work, we report the fabrication of a charge-tunable GaAs/Al{sub 0.25}Ga{sub 0.75}As quantum dot (QD) device containing QDs deposited by modified droplet epitaxy producing almost strain and composition gradient free QDs. We obtained a QD density in the low 10{sup 9?}cm{sup ?2} range that enables us to perform spectroscopy on single droplet QDs showing linewidths as narrow as 40??eV. The integration of the QDs into a Schottky diode allows us to controllably charge a single QD with up to four electrons, while non-classical photoluminescence is proven by photon auto-correlation measurements showing photon-antibunching (g{sup (2)}(0)?=?0.05).

  19. Finite size scaling analysis of compact QED

    E-Print Network [OSTI]

    G. Arnold; Th. Lippert; Th. Neuhaus; K. Schilling

    2000-11-13

    We describe results of a high-statistics finite size scaling analysis of 4d compact U(1) lattice gauge theory with Wilson action at the phase transition point. Using a multicanonical hybrid Monte Carlo algorithm we generate data samples with more than 150 tunneling events between the metastable states of the system, on lattice sizes up to 18^4. We performed a first analysis within the Borgs-Kotecky finite size scaling scheme. As a result, we report evidence for a first-order phase transition with a plaquette energy gap, G=0.02667(20), at a transition coupling, beta_T=1.011128(11).

  20. Distributed Wind 2015

    Broader source: Energy.gov [DOE]

    Distributed Wind 2015 is committed to the advancement of both distributed and community wind energy. This two day event includes a Business Conference with sessions focused on advancing the...

  1. Structure Optimization of FePt Nanoparticles of Various Sizes for Magnetic Data Storage

    E-Print Network [OSTI]

    Laughlin, David E.

    to a modified reaction route based on Sun et al.[1] Hexane dispersions of nanoparticles were dried increases with particle size and with the temperature in the range 600 °C to 650 °C, being close to unity-assembly over large areas, and a narrow distribution of switching fields. The long storage time and high storage

  2. Ecological and allometric determinants of home-range size for mountain lions (Puma concolor)

    E-Print Network [OSTI]

    Beier, Paul

    Ecological and allometric determinants of home-range size for mountain lions (Puma concolor) INTRODUCTION Mountain lions (Puma concolor) are distributed through- out much of California, including the Sierra Nevada mountains, Coastal Ranges, eastern Sierran deserts and suburban areas. Despite our

  3. Source apportionment of time-and size-resolved ambient particulate matter , Philip K. Hopke b,

    E-Print Network [OSTI]

    Navasca, Carmeliza

    , analyses of particle size distribution data have also been performed to identify air pollution sources of Mathematics, Clarkson University, Box 5815, Potsdam, NY 13699, USA b Center for Air Resource Engineering and Science, Clarkson University, Box 5708, Potsdam, NY 13699, USA c Air Quality Research Center, University

  4. Real Estate and MLR Diagnostics Bivariate Fit of condition By size

    E-Print Network [OSTI]

    Vardeman, Stephen B.

    Real Estate and MLR Diagnostics Bivariate Fit of condition By size 0 2 4 6 8 10 condition 10 15 20Real Estate MLR Residuals Distributions Residual price -2 -1.5 -1 -0.5 0 .5 1 1.5 Normal(7.1e

  5. COMPETITION POLICY TOWARDS RETAILERS: SIZE, SELLER MARKET POWER AND BUYER POWER

    E-Print Network [OSTI]

    Feigon, Brooke

    1 COMPETITION POLICY TOWARDS RETAILERS: SIZE, SELLER MARKET POWER AND BUYER POWER by Nicola the wholesale price in which retailers serve different distribution markets. The model shows that the current in this practice. JEL: L20; L40. Keywords : Market Definition; Bargaining; Retail Sector. ISSN 1473-8473 #12;2 1

  6. Router Buffer Sizing for TCP Traffic and the Role of the Output/Input Capacity Ratio

    E-Print Network [OSTI]

    Dovrolis, Constantinos

    of packets", "a bandwidth-delay product", or "a multiple of the number of large TCP flows in that link TCP flows. This paper differs in two ways. First, it considers the more realistic case of non-persistent TCP flows with heavy-tailed size distribution. Second, instead of only looking at link metrics

  7. Determination of the total grain size distributionin a vulcanian eruption column, and its implications to stratospheric aerosol perturbation

    SciTech Connect (OSTI)

    Murrow, P.J.; Rose, W.I. Jr.; Self, S.

    1980-11-01

    Grain size analysis of samples representing all sampleable portions of the airfall deposit produced by the Fuego volcano in Guatemala on 14 October 1974 form the basis for estimating the total grain size distribution of tephra from this eruption. The region enclosed by each isopach has a particular average grain size distribution which can be weighted proportionally to its percentage volume. The grain size of pyroclastic avalanche deposits produced during the eruption are also included. The total grain size distribution calculated as a sum of weighted distributions has a median grain size of 0.80 (0.6mm) and a sorting coefficient (sigma0) of 2.3. The size distribution seems to approximate Rosin and Rammler's law of crushing and this observation allows us to estimate that no more than 15% volume of the fine tail of the total size distribution is likely to be missing. The ash composed of these fine particles did not fall in the region of the volcano as part of the recognizable tephra blanket. The eruption column reached well into the stratosphere: heights estimated from the ground were 10 to 12 km above sea level but estimated heights based on mass flux rates are higher (18 to 23 km). The proportion of ash smaller than 2 ..mu..m, which could remain for substantial periods in the stratosphere, is no more than 0.8% volume of the total. It seems probable that acid aerosol particles from vulcanian type eruptions are more important to stratospheric aerosol perturbation than fine silicate ash particles by at least an order of magnitude.

  8. Control of gene expression by cell size

    E-Print Network [OSTI]

    Wu, Chia-Yung

    2010-01-01

    Polyploidy, increased copy number of whole chromosome sets in the genome, is a common cellular state in evolution, development and disease. Polyploidy enlarges cell size and alters gene expression, producing novel phenotypes ...

  9. Software Productivity Measurement Using Multiple Size Measures

    E-Print Network [OSTI]

    Bae, Doo-Hwan

    Software Productivity Measurement Using Multiple Size Measures Software Productivity MeasurementContents Introduction Background Related work Motivation Productivity measurement - Measurement model - Productivity measure construction - Productivity analysis Conclusion Discussion #12;Software Engineering Lab, KAIST 3

  10. Continuous Nanoparticle Sizing and Characterization via Microfluidics 

    E-Print Network [OSTI]

    Meng, Fanxu

    2015-04-27

    conductivity measurements can be exploited to instantaneously obtain size and species information in oxide nanoparticle suspensions. This approach is readily implemented in an easy to build platform that can be employed either online to provide real...

  11. Antiferromagnetic domain size and exchange bias 

    E-Print Network [OSTI]

    Fitzsimmons, M. R.; Lederman, D.; Cheon, M.; Shi, H.; Olamit, J.; Roshchin, Igor V.; Schuller, Ivan K.

    2008-01-01

    Using neutron diffraction, we measured the sizes of antiferromagnetic domains in three ferromagnet/antiferromagnet bilayer samples as a function of the magnitude and sign of exchange bias, temperature, and antiferromagnet composition. Neutron...

  12. Inside-Out Infall Formation of Disk Galaxies: Do Predictions Differ from Models without Size Evolution?

    E-Print Network [OSTI]

    Rychard J. Bouwens; Laura Cayon; Joseph Silk

    1997-09-13

    We develop an idealized inside-out formation model for disk galaxies to include a realistic mix of galaxy types and luminosities that provides a fair match to the traditional observables. The predictions of our infall models are compared against identical models with no-size evolution by generating fully realistic simulations of the HDF, from which we recover the angular size distributions. We find that our infall models produce nearly identical angular size distributions to those of our no-size evolution models in the case of a Omega = 0 geometry but produce slightly smaller sizes in the case of a Omega = 1 geometry, a difference we associate with the fact that there is a different amount of cosmic time in our two models for evolving to relatively low redshifts (z \\approx 1-2). Our infall models also predict a slightly smaller (11% - 29%) number of large (disk scale lengths > 4 h_{50} ^{-1} kpc) galaxies at z \\approx 0.7 for the CFRS as well as different increases in the central surface brightness of the disks for early-type spirals, the infall model predicting an increase by 1.2 magnitudes out to z \\approx 2 (Omega = 0), 1 (Omega = 1), while our no-size evolution models predict an increase of only 0.5 magnitude. This result suggests that infall models could be important for explaining the 1.2-1.6 magnitude increase in surface brightness reported by Schade et al. (1995, 1996a, 1996b).

  13. FRIB cryogenic distribution system

    SciTech Connect (OSTI)

    Ganni, V.; Dixon, K.; Laverdure, N.; Knudsen, P.; Arenius, D. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States); Barrios, M.; Jones, S.; Johnson, M.; Casagrande, F. [Facility for Rare Isotope Beams (FRIB), Michigan State University, East Lansing, MI 48824 (United States)

    2014-01-29

    The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.

  14. FRIB cryogenic distribution system

    SciTech Connect (OSTI)

    Ganni, Venkatarao [JLAB; Dixon, Kelly D. [JLAB; Laverdure, Nathaniel A. [JLAB; Knudsen, Peter N. [JLAB; Arenius, Dana M. [JLAB; Barrios, Matthew N. [Michigan State; Jones, S. [Michigan State; Johnson, M. [Michigan State; Casagrande, Fabio [Michigan State

    2014-01-01

    The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.

  15. NEW DATA ON THE POPULATION, DISTRIBUTION AND HABITAT PREFERENCES OF THE

    E-Print Network [OSTI]

    Seoane, Javier

    NEW DATA ON THE POPULATION, DISTRIBUTION AND HABITAT PREFERENCES OF THE CANARY ISLANDS STONECHAT, distribution and habitat preferences of the Canary Islands stonechat Saxicola dacotiae. This paper updates estimates of population size, distribution and habitat preferences of the endemic Canary Islands stonechat

  16. book review: Species distribution models for species distribution modellers

    E-Print Network [OSTI]

    Dormann, Carsten F

    2012-01-01

    Mapping  species  distributions:  spa? tial inference and news and update  book review  Species distribution models for species distribution modellers  Ecological niches and 

  17. Investigations of initiation spot size effects

    SciTech Connect (OSTI)

    Clarke, Steven A; Akinci, Adrian A; Leichty, Gary; Schaffer, Timothy; Murphy, Michael J; Munger, Alan; Thomas, Keith A

    2010-01-01

    As explosive components become smaller, a greater understanding of the effect of initiation spot size on detonation becomes increasingly critical. A series of tests of the effect of initiation spot size will be described. A series of DOI (direct optical initiation) detonators with initiation spots sizes from {approx}50 um to 1000um have been tested to determine laser parameters for threshold firing of low density PETN pressings. Results will be compared with theoretical predictions. Outputs of the initiation source (DOI ablation) have been characterized by a suite of diagnostics including PDV and schlieren imaging. Outputs of complete detonators have been characterized using PDV, streak, and/or schlieren imaging. At present, we have not found the expected change in the threshold energy to spot size relationship for DOI type detonators found in similar earlier for projectiles, slappers and EBWs. New detonators designs (Type C) are currently being tested that will allow the determination of the threshold for spot sizes from 250 um to 105um, where we hope to see change in the threshold vs. spot size relationship. Also, one test of an extremely small diameter spot size (50um) has resulted in preliminary NoGo only results even at energy densities as much as 8 times the energy density of the threshold results presented here. This gives preliminary evidence that 50um spot may be beyond the critical initiation diameter. The constant threshold energy to spot size relationship in the data to date does however still give some insight into the initiation mechanism of DOI detonators. If the DOI initiation mechanism were a 1D mechanism similar to a slapper or a flyer impact, the expected inflection point in the graph would have been between 300um and 500um diameter spot size, within the range of the data presented here. The lack of that inflection point indicates that the DOI initiation mechanism is more likely a 2D mechanism similar to a sphere or rod projectile. We expect to see a three region response as the results from the smaller spot size Type C detonators are completed.

  18. Lunar mare basalt flow units: Thicknesses determined from crater size-frequency distributions

    E-Print Network [OSTI]

    Head III, James William

    . Hiesinger and J. W. Head III Department of Geological Sciences, Brown University, Providence, RI, USA U, and Insularum) allowed us to identify flow units that have not been detected in low-sun images. We found and their relation to the thermal evolution of the Moon [Head and Wilson, 1992]. Early work focused on estimating

  19. Optimal site selection and sizing of distributed utility-scale wind power plants

    SciTech Connect (OSTI)

    Milligan, M.R. [National Renewable Energy Lab., Golden, CO (United States); Artig, R. [Minnesota Dept. of Public Service, St. Paul, MN (United States)

    1998-04-01

    As electric market product unbundling occurs, sellers in the wholesale market for electricity will find it to their advantage to be able to specify the quantity of electricity available and the time of availability. Since wind power plants are driven by the stochastic nature of the wind itself, this can present difficulties. To the extent that an accurate wind forecast is available, contract deviations, and therefore penalties, can be significantly reduced. Even though one might have the ability to accurately forecast the availability of wind power, it might not be available during enough of the peak period to provide sufficient value. However, if the wind power plant is developed over geographically disperse locations, the timing and availability of wind power from these multiple sources could provide a better match with the utility`s peak load than a single site. There are several wind plants in various stages of planning or development in the US. Although some of these are small-scale demonstration projects, significant wind capacity has been developed in Minnesota, with additional developments planned in Wyoming and Iowa. As these and other projects are planned and developed, there is a need to perform analysis of the value of geographically diverse sites on the efficiency of the overall wind plant. In this paper, the authors use hourly wind-speed data from six geographically diverse sites to provide some insight into the potential benefits of disperse wind plant development. They provide hourly wind power from each of these sites to an electric reliability simulation model. This model uses generating plant characteristics of the generators within the state of Minnesota to calculate various reliability indices. Since they lack data on wholesale power transactions, they do not include them in the analysis, and they reduce the hourly load data accordingly. The authors present and compare results of their methods and suggest some areas of future research.

  20. Earthquake size distribution: power-law with exponent beta=1/2 ?

    E-Print Network [OSTI]

    Kagan, Yan Y

    2010-01-01

    Intermittent Flow in Crystal Plasticity, Science, 312, 1188-phenomena in crystal plasticity – a continuum model, J.theoretical approach to crystal plasticity (Zaiser, 2006).

  1. Problems with determining the particle size distribution of chalk soil and some of their implications

    E-Print Network [OSTI]

    Ahmad, Sajjad

    Young University, 690 SWKT, Provo, UT, USA b British Geological Survey, Keyworth, Nottingham, UK c the properties of chalk soil, psd analyses should be based on the original material (including carbonates Edinburgh 1823, Transactions of the Royal Society of Edinburgh. © 2009 Natural Environment Research Council

  2. Earthquake size distribution: power-law with exponent beta=1/2 ?

    E-Print Network [OSTI]

    Kagan, Yan Y

    2010-01-01

    and T. H. Jordan, 2004. Earthquake scaling relations for1981. Determination of earthquake source parameters fromStochastic model of earthquake fault geometry, Geophys. J.

  3. Discovery of oscillatory dynamics of city-size distributions in world

    E-Print Network [OSTI]

    White, Douglas R.

    of pdf thru Skype you can ask questions, thru Humberto he will have a chat box to relay questions I test) China leads by 50 years in its Q values ­ up to 1850 PART III: Scaling Examples: Chinese-results are very similar, as reported for the 1- factor test. Q1 Q3 Q5 Q2 Q4 Q6 #12;7 Multiple measures of Q

  4. On the Limiting Distribution of Program Sizes in Tree-Based Genetic Programming

    E-Print Network [OSTI]

    Poli, Riccardo

    in a tree and pa is a constant. This result generalises the result previously reported for the case a = 1. 1 understood for mutation and crossover in the case of fixed-length representations (e.g., binary GAs) [4 in which each individual in a generation produces some random number of descendants, and where

  5. Lattice model for kinetics and grain-size distribution in crystallization Mario Castro*

    E-Print Network [OSTI]

    Sánchez, Angel "Anxo"

    deposition has been driven by the technological development of active matrix addressed flat-panel displays1 and thin-film solar cells.2 With these and similar applications in mind, the capability to en- gineer that in crystal- lization of Si over SiO2 substrates, nucleation develops in the Si/SiO2 interface due

  6. Effect of Engine-Out NOx Control Strategies on PM Size Distribution...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    deer08ardanese.pdf More Documents & Publications Development of ADECS to Meet 2010 Emission Levels: Optimization of NOx, NH3 and Fuel Consumption Using High and Low...

  7. Size distribution measurement of fine and ultrafine particle emission from cooking Evelyne Ghina

    E-Print Network [OSTI]

    Boyer, Edmond

    ) for particle with diameter between d and (d+dd) including emission rate of the source, nucleation, re-suspension meat or fish lead to a total mean equivalent emission rate of (9±6)×1010 s-1 while cooking meat or fish in an oven lead to total mean equivalent emission rate of (9±4)×1010 s-1 . Cooking pasta or heat the stove

  8. Earthquake size distribution: power-law with exponent beta=1/2 ?

    E-Print Network [OSTI]

    Kagan, Yan Y

    2010-01-01

    branching process simulation, we sum up seismic momentSeismic Moment Time Figure 5: Simulated source-time functions in a critical branching process.

  9. Diffusivity of rocks: Gas diffusion measurements and correlation to porosity and pore size distribution

    E-Print Network [OSTI]

    Hu, Qinhong "Max"

    scenarios, such as geologic disposal of radioactive waste [Gillham et al., 1984], contaminant remediation [e been used to determine gas transport parameters includ- ing permeability, diffusion coefficient

  10. VARIABILITY IN RAINFALL DROP-SIZE DISTRIBUTIONS OBSERVED AT THE ARM DARWIN SITE

    E-Print Network [OSTI]

    Department/Atmospheric Sciences Division Brookhaven National Laboratory U.S. Department of Energy Office Associates, LLC under Contract No. DE-AC02- 98CH10886 with the U.S. Department of Energy. The publisher-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript

  11. Fidelity of Analytic Drop Size Distributions in Drizzling Stratiform Clouds Based on Large-Eddy Simulations

    E-Print Network [OSTI]

    Kogan, Yefim L.; Kogan, Zena N.; Mechem, David B.

    2009-08-01

    by the Cooperative Institute for Mesoscale Meteorological Studies Large-Eddy Simulation (CIMMS LES) explicit microphysics model for stratocumulus cases observed during the Atlantic Stratocumulus Transition Experiment (ASTEX) field project. The fidelity of analytic...

  12. Submitted to the Journal of Geophysical Research Pore and throat size distributions measured from synchrotron Xray

    E-Print Network [OSTI]

    New York at Stoney Brook, State University of

    Donald et al., 1986(I) and computa­ tion of the specific genus for a sample of Berea sand­ stone presented of this investigative technique. While the technique of pore casting [Wardlaw, 1976] and Wood's metal porosimetry measurements are ex­ tremely difficult to make on the casts without destruc­ tive polishing

  13. VARIABILITY IN RAINFALL DROP-SIZE DISTRIBUTIONS OBSERVED AT THE DARWIN ARM SITE

    E-Print Network [OSTI]

    , microwave radiometer, radiosondes, solar and infrared radiometers, etc...provide a means to describe

  14. Atmospheric Environment 41 (2007) 49084919 Particle size and composition distribution analysis of automotive

    E-Print Network [OSTI]

    Short, Daniel

    2007-01-01

    of automotive brake abrasion dusts for the evaluation of antimony sources of airborne particulate matter Akihiro

  15. SEX, AGE, AND BODY SIZE DISTRIBUTIONS OF WESTERN SANDPIPERS DURING THE NONBREEDING SEASON WITH

    E-Print Network [OSTI]

    poblacional de C. mauri difirio´ entre ha´bitats. La densidad de aves fue alta en planicies lodosas, el ha respecto al Tipo de Ha´bitat Durante la E´ poca No-Reproductiva Resumen. Se determino´ la densidad y densidad de invertebrados y de menor a mayor con respecto al riesgo de depredacio´n. La estructura

  16. Time Evolution of the Mutual Fund Size Distribution Yonathan Schwarzkopf1,2

    E-Print Network [OSTI]

    -33 Pasadena, CA 91125 2 Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501 3 Luiss Guido Carli, Viale into a power law only over long time scales, suggesting that log-normality comes about because the industry

  17. Time Evolution of the Mutual Fund Size Distribution Yonathan Schwarzkopf1,2

    E-Print Network [OSTI]

    -33 Pasadena, CA 91125 2 Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501 3 Luiss Guido Carli, Viale Pola 12 00198, ROMA Italy (Dated: August 21, 2008) The mutual fund industry manages about a quarter long time scales, suggesting that log-normality comes about because the industry is still young due

  18. The Dependence of Cirrus Cloud-Property Retrievals on Size-Distribution

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S.Week Day Year(active tab) 2016The Dark SideShape The

  19. Measuring the Raindrop Size Distribution, ARM's Efforts at Darwin and SGP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on dark matter By SarahMODELING CLOUD1 H(

  20. Disk radii and grain sizes in Herschel-resolved debris disks

    SciTech Connect (OSTI)

    Pawellek, Nicole; Krivov, Alexander V. [Astrophysikalisches Institut und Universitätssternwarte, Friedrich-Schiller-Universität Jena, Schillergäßchen 2-3, 07745 Jena (Germany); Marshall, Jonathan P. [School of Physics, University of New South Wales, Sydney NSW 2052 (Australia); Montesinos, Benjamin [Departmento de Astrofísica, Centro de Astrobiología (CAB, CSIC-INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain); Ábrahám, Péter; Moór, Attila [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, H-1525 Budapest (Hungary); Bryden, Geoffrey [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Eiroa, Carlos [Departamento de Física Teórica, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain)

    2014-09-01

    The radii of debris disks and the sizes of their dust grains are important tracers of the planetesimal formation mechanisms and physical processes operating in these systems. Here we use a representative sample of 34 debris disks resolved in various Herschel Space Observatory (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) programs to constrain the disk radii and the size distribution of their dust. While we modeled disks with both warm and cold components, and identified warm inner disks around about two-thirds of the stars, we focus our analysis only on the cold outer disks, i.e., Kuiper-belt analogs. We derive the disk radii from the resolved images and find a large dispersion for host stars of any spectral class, but no significant trend with the stellar luminosity. This argues against ice lines as a dominant player in setting the debris disk sizes, since the ice line location varies with the luminosity of the central star. Fixing the disk radii to those inferred from the resolved images, we model the spectral energy distribution to determine the dust temperature and the grain size distribution for each target. While the dust temperature systematically increases toward earlier spectral types, the ratio of the dust temperature to the blackbody temperature at the disk radius decreases with the stellar luminosity. This is explained by a clear trend of typical sizes increasing toward more luminous stars. The typical grain sizes are compared to the radiation pressure blowout limit s {sub blow} that is proportional to the stellar luminosity-to-mass ratio and thus also increases toward earlier spectral classes. The grain sizes in the disks of G- to A-stars are inferred to be several times s {sub blow} at all stellar luminosities, in agreement with collisional models of debris disks. The sizes, measured in the units of s {sub blow}, appear to decrease with the luminosity, which may be suggestive of the disk's stirring level increasing toward earlier-type stars. The dust opacity index ? ranges between zero and two, and the size distribution index q varies between three and five for all the disks in the sample.

  1. Cooling water distribution system

    DOE Patents [OSTI]

    Orr, Richard (Pittsburgh, PA)

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  2. MEMORANDUM FOR DISTRIBUTION

    Energy Savers [EERE]

    * Department of Energy Washington, DC 20585 December 20, 2007 MEMORANDUM FOR DISTRIBUTION FROM: MICHAEL W. OWEN

  3. Distribution of Correspondence

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1996-08-30

    Defines correct procedures for distribution of correspondence to the Naval Reactors laboratories. Does not cancel another directive. Expired 8-30-97.

  4. Effects of viscoelasticity on droplet dynamics and break-up in microfluidic T-Junctions: a lattice Boltzmann study

    E-Print Network [OSTI]

    Anupam Gupta; Mauro Sbragaglia

    2015-08-01

    The effects of viscoelasticity on the dynamics and break-up of fluid threads in microfluidic T-junctions are investigated using numerical simulations of dilute polymer solutions at changing the Capillary number ($\\mbox {Ca}$), i.e. at changing the balance between the viscous forces and the surface tension at the interface, up to $\\mbox{Ca} \\approx 3 \\times 10^{-2}$. A Navier-Stokes (NS) description of the solvent based on the lattice Boltzmann models (LBM) is here coupled to constitutive equations for finite extensible non-linear elastic dumbbells with the closure proposed by Peterlin (FENE-P model). We present the results of three-dimensional simulations in a range of $\\mbox{Ca}$ which is broad enough to characterize all the three characteristic mechanisms of breakup in the confined T-junction, i.e. ${\\it squeezing}$, ${\\it dripping}$ and ${\\it jetting}$ regimes. The various model parameters of the FENE-P constitutive equations, including the polymer relaxation time $\\tau_P$ and the finite extensibility parameter $L^2$, are changed to provide quantitative details on how the dynamics and break-up properties are affected by viscoelasticity. We will analyze cases with ${\\it Droplet ~Viscoelasticity}$ (DV), where viscoelastic properties are confined in the dispersed (d) phase, as well as cases with ${\\it Matrix ~Viscoelasticity}$ (MV), where viscoelastic properties are confined in the continuous (c) phase. Moderate flow-rate ratios $Q \\approx {\\cal O}(1)$ of the two phases are considered in the present study. Overall, we find that the effects are more pronounced in the case with MV, as the flow driving the break-up process upstream of the emerging thread can be sensibly perturbed by the polymer stresses.

  5. Detecting bacteria and Determining Their Susceptibility to Antibiotics by Stochastic Confinement in Nanoliter Droplets using Plug-Based Microfluidics

    SciTech Connect (OSTI)

    Boedicker, J.; Li, L; Kline, T; Ismagilov, R

    2008-01-01

    This article describes plug-based microfluidic technology that enables rapid detection and drug susceptibility screening of bacteria in samples, including complex biological matrices, without pre-incubation. Unlike conventional bacterial culture and detection methods, which rely on incubation of a sample to increase the concentration of bacteria to detectable levels, this method confines individual bacteria into droplets nanoliters in volume. When single cells are confined into plugs of small volume such that the loading is less than one bacterium per plug, the detection time is proportional to plug volume. Confinement increases cell density and allows released molecules to accumulate around the cell, eliminating the pre-incubation step and reducing the time required to detect the bacteria. We refer to this approach as stochastic confinement. Using the microfluidic hybrid method, this technology was used to determine the antibiogram - or chart of antibiotic sensitivity - of methicillin-resistant Staphylococcus aureus (MRSA) to many antibiotics in a single experiment and to measure the minimal inhibitory concentration (MIC) of the drug cefoxitin (CFX) against this strain. In addition, this technology was used to distinguish between sensitive and resistant strains of S. aureus in samples of human blood plasma. High-throughput microfluidic techniques combined with single-cell measurements also enable multiple tests to be performed simultaneously on a single sample containing bacteria. This technology may provide a method of rapid and effective patient-specific treatment of bacterial infections and could be extended to a variety of applications that require multiple functional tests of bacterial samples on reduced timescales.

  6. Study of NH stretching vibrations in small ammonia clusters by infrared spectroscopy in He droplets and ab initio calculations

    SciTech Connect (OSTI)

    Slipchenko, Mikhail N.; Sartakov, Boris G.; Vilesov, Andrey F.; Xantheas, Sotiris S.

    2007-08-09

    Infrared spectra of the NH stretching vibrations of (NH3)n clusters (n=2-4) have been obtained using the helium droplet isolation technique and first principles electronic structure anharmonic calculations. The measured spectra exhibit well-resolved bands, which have been assigned to the ?1, ?3, and 2?4 modes of the ammonia fragments in the clusters. The formation of a hydrogen bond in ammonia dimers leads to an increase of the infrared intensity by about a factor of four. In the larger clusters the infrared intensity per hydrogen bond is close to the one for dimers and approaches the value in the NH3 crystal. The intensity of the 2?4 overtone band in the trimer and tetramer increases by a factor of 10 relative to that in the monomer and dimer, and is comparable to the intensity of the ?1 and ?3 fundamental bands in larger clusters. This indicates the onset of the strong anharmonic coupling of the 2?4 and ?1 modes in larger clusters. The experimental assignments are compared to the ones obtained from first principles electronic structure anharmonic calculations for the dimer and trimer clusters. The anharmonic calculations were performed at the Møller-Plesset (MP2) level of electronic structure theory and were based on a second-order perturbative evaluation of rovibrational parameters and their effects on the vibrational spectra and average structures. In general there is excellent (<20 cm-1) agreement between the experimentally measured band origins for the N-H stretching frequencies and the calculated anharmonic vibrational frequencies. However, the calculations were found to overestimate the infrared intensities in clusters by about a factor of four. This work was supported by the Office of Basic Energy Sciences of the Department of Energy, in part by the Chemical Sciences program and in part by the Engineering and Geosciences Division. The Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  7. Can amphiphile architecture directly control vesicle size?

    E-Print Network [OSTI]

    M. J. Greenall; C. M. Marques

    2013-01-28

    Bilayer membranes self-assembled from simple amphiphiles in solution always have a planar ground-state shape. This is a consequence of several internal relaxation mechanisms of the membrane and prevents the straightforward control of vesicle size. Here, we show that this principle can be circumvented and that direct size control by molecular design is a realistic possibility. Using coarse-grained calculations, we design tetrablock copolymers that form membranes with a preferred curvature, and demonstrate how to form low-polydispersity vesicles while suppressing micellization.

  8. Size-dependent structure of silver nanoparticles under high pressure

    SciTech Connect (OSTI)

    Koski, Kristie Jo

    2008-12-31

    Silver noble metal nanoparticles that are<10 nm often possess multiply twinned grains allowing them to adopt shapes and atomic structures not observed in bulk materials. The properties exhibited by particles with multiply twinned polycrystalline structures are often far different from those of single-crystalline particles and from the bulk. I will present experimental evidence that silver nanoparticles<10 nm undergo a reversible structural transformation under hydrostatic pressures up to 10 GPa. Results for nanoparticles in the intermediate size range of 5 to 10 nm suggest a reversible linear pressure-dependent rhombohedral distortion which has not been previously observed in bulk silver. I propose a mechanism for this transitiion that considers the bond-length distribution in idealized multiply twinned icosahedral particles. Results for nanoparticles of 3.9 nm suggest a reversible linear pressure-dependent orthorhombic distortion. This distortion is interpreted in the context of idealized decahedral particles. In addition, given these size-dependent measurements of silver nanoparticle compression with pressure, we have constructed a pressure calibration curve. Encapsulating these silver nanoparticles in hollow metal oxide nanospheres then allows us to measure the pressure inside a nanoshell using x-ray diffraction. We demonstrate the measurement of pressure gradients across nanoshells and show that these nanoshells have maximum resolved shear strengths on the order of 500 MPa to IGPa.

  9. The dust grain size - stellar luminosity trend in debris discs

    E-Print Network [OSTI]

    Pawellek, Nicole

    2015-01-01

    The cross section of material in debris discs is thought to be dominated by the smallest grains that can still stay in bound orbits despite the repelling action of stellar radiation pressure. Thus the minimum (and typical) grain size $s_\\text{min}$ is expected to be close to the radiation pressure blowout size $s_\\text{blow}$. Yet a recent analysis of a sample of Herschel-resolved debris discs showed the ratio $s_\\text{min}/s_\\text{blow}$ to systematically decrease with the stellar luminosity from about ten for solar-type stars to nearly unity in the discs around the most luminous A-type stars. Here we explore this trend in more detail, checking how significant it is and seeking to find possible explanations. We show that the trend is robust to variation of the composition and porosity of dust particles. For any assumed grain properties and stellar parameters, we suggest a recipe of how to estimate the "true" radius of a spatially unresolved debris disc, based solely on its spectral energy distribution. The r...

  10. Test of two hypotheses explaining the size of populations in a system of cities

    E-Print Network [OSTI]

    Vitanov, Nikolay K

    2015-01-01

    Two classical hypotheses are examined about the population growth in a system of cities: Hypothesis 1 pertains to Gibrat's and Zipf's theory which states that the city growth-decay process is size independent; Hypothesis 2 pertains to the so called Yule process which states that the growth of populations in cities happens when (i) the distribution of the city population initial size obeys a log-normal function, (ii) the growth of the settlements follows a stochastic process. The basis for the test is some official data on Bulgarian cities at various times. This system was chosen because (i) Bulgaria is a country for which one does not expect biased theoretical conditions; (ii) the city populations were determined rather precisely. The present results show that: (i) the population size growth of the Bulgarian cities is size dependent, whence Hypothesis 1 is not confirmed for Bulgaria; (ii) the population size growth of Bulgarian cities can be described by a double Pareto log-normal distribution, whence Hypothe...

  11. Unwinding of circular helicoidal molecules versus size

    E-Print Network [OSTI]

    Marco Zoli

    2015-04-12

    The thermodynamical stability of a set of circular double helical molecules is analyzed by path integral techniques. The minicircles differ only in \\textit{i)} the radius and \\textit{ii)} the number of base pairs ($N$) arranged along the molecule axis. Instead, the rise distance is kept constant. For any molecule size, the computational method simulates a broad ensemble of possible helicoidal configurations while the partition function is a sum over the path trajectories describing the base pair fluctuational states. The stablest helical repeat of every minicircle is determined by free energy minimization. We find that, for molecules with $N$ larger than $100$, the helical repeat grows linearly with the size and the twist number is constant. On the other hand, by reducing the size below $100$ base pairs, the double helices sharply unwind and the twist number drops to one for $N=\\,20$. This is predicted as the minimum size for the existence of helicoidal molecules in the closed form. The helix unwinding appears as a strategy to release the bending stress associated to the circularization of the molecules.

  12. NEEDS SIZE ADJUSTMENT 2 Perfect Chemistry

    E-Print Network [OSTI]

    Chapman, Michael S.

    NEEDS SIZE ADJUSTMENT #12;2 Perfect Chemistry 8 Starr Power 10 Balancing Act 14 A Rare Thing.B.A. EDitors Dee Metaj Jill Smith DEsigN Anderson McConaughy Design Co. WritErs Todd Schwartz Jill Smith Jim and friends. Please send correspondence to: Bridges Magazine sm-alum@ohsu.edu OHSU School of Medicine 3181 SW

  13. Surface plasmon standing waves on Ag nanorods: observations of finite size effects and size dependency

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Surface plasmon standing waves on Ag nanorods: observations of finite size effects and size to have clear configuration of standing waves of the nanorod. The nm resolution of the electron probe standing wave on a string with fixed ends, we observed that the wavelength of the SP standing wave

  14. Size dependence of solar X-ray flare properties

    E-Print Network [OSTI]

    Marina Battaglia; Paolo C. Grigis; Arnold O. Benz

    2005-05-09

    Non-thermal and thermal parameters of 85 solar flares of GOES class B1 to M6 (background subtracted classes A1 to M6) have been compared to each other. The hard X-ray flux has been measured by RHESSI and a spectral fitting provided flux and spectral index of the non-thermal emission, as well as temperature and emission measure of the thermal emission. The soft X-ray flux was taken from GOES measurements. We find a linear correlation in a double logarithmic plot between the non-thermal flux and the spectral index. The higher the acceleration rate of a flare, the harder the non-thermal electron distribution. The relation is similar to the one found by a comparison of the same parameters from several sub-peaks of a single flare. Thus small flares behave like small subpeaks of large flares. Thermal flare properties such as temperature, emission measure and the soft X-ray flux also correlate with peak non-thermal flux. A large non-thermal peak flux entails an enhancement in both thermal parameters. The relation between spectral index and the non-thermal flux is an intrinsic feature of the particle acceleration process, depending on flare size. This property affects the reported frequency distribution of flare energies.

  15. Distributed Road Grade Estimation

    E-Print Network [OSTI]

    Johansson, Karl Henrik

    Distributed Road Grade Estimation for Heavy Duty Vehicles PER SAH LHOLM Doctoral Thesis in Automatic Control Stockholm, Sweden 2011 #12;Distributed Road Grade Estimation for Heavy Duty Vehicles PER state-of-charge control decrease the energy consumption of vehicles and increase the safety

  16. Streched String with Self-Interaction at the Hagedorn Point: Spatial Sizes and Black Hole

    E-Print Network [OSTI]

    Qian, Yachao

    2015-01-01

    We analyze the length, mass and spatial distribution of a discretized transverse string in $D_\\perp$ dimensions with fixed end-points near its Hagedorn temperature. We suggest that such a string may dominate the (holographic) Pomeron kinematics for dipole-dipole scattering at intermediate and small impact parameters. Attractive self-string interactions cause the transverse string size to contract away from its diffusive size, a mechanism reminiscent of the string-black-hole transmutation. The string shows sizable asymmetries in the transverse plane that translate to primordial azimuthal asymmetries in the stringy particle production in the Pomeron kinematics for current pp and pA collisions at collider energies.

  17. Streched String with Self-Interaction at the Hagedorn Point: Spatial Sizes and Black Hole

    E-Print Network [OSTI]

    Yachao Qian; Ismail Zahed

    2015-08-15

    We analyze the length, mass and spatial distribution of a discretized transverse string in $D_\\perp$ dimensions with fixed end-points near its Hagedorn temperature. We suggest that such a string may dominate the (holographic) Pomeron kinematics for dipole-dipole scattering at intermediate and small impact parameters. Attractive self-string interactions cause the transverse string size to contract away from its diffusive size, a mechanism reminiscent of the string-black-hole transmutation. The string shows sizable asymmetries in the transverse plane that translate to primordial azimuthal asymmetries in the stringy particle production in the Pomeron kinematics for current pp and pA collisions at collider energies.

  18. Size of nanoobjects in oil and gas species and materials with positron annihilation spectroscopy

    E-Print Network [OSTI]

    Grafutin, V I; Elnikova, L V

    2012-01-01

    The analytical method to determine geometry and size of nano-scale defects in oil and gas species and materials is proposed. The modeling is carried out with the parameters of the positron spectra in the angular distribution method of positron annihilation spectroscopy, and is based on the 'free electron' approximation. From the annihilation decay kinetics, it is possible to express the trapping velocity of parapositronium in pores via intensities of the positronium components and to define the concentration and radii of pores in a porous layer. As the result, size and the concentration of micro-porous cylindrical nano-objects in the silicon samples are estimated.

  19. Measuring the mass, density, and size of particles and cells using a suspended microchannel resonator

    SciTech Connect (OSTI)

    Godin, Michel; Bryan, Andrea K.; Burg, Thomas P.; Babcock, Ken; Manalis, Scott R.

    2007-09-17

    We demonstrate the measurement of mass, density, and size of cells and nanoparticles using suspended microchannel resonators. The masses of individual particles are quantified as transient frequency shifts, while the particles transit a microfluidic channel embedded in the resonating cantilever. Mass histograms resulting from these data reveal the distribution of a population of heterogeneously sized particles. Particle density is inferred from measurements made in different carrier fluids since the frequency shift for a particle is proportional to the mass difference relative to the displaced solution. We have characterized the density of polystyrene particles, Escherichia coli, and human red blood cells with a resolution down to 10{sup -4} g/cm{sup 3}.

  20. Strategy Guideline: Compact Air Distribution Systems

    SciTech Connect (OSTI)

    Burdick, A.

    2013-06-01

    This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.